/* GIMP - The GNU Image Manipulation Program
 * Copyright (C) 1995 Spencer Kimball and Peter Mattis
 *
 * gimptoolrectangle.c
 * Copyright (C) 2017 Michael Natterer <mitch@gimp.org>
 *
 * Based on GimpRectangleTool
 * Copyright (C) 2007 Martin Nordholts
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <https://www.gnu.org/licenses/>.
 */

#include "config.h"

#include <gegl.h>
#include <gtk/gtk.h>
#include <gdk/gdkkeysyms.h>

#include "libgimpbase/gimpbase.h"
#include "libgimpmath/gimpmath.h"

#include "display-types.h"

#include "core/gimp.h"
#include "core/gimpcontext.h"
#include "core/gimpimage.h"
#include "core/gimpitem.h"
#include "core/gimppickable.h"
#include "core/gimppickable-auto-shrink.h"

#include "widgets/gimpwidgets-utils.h"

#include "gimpcanvasarc.h"
#include "gimpcanvascorner.h"
#include "gimpcanvashandle.h"
#include "gimpcanvasitem-utils.h"
#include "gimpcanvasrectangle.h"
#include "gimpcanvasrectangleguides.h"
#include "gimpdisplay.h"
#include "gimpdisplayshell.h"
#include "gimpdisplayshell-scroll.h"
#include "gimptoolrectangle.h"

#include "gimp-intl.h"


/*  speed of key movement  */
#define ARROW_VELOCITY   25

#define MAX_HANDLE_SIZE         50
#define MIN_HANDLE_SIZE         15
#define NARROW_MODE_HANDLE_SIZE 15
#define NARROW_MODE_THRESHOLD   45


enum
{
  PROP_0,
  PROP_X1,
  PROP_Y1,
  PROP_X2,
  PROP_Y2,
  PROP_CONSTRAINT,
  PROP_PRECISION,
  PROP_NARROW_MODE,
  PROP_FORCE_NARROW_MODE,
  PROP_DRAW_ELLIPSE,
  PROP_ROUND_CORNERS,
  PROP_CORNER_RADIUS,
  PROP_STATUS_TITLE,

  PROP_HIGHLIGHT,
  PROP_HIGHLIGHT_OPACITY,
  PROP_GUIDE,
  PROP_X,
  PROP_Y,
  PROP_WIDTH,
  PROP_HEIGHT,
  PROP_FIXED_RULE_ACTIVE,
  PROP_FIXED_RULE,
  PROP_DESIRED_FIXED_WIDTH,
  PROP_DESIRED_FIXED_HEIGHT,
  PROP_DESIRED_FIXED_SIZE_WIDTH,
  PROP_DESIRED_FIXED_SIZE_HEIGHT,
  PROP_ASPECT_NUMERATOR,
  PROP_ASPECT_DENOMINATOR,
  PROP_FIXED_CENTER
};

enum
{
  CHANGE_COMPLETE,
  LAST_SIGNAL
};

typedef enum
{
  CLAMPED_NONE   = 0,
  CLAMPED_LEFT   = 1 << 0,
  CLAMPED_RIGHT  = 1 << 1,
  CLAMPED_TOP    = 1 << 2,
  CLAMPED_BOTTOM = 1 << 3
} ClampedSide;

typedef enum
{
  SIDE_TO_RESIZE_NONE,
  SIDE_TO_RESIZE_LEFT,
  SIDE_TO_RESIZE_RIGHT,
  SIDE_TO_RESIZE_TOP,
  SIDE_TO_RESIZE_BOTTOM,
  SIDE_TO_RESIZE_LEFT_AND_RIGHT_SYMMETRICALLY,
  SIDE_TO_RESIZE_TOP_AND_BOTTOM_SYMMETRICALLY,
} SideToResize;


#define FEQUAL(a,b)       (fabs ((a) - (b)) < 0.0001)
#define PIXEL_FEQUAL(a,b) (fabs ((a) - (b)) < 0.5)


struct _GimpToolRectanglePrivate
{
  /* The following members are "constants", that is, variables that are setup
   * during gimp_tool_rectangle_button_press and then only read.
   */

  /* Whether or not the rectangle currently being rubber-banded is the
   * first one created with this instance, this determines if we can
   * undo it on button_release.
   */
  gboolean                is_first;

  /* Whether or not the rectangle currently being rubber-banded was
   * created from scratch.
   */
  gboolean                is_new;

  /* Holds the coordinate that should be used as the "other side" when
   * fixed-center is turned off.
   */
  gdouble                 other_side_x;
  gdouble                 other_side_y;

  /* Holds the coordinate to be used as center when fixed-center is used. */
  gdouble                 center_x_on_fixed_center;
  gdouble                 center_y_on_fixed_center;

  /* True when the rectangle is being adjusted (moved or
   * rubber-banded).
   */
  gboolean                rect_adjusting;


  /* The rest of the members are internal state variables, that is, variables
   * that might change during the manipulation session of the rectangle. Make
   * sure these variables are in consistent states.
   */

  /* Coordinates of upper left and lower right rectangle corners. */
  gdouble                 x1, y1;
  gdouble                 x2, y2;

  /* Integer coordinates of upper left corner and size. We must
   * calculate this separately from the gdouble ones because sometimes
   * we don't want to affect the integer size (e.g. when moving the
   * rectangle), but that will be the case if we always calculate the
   * integer coordinates based on rounded values of the gdouble
   * coordinates even if the gdouble width remains constant.
   *
   * TODO: Change the internal double-representation of the rectangle
   * to x,y width,height instead of x1,y1 x2,y2. That way we don't
   * need to keep a separate representation of the integer version of
   * the rectangle; rounding width an height will yield consistent
   * results and not depend on position of the rectangle.
   */
  gint                    x1_int,    y1_int;
  gint                    width_int, height_int;

  /* How to constrain the rectangle. */
  GimpRectangleConstraint constraint;

  /* What precision the rectangle will appear to have externally (it
   * will always be double internally)
   */
  GimpRectanglePrecision  precision;

  /* Previous coordinate applied to the rectangle. */
  gdouble                 lastx;
  gdouble                 lasty;

  /* Width and height of corner handles. */
  gint                    corner_handle_w;
  gint                    corner_handle_h;

  /* Width and height of side handles. */
  gint                    top_and_bottom_handle_w;
  gint                    left_and_right_handle_h;

  /* Whether or not the rectangle is in a 'narrow situation' i.e. it is
   * too small for reasonable sized handle to be inside. In this case
   * we put handles on the outside.
   */
  gboolean                narrow_mode;

  /* This boolean allows to always set narrow mode */
  gboolean                force_narrow_mode;

  /* Whether or not to draw an ellipse inside the rectangle */
  gboolean                draw_ellipse;

  /* Whether to draw round corners */
  gboolean                round_corners;
  gdouble                 corner_radius;

  /* The title for the statusbar coords */
  gchar                  *status_title;

  /* For saving in case of cancellation. */
  gdouble                 saved_x1;
  gdouble                 saved_y1;
  gdouble                 saved_x2;
  gdouble                 saved_y2;

  gint                    suppress_updates;

  GimpRectangleFunction   function;

  /* The following values are externally synced with GimpRectangleOptions */

  gboolean                highlight;
  gdouble                 highlight_opacity;
  GimpGuidesType          guide;

  gdouble                 x;
  gdouble                 y;
  gdouble                 width;
  gdouble                 height;

  gboolean                fixed_rule_active;
  GimpRectangleFixedRule  fixed_rule;
  gdouble                 desired_fixed_width;
  gdouble                 desired_fixed_height;
  gdouble                 desired_fixed_size_width;
  gdouble                 desired_fixed_size_height;
  gdouble                 aspect_numerator;
  gdouble                 aspect_denominator;
  gboolean                fixed_center;

  /* Canvas items for drawing the GUI */

  GimpCanvasItem         *guides;
  GimpCanvasItem         *rectangle;
  GimpCanvasItem         *ellipse;
  GimpCanvasItem         *corners[4];
  GimpCanvasItem         *center;
  GimpCanvasItem         *creating_corners[4];
  GimpCanvasItem         *handles[GIMP_N_TOOL_RECTANGLE_FUNCTIONS];
  GimpCanvasItem         *highlight_handles[GIMP_N_TOOL_RECTANGLE_FUNCTIONS];
};


/*  local function prototypes  */

static void     gimp_tool_rectangle_constructed     (GObject               *object);
static void     gimp_tool_rectangle_finalize        (GObject               *object);
static void     gimp_tool_rectangle_set_property    (GObject               *object,
                                                     guint                  property_id,
                                                     const GValue          *value,
                                                     GParamSpec            *pspec);
static void     gimp_tool_rectangle_get_property    (GObject               *object,
                                                     guint                  property_id,
                                                     GValue                *value,
                                                     GParamSpec            *pspec);
static void     gimp_tool_rectangle_notify          (GObject               *object,
                                                     GParamSpec            *pspec);

static void     gimp_tool_rectangle_changed         (GimpToolWidget        *widget);
static gint     gimp_tool_rectangle_button_press    (GimpToolWidget        *widget,
                                                     const GimpCoords      *coords,
                                                     guint32                time,
                                                     GdkModifierType        state,
                                                     GimpButtonPressType    press_type);
static void     gimp_tool_rectangle_button_release  (GimpToolWidget        *widget,
                                                     const GimpCoords      *coords,
                                                     guint32                time,
                                                     GdkModifierType        state,
                                                     GimpButtonReleaseType  release_type);
static void     gimp_tool_rectangle_motion          (GimpToolWidget        *widget,
                                                     const GimpCoords      *coords,
                                                     guint32                time,
                                                     GdkModifierType        state);
static GimpHit  gimp_tool_rectangle_hit             (GimpToolWidget        *widget,
                                                     const GimpCoords      *coords,
                                                     GdkModifierType        state,
                                                     gboolean               proximity);
static void     gimp_tool_rectangle_hover           (GimpToolWidget        *widget,
                                                     const GimpCoords      *coords,
                                                     GdkModifierType        state,
                                                     gboolean               proximity);
static void     gimp_tool_rectangle_leave_notify    (GimpToolWidget        *widget);
static gboolean gimp_tool_rectangle_key_press       (GimpToolWidget        *widget,
                                                     GdkEventKey           *kevent);
static void     gimp_tool_rectangle_motion_modifier (GimpToolWidget        *widget,
                                                     GdkModifierType        key,
                                                     gboolean               press,
                                                     GdkModifierType        state);
static gboolean gimp_tool_rectangle_get_cursor      (GimpToolWidget        *widget,
                                                     const GimpCoords      *coords,
                                                     GdkModifierType        state,
                                                     GimpCursorType        *cursor,
                                                     GimpToolCursorType    *tool_cursor,
                                                     GimpCursorModifier    *modifier);

static void     gimp_tool_rectangle_change_complete (GimpToolRectangle     *rectangle);

static void     gimp_tool_rectangle_update_options  (GimpToolRectangle     *rectangle);
static void     gimp_tool_rectangle_update_handle_sizes
                                                    (GimpToolRectangle     *rectangle);
static void     gimp_tool_rectangle_update_status   (GimpToolRectangle     *rectangle);

static void     gimp_tool_rectangle_synthesize_motion
                                                    (GimpToolRectangle     *rectangle,
                                                     gint               function,
                                                     gdouble            new_x,
                                                     gdouble            new_y);

static GimpRectangleFunction
                gimp_tool_rectangle_calc_function   (GimpToolRectangle     *rectangle,
                                                     const GimpCoords      *coords,
                                                     gboolean               proximity);
static void     gimp_tool_rectangle_check_function  (GimpToolRectangle     *rectangle);

static gboolean gimp_tool_rectangle_coord_outside   (GimpToolRectangle     *rectangle,
                                                     const GimpCoords      *coords);

static gboolean gimp_tool_rectangle_coord_on_handle (GimpToolRectangle     *rectangle,
                                                     const GimpCoords      *coords,
                                                     GimpHandleAnchor       anchor);

static GimpHandleAnchor gimp_tool_rectangle_get_anchor
                                                    (GimpRectangleFunction  function);
static gboolean gimp_tool_rectangle_rect_rubber_banding_func
                                                    (GimpToolRectangle     *rectangle);
static gboolean gimp_tool_rectangle_rect_adjusting_func
                                                    (GimpToolRectangle     *rectangle);

static void     gimp_tool_rectangle_get_other_side  (GimpToolRectangle     *rectangle,
                                                     gdouble              **other_x,
                                                     gdouble              **other_y);
static void     gimp_tool_rectangle_get_other_side_coord
                                                    (GimpToolRectangle     *rectangle,
                                                     gdouble               *other_side_x,
                                                     gdouble               *other_side_y);
static void     gimp_tool_rectangle_set_other_side_coord
                                                    (GimpToolRectangle     *rectangle,
                                                     gdouble                other_side_x,
                                                     gdouble                other_side_y);

static void     gimp_tool_rectangle_apply_coord     (GimpToolRectangle     *rectangle,
                                                     gdouble                coord_x,
                                                     gdouble                coord_y);
static void     gimp_tool_rectangle_setup_snap_offsets
                                                    (GimpToolRectangle     *rectangle,
                                                     const GimpCoords      *coords);

static void     gimp_tool_rectangle_clamp           (GimpToolRectangle     *rectangle,
                                                     ClampedSide           *clamped_sides,
                                                     GimpRectangleConstraint constraint,
                                                     gboolean               symmetrically);
static void     gimp_tool_rectangle_clamp_width     (GimpToolRectangle     *rectangle,
                                                     ClampedSide           *clamped_sides,
                                                     GimpRectangleConstraint constraint,
                                                     gboolean               symmetrically);
static void     gimp_tool_rectangle_clamp_height    (GimpToolRectangle     *rectangle,
                                                     ClampedSide           *clamped_sides,
                                                     GimpRectangleConstraint constraint,
                                                     gboolean               symmetrically);

static void     gimp_tool_rectangle_keep_inside     (GimpToolRectangle     *rectangle,
                                                     GimpRectangleConstraint constraint);
static void     gimp_tool_rectangle_keep_inside_horizontally
                                                    (GimpToolRectangle     *rectangle,
                                                     GimpRectangleConstraint constraint);
static void     gimp_tool_rectangle_keep_inside_vertically
                                                    (GimpToolRectangle     *rectangle,
                                                     GimpRectangleConstraint constraint);

static void     gimp_tool_rectangle_apply_fixed_width
                                                    (GimpToolRectangle     *rectangle,
                                                     GimpRectangleConstraint constraint,
                                                     gdouble                width);
static void     gimp_tool_rectangle_apply_fixed_height
                                                    (GimpToolRectangle     *rectangle,
                                                     GimpRectangleConstraint constraint,
                                                     gdouble                height);

static void     gimp_tool_rectangle_apply_aspect    (GimpToolRectangle     *rectangle,
                                                     gdouble                aspect,
                                                     gint                   clamped_sides);

static void     gimp_tool_rectangle_update_with_coord
                                                    (GimpToolRectangle     *rectangle,
                                                     gdouble                new_x,
                                                     gdouble                new_y);
static void     gimp_tool_rectangle_apply_fixed_rule(GimpToolRectangle     *rectangle);

static void     gimp_tool_rectangle_get_constraints (GimpToolRectangle     *rectangle,
                                                     gint                  *min_x,
                                                     gint                  *min_y,
                                                     gint                  *max_x,
                                                     gint                  *max_y,
                                                     GimpRectangleConstraint constraint);

static void     gimp_tool_rectangle_handle_general_clamping
                                                    (GimpToolRectangle     *rectangle);
static void     gimp_tool_rectangle_update_int_rect (GimpToolRectangle     *rectangle);
static void     gimp_tool_rectangle_adjust_coord    (GimpToolRectangle     *rectangle,
                                                     gdouble                coord_x_input,
                                                     gdouble                coord_y_input,
                                                     gdouble               *coord_x_output,
                                                     gdouble               *coord_y_output);
static void     gimp_tool_rectangle_recalculate_center_xy
                                                    (GimpToolRectangle     *rectangle);


G_DEFINE_TYPE_WITH_PRIVATE (GimpToolRectangle, gimp_tool_rectangle,
                            GIMP_TYPE_TOOL_WIDGET)

#define parent_class gimp_tool_rectangle_parent_class

static guint rectangle_signals[LAST_SIGNAL] = { 0, };


static void
gimp_tool_rectangle_class_init (GimpToolRectangleClass *klass)
{
  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
  GimpToolWidgetClass *widget_class = GIMP_TOOL_WIDGET_CLASS (klass);

  object_class->constructed     = gimp_tool_rectangle_constructed;
  object_class->finalize        = gimp_tool_rectangle_finalize;
  object_class->set_property    = gimp_tool_rectangle_set_property;
  object_class->get_property    = gimp_tool_rectangle_get_property;
  object_class->notify          = gimp_tool_rectangle_notify;

  widget_class->changed         = gimp_tool_rectangle_changed;
  widget_class->button_press    = gimp_tool_rectangle_button_press;
  widget_class->button_release  = gimp_tool_rectangle_button_release;
  widget_class->motion          = gimp_tool_rectangle_motion;
  widget_class->hit             = gimp_tool_rectangle_hit;
  widget_class->hover           = gimp_tool_rectangle_hover;
  widget_class->leave_notify    = gimp_tool_rectangle_leave_notify;
  widget_class->key_press       = gimp_tool_rectangle_key_press;
  widget_class->motion_modifier = gimp_tool_rectangle_motion_modifier;
  widget_class->get_cursor      = gimp_tool_rectangle_get_cursor;
  widget_class->update_on_scale = TRUE;

  rectangle_signals[CHANGE_COMPLETE] =
    g_signal_new ("change-complete",
                  G_TYPE_FROM_CLASS (klass),
                  G_SIGNAL_RUN_FIRST,
                  G_STRUCT_OFFSET (GimpToolRectangleClass, change_complete),
                  NULL, NULL, NULL,
                  G_TYPE_NONE, 0);

  g_object_class_install_property (object_class, PROP_X1,
                                   g_param_spec_double ("x1",
                                                        NULL, NULL,
                                                        -GIMP_MAX_IMAGE_SIZE,
                                                        GIMP_MAX_IMAGE_SIZE,
                                                        0.0,
                                                        GIMP_PARAM_READWRITE |
                                                        G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_Y1,
                                   g_param_spec_double ("y1",
                                                        NULL, NULL,
                                                        -GIMP_MAX_IMAGE_SIZE,
                                                        GIMP_MAX_IMAGE_SIZE,
                                                        0.0,
                                                        GIMP_PARAM_READWRITE |
                                                        G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_X2,
                                   g_param_spec_double ("x2",
                                                        NULL, NULL,
                                                        -GIMP_MAX_IMAGE_SIZE,
                                                        GIMP_MAX_IMAGE_SIZE,
                                                        0.0,
                                                        GIMP_PARAM_READWRITE |
                                                        G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_Y2,
                                   g_param_spec_double ("y2",
                                                        NULL, NULL,
                                                        -GIMP_MAX_IMAGE_SIZE,
                                                        GIMP_MAX_IMAGE_SIZE,
                                                        0.0,
                                                        GIMP_PARAM_READWRITE |
                                                        G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_CONSTRAINT,
                                   g_param_spec_enum ("constraint",
                                                      NULL, NULL,
                                                      GIMP_TYPE_RECTANGLE_CONSTRAINT,
                                                      GIMP_RECTANGLE_CONSTRAIN_NONE,
                                                      GIMP_PARAM_READWRITE |
                                                      G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_PRECISION,
                                   g_param_spec_enum ("precision",
                                                      NULL, NULL,
                                                      GIMP_TYPE_RECTANGLE_PRECISION,
                                                      GIMP_RECTANGLE_PRECISION_INT,
                                                      GIMP_PARAM_READWRITE |
                                                      G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_NARROW_MODE,
                                   g_param_spec_boolean ("narrow-mode",
                                                         NULL, NULL,
                                                         FALSE,
                                                         GIMP_PARAM_READWRITE |
                                                         G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_FORCE_NARROW_MODE,
                                   g_param_spec_boolean ("force-narrow-mode",
                                                         NULL, NULL,
                                                         FALSE,
                                                         GIMP_PARAM_READWRITE |
                                                         G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_DRAW_ELLIPSE,
                                   g_param_spec_boolean ("draw-ellipse",
                                                         NULL, NULL,
                                                         FALSE,
                                                         GIMP_PARAM_READWRITE |
                                                         G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_ROUND_CORNERS,
                                   g_param_spec_boolean ("round-corners",
                                                         NULL, NULL,
                                                         FALSE,
                                                         GIMP_PARAM_READWRITE |
                                                         G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_CORNER_RADIUS,
                                   g_param_spec_double ("corner-radius",
                                                        NULL, NULL,
                                                        0.0, 10000.0, 10.0,
                                                        GIMP_PARAM_READWRITE |
                                                        G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_STATUS_TITLE,
                                   g_param_spec_string ("status-title",
                                                        NULL, NULL,
                                                        _("Rectangle: "),
                                                        GIMP_PARAM_READWRITE |
                                                        G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_HIGHLIGHT,
                                   g_param_spec_boolean ("highlight",
                                                         NULL, NULL,
                                                         FALSE,
                                                         GIMP_PARAM_READWRITE |
                                                         G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_HIGHLIGHT_OPACITY,
                                   g_param_spec_double ("highlight-opacity",
                                                        NULL, NULL,
                                                        0.0, 1.0, 0.5,
                                                        GIMP_PARAM_READWRITE |
                                                        G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_GUIDE,
                                   g_param_spec_enum ("guide",
                                                      NULL, NULL,
                                                      GIMP_TYPE_GUIDES_TYPE,
                                                      GIMP_GUIDES_NONE,
                                                      GIMP_PARAM_READWRITE |
                                                      G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_X,
                                   g_param_spec_double ("x",
                                                        NULL, NULL,
                                                        -GIMP_MAX_IMAGE_SIZE,
                                                        GIMP_MAX_IMAGE_SIZE,
                                                        0.0,
                                                        GIMP_PARAM_READWRITE |
                                                        G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_Y,
                                   g_param_spec_double ("y",
                                                        NULL, NULL,
                                                        -GIMP_MAX_IMAGE_SIZE,
                                                        GIMP_MAX_IMAGE_SIZE,
                                                        0.0,
                                                        GIMP_PARAM_READWRITE |
                                                        G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_WIDTH,
                                   g_param_spec_double ("width",
                                                        NULL, NULL,
                                                        0.0,
                                                        GIMP_MAX_IMAGE_SIZE,
                                                        0.0,
                                                        GIMP_PARAM_READWRITE |
                                                        G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_HEIGHT,
                                   g_param_spec_double ("height",
                                                        NULL, NULL,
                                                        0.0,
                                                        GIMP_MAX_IMAGE_SIZE,
                                                        0.0,
                                                        GIMP_PARAM_READWRITE |
                                                        G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_FIXED_RULE_ACTIVE,
                                   g_param_spec_boolean ("fixed-rule-active",
                                                         NULL, NULL,
                                                         FALSE,
                                                         GIMP_PARAM_READWRITE |
                                                         G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_FIXED_RULE,
                                   g_param_spec_enum ("fixed-rule",
                                                      NULL, NULL,
                                                      GIMP_TYPE_RECTANGLE_FIXED_RULE,
                                                      GIMP_RECTANGLE_FIXED_ASPECT,
                                                      GIMP_PARAM_READWRITE |
                                                      G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_DESIRED_FIXED_WIDTH,
                                   g_param_spec_double ("desired-fixed-width",
                                                        NULL, NULL,
                                                        0.0, GIMP_MAX_IMAGE_SIZE,
                                                        100.0,
                                                        GIMP_PARAM_READWRITE |
                                                        G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_DESIRED_FIXED_HEIGHT,
                                   g_param_spec_double ("desired-fixed-height",
                                                        NULL, NULL,
                                                        0.0, GIMP_MAX_IMAGE_SIZE,
                                                        100.0,
                                                        GIMP_PARAM_READWRITE |
                                                        G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_DESIRED_FIXED_SIZE_WIDTH,
                                   g_param_spec_double ("desired-fixed-size-width",
                                                        NULL, NULL,
                                                        0.0, GIMP_MAX_IMAGE_SIZE,
                                                        100.0,
                                                        GIMP_PARAM_READWRITE |
                                                        G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_DESIRED_FIXED_SIZE_HEIGHT,
                                   g_param_spec_double ("desired-fixed-size-height",
                                                        NULL, NULL,
                                                        0.0, GIMP_MAX_IMAGE_SIZE,
                                                        100.0,
                                                        GIMP_PARAM_READWRITE |
                                                        G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_ASPECT_NUMERATOR,
                                   g_param_spec_double ("aspect-numerator",
                                                        NULL, NULL,
                                                        0.0, GIMP_MAX_IMAGE_SIZE,
                                                        1.0,
                                                        GIMP_PARAM_READWRITE |
                                                        G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_ASPECT_DENOMINATOR,
                                   g_param_spec_double ("aspect-denominator",
                                                        NULL, NULL,
                                                        0.0, GIMP_MAX_IMAGE_SIZE,
                                                        1.0,
                                                        GIMP_PARAM_READWRITE |
                                                        G_PARAM_CONSTRUCT));

  g_object_class_install_property (object_class, PROP_FIXED_CENTER,
                                   g_param_spec_boolean ("fixed-center",
                                                         NULL, NULL,
                                                         FALSE,
                                                         GIMP_PARAM_READWRITE |
                                                         G_PARAM_CONSTRUCT));
}

static void
gimp_tool_rectangle_init (GimpToolRectangle *rectangle)
{
  rectangle->private = gimp_tool_rectangle_get_instance_private (rectangle);

  rectangle->private->function = GIMP_TOOL_RECTANGLE_CREATING;
  rectangle->private->is_first = TRUE;
}

static void
gimp_tool_rectangle_constructed (GObject *object)
{
  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (object);
  GimpToolWidget           *widget    = GIMP_TOOL_WIDGET (object);
  GimpToolRectanglePrivate *private   = rectangle->private;
  GimpCanvasGroup          *stroke_group;
  gint                      i;

  G_OBJECT_CLASS (parent_class)->constructed (object);

  stroke_group = gimp_tool_widget_add_stroke_group (widget);

  gimp_tool_widget_push_group (widget, stroke_group);

  private->guides = gimp_tool_widget_add_rectangle_guides (widget,
                                                           0, 0, 10, 10,
                                                           GIMP_GUIDES_NONE);

  private->rectangle = gimp_tool_widget_add_rectangle (widget,
                                                       0, 0, 10, 10,
                                                       FALSE);

  private->ellipse = gimp_tool_widget_add_arc (widget,
                                               0, 0, 10, 10,
                                               0.0, 2 * G_PI,
                                               FALSE);

  for (i = 0; i < 4; i++)
    private->corners[i] = gimp_tool_widget_add_arc (widget,
                                                    0, 0, 10, 10,
                                                    0.0, 2 * G_PI,
                                                    FALSE);

  gimp_tool_widget_pop_group (widget);

  private->center = gimp_tool_widget_add_handle (widget,
                                                 GIMP_HANDLE_CROSS,
                                                 0, 0,
                                                 GIMP_CANVAS_HANDLE_SIZE_SMALL,
                                                 GIMP_CANVAS_HANDLE_SIZE_SMALL,
                                                 GIMP_HANDLE_ANCHOR_CENTER);

  gimp_tool_widget_push_group (widget, stroke_group);

  private->creating_corners[0] =
    gimp_tool_widget_add_corner (widget,
                                 0, 0, 10, 10,
                                 GIMP_HANDLE_ANCHOR_NORTH_WEST,
                                 10, 10,
                                 FALSE);

  private->creating_corners[1] =
    gimp_tool_widget_add_corner (widget,
                                 0, 0, 10, 10,
                                 GIMP_HANDLE_ANCHOR_NORTH_EAST,
                                 10, 10,
                                 FALSE);

  private->creating_corners[2] =
    gimp_tool_widget_add_corner (widget,
                                 0, 0, 10, 10,
                                 GIMP_HANDLE_ANCHOR_SOUTH_WEST,
                                 10, 10,
                                 FALSE);

  private->creating_corners[3] =
    gimp_tool_widget_add_corner (widget,
                                 0, 0, 10, 10,
                                 GIMP_HANDLE_ANCHOR_SOUTH_EAST,
                                 10, 10,
                                 FALSE);

  gimp_tool_widget_pop_group (widget);

  for (i = GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT;
       i <= GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM;
       i++)
    {
      GimpHandleAnchor anchor;

      anchor = gimp_tool_rectangle_get_anchor (i);

      gimp_tool_widget_push_group (widget, stroke_group);

      private->handles[i] = gimp_tool_widget_add_corner (widget,
                                                         0, 0, 10, 10,
                                                         anchor,
                                                         10, 10,
                                                         FALSE);

      gimp_tool_widget_pop_group (widget);

      private->highlight_handles[i] = gimp_tool_widget_add_corner (widget,
                                                                   0, 0, 10, 10,
                                                                   anchor,
                                                                   10, 10,
                                                                   FALSE);
      gimp_canvas_item_set_highlight (private->highlight_handles[i], TRUE);
    }

  gimp_tool_rectangle_changed (widget);
}

static void
gimp_tool_rectangle_finalize (GObject *object)
{
  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (object);
  GimpToolRectanglePrivate *private   = rectangle->private;

  g_clear_pointer (&private->status_title, g_free);

  G_OBJECT_CLASS (parent_class)->finalize (object);
}

static void
gimp_tool_rectangle_set_property (GObject      *object,
                                  guint         property_id,
                                  const GValue *value,
                                  GParamSpec   *pspec)
{
  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (object);
  GimpToolRectanglePrivate *private   = rectangle->private;

  switch (property_id)
    {
    case PROP_X1:
      private->x1 = g_value_get_double (value);
      break;
    case PROP_Y1:
      private->y1 = g_value_get_double (value);
      break;
    case PROP_X2:
      private->x2 = g_value_get_double (value);
      break;
    case PROP_Y2:
      private->y2 = g_value_get_double (value);
      break;

    case PROP_CONSTRAINT:
      private->constraint = g_value_get_enum (value);
      break;
    case PROP_PRECISION:
      private->precision = g_value_get_enum (value);
      break;

    case PROP_NARROW_MODE:
      private->narrow_mode = g_value_get_boolean (value);
      break;
    case PROP_FORCE_NARROW_MODE:
      private->force_narrow_mode = g_value_get_boolean (value);
      break;
    case PROP_DRAW_ELLIPSE:
      private->draw_ellipse = g_value_get_boolean (value);
      break;
    case PROP_ROUND_CORNERS:
      private->round_corners = g_value_get_boolean (value);
      break;
    case PROP_CORNER_RADIUS:
      private->corner_radius = g_value_get_double (value);
      break;

    case PROP_STATUS_TITLE:
      g_free (private->status_title);
      private->status_title = g_value_dup_string (value);
      if (! private->status_title)
        private->status_title = g_strdup (_("Rectangle: "));
      break;

    case PROP_HIGHLIGHT:
      private->highlight = g_value_get_boolean (value);
      break;
    case PROP_HIGHLIGHT_OPACITY:
      private->highlight_opacity = g_value_get_double (value);
      break;
    case PROP_GUIDE:
      private->guide = g_value_get_enum (value);
      break;

    case PROP_X:
      private->x = g_value_get_double (value);
      break;
    case PROP_Y:
      private->y = g_value_get_double (value);
      break;
    case PROP_WIDTH:
      private->width = g_value_get_double (value);
      break;
    case PROP_HEIGHT:
      private->height = g_value_get_double (value);
      break;

    case PROP_FIXED_RULE_ACTIVE:
      private->fixed_rule_active = g_value_get_boolean (value);
      break;
    case PROP_FIXED_RULE:
      private->fixed_rule = g_value_get_enum (value);
      break;
    case PROP_DESIRED_FIXED_WIDTH:
      private->desired_fixed_width = g_value_get_double (value);
      break;
    case PROP_DESIRED_FIXED_HEIGHT:
      private->desired_fixed_height = g_value_get_double (value);
      break;
    case PROP_DESIRED_FIXED_SIZE_WIDTH:
      private->desired_fixed_size_width = g_value_get_double (value);
      break;
    case PROP_DESIRED_FIXED_SIZE_HEIGHT:
      private->desired_fixed_size_height = g_value_get_double (value);
      break;
    case PROP_ASPECT_NUMERATOR:
      private->aspect_numerator = g_value_get_double (value);
      break;
    case PROP_ASPECT_DENOMINATOR:
      private->aspect_denominator = g_value_get_double (value);
      break;

    case PROP_FIXED_CENTER:
      private->fixed_center = g_value_get_boolean (value);
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
      break;
    }
}

static void
gimp_tool_rectangle_get_property (GObject    *object,
                                  guint       property_id,
                                  GValue     *value,
                                  GParamSpec *pspec)
{
  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (object);
  GimpToolRectanglePrivate *private   = rectangle->private;

  switch (property_id)
    {
    case PROP_X1:
      g_value_set_double (value, private->x1);
      break;
    case PROP_Y1:
      g_value_set_double (value, private->y1);
      break;
    case PROP_X2:
      g_value_set_double (value, private->x2);
      break;
    case PROP_Y2:
      g_value_set_double (value, private->y2);
      break;

    case PROP_CONSTRAINT:
      g_value_set_enum (value, private->constraint);
      break;
    case PROP_PRECISION:
      g_value_set_enum (value, private->precision);
      break;

    case PROP_NARROW_MODE:
      g_value_set_boolean (value, private->narrow_mode);
      break;
    case PROP_FORCE_NARROW_MODE:
      g_value_set_boolean (value, private->force_narrow_mode);
      break;
    case PROP_DRAW_ELLIPSE:
      g_value_set_boolean (value, private->draw_ellipse);
      break;
    case PROP_ROUND_CORNERS:
      g_value_set_boolean (value, private->round_corners);
      break;
    case PROP_CORNER_RADIUS:
      g_value_set_double (value, private->corner_radius);
      break;

    case PROP_STATUS_TITLE:
      g_value_set_string (value, private->status_title);
      break;

    case PROP_HIGHLIGHT:
      g_value_set_boolean (value, private->highlight);
      break;
    case PROP_HIGHLIGHT_OPACITY:
      g_value_set_double (value, private->highlight_opacity);
      break;
    case PROP_GUIDE:
      g_value_set_enum (value, private->guide);
      break;

    case PROP_X:
      g_value_set_double (value, private->x);
      break;
    case PROP_Y:
      g_value_set_double (value, private->y);
      break;
    case PROP_WIDTH:
      g_value_set_double (value, private->width);
      break;
    case PROP_HEIGHT:
      g_value_set_double (value, private->height);
      break;

    case PROP_FIXED_RULE_ACTIVE:
      g_value_set_boolean (value, private->fixed_rule_active);
      break;
    case PROP_FIXED_RULE:
      g_value_set_enum (value, private->fixed_rule);
      break;
    case PROP_DESIRED_FIXED_WIDTH:
      g_value_set_double (value, private->desired_fixed_width);
      break;
    case PROP_DESIRED_FIXED_HEIGHT:
      g_value_set_double (value, private->desired_fixed_height);
      break;
    case PROP_DESIRED_FIXED_SIZE_WIDTH:
      g_value_set_double (value, private->desired_fixed_size_width);
      break;
    case PROP_DESIRED_FIXED_SIZE_HEIGHT:
      g_value_set_double (value, private->desired_fixed_size_height);
      break;
    case PROP_ASPECT_NUMERATOR:
      g_value_set_double (value, private->aspect_numerator);
      break;
    case PROP_ASPECT_DENOMINATOR:
      g_value_set_double (value, private->aspect_denominator);
      break;

    case PROP_FIXED_CENTER:
      g_value_set_boolean (value, private->fixed_center);
      break;

    default:
      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
      break;
    }
}

static void
gimp_tool_rectangle_notify (GObject    *object,
                            GParamSpec *pspec)
{
  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (object);
  GimpToolRectanglePrivate *private   = rectangle->private;

  if (G_OBJECT_CLASS (parent_class)->notify)
    G_OBJECT_CLASS (parent_class)->notify (object, pspec);

  if (! strcmp (pspec->name, "x1") ||
      ! strcmp (pspec->name, "y1") ||
      ! strcmp (pspec->name, "x2") ||
      ! strcmp (pspec->name, "y2"))
    {
      gimp_tool_rectangle_update_int_rect (rectangle);

      gimp_tool_rectangle_recalculate_center_xy (rectangle);

      gimp_tool_rectangle_update_options (rectangle);
    }
  else if (! strcmp  (pspec->name, "x") &&
           ! PIXEL_FEQUAL (private->x1, private->x))
    {
      gimp_tool_rectangle_synthesize_motion (rectangle,
                                             GIMP_TOOL_RECTANGLE_MOVING,
                                             private->x,
                                             private->y1);
    }
  else if (! strcmp  (pspec->name, "y") &&
           ! PIXEL_FEQUAL (private->y1, private->y))
    {
      gimp_tool_rectangle_synthesize_motion (rectangle,
                                             GIMP_TOOL_RECTANGLE_MOVING,
                                             private->x1,
                                             private->y);
    }
  else if (! strcmp  (pspec->name, "width") &&
           ! PIXEL_FEQUAL (private->x2 - private->x1, private->width))
    {
      /* Calculate x2, y2 that will create a rectangle of given width,
       * for the current options.
       */
      gdouble x2;

      if (private->fixed_center)
        {
          x2 = private->center_x_on_fixed_center +
               private->width / 2;
        }
      else
        {
          x2 = private->x1 + private->width;
        }

      gimp_tool_rectangle_synthesize_motion (rectangle,
                                             GIMP_TOOL_RECTANGLE_RESIZING_RIGHT,
                                             x2,
                                             private->y2);
    }
  else if (! strcmp  (pspec->name, "height") &&
           ! PIXEL_FEQUAL (private->y2 - private->y1, private->height))
    {
      /* Calculate x2, y2 that will create a rectangle of given
       * height, for the current options.
       */
      gdouble y2;

      if (private->fixed_center)
        {
          y2 = private->center_y_on_fixed_center +
               private->height / 2;
        }
      else
        {
          y2 = private->y1 + private->height;
        }

      gimp_tool_rectangle_synthesize_motion (rectangle,
                                             GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM,
                                             private->x2,
                                             y2);
    }
  else if (! strcmp (pspec->name, "desired-fixed-size-width"))
    {
      /* We are only interested in when width and height swaps, so
       * it's enough to only check e.g. for width.
       */

      gdouble width  = private->x2 - private->x1;
      gdouble height = private->y2 - private->y1;

      /* Depending on a bunch of conditions, we might want to
       * immedieately switch width and height of the pending
       * rectangle.
       */
      if (private->fixed_rule_active                          &&
#if 0
          tool->button_press_state                            == 0    &&
          tool->active_modifier_state                         == 0    &&
#endif
          FEQUAL (private->desired_fixed_size_width,  height) &&
          FEQUAL (private->desired_fixed_size_height, width))
        {
          gdouble x = private->x1;
          gdouble y = private->y1;

          gimp_tool_rectangle_synthesize_motion (rectangle,
                                                 GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT,
                                                 private->x2,
                                                 private->y2);

          /* For some reason these needs to be set separately... */
          g_object_set (rectangle,
                        "x", x,
                        NULL);
          g_object_set (rectangle,
                        "y", y,
                        NULL);
        }
    }
  else if (! strcmp (pspec->name, "aspect-numerator"))
    {
      /* We are only interested in when numerator and denominator
       * swaps, so it's enough to only check e.g. for numerator.
       */

      double    width             = private->x2 - private->x1;
      double    height            = private->y2 - private->y1;
      gdouble   new_inverse_ratio = private->aspect_denominator /
                                    private->aspect_numerator;
      gdouble   lower_ratio;
      gdouble   higher_ratio;

      /* The ratio of the Fixed: Aspect ratio rule and the pending
       * rectangle is very rarely exactly the same so use an
       * interval. For small rectangles the below code will
       * automatically yield a more generous accepted ratio interval
       * which is exactly what we want.
       */
      if (width > height && height > 1.0)
        {
          lower_ratio  = width / (height + 1.0);
          higher_ratio = width / (height - 1.0);
        }
      else
        {
          lower_ratio  = (width - 1.0) / height;
          higher_ratio = (width + 1.0) / height;
        }

      /* Depending on a bunch of conditions, we might want to
       * immedieately switch width and height of the pending
       * rectangle.
       */
      if (private->fixed_rule_active               &&
#if 0
          tool->button_press_state    == 0                 &&
          tool->active_modifier_state == 0                 &&
#endif
          lower_ratio                 <  new_inverse_ratio &&
          higher_ratio                >  new_inverse_ratio)
        {
          gdouble new_x2 = private->x1 + private->y2 - private->y1;
          gdouble new_y2 = private->y1 + private->x2 - private->x1;

          gimp_tool_rectangle_synthesize_motion (rectangle,
                                                 GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT,
                                                 new_x2,
                                                 new_y2);
        }
    }
}

static void
gimp_tool_rectangle_changed (GimpToolWidget *widget)
{
  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (widget);
  GimpToolRectanglePrivate *private   = rectangle->private;
  GimpDisplayShell         *shell     = gimp_tool_widget_get_shell (widget);
  gdouble                   x1, y1, x2, y2;
  gint                      handle_width;
  gint                      handle_height;
  gint                      i;

  gimp_tool_rectangle_update_handle_sizes (rectangle);

  gimp_tool_rectangle_get_public_rect (rectangle, &x1, &y1, &x2, &y2);

  gimp_canvas_rectangle_guides_set (private->guides,
                                    x1, y1,
                                    x2 - x1,
                                    y2 - y1,
                                    private->guide, 4);

  gimp_canvas_rectangle_set (private->rectangle,
                             x1, y1,
                             x2 - x1,
                             y2 - y1);

  if (private->draw_ellipse)
    {
      gimp_canvas_arc_set (private->ellipse,
                           (x1 + x2) / 2.0,
                           (y1 + y2) / 2.0,
                           (x2 - x1) / 2.0,
                           (y2 - y1) / 2.0,
                           0.0, 2 * G_PI);
      gimp_canvas_item_set_visible (private->ellipse, TRUE);
    }
  else
    {
      gimp_canvas_item_set_visible (private->ellipse, FALSE);
    }

  if (private->round_corners && private->corner_radius > 0.0)
    {
      gdouble radius;

      radius = MIN (private->corner_radius,
                    MIN ((x2 - x1) / 2.0, (y2 - y1) / 2.0));

      gimp_canvas_arc_set (private->corners[0],
                           x1 + radius,
                           y1 + radius,
                           radius, radius,
                           G_PI / 2.0, G_PI / 2.0);

      gimp_canvas_arc_set (private->corners[1],
                           x2 - radius,
                           y1 + radius,
                           radius, radius,
                           0.0, G_PI / 2.0);

      gimp_canvas_arc_set (private->corners[2],
                           x1 + radius,
                           y2 - radius,
                           radius, radius,
                           G_PI, G_PI / 2.0);

      gimp_canvas_arc_set (private->corners[3],
                           x2 - radius,
                           y2 - radius,
                           radius, radius,
                           G_PI * 1.5, G_PI / 2.0);

      for (i = 0; i < 4; i++)
        gimp_canvas_item_set_visible (private->corners[i], TRUE);
    }
  else
    {
      for (i = 0; i < 4; i++)
        gimp_canvas_item_set_visible (private->corners[i], FALSE);
    }

  gimp_canvas_item_set_visible (private->center, FALSE);

  for (i = 0; i < 4; i++)
    {
      gimp_canvas_item_set_visible (private->creating_corners[i], FALSE);
      gimp_canvas_item_set_highlight (private->creating_corners[i], FALSE);
    }

  for (i = GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT;
       i <= GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM;
       i++)
    {
      gimp_canvas_item_set_visible (private->handles[i], FALSE);
      gimp_canvas_item_set_visible (private->highlight_handles[i], FALSE);
    }

  handle_width  = private->corner_handle_w;
  handle_height = private->corner_handle_h;

  switch (private->function)
    {
    case GIMP_TOOL_RECTANGLE_MOVING:
      if (private->rect_adjusting)
        {
          /* Mark the center because we snap to it */
          gimp_canvas_handle_set_position (private->center,
                                           (x1 + x2) / 2.0,
                                           (y1 + y2) / 2.0);
          gimp_canvas_item_set_visible (private->center, TRUE);
          break;
        }

      /* else fallthrough */

    case GIMP_TOOL_RECTANGLE_DEAD:
    case GIMP_TOOL_RECTANGLE_CREATING:
    case GIMP_TOOL_RECTANGLE_AUTO_SHRINK:
      for (i = 0; i < 4; i++)
        {
          gimp_canvas_corner_set (private->creating_corners[i],
                                  x1, y1, x2 - x1, y2 - y1,
                                  handle_width, handle_height,
                                  private->narrow_mode);
          gimp_canvas_item_set_visible (private->creating_corners[i], TRUE);
        }
      break;

    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
      handle_width = private->top_and_bottom_handle_w;
      break;

    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
      handle_height = private->left_and_right_handle_h;
      break;

    default:
      break;
    }

  if (handle_width  >= 3                                           &&
      handle_height >= 3                                           &&
      private->function >= GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT &&
      private->function <= GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM)
    {
      GimpCanvasItem *corner;

      if (private->rect_adjusting)
        corner = private->handles[private->function];
      else
        corner = private->highlight_handles[private->function];

      gimp_canvas_corner_set (corner,
                              x1, y1, x2 - x1, y2 - y1,
                              handle_width, handle_height,
                              private->narrow_mode);
      gimp_canvas_item_set_visible (corner, TRUE);
    }

  if (private->highlight && ! private->rect_adjusting)
    {
      GdkRectangle rect;

      rect.x      = x1;
      rect.y      = y1;
      rect.width  = x2 - x1;
      rect.height = y2 - y1;

      gimp_display_shell_set_highlight (shell, &rect, private->highlight_opacity);
    }
  else
    {
      gimp_display_shell_set_highlight (shell, NULL, 0.0);
    }
}

gint
gimp_tool_rectangle_button_press (GimpToolWidget      *widget,
                                  const GimpCoords    *coords,
                                  guint32              time,
                                  GdkModifierType      state,
                                  GimpButtonPressType  press_type)
{
  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (widget);
  GimpToolRectanglePrivate *private   = rectangle->private;
  gdouble                   snapped_x, snapped_y;
  gint                      snap_x, snap_y;

  /* save existing shape in case of cancellation */
  private->saved_x1 = private->x1;
  private->saved_y1 = private->y1;
  private->saved_x2 = private->x2;
  private->saved_y2 = private->y2;

  gimp_tool_rectangle_setup_snap_offsets (rectangle, coords);
  gimp_tool_widget_get_snap_offsets (widget, &snap_x, &snap_y, NULL, NULL);

  snapped_x = coords->x + snap_x;
  snapped_y = coords->y + snap_y;

  private->lastx = snapped_x;
  private->lasty = snapped_y;

  if (private->function == GIMP_TOOL_RECTANGLE_CREATING)
    {
      /* Remember that this rectangle was created from scratch. */
      private->is_new = TRUE;

      private->x1 = private->x2 = snapped_x;
      private->y1 = private->y2 = snapped_y;

      /* Unless forced, created rectangles should not be started in
       * narrow-mode
       */
      if (private->force_narrow_mode)
        private->narrow_mode = TRUE;
      else
        private->narrow_mode = FALSE;

      /* If the rectangle is being modified we want the center on
       * fixed_center to be at the center of the currently existing
       * rectangle, otherwise we want the point where the user clicked
       * to be the center on fixed_center.
       */
      private->center_x_on_fixed_center = snapped_x;
      private->center_y_on_fixed_center = snapped_y;

      /* When the user toggles modifier keys, we want to keep track of
       * what coordinates the "other side" should have. If we are
       * creating a rectangle, use the current mouse coordinates as
       * the coordinate of the "other side", otherwise use the
       * immediate "other side" for that.
       */
      private->other_side_x = snapped_x;
      private->other_side_y = snapped_y;
    }
  else
    {
      /* This rectangle was not created from scratch. */
      private->is_new = FALSE;

      private->center_x_on_fixed_center = (private->x1 + private->x2) / 2;
      private->center_y_on_fixed_center = (private->y1 + private->y2) / 2;

      gimp_tool_rectangle_get_other_side_coord (rectangle,
                                                &private->other_side_x,
                                                &private->other_side_y);
    }

  gimp_tool_rectangle_update_int_rect (rectangle);

  /* Is the rectangle being rubber-banded? */
  private->rect_adjusting = gimp_tool_rectangle_rect_adjusting_func (rectangle);

  gimp_tool_rectangle_changed (widget);

  gimp_tool_rectangle_update_status (rectangle);

  return 1;
}

void
gimp_tool_rectangle_button_release (GimpToolWidget        *widget,
                                    const GimpCoords      *coords,
                                    guint32                time,
                                    GdkModifierType        state,
                                    GimpButtonReleaseType  release_type)
{
  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (widget);
  GimpToolRectanglePrivate *private   = rectangle->private;
  gint                      response  = 0;

  gimp_tool_widget_set_status (widget, NULL);

  /* On button release, we are not rubber-banding the rectangle any longer. */
  private->rect_adjusting = FALSE;

  gimp_tool_widget_set_snap_offsets (widget, 0, 0, 0, 0);

  switch (release_type)
    {
    case GIMP_BUTTON_RELEASE_NO_MOTION:
      /* If the first created rectangle was not expanded, halt the
       * tool...
       */
      if (gimp_tool_rectangle_rectangle_is_first (rectangle))
        {
          response = GIMP_TOOL_WIDGET_RESPONSE_CANCEL;
          break;
        }

      /* ...else fallthrough and treat a long click without movement
       * like a normal change
       */

    case GIMP_BUTTON_RELEASE_NORMAL:
      /* If a normal click-drag-release actually created a rectangle
       * with content...
       */
      if (private->x1 != private->x2 &&
          private->y1 != private->y2)
        {
          gimp_tool_rectangle_change_complete (rectangle);
          break;
        }

      /* ...else fallthrough and undo the operation, we can't have
       * zero-extent rectangles
       */

    case GIMP_BUTTON_RELEASE_CANCEL:
      private->x1 = private->saved_x1;
      private->y1 = private->saved_y1;
      private->x2 = private->saved_x2;
      private->y2 = private->saved_y2;

      gimp_tool_rectangle_update_int_rect (rectangle);

      /* If the first created rectangle was canceled, halt the tool */
      if (gimp_tool_rectangle_rectangle_is_first (rectangle))
        response = GIMP_TOOL_WIDGET_RESPONSE_CANCEL;
      break;

    case GIMP_BUTTON_RELEASE_CLICK:
      /* When a dead area is clicked, don't execute. */
      if (private->function != GIMP_TOOL_RECTANGLE_DEAD)
        response = GIMP_TOOL_WIDGET_RESPONSE_CONFIRM;
      break;
    }

  /* We must update this. */
  gimp_tool_rectangle_recalculate_center_xy (rectangle);

  gimp_tool_rectangle_update_options (rectangle);

  gimp_tool_rectangle_changed (widget);

  private->is_first = FALSE;

  /*  emit response at the end, so everything is up to date even if
   *  a signal handler decides hot to shut down the rectangle
   */
  if (response != 0)
    gimp_tool_widget_response (widget, response);
}

void
gimp_tool_rectangle_motion (GimpToolWidget   *widget,
                            const GimpCoords *coords,
                            guint32           time,
                            GdkModifierType   state)
{
  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (widget);
  GimpToolRectanglePrivate *private   = rectangle->private;
  gdouble                   snapped_x;
  gdouble                   snapped_y;
  gint                      snap_x, snap_y;

  /* Motion events should be ignored when we're just waiting for the
   * button release event to execute or if the user has grabbed a dead
   * area of the rectangle.
   */
  if (private->function == GIMP_TOOL_RECTANGLE_EXECUTING ||
      private->function == GIMP_TOOL_RECTANGLE_DEAD)
    return;

  /* Handle snapping. */
  gimp_tool_widget_get_snap_offsets (widget, &snap_x, &snap_y, NULL, NULL);

  snapped_x = coords->x + snap_x;
  snapped_y = coords->y + snap_y;

  /* This is the core rectangle shape updating function: */
  gimp_tool_rectangle_update_with_coord (rectangle, snapped_x, snapped_y);

  gimp_tool_rectangle_update_status (rectangle);

  if (private->function == GIMP_TOOL_RECTANGLE_CREATING)
    {
      GimpRectangleFunction function = GIMP_TOOL_RECTANGLE_CREATING;
      gdouble               dx       = snapped_x - private->lastx;
      gdouble               dy       = snapped_y - private->lasty;

      /* When the user starts to move the cursor, set the current
       * function to one of the corner-grabbed functions, depending on
       * in what direction the user starts dragging the rectangle.
       */
      if (dx < 0)
        {
          function = (dy < 0 ?
                      GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT :
                      GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT);
        }
      else if (dx > 0)
        {
          function = (dy < 0 ?
                      GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT :
                      GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT);
        }
      else if (dy < 0)
        {
          function = (dx < 0 ?
                      GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT :
                      GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT);
        }
      else if (dy > 0)
        {
          function = (dx < 0 ?
                      GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT :
                      GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT);
        }

      gimp_tool_rectangle_set_function (rectangle, function);

      if (private->fixed_rule_active &&
          private->fixed_rule == GIMP_RECTANGLE_FIXED_SIZE)
        {
          /* For fixed size, set the function to moving immediately since the
           * rectangle can not be resized anyway.
           */

          /* We fake a coord update to get the right size. */
          gimp_tool_rectangle_update_with_coord (rectangle,
                                                 snapped_x,
                                                 snapped_y);

          gimp_tool_widget_set_snap_offsets (widget,
                                             -(private->x2 - private->x1) / 2,
                                             -(private->y2 - private->y1) / 2,
                                             private->x2 - private->x1,
                                             private->y2 - private->y1);

          gimp_tool_rectangle_set_function (rectangle,
                                            GIMP_TOOL_RECTANGLE_MOVING);
        }
    }

  gimp_tool_rectangle_update_options (rectangle);

  private->lastx = snapped_x;
  private->lasty = snapped_y;
}

GimpHit
gimp_tool_rectangle_hit (GimpToolWidget   *widget,
                         const GimpCoords *coords,
                         GdkModifierType   state,
                         gboolean          proximity)
{
  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (widget);
  GimpToolRectanglePrivate *private   = rectangle->private;
  GimpRectangleFunction     function;

  if (private->suppress_updates)
    {
      function = gimp_tool_rectangle_get_function (rectangle);
    }
  else
    {
      function = gimp_tool_rectangle_calc_function (rectangle,
                                                    coords, proximity);
    }

  switch (function)
    {
    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
      return GIMP_HIT_DIRECT;

    case GIMP_TOOL_RECTANGLE_CREATING:
    case GIMP_TOOL_RECTANGLE_MOVING:
      return GIMP_HIT_INDIRECT;

    case GIMP_TOOL_RECTANGLE_DEAD:
    case GIMP_TOOL_RECTANGLE_AUTO_SHRINK:
    case GIMP_TOOL_RECTANGLE_EXECUTING:
    default:
      return GIMP_HIT_NONE;
    }
}

void
gimp_tool_rectangle_hover (GimpToolWidget   *widget,
                           const GimpCoords *coords,
                           GdkModifierType   state,
                           gboolean          proximity)
{
  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (widget);
  GimpToolRectanglePrivate *private   = rectangle->private;
  GimpRectangleFunction     function;

  if (private->suppress_updates)
    {
      private->suppress_updates--;
      return;
    }

  function = gimp_tool_rectangle_calc_function (rectangle, coords, proximity);

  gimp_tool_rectangle_set_function (rectangle, function);
}

static void
gimp_tool_rectangle_leave_notify (GimpToolWidget *widget)
{
  GimpToolRectangle *rectangle = GIMP_TOOL_RECTANGLE (widget);

  gimp_tool_rectangle_set_function (rectangle, GIMP_TOOL_RECTANGLE_DEAD);

  GIMP_TOOL_WIDGET_CLASS (parent_class)->leave_notify (widget);
}

static gboolean
gimp_tool_rectangle_key_press (GimpToolWidget *widget,
                               GdkEventKey    *kevent)
{
  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (widget);
  GimpToolRectanglePrivate *private   = rectangle->private;
  gint                      dx        = 0;
  gint                      dy        = 0;
  gdouble                   new_x     = 0;
  gdouble                   new_y     = 0;

  switch (kevent->keyval)
    {
    case GDK_KEY_Up:
      dy = -1;
      break;
    case GDK_KEY_Left:
      dx = -1;
      break;
    case GDK_KEY_Right:
      dx = 1;
      break;
    case GDK_KEY_Down:
      dy = 1;
      break;

    default:
      return GIMP_TOOL_WIDGET_CLASS (parent_class)->key_press (widget, kevent);
    }

  /*  If the shift key is down, move by an accelerated increment  */
  if (kevent->state & gimp_get_extend_selection_mask ())
    {
      dx *= ARROW_VELOCITY;
      dy *= ARROW_VELOCITY;
    }

  gimp_tool_widget_set_snap_offsets (widget, 0, 0, 0, 0);

  /*  Resize the rectangle if the mouse is over a handle, otherwise move it  */
  switch (private->function)
    {
    case GIMP_TOOL_RECTANGLE_MOVING:
    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
      new_x = private->x1 + dx;
      new_y = private->y1 + dy;
      private->lastx = new_x;
      private->lasty = new_y;
      break;
    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
      new_x = private->x2 + dx;
      new_y = private->y1 + dy;
      private->lastx = new_x;
      private->lasty = new_y;
      break;
    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
      new_x = private->x1 + dx;
      new_y = private->y2 + dy;
      private->lastx = new_x;
      private->lasty = new_y;
      break;
    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
      new_x = private->x2 + dx;
      new_y = private->y2 + dy;
      private->lastx = new_x;
      private->lasty = new_y;
      break;
    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
      new_x = private->x1 + dx;
      private->lastx = new_x;
      break;
    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
      new_x = private->x2 + dx;
      private->lastx = new_x;
      break;
    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
      new_y = private->y1 + dy;
      private->lasty = new_y;
      break;
    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
      new_y = private->y2 + dy;
      private->lasty = new_y;
      break;

    default:
      return TRUE;
    }

  gimp_tool_rectangle_update_with_coord (rectangle, new_x, new_y);

  gimp_tool_rectangle_recalculate_center_xy (rectangle);

  gimp_tool_rectangle_update_options (rectangle);

  gimp_tool_rectangle_change_complete (rectangle);

  /*  Evil hack to suppress oper updates. We do this because we don't
   *  want the rectangle tool to change function while the rectangle
   *  is being resized or moved using the keyboard.
   */
  private->suppress_updates = 2;

  return TRUE;
}

static void
gimp_tool_rectangle_motion_modifier (GimpToolWidget  *widget,
                                     GdkModifierType  key,
                                     gboolean         press,
                                     GdkModifierType  state)
{
  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (widget);
  GimpToolRectanglePrivate *private   = rectangle->private;
  gboolean                  button1_down;

  button1_down = (state & GDK_BUTTON1_MASK);

  if (key == gimp_get_extend_selection_mask ())
    {
#if 0
      /* Here we want to handle manually when to update the rectangle, so we
       * don't want gimp_tool_rectangle_options_notify to do anything.
       */
      g_signal_handlers_block_by_func (options,
                                       gimp_tool_rectangle_options_notify,
                                       rectangle);
#endif

      g_object_set (rectangle,
                    "fixed-rule-active", ! private->fixed_rule_active,
                    NULL);

#if 0
      g_signal_handlers_unblock_by_func (options,
                                         gimp_tool_rectangle_options_notify,
                                         rectangle);
#endif

      /* Only change the shape if the mouse is still down (i.e. the user is
       * still editing the rectangle.
       */
      if (button1_down)
        {
          if (! private->fixed_rule_active)
            {
              /* Reset anchor point */
              gimp_tool_rectangle_set_other_side_coord (rectangle,
                                                        private->other_side_x,
                                                        private->other_side_y);
            }

          gimp_tool_rectangle_update_with_coord (rectangle,
                                                 private->lastx,
                                                 private->lasty);
        }
    }

  if (key == gimp_get_toggle_behavior_mask ())
    {
      g_object_set (rectangle,
                    "fixed-center", ! private->fixed_center,
                    NULL);

      if (private->fixed_center)
        {
          gimp_tool_rectangle_update_with_coord (rectangle,
                                                 private->lastx,
                                                 private->lasty);

          /* Only emit the rectangle-changed signal if the button is
           * not down. If it is down, the signal will and shall be
           * emitted on _button_release instead.
           */
          if (! button1_down)
            {
              gimp_tool_rectangle_change_complete (rectangle);
            }
        }
      else if (button1_down)
        {
          /* If we are leaving fixed_center mode we want to set the
           * "other side" where it should be. Don't do anything if we
           * came here by a mouse-click though, since then the user
           * has confirmed the shape and we don't want to modify it
           * afterwards.
           */
          gimp_tool_rectangle_set_other_side_coord (rectangle,
                                                    private->other_side_x,
                                                    private->other_side_y);
        }
    }

  gimp_tool_rectangle_update_options (rectangle);
}

static gboolean
gimp_tool_rectangle_get_cursor (GimpToolWidget     *widget,
                                const GimpCoords   *coords,
                                GdkModifierType     state,
                                GimpCursorType     *cursor,
                                GimpToolCursorType *tool_cursor,
                                GimpCursorModifier *modifier)
{
  GimpToolRectangle        *rectangle = GIMP_TOOL_RECTANGLE (widget);
  GimpToolRectanglePrivate *private   = rectangle->private;

  switch (private->function)
    {
    case GIMP_TOOL_RECTANGLE_CREATING:
      *cursor = GIMP_CURSOR_CROSSHAIR_SMALL;
      break;
    case GIMP_TOOL_RECTANGLE_MOVING:
      *cursor   = GIMP_CURSOR_MOVE;
      *modifier = GIMP_CURSOR_MODIFIER_MOVE;
      break;
    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
      *cursor = GIMP_CURSOR_CORNER_TOP_LEFT;
      break;
    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
      *cursor = GIMP_CURSOR_CORNER_TOP_RIGHT;
      break;
    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
      *cursor = GIMP_CURSOR_CORNER_BOTTOM_LEFT;
      break;
    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
      *cursor = GIMP_CURSOR_CORNER_BOTTOM_RIGHT;
      break;
    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
      *cursor = GIMP_CURSOR_SIDE_LEFT;
      break;
    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
      *cursor = GIMP_CURSOR_SIDE_RIGHT;
      break;
    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
      *cursor = GIMP_CURSOR_SIDE_TOP;
      break;
    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
      *cursor = GIMP_CURSOR_SIDE_BOTTOM;
      break;

    default:
      return FALSE;
    }

  return TRUE;
}

static void
gimp_tool_rectangle_change_complete (GimpToolRectangle *rectangle)
{
  g_signal_emit (rectangle, rectangle_signals[CHANGE_COMPLETE], 0);
}

static void
gimp_tool_rectangle_update_options (GimpToolRectangle *rectangle)
{
  GimpToolRectanglePrivate *private = rectangle->private;
  gdouble                   x1, y1;
  gdouble                   x2, y2;

  gimp_tool_rectangle_get_public_rect (rectangle, &x1, &y1, &x2, &y2);

#if 0
  g_signal_handlers_block_by_func (options,
                                   gimp_tool_rectangle_options_notify,
                                   rect_tool);
#endif

  g_object_freeze_notify (G_OBJECT (rectangle));

  if (! FEQUAL (private->x, x1))
    g_object_set (rectangle, "x", x1, NULL);

  if (! FEQUAL (private->y, y1))
    g_object_set (rectangle, "y", y1, NULL);

  if (! FEQUAL (private->width, x2 - x1))
    g_object_set (rectangle, "width", x2 - x1, NULL);

  if (! FEQUAL (private->height, y2 - y1))
    g_object_set (rectangle, "height", y2 - y1, NULL);

  g_object_thaw_notify (G_OBJECT (rectangle));

#if 0
  g_signal_handlers_unblock_by_func (options,
                                     gimp_tool_rectangle_options_notify,
                                     rect_tool);
#endif
}

static void
gimp_tool_rectangle_update_handle_sizes (GimpToolRectangle *rectangle)
{
  GimpToolRectanglePrivate *private = rectangle->private;
  GimpDisplayShell         *shell;
  gint                      visible_rectangle_width;
  gint                      visible_rectangle_height;
  gint                      rectangle_width;
  gint                      rectangle_height;
  gdouble                   pub_x1, pub_y1;
  gdouble                   pub_x2, pub_y2;

  shell = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (rectangle));

  gimp_tool_rectangle_get_public_rect (rectangle,
                                       &pub_x1, &pub_y1, &pub_x2, &pub_y2);
  {
    /* Calculate rectangles of the selection rectangle and the display
     * shell, with origin at (0, 0) of image, and in screen coordinate
     * scale.
     */
    gint x1 =  pub_x1 * shell->scale_x;
    gint y1 =  pub_y1 * shell->scale_y;
    gint w1 = (pub_x2 - pub_x1) * shell->scale_x;
    gint h1 = (pub_y2 - pub_y1) * shell->scale_y;

    gint x2, y2, w2, h2;

    gimp_display_shell_scroll_get_scaled_viewport (shell, &x2, &y2, &w2, &h2);

    rectangle_width  = w1;
    rectangle_height = h1;

    /* Handle size calculations shall be based on the visible part of
     * the rectangle, so calculate the size for the visible rectangle
     * by intersecting with the viewport rectangle.
     */
    gimp_rectangle_intersect (x1, y1,
                              w1, h1,
                              x2, y2,
                              w2, h2,
                              NULL, NULL,
                              &visible_rectangle_width,
                              &visible_rectangle_height);

    /* Determine if we are in narrow-mode or not. */
    if (private->force_narrow_mode)
      private->narrow_mode = TRUE;
    else
      private->narrow_mode = (visible_rectangle_width  < NARROW_MODE_THRESHOLD ||
                              visible_rectangle_height < NARROW_MODE_THRESHOLD);
  }

  if (private->narrow_mode)
    {
      /* Corner handles always have the same (on-screen) size in
       * narrow-mode.
       */
      private->corner_handle_w = NARROW_MODE_HANDLE_SIZE;
      private->corner_handle_h = NARROW_MODE_HANDLE_SIZE;

      private->top_and_bottom_handle_w = CLAMP (rectangle_width,
                                                MIN (rectangle_width - 2,
                                                     NARROW_MODE_HANDLE_SIZE),
                                                G_MAXINT);
      private->left_and_right_handle_h = CLAMP (rectangle_height,
                                                MIN (rectangle_height - 2,
                                                     NARROW_MODE_HANDLE_SIZE),
                                                G_MAXINT);
    }
  else
    {
      /* Calculate and clamp corner handle size. */

      private->corner_handle_w = visible_rectangle_width  / 4;
      private->corner_handle_h = visible_rectangle_height / 4;

      private->corner_handle_w = CLAMP (private->corner_handle_w,
                                        MIN_HANDLE_SIZE,
                                        MAX_HANDLE_SIZE);
      private->corner_handle_h = CLAMP (private->corner_handle_h,
                                        MIN_HANDLE_SIZE,
                                        MAX_HANDLE_SIZE);

      /* Calculate and clamp side handle size. */

      private->top_and_bottom_handle_w = rectangle_width  - 3 * private->corner_handle_w;
      private->left_and_right_handle_h = rectangle_height - 3 * private->corner_handle_h;

      private->top_and_bottom_handle_w = CLAMP (private->top_and_bottom_handle_w,
                                                MIN_HANDLE_SIZE,
                                                G_MAXINT);
      private->left_and_right_handle_h = CLAMP (private->left_and_right_handle_h,
                                                MIN_HANDLE_SIZE,
                                                G_MAXINT);
    }
}

static void
gimp_tool_rectangle_update_status (GimpToolRectangle *rectangle)
{
  GimpToolRectanglePrivate *private = rectangle->private;
  gdouble                   x1, y1, x2, y2;

  gimp_tool_rectangle_get_public_rect (rectangle, &x1, &y1, &x2, &y2);

  if (private->function == GIMP_TOOL_RECTANGLE_MOVING)
    {
      gimp_tool_widget_set_status_coords (GIMP_TOOL_WIDGET (rectangle),
                                          _("Position: "),
                                          x1, ", ", y1,
                                          NULL);
    }
  else
    {
      gchar *aspect_text = NULL;
      gint   width       = x2 - x1;
      gint   height      = y2 - y1;

      if (width > 0.0 && height > 0.0)
        {
          aspect_text = g_strdup_printf ("  (%.2f:1)",
                                         (gdouble) width / (gdouble) height);
        }

      gimp_tool_widget_set_status_coords (GIMP_TOOL_WIDGET (rectangle),
                                          private->status_title,
                                          width, " × ", height,
                                          aspect_text);
      g_free (aspect_text);
    }
}

static void
gimp_tool_rectangle_synthesize_motion (GimpToolRectangle *rectangle,
                                       gint               function,
                                       gdouble            new_x,
                                       gdouble            new_y)
{
  GimpToolRectanglePrivate *private = rectangle->private;
  GimpRectangleFunction     old_function;

  /* We don't want to synthesize motions if the tool control is active
   * since that means the mouse button is down and the rectangle will
   * get updated in _motion anyway. The reason we want to prevent this
   * function from executing is that is emits the
   * rectangle-changed-complete signal which we don't want in the
   * middle of a rectangle change.
   *
   * In addition to that, we don't want to synthesize a motion if
   * there is no pending rectangle because that doesn't make any
   * sense.
   */
  if (private->rect_adjusting)
    return;

  old_function = private->function;

  gimp_tool_rectangle_set_function (rectangle, function);

  gimp_tool_rectangle_update_with_coord (rectangle, new_x, new_y);

  /* We must update this. */
  gimp_tool_rectangle_recalculate_center_xy (rectangle);

  gimp_tool_rectangle_update_options (rectangle);

  gimp_tool_rectangle_set_function (rectangle, old_function);

  gimp_tool_rectangle_change_complete (rectangle);
}

static void
swap_doubles (gdouble *i,
              gdouble *j)
{
  gdouble tmp;

  tmp = *i;
  *i = *j;
  *j = tmp;
}

static GimpRectangleFunction
gimp_tool_rectangle_calc_function (GimpToolRectangle *rectangle,
                                   const GimpCoords  *coords,
                                   gboolean           proximity)
{
  if (! proximity)
    {
      return GIMP_TOOL_RECTANGLE_DEAD;
    }
  else if (gimp_tool_rectangle_coord_outside (rectangle, coords))
    {
      /* The cursor is outside of the rectangle, clicking should
       * create a new rectangle.
       */
      return GIMP_TOOL_RECTANGLE_CREATING;
    }
  else if (gimp_tool_rectangle_coord_on_handle (rectangle,
                                                coords,
                                                GIMP_HANDLE_ANCHOR_NORTH_WEST))
    {
      return GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT;
    }
  else if (gimp_tool_rectangle_coord_on_handle (rectangle,
                                                coords,
                                                GIMP_HANDLE_ANCHOR_SOUTH_EAST))
    {
      return GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT;
    }
  else if  (gimp_tool_rectangle_coord_on_handle (rectangle,
                                                 coords,
                                                 GIMP_HANDLE_ANCHOR_NORTH_EAST))
    {
      return GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT;
    }
  else if (gimp_tool_rectangle_coord_on_handle (rectangle,
                                                coords,
                                                GIMP_HANDLE_ANCHOR_SOUTH_WEST))
    {
      return GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT;
    }
  else if (gimp_tool_rectangle_coord_on_handle (rectangle,
                                                coords,
                                                GIMP_HANDLE_ANCHOR_WEST))
    {
      return GIMP_TOOL_RECTANGLE_RESIZING_LEFT;
    }
  else if (gimp_tool_rectangle_coord_on_handle (rectangle,
                                                coords,
                                                GIMP_HANDLE_ANCHOR_EAST))
    {
      return GIMP_TOOL_RECTANGLE_RESIZING_RIGHT;
    }
  else if (gimp_tool_rectangle_coord_on_handle (rectangle,
                                                coords,
                                                GIMP_HANDLE_ANCHOR_NORTH))
    {
      return GIMP_TOOL_RECTANGLE_RESIZING_TOP;
    }
  else if (gimp_tool_rectangle_coord_on_handle (rectangle,
                                                coords,
                                                GIMP_HANDLE_ANCHOR_SOUTH))
    {
      return GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM;
    }
  else if (gimp_tool_rectangle_coord_on_handle (rectangle,
                                                coords,
                                                GIMP_HANDLE_ANCHOR_CENTER))
    {
      return GIMP_TOOL_RECTANGLE_MOVING;
    }
  else
    {
      return GIMP_TOOL_RECTANGLE_DEAD;
    }
}

/* gimp_tool_rectangle_check_function() is needed to deal with
 * situations where the user drags a corner or edge across one of the
 * existing edges, thereby changing its function.  Ugh.
 */
static void
gimp_tool_rectangle_check_function (GimpToolRectangle *rectangle)

{
  GimpToolRectanglePrivate *private  = rectangle->private;
  GimpRectangleFunction     function = private->function;

  if (private->x2 < private->x1)
    {
      swap_doubles (&private->x1, &private->x2);

      switch (function)
        {
        case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
          function = GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT;
          break;
        case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
          function = GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT;
          break;
        case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
          function = GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT;
          break;
        case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
          function = GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT;
          break;
        case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
          function = GIMP_TOOL_RECTANGLE_RESIZING_RIGHT;
          break;
        case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
          function = GIMP_TOOL_RECTANGLE_RESIZING_LEFT;
          break;
          /* avoid annoying warnings about unhandled enums */
        default:
          break;
        }
    }

  if (private->y2 < private->y1)
    {
      swap_doubles (&private->y1, &private->y2);

      switch (function)
        {
        case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
          function = GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT;
          break;
        case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
          function = GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT;
          break;
        case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
          function = GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT;
          break;
        case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
          function = GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT;
          break;
        case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
          function = GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM;
          break;
        case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
          function = GIMP_TOOL_RECTANGLE_RESIZING_TOP;
          break;
        default:
          break;
        }
    }

  gimp_tool_rectangle_set_function (rectangle, function);
}

/**
 * gimp_tool_rectangle_coord_outside:
 *
 * Returns: %TRUE if the coord is outside the rectangle bounds
 *          including any outside handles.
 */
static gboolean
gimp_tool_rectangle_coord_outside (GimpToolRectangle *rectangle,
                                   const GimpCoords  *coord)
{
  GimpToolRectanglePrivate *private = rectangle->private;
  GimpDisplayShell         *shell;
  gboolean                  narrow_mode = private->narrow_mode;
  gdouble                   x1, y1, x2, y2;
  gdouble                   x1_b, y1_b, x2_b, y2_b;

  shell = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (rectangle));

  gimp_tool_rectangle_get_public_rect (rectangle, &x1, &y1, &x2, &y2);

  x1_b = x1 - (narrow_mode ? private->corner_handle_w / shell->scale_x : 0);
  x2_b = x2 + (narrow_mode ? private->corner_handle_w / shell->scale_x : 0);
  y1_b = y1 - (narrow_mode ? private->corner_handle_h / shell->scale_y : 0);
  y2_b = y2 + (narrow_mode ? private->corner_handle_h / shell->scale_y : 0);

  return (coord->x < x1_b ||
          coord->x > x2_b ||
          coord->y < y1_b ||
          coord->y > y2_b);
}

/**
 * gimp_tool_rectangle_coord_on_handle:
 *
 * Returns: %TRUE if the coord is on the handle that corresponds to
 *          @anchor.
 */
static gboolean
gimp_tool_rectangle_coord_on_handle (GimpToolRectangle *rectangle,
                                     const GimpCoords  *coords,
                                     GimpHandleAnchor   anchor)
{
  GimpToolRectanglePrivate *private = rectangle->private;
  GimpDisplayShell         *shell;
  gdouble                   x1, y1, x2, y2;
  gdouble                   rect_w, rect_h;
  gdouble                   handle_x          = 0;
  gdouble                   handle_y          = 0;
  gdouble                   handle_width      = 0;
  gdouble                   handle_height     = 0;
  gint                      narrow_mode_x_dir = 0;
  gint                      narrow_mode_y_dir = 0;

  shell = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (rectangle));

  gimp_tool_rectangle_get_public_rect (rectangle, &x1, &y1, &x2, &y2);

  rect_w = x2 - x1;
  rect_h = y2 - y1;

  switch (anchor)
    {
    case GIMP_HANDLE_ANCHOR_NORTH_WEST:
      handle_x      = x1;
      handle_y      = y1;
      handle_width  = private->corner_handle_w;
      handle_height = private->corner_handle_h;

      narrow_mode_x_dir = -1;
      narrow_mode_y_dir = -1;
      break;

    case GIMP_HANDLE_ANCHOR_SOUTH_EAST:
      handle_x      = x2;
      handle_y      = y2;
      handle_width  = private->corner_handle_w;
      handle_height = private->corner_handle_h;

      narrow_mode_x_dir =  1;
      narrow_mode_y_dir =  1;
      break;

    case GIMP_HANDLE_ANCHOR_NORTH_EAST:
      handle_x      = x2;
      handle_y      = y1;
      handle_width  = private->corner_handle_w;
      handle_height = private->corner_handle_h;

      narrow_mode_x_dir =  1;
      narrow_mode_y_dir = -1;
      break;

    case GIMP_HANDLE_ANCHOR_SOUTH_WEST:
      handle_x      = x1;
      handle_y      = y2;
      handle_width  = private->corner_handle_w;
      handle_height = private->corner_handle_h;

      narrow_mode_x_dir = -1;
      narrow_mode_y_dir =  1;
      break;

    case GIMP_HANDLE_ANCHOR_WEST:
      handle_x      = x1;
      handle_y      = y1 + rect_h / 2;
      handle_width  = private->corner_handle_w;
      handle_height = private->left_and_right_handle_h;

      narrow_mode_x_dir = -1;
      narrow_mode_y_dir =  0;
      break;

    case GIMP_HANDLE_ANCHOR_EAST:
      handle_x      = x2;
      handle_y      = y1 + rect_h / 2;
      handle_width  = private->corner_handle_w;
      handle_height = private->left_and_right_handle_h;

      narrow_mode_x_dir =  1;
      narrow_mode_y_dir =  0;
      break;

    case GIMP_HANDLE_ANCHOR_NORTH:
      handle_x      = x1 + rect_w / 2;
      handle_y      = y1;
      handle_width  = private->top_and_bottom_handle_w;
      handle_height = private->corner_handle_h;

      narrow_mode_x_dir =  0;
      narrow_mode_y_dir = -1;
      break;

    case GIMP_HANDLE_ANCHOR_SOUTH:
      handle_x      = x1 + rect_w / 2;
      handle_y      = y2;
      handle_width  = private->top_and_bottom_handle_w;
      handle_height = private->corner_handle_h;

      narrow_mode_x_dir =  0;
      narrow_mode_y_dir =  1;
      break;

    case GIMP_HANDLE_ANCHOR_CENTER:
      handle_x      = x1 + rect_w / 2;
      handle_y      = y1 + rect_h / 2;

      if (private->narrow_mode)
        {
          handle_width  = rect_w * shell->scale_x;
          handle_height = rect_h * shell->scale_y;
        }
      else
        {
          handle_width  = rect_w * shell->scale_x - private->corner_handle_w * 2;
          handle_height = rect_h * shell->scale_y - private->corner_handle_h * 2;
        }

      narrow_mode_x_dir =  0;
      narrow_mode_y_dir =  0;
      break;
    }

  if (private->narrow_mode)
    {
      handle_x += narrow_mode_x_dir * handle_width  / shell->scale_x;
      handle_y += narrow_mode_y_dir * handle_height / shell->scale_y;
    }

  return gimp_canvas_item_on_handle (private->rectangle,
                                     coords->x, coords->y,
                                     GIMP_HANDLE_SQUARE,
                                     handle_x,     handle_y,
                                     handle_width, handle_height,
                                     anchor);
}

static GimpHandleAnchor
gimp_tool_rectangle_get_anchor (GimpRectangleFunction function)
{
  switch (function)
    {
    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
      return GIMP_HANDLE_ANCHOR_NORTH_WEST;

    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
      return GIMP_HANDLE_ANCHOR_NORTH_EAST;

    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
      return GIMP_HANDLE_ANCHOR_SOUTH_WEST;

    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
      return GIMP_HANDLE_ANCHOR_SOUTH_EAST;

    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
      return GIMP_HANDLE_ANCHOR_WEST;

    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
      return GIMP_HANDLE_ANCHOR_EAST;

    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
      return GIMP_HANDLE_ANCHOR_NORTH;

    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
      return GIMP_HANDLE_ANCHOR_SOUTH;

    default:
      return GIMP_HANDLE_ANCHOR_CENTER;
    }
}

static gboolean
gimp_tool_rectangle_rect_rubber_banding_func (GimpToolRectangle *rectangle)
{
  GimpToolRectanglePrivate *private = rectangle->private;

  switch (private->function)
    {
    case GIMP_TOOL_RECTANGLE_CREATING:
    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
    case GIMP_TOOL_RECTANGLE_AUTO_SHRINK:
      return TRUE;

    case GIMP_TOOL_RECTANGLE_MOVING:
    case GIMP_TOOL_RECTANGLE_DEAD:
    default:
      break;
    }

  return FALSE;
}

/**
 * gimp_tool_rectangle_rect_adjusting_func:
 * @rectangle:
 *
 * Returns: %TRUE if the current function is a rectangle adjusting
 *          function.
 */
static gboolean
gimp_tool_rectangle_rect_adjusting_func (GimpToolRectangle *rectangle)
{
  GimpToolRectanglePrivate *private = rectangle->private;

  return (gimp_tool_rectangle_rect_rubber_banding_func (rectangle) ||
          private->function == GIMP_TOOL_RECTANGLE_MOVING);
}

/**
 * gimp_tool_rectangle_get_other_side:
 * @rectangle: A #GimpToolRectangle.
 * @other_x:   Pointer to double of the other-x double.
 * @other_y:   Pointer to double of the other-y double.
 *
 * Calculates pointers to member variables that hold the coordinates
 * of the opposite side (either the opposite corner or literally the
 * opposite side), based on the current function. The opposite of a
 * corner needs two coordinates, the opposite of a side only needs
 * one.
 */
static void
gimp_tool_rectangle_get_other_side (GimpToolRectangle  *rectangle,
                                    gdouble           **other_x,
                                    gdouble           **other_y)
{
  GimpToolRectanglePrivate *private = rectangle->private;

  switch (private->function)
    {
    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
      *other_x = &private->x1;
      break;

    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
      *other_x = &private->x2;
      break;

    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
    default:
      *other_x = NULL;
      break;
    }

  switch (private->function)
    {
    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
      *other_y = &private->y1;
      break;

    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
      *other_y = &private->y2;
      break;

    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
    default:
      *other_y = NULL;
      break;
    }
}

static void
gimp_tool_rectangle_get_other_side_coord (GimpToolRectangle *rectangle,
                                          gdouble           *other_side_x,
                                          gdouble           *other_side_y)
{
  gdouble *other_x = NULL;
  gdouble *other_y = NULL;

  gimp_tool_rectangle_get_other_side (rectangle, &other_x, &other_y);

  if (other_x)
    *other_side_x = *other_x;
  if (other_y)
    *other_side_y = *other_y;
}

static void
gimp_tool_rectangle_set_other_side_coord (GimpToolRectangle *rectangle,
                                          gdouble            other_side_x,
                                          gdouble            other_side_y)
{
  gdouble *other_x = NULL;
  gdouble *other_y = NULL;

  gimp_tool_rectangle_get_other_side (rectangle, &other_x, &other_y);

  if (other_x)
    *other_x = other_side_x;
  if (other_y)
    *other_y = other_side_y;

  gimp_tool_rectangle_check_function (rectangle);

  gimp_tool_rectangle_update_int_rect (rectangle);
}

/**
 * gimp_tool_rectangle_apply_coord:
 * @param:     A #GimpToolRectangle.
 * @coord_x:   X of coord.
 * @coord_y:   Y of coord.
 *
 * Adjust the rectangle to the new position specified by passed
 * coordinate, taking fixed_center into account, which means it
 * expands the rectangle around the center point.
 */
static void
gimp_tool_rectangle_apply_coord (GimpToolRectangle *rectangle,
                                 gdouble            coord_x,
                                 gdouble            coord_y)
{
  GimpToolRectanglePrivate *private = rectangle->private;

  if (private->function == GIMP_TOOL_RECTANGLE_MOVING)
    {
      /* Preserve width and height while moving the grab-point to where the
       * cursor is.
       */
      gdouble w = private->x2 - private->x1;
      gdouble h = private->y2 - private->y1;

      private->x1 = coord_x;
      private->y1 = coord_y;

      private->x2 = private->x1 + w;
      private->y2 = private->y1 + h;

      /* We are done already. */
      return;
    }

  switch (private->function)
    {
    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
      private->x1 = coord_x;

      if (private->fixed_center)
        private->x2 = 2 * private->center_x_on_fixed_center - private->x1;

      break;

    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
      private->x2 = coord_x;

      if (private->fixed_center)
        private->x1 = 2 * private->center_x_on_fixed_center - private->x2;

      break;

    default:
      break;
    }

  switch (private->function)
    {
    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
      private->y1 = coord_y;

      if (private->fixed_center)
        private->y2 = 2 * private->center_y_on_fixed_center - private->y1;

      break;

    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
      private->y2 = coord_y;

      if (private->fixed_center)
        private->y1 = 2 * private->center_y_on_fixed_center - private->y2;

      break;

    default:
      break;
    }
}

static void
gimp_tool_rectangle_setup_snap_offsets (GimpToolRectangle *rectangle,
                                        const GimpCoords  *coords)
{
  GimpToolWidget           *widget  = GIMP_TOOL_WIDGET (rectangle);
  GimpToolRectanglePrivate *private = rectangle->private;
  gdouble                   x1, y1, x2, y2;
  gdouble                   coord_x, coord_y;

  gimp_tool_rectangle_get_public_rect (rectangle, &x1, &y1, &x2, &y2);
  gimp_tool_rectangle_adjust_coord (rectangle,
                                    coords->x, coords->y,
                                    &coord_x, &coord_y);

  switch (private->function)
    {
    case GIMP_TOOL_RECTANGLE_CREATING:
      gimp_tool_widget_set_snap_offsets (widget, 0, 0, 0, 0);
      break;

    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
      gimp_tool_widget_set_snap_offsets (widget,
                                         x1 - coord_x,
                                         y1 - coord_y,
                                         0, 0);
      break;

    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
      gimp_tool_widget_set_snap_offsets (widget,
                                         x2 - coord_x,
                                         y1 - coord_y,
                                         0, 0);
      break;

    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
      gimp_tool_widget_set_snap_offsets (widget,
                                         x1 - coord_x,
                                         y2 - coord_y,
                                         0, 0);
      break;

    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
      gimp_tool_widget_set_snap_offsets (widget,
                                         x2 - coord_x,
                                         y2 - coord_y,
                                         0, 0);
      break;

    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
      gimp_tool_widget_set_snap_offsets (widget,
                                         x1 - coord_x, 0,
                                         0, 0);
      break;

    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
      gimp_tool_widget_set_snap_offsets (widget,
                                         x2 - coord_x, 0,
                                         0, 0);
      break;

    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
      gimp_tool_widget_set_snap_offsets (widget,
                                         0, y1 - coord_y,
                                         0, 0);
      break;

    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
      gimp_tool_widget_set_snap_offsets (widget,
                                         0, y2 - coord_y,
                                         0, 0);
      break;

    case GIMP_TOOL_RECTANGLE_MOVING:
      gimp_tool_widget_set_snap_offsets (widget,
                                         x1 - coord_x,
                                         y1 - coord_y,
                                         x2 - x1,
                                         y2 - y1);
      break;

    default:
      break;
    }
}

/**
 * gimp_tool_rectangle_clamp:
 * @rectangle:      A #GimpToolRectangle.
 * @clamped_sides:  Where to put contrainment information.
 * @constraint:     Constraint to use.
 * @symmetrically:  Whether or not to clamp symmetrically.
 *
 * Clamps rectangle inside specified bounds, providing information of
 * where clamping was done. Can also clamp symmetrically.
 */
static void
gimp_tool_rectangle_clamp (GimpToolRectangle       *rectangle,
                           ClampedSide             *clamped_sides,
                           GimpRectangleConstraint  constraint,
                           gboolean                 symmetrically)
{
  gimp_tool_rectangle_clamp_width (rectangle,
                                   clamped_sides,
                                   constraint,
                                   symmetrically);

  gimp_tool_rectangle_clamp_height (rectangle,
                                    clamped_sides,
                                    constraint,
                                    symmetrically);
}

/**
 * gimp_tool_rectangle_clamp_width:
 * @rectangle:      A #GimpToolRectangle.
 * @clamped_sides:  Where to put contrainment information.
 * @constraint:     Constraint to use.
 * @symmetrically:  Whether or not to clamp symmetrically.
 *
 * Clamps height of rectangle. Set symmetrically to true when using
 * for fixed_center:ed rectangles, since that will clamp symmetrically
 * which is just what is needed.
 *
 * When this function constrains, it puts what it constrains in
 * @constraint. This information is essential when an aspect ratio is
 * to be applied.
 */
static void
gimp_tool_rectangle_clamp_width (GimpToolRectangle       *rectangle,
                                 ClampedSide             *clamped_sides,
                                 GimpRectangleConstraint  constraint,
                                 gboolean                 symmetrically)
{
  GimpToolRectanglePrivate *private = rectangle->private;
  gint                      min_x;
  gint                      max_x;

  if (constraint == GIMP_RECTANGLE_CONSTRAIN_NONE)
    return;

  gimp_tool_rectangle_get_constraints (rectangle,
                                       &min_x, NULL,
                                       &max_x, NULL,
                                       constraint);
  if (private->x1 < min_x)
    {
      gdouble dx = min_x - private->x1;

      private->x1 += dx;

      if (symmetrically)
        private->x2 -= dx;

      if (private->x2 < min_x)
        private->x2 = min_x;

      if (clamped_sides)
        *clamped_sides |= CLAMPED_LEFT;
    }

  if (private->x2 > max_x)
    {
      gdouble dx = max_x - private->x2;

      private->x2 += dx;

      if (symmetrically)
        private->x1 -= dx;

      if (private->x1 > max_x)
        private->x1 = max_x;

      if (clamped_sides)
        *clamped_sides |= CLAMPED_RIGHT;
    }
}

/**
 * gimp_tool_rectangle_clamp_height:
 * @rectangle:      A #GimpToolRectangle.
 * @clamped_sides:  Where to put contrainment information.
 * @constraint:     Constraint to use.
 * @symmetrically:  Whether or not to clamp symmetrically.
 *
 * Clamps height of rectangle. Set symmetrically to true when using for
 * fixed_center:ed rectangles, since that will clamp symmetrically which is just
 * what is needed.
 *
 * When this function constrains, it puts what it constrains in
 * @constraint. This information is essential when an aspect ratio is to be
 * applied.
 */
static void
gimp_tool_rectangle_clamp_height (GimpToolRectangle       *rectangle,
                                  ClampedSide             *clamped_sides,
                                  GimpRectangleConstraint  constraint,
                                  gboolean                 symmetrically)
{
  GimpToolRectanglePrivate *private = rectangle->private;
  gint                      min_y;
  gint                      max_y;

  if (constraint == GIMP_RECTANGLE_CONSTRAIN_NONE)
    return;

  gimp_tool_rectangle_get_constraints (rectangle,
                                       NULL, &min_y,
                                       NULL, &max_y,
                                       constraint);
  if (private->y1 < min_y)
    {
      gdouble dy = min_y - private->y1;

      private->y1 += dy;

      if (symmetrically)
        private->y2 -= dy;

      if (private->y2 < min_y)
        private->y2 = min_y;

      if (clamped_sides)
        *clamped_sides |= CLAMPED_TOP;
    }

  if (private->y2 > max_y)
    {
      gdouble dy = max_y - private->y2;

      private->y2 += dy;

      if (symmetrically)
        private->y1 -= dy;

      if (private->y1 > max_y)
        private->y1 = max_y;

      if (clamped_sides)
        *clamped_sides |= CLAMPED_BOTTOM;
    }
}

/**
 * gimp_tool_rectangle_keep_inside:
 * @rectangle: A #GimpToolRectangle.
 *
 * If the rectangle is outside of the canvas, move it into it. If the rectangle is
 * larger than the canvas in any direction, make it fill the canvas in that direction.
 */
static void
gimp_tool_rectangle_keep_inside (GimpToolRectangle      *rectangle,
                                 GimpRectangleConstraint constraint)
{
  gimp_tool_rectangle_keep_inside_horizontally (rectangle, constraint);
  gimp_tool_rectangle_keep_inside_vertically   (rectangle, constraint);
}

/**
 * gimp_tool_rectangle_keep_inside_horizontally:
 * @rectangle:      A #GimpToolRectangle.
 * @constraint:     Constraint to use.
 *
 * If the rectangle is outside of the given constraint horizontally, move it
 * inside. If it is too big to fit inside, make it just as big as the width
 * limit.
 */
static void
gimp_tool_rectangle_keep_inside_horizontally (GimpToolRectangle       *rectangle,
                                              GimpRectangleConstraint  constraint)
{
  GimpToolRectanglePrivate *private = rectangle->private;
  gint                      min_x;
  gint                      max_x;

  if (constraint == GIMP_RECTANGLE_CONSTRAIN_NONE)
    return;

  gimp_tool_rectangle_get_constraints (rectangle,
                                       &min_x, NULL,
                                       &max_x, NULL,
                                       constraint);

  if (max_x - min_x < private->x2 - private->x1)
    {
      private->x1 = min_x;
      private->x2 = max_x;
    }
  else
    {
      if (private->x1 < min_x)
        {
          gdouble dx = min_x - private->x1;

          private->x1 += dx;
          private->x2 += dx;
        }
      if (private->x2 > max_x)
        {
          gdouble dx = max_x - private->x2;

          private->x1 += dx;
          private->x2 += dx;
        }
    }
}

/**
 * gimp_tool_rectangle_keep_inside_vertically:
 * @rectangle:      A #GimpToolRectangle.
 * @constraint:     Constraint to use.
 *
 * If the rectangle is outside of the given constraint vertically,
 * move it inside. If it is too big to fit inside, make it just as big
 * as the width limit.
 */
static void
gimp_tool_rectangle_keep_inside_vertically (GimpToolRectangle       *rectangle,
                                            GimpRectangleConstraint  constraint)
{
  GimpToolRectanglePrivate *private = rectangle->private;
  gint                      min_y;
  gint                      max_y;

  if (constraint == GIMP_RECTANGLE_CONSTRAIN_NONE)
    return;

  gimp_tool_rectangle_get_constraints (rectangle,
                                       NULL, &min_y,
                                       NULL, &max_y,
                                       constraint);

  if (max_y - min_y < private->y2 - private->y1)
    {
      private->y1 = min_y;
      private->y2 = max_y;
    }
  else
    {
      if (private->y1 < min_y)
        {
          gdouble dy = min_y - private->y1;

          private->y1 += dy;
          private->y2 += dy;
        }
      if (private->y2 > max_y)
        {
          gdouble dy = max_y - private->y2;

          private->y1 += dy;
          private->y2 += dy;
        }
    }
}

/**
 * gimp_tool_rectangle_apply_fixed_width:
 * @rectangle:      A #GimpToolRectangle.
 * @constraint:     Constraint to use.
 * @width:
 *
 * Makes the rectangle have a fixed_width, following the constrainment
 * rules of fixed widths as well. Please refer to the rectangle tools
 * spec.
 */
static void
gimp_tool_rectangle_apply_fixed_width (GimpToolRectangle      *rectangle,
                                       GimpRectangleConstraint constraint,
                                       gdouble                 width)
{
  GimpToolRectanglePrivate *private = rectangle->private;

  switch (private->function)
    {
    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
      /* We always want to center around fixed_center here, since we want the
       * anchor point to be directly on the opposite side.
       */
      private->x1 = private->center_x_on_fixed_center -
                    width / 2;
      private->x2 = private->x1 + width;
      break;

    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
    case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
      /* We always want to center around fixed_center here, since we want the
       * anchor point to be directly on the opposite side.
       */
      private->x1 = private->center_x_on_fixed_center -
                    width / 2;
      private->x2 = private->x1 + width;
      break;

    default:
      break;
    }

  /* Width shall be kept even after constraints, so we move the
   * rectangle sideways rather than adjusting a side.
   */
  gimp_tool_rectangle_keep_inside_horizontally (rectangle, constraint);
}

/**
 * gimp_tool_rectangle_apply_fixed_height:
 * @rectangle:      A #GimpToolRectangle.
 * @constraint:     Constraint to use.
 * @height:
 *
 * Makes the rectangle have a fixed_height, following the
 * constrainment rules of fixed heights as well. Please refer to the
 * rectangle tools spec.
 */
static void
gimp_tool_rectangle_apply_fixed_height (GimpToolRectangle      *rectangle,
                                        GimpRectangleConstraint constraint,
                                        gdouble                 height)

{
  GimpToolRectanglePrivate *private = rectangle->private;

  switch (private->function)
    {
    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
    case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
      /* We always want to center around fixed_center here, since we
       * want the anchor point to be directly on the opposite side.
       */
      private->y1 = private->center_y_on_fixed_center -
                    height / 2;
      private->y2 = private->y1 + height;
      break;

    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
    case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
    case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
      /* We always want to center around fixed_center here, since we
       * want the anchor point to be directly on the opposite side.
       */
      private->y1 = private->center_y_on_fixed_center -
                    height / 2;
      private->y2 = private->y1 + height;
      break;

    default:
      break;
    }

  /* Width shall be kept even after constraints, so we move the
   * rectangle sideways rather than adjusting a side.
   */
  gimp_tool_rectangle_keep_inside_vertically (rectangle, constraint);
}

/**
 * gimp_tool_rectangle_apply_aspect:
 * @rectangle:      A #GimpToolRectangle.
 * @aspect:         The desired aspect.
 * @clamped_sides:  Bitfield of sides that have been clamped.
 *
 * Adjust the rectangle to the desired aspect.
 *
 * Sometimes, a side must not be moved outwards, for example if a the
 * RIGHT side has been clamped previously, we must not move the RIGHT
 * side to the right, since that would violate the constraint
 * again. The clamped_sides bitfield keeps track of sides that have
 * previously been clamped.
 *
 * If fixed_center is used, the function adjusts the aspect by
 * symmetrically adjusting the left and right, or top and bottom side.
 */
static void
gimp_tool_rectangle_apply_aspect (GimpToolRectangle *rectangle,
                                  gdouble            aspect,
                                  gint               clamped_sides)
{
  GimpToolRectanglePrivate *private = rectangle->private;
  gdouble                   current_w;
  gdouble                   current_h;
  gdouble                   current_aspect;
  SideToResize              side_to_resize = SIDE_TO_RESIZE_NONE;

  current_w = private->x2 - private->x1;
  current_h = private->y2 - private->y1;

  current_aspect = (gdouble) current_w / (gdouble) current_h;

  /* Do we have to do anything? */
  if (current_aspect == aspect)
    return;

  if (private->fixed_center)
    {
      /* We may only adjust the sides symmetrically to get desired aspect. */
      if (current_aspect > aspect)
        {
          /* We prefer to use top and bottom (since that will make the
           * cursor remain on the rectangle edge), unless that is what
           * the user has grabbed.
           */
          switch (private->function)
            {
            case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
            case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
            case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
            case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
            case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
            case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
              if (! (clamped_sides & CLAMPED_TOP) &&
                  ! (clamped_sides & CLAMPED_BOTTOM))
                {
                  side_to_resize = SIDE_TO_RESIZE_TOP_AND_BOTTOM_SYMMETRICALLY;
                }
              else
                {
                  side_to_resize = SIDE_TO_RESIZE_LEFT_AND_RIGHT_SYMMETRICALLY;
                }
              break;

            case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
            case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
            default:
              side_to_resize = SIDE_TO_RESIZE_LEFT_AND_RIGHT_SYMMETRICALLY;
              break;
            }
        }
      else /* (current_aspect < aspect) */
        {
          /* We prefer to use left and right (since that will make the
           * cursor remain on the rectangle edge), unless that is what
           * the user has grabbed.
           */
          switch (private->function)
            {
            case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
            case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
            case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
            case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
            case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
            case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
              if (! (clamped_sides & CLAMPED_LEFT) &&
                  ! (clamped_sides & CLAMPED_RIGHT))
                {
                  side_to_resize = SIDE_TO_RESIZE_LEFT_AND_RIGHT_SYMMETRICALLY;
                }
              else
                {
                  side_to_resize = SIDE_TO_RESIZE_TOP_AND_BOTTOM_SYMMETRICALLY;
                }
              break;

            case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
            case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
            default:
              side_to_resize = SIDE_TO_RESIZE_TOP_AND_BOTTOM_SYMMETRICALLY;
              break;
            }
        }
    }
  else if (current_aspect > aspect)
    {
      /* We can safely pick LEFT or RIGHT, since using those sides
       * will make the rectangle smaller, so we don't need to check
       * for clamped_sides. We may only use TOP and BOTTOM if not
       * those sides have been clamped, since using them will make the
       * rectangle bigger.
       */
      switch (private->function)
        {
        case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
          if (! (clamped_sides & CLAMPED_TOP))
            side_to_resize = SIDE_TO_RESIZE_TOP;
          else
            side_to_resize = SIDE_TO_RESIZE_LEFT;
          break;

        case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
          if (! (clamped_sides & CLAMPED_TOP))
            side_to_resize = SIDE_TO_RESIZE_TOP;
          else
            side_to_resize = SIDE_TO_RESIZE_RIGHT;
          break;

        case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
          if (! (clamped_sides & CLAMPED_BOTTOM))
            side_to_resize = SIDE_TO_RESIZE_BOTTOM;
          else
            side_to_resize = SIDE_TO_RESIZE_LEFT;
          break;

        case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
          if (! (clamped_sides & CLAMPED_BOTTOM))
            side_to_resize = SIDE_TO_RESIZE_BOTTOM;
          else
            side_to_resize = SIDE_TO_RESIZE_RIGHT;
          break;

        case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
          if (! (clamped_sides & CLAMPED_TOP) &&
              ! (clamped_sides & CLAMPED_BOTTOM))
            side_to_resize = SIDE_TO_RESIZE_TOP_AND_BOTTOM_SYMMETRICALLY;
          else
            side_to_resize = SIDE_TO_RESIZE_LEFT;
          break;

        case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
          if (! (clamped_sides & CLAMPED_TOP) &&
              ! (clamped_sides & CLAMPED_BOTTOM))
            side_to_resize = SIDE_TO_RESIZE_TOP_AND_BOTTOM_SYMMETRICALLY;
          else
            side_to_resize = SIDE_TO_RESIZE_RIGHT;
          break;

        case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
        case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
          side_to_resize = SIDE_TO_RESIZE_LEFT_AND_RIGHT_SYMMETRICALLY;
          break;

        case GIMP_TOOL_RECTANGLE_MOVING:
        default:
          if (! (clamped_sides & CLAMPED_BOTTOM))
            side_to_resize = SIDE_TO_RESIZE_BOTTOM;
          else if (! (clamped_sides & CLAMPED_RIGHT))
            side_to_resize = SIDE_TO_RESIZE_RIGHT;
          else if (! (clamped_sides & CLAMPED_TOP))
            side_to_resize = SIDE_TO_RESIZE_TOP;
          else if (! (clamped_sides & CLAMPED_LEFT))
            side_to_resize = SIDE_TO_RESIZE_LEFT;
          break;
        }
    }
  else /* (current_aspect < aspect) */
    {
      /* We can safely pick TOP or BOTTOM, since using those sides
       * will make the rectangle smaller, so we don't need to check
       * for clamped_sides. We may only use LEFT and RIGHT if not
       * those sides have been clamped, since using them will make the
       * rectangle bigger.
       */
      switch (private->function)
        {
        case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_LEFT:
          if (! (clamped_sides & CLAMPED_LEFT))
            side_to_resize = SIDE_TO_RESIZE_LEFT;
          else
            side_to_resize = SIDE_TO_RESIZE_TOP;
          break;

        case GIMP_TOOL_RECTANGLE_RESIZING_UPPER_RIGHT:
          if (! (clamped_sides & CLAMPED_RIGHT))
            side_to_resize = SIDE_TO_RESIZE_RIGHT;
          else
            side_to_resize = SIDE_TO_RESIZE_TOP;
          break;

        case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_LEFT:
          if (! (clamped_sides & CLAMPED_LEFT))
            side_to_resize = SIDE_TO_RESIZE_LEFT;
          else
            side_to_resize = SIDE_TO_RESIZE_BOTTOM;
          break;

        case GIMP_TOOL_RECTANGLE_RESIZING_LOWER_RIGHT:
          if (! (clamped_sides & CLAMPED_RIGHT))
            side_to_resize = SIDE_TO_RESIZE_RIGHT;
          else
            side_to_resize = SIDE_TO_RESIZE_BOTTOM;
          break;

        case GIMP_TOOL_RECTANGLE_RESIZING_TOP:
          if (! (clamped_sides & CLAMPED_LEFT) &&
              ! (clamped_sides & CLAMPED_RIGHT))
            side_to_resize = SIDE_TO_RESIZE_LEFT_AND_RIGHT_SYMMETRICALLY;
          else
            side_to_resize = SIDE_TO_RESIZE_TOP;
          break;

        case GIMP_TOOL_RECTANGLE_RESIZING_BOTTOM:
          if (! (clamped_sides & CLAMPED_LEFT) &&
              ! (clamped_sides & CLAMPED_RIGHT))
            side_to_resize = SIDE_TO_RESIZE_LEFT_AND_RIGHT_SYMMETRICALLY;
          else
            side_to_resize = SIDE_TO_RESIZE_BOTTOM;
          break;

        case GIMP_TOOL_RECTANGLE_RESIZING_LEFT:
        case GIMP_TOOL_RECTANGLE_RESIZING_RIGHT:
          side_to_resize = SIDE_TO_RESIZE_TOP_AND_BOTTOM_SYMMETRICALLY;
          break;

        case GIMP_TOOL_RECTANGLE_MOVING:
        default:
          if (! (clamped_sides & CLAMPED_BOTTOM))
            side_to_resize = SIDE_TO_RESIZE_BOTTOM;
          else if (! (clamped_sides & CLAMPED_RIGHT))
            side_to_resize = SIDE_TO_RESIZE_RIGHT;
          else if (! (clamped_sides & CLAMPED_TOP))
            side_to_resize = SIDE_TO_RESIZE_TOP;
          else if (! (clamped_sides & CLAMPED_LEFT))
            side_to_resize = SIDE_TO_RESIZE_LEFT;
          break;
        }
    }

  /* We now know what side(s) we should resize, so now we just solve
   * the aspect equation for that side(s).
   */
  switch (side_to_resize)
    {
    case SIDE_TO_RESIZE_NONE:
      return;

    case SIDE_TO_RESIZE_LEFT:
      private->x1 = private->x2 - aspect * current_h;
      break;

    case SIDE_TO_RESIZE_RIGHT:
      private->x2 = private->x1 + aspect * current_h;
      break;

    case SIDE_TO_RESIZE_TOP:
      private->y1 = private->y2 - current_w / aspect;
      break;

    case SIDE_TO_RESIZE_BOTTOM:
      private->y2 = private->y1 + current_w / aspect;
      break;

    case SIDE_TO_RESIZE_TOP_AND_BOTTOM_SYMMETRICALLY:
      {
        gdouble correct_h = current_w / aspect;

        private->y1 = private->center_y_on_fixed_center - correct_h / 2;
        private->y2 = private->y1 + correct_h;
      }
      break;

    case SIDE_TO_RESIZE_LEFT_AND_RIGHT_SYMMETRICALLY:
      {
        gdouble correct_w = current_h * aspect;

        private->x1 = private->center_x_on_fixed_center - correct_w / 2;
        private->x2 = private->x1 + correct_w;
      }
      break;
    }
}

/**
 * gimp_tool_rectangle_update_with_coord:
 * @rectangle:      A #GimpToolRectangle.
 * @new_x:          New X-coordinate in the context of the current function.
 * @new_y:          New Y-coordinate in the context of the current function.
 *
 * The core rectangle adjustment function. It updates the rectangle
 * for the passed cursor coordinate, taking current function and tool
 * options into account.  It also updates the current
 * private->function if necessary.
 */
static void
gimp_tool_rectangle_update_with_coord (GimpToolRectangle *rectangle,
                                       gdouble            new_x,
                                       gdouble            new_y)
{
  GimpToolRectanglePrivate *private = rectangle->private;

  /* Move the corner or edge the user currently has grabbed. */
  gimp_tool_rectangle_apply_coord (rectangle, new_x, new_y);

  /* Update private->function. The function changes if the user
   * "flips" the rectangle.
   */
  gimp_tool_rectangle_check_function (rectangle);

  /* Clamp the rectangle if necessary */
  gimp_tool_rectangle_handle_general_clamping (rectangle);

  /* If the rectangle is being moved, do not run through any further
   * rectangle adjusting functions since it's shape should not change
   * then.
   */
  if (private->function != GIMP_TOOL_RECTANGLE_MOVING)
    {
      gimp_tool_rectangle_apply_fixed_rule (rectangle);
    }

  gimp_tool_rectangle_update_int_rect (rectangle);
}

static void
gimp_tool_rectangle_apply_fixed_rule (GimpToolRectangle *rectangle)
{
  GimpToolRectanglePrivate    *private = rectangle->private;
  GimpRectangleConstraint      constraint_to_use;
  GimpDisplayShell            *shell;
  GimpImage                   *image;

  shell = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (rectangle));
  image = gimp_display_get_image (shell->display);

  /* Calculate what constraint to use when needed. */
  constraint_to_use = gimp_tool_rectangle_get_constraint (rectangle);

  if (private->fixed_rule_active &&
      private->fixed_rule == GIMP_RECTANGLE_FIXED_ASPECT)
    {
      gdouble aspect;

      aspect = CLAMP (private->aspect_numerator /
                      private->aspect_denominator,
                      1.0 / gimp_image_get_height (image),
                      gimp_image_get_width (image));

      if (constraint_to_use == GIMP_RECTANGLE_CONSTRAIN_NONE)
        {
          gimp_tool_rectangle_apply_aspect (rectangle,
                                            aspect,
                                            CLAMPED_NONE);
        }
      else
        {
          if (private->function != GIMP_TOOL_RECTANGLE_MOVING)
            {
              ClampedSide clamped_sides = CLAMPED_NONE;

              gimp_tool_rectangle_apply_aspect (rectangle,
                                                aspect,
                                                clamped_sides);

              /* After we have applied aspect, we might have taken the
               * rectangle outside of constraint, so clamp and apply
               * aspect again. We will get the right result this time,
               * since 'clamped_sides' will be setup correctly now.
               */
              gimp_tool_rectangle_clamp (rectangle,
                                         &clamped_sides,
                                         constraint_to_use,
                                         private->fixed_center);

              gimp_tool_rectangle_apply_aspect (rectangle,
                                                aspect,
                                                clamped_sides);
            }
          else
            {
              gimp_tool_rectangle_apply_aspect (rectangle,
                                                aspect,
                                                CLAMPED_NONE);

              gimp_tool_rectangle_keep_inside (rectangle,
                                               constraint_to_use);
            }
        }
    }
  else if (private->fixed_rule_active &&
           private->fixed_rule == GIMP_RECTANGLE_FIXED_SIZE)
    {
      gimp_tool_rectangle_apply_fixed_width (rectangle,
                                             constraint_to_use,
                                             private->desired_fixed_size_width);
      gimp_tool_rectangle_apply_fixed_height (rectangle,
                                              constraint_to_use,
                                              private->desired_fixed_size_height);
    }
  else if (private->fixed_rule_active &&
           private->fixed_rule == GIMP_RECTANGLE_FIXED_WIDTH)
    {
      gimp_tool_rectangle_apply_fixed_width (rectangle,
                                             constraint_to_use,
                                             private->desired_fixed_width);
    }
  else if (private->fixed_rule_active &&
           private->fixed_rule == GIMP_RECTANGLE_FIXED_HEIGHT)
    {
      gimp_tool_rectangle_apply_fixed_height (rectangle,
                                              constraint_to_use,
                                              private->desired_fixed_height);
    }
}

/**
 * gimp_tool_rectangle_get_constraints:
 * @rectangle:      A #GimpToolRectangle.
 * @min_x:
 * @min_y:
 * @max_x:
 * @max_y:          Pointers of where to put constraints. NULL allowed.
 * @constraint:     Whether to return image or layer constraints.
 *
 * Calculates constraint coordinates for image or layer.
 */
static void
gimp_tool_rectangle_get_constraints (GimpToolRectangle       *rectangle,
                                     gint                    *min_x,
                                     gint                    *min_y,
                                     gint                    *max_x,
                                     gint                    *max_y,
                                     GimpRectangleConstraint  constraint)
{
  GimpDisplayShell *shell;
  GimpImage        *image;
  gint              min_x_dummy;
  gint              min_y_dummy;
  gint              max_x_dummy;
  gint              max_y_dummy;

  shell = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (rectangle));
  image = gimp_display_get_image (shell->display);

  if (! min_x) min_x = &min_x_dummy;
  if (! min_y) min_y = &min_y_dummy;
  if (! max_x) max_x = &max_x_dummy;
  if (! max_y) max_y = &max_y_dummy;

  *min_x = 0;
  *min_y = 0;
  *max_x = 0;
  *max_y = 0;

  switch (constraint)
    {
    case GIMP_RECTANGLE_CONSTRAIN_IMAGE:
      if (image)
        {
          *min_x = 0;
          *min_y = 0;
          *max_x = gimp_image_get_width  (image);
          *max_y = gimp_image_get_height (image);
        }
      break;

    case GIMP_RECTANGLE_CONSTRAIN_DRAWABLE:
      if (image)
        {
          GList *items = gimp_image_get_selected_drawables (image);
          GList *iter;

          /* Min and max constraints are respectively the smallest and
           * highest drawable coordinates.
           */
          for (iter = items; iter; iter = iter->next)
            {
              gint item_min_x;
              gint item_min_y;

              gimp_item_get_offset (iter->data, &item_min_x, &item_min_y);

              *min_x = MIN (*min_x, item_min_x);
              *min_y = MIN (*min_y, item_min_y);
              *max_x = MAX (*max_x, item_min_x + gimp_item_get_width  (iter->data));
              *max_y = MAX (*max_y, item_min_y + gimp_item_get_height (iter->data));
            }

          g_list_free (items);
        }
      break;

    default:
      g_warning ("Invalid rectangle constraint.\n");
      return;
    }
}

/**
 * gimp_tool_rectangle_handle_general_clamping:
 * @rectangle: A #GimpToolRectangle.
 *
 * Make sure that constraints are applied to the rectangle, either by
 * manually doing it, or by looking at the rectangle tool options and
 * concluding it will be done later.
 */
static void
gimp_tool_rectangle_handle_general_clamping (GimpToolRectangle *rectangle)
{
  GimpToolRectanglePrivate *private = rectangle->private;
  GimpRectangleConstraint   constraint;

  constraint = gimp_tool_rectangle_get_constraint (rectangle);

  /* fixed_aspect takes care of clamping by it self, so just return in
   * case that is in use. Also return if no constraints should be
   * enforced.
   */
  if (constraint == GIMP_RECTANGLE_CONSTRAIN_NONE)
    return;

  if (private->function != GIMP_TOOL_RECTANGLE_MOVING)
    {
      gimp_tool_rectangle_clamp (rectangle,
                                 NULL,
                                 constraint,
                                 private->fixed_center);
    }
  else
    {
      gimp_tool_rectangle_keep_inside (rectangle, constraint);
    }
}

/**
 * gimp_tool_rectangle_update_int_rect:
 * @rectangle:
 *
 * Update integer representation of rectangle.
 **/
static void
gimp_tool_rectangle_update_int_rect (GimpToolRectangle *rectangle)
{
  GimpToolRectanglePrivate *private = rectangle->private;

  private->x1_int = SIGNED_ROUND (private->x1);
  private->y1_int = SIGNED_ROUND (private->y1);

  if (gimp_tool_rectangle_rect_rubber_banding_func (rectangle))
    {
      private->width_int  = (gint) SIGNED_ROUND (private->x2) - private->x1_int;
      private->height_int = (gint) SIGNED_ROUND (private->y2) - private->y1_int;
    }
}

/**
 * gimp_tool_rectangle_adjust_coord:
 * @rectangle:
 * @ccoord_x_input:
 * @ccoord_x_input:
 * @ccoord_x_output:
 * @ccoord_x_output:
 *
 * Transforms a coordinate to better fit the public behaviour of the
 * rectangle.
 */
static void
gimp_tool_rectangle_adjust_coord (GimpToolRectangle *rectangle,
                                  gdouble            coord_x_input,
                                  gdouble            coord_y_input,
                                  gdouble           *coord_x_output,
                                  gdouble           *coord_y_output)
{
  GimpToolRectanglePrivate *priv = rectangle->private;

  switch (priv->precision)
    {
    case GIMP_RECTANGLE_PRECISION_INT:
      *coord_x_output = RINT (coord_x_input);
      *coord_y_output = RINT (coord_y_input);
      break;

    case GIMP_RECTANGLE_PRECISION_DOUBLE:
    default:
      *coord_x_output = coord_x_input;
      *coord_y_output = coord_y_input;
      break;
    }
}

static void
gimp_tool_rectangle_recalculate_center_xy (GimpToolRectangle *rectangle)
{
  GimpToolRectanglePrivate *private = rectangle->private;

  private->center_x_on_fixed_center = (private->x1 + private->x2) / 2;
  private->center_y_on_fixed_center = (private->y1 + private->y2) / 2;
}


/*  public functions  */

GimpToolWidget *
gimp_tool_rectangle_new (GimpDisplayShell  *shell)
{
  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);

  return g_object_new (GIMP_TYPE_TOOL_RECTANGLE,
                       "shell",      shell,
                       NULL);
}

GimpRectangleFunction
gimp_tool_rectangle_get_function (GimpToolRectangle *rectangle)
{
  g_return_val_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle),
                        GIMP_TOOL_RECTANGLE_DEAD);

  return rectangle->private->function;
}

void
gimp_tool_rectangle_set_function (GimpToolRectangle     *rectangle,
                                  GimpRectangleFunction  function)
{
  GimpToolRectanglePrivate *private;

  g_return_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle));

  private = rectangle->private;

  if (private->function != function)
    {
      private->function = function;

      gimp_tool_rectangle_changed (GIMP_TOOL_WIDGET (rectangle));
    }
}

void
gimp_tool_rectangle_set_constraint (GimpToolRectangle       *rectangle,
                                    GimpRectangleConstraint  constraint)
{
  GimpToolRectanglePrivate *private;

  g_return_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle));

  private = rectangle->private;

  if (constraint != private->constraint)
    {
      g_object_freeze_notify (G_OBJECT (rectangle));

      private->constraint = constraint;
      g_object_notify (G_OBJECT (rectangle), "constraint");

      gimp_tool_rectangle_clamp (rectangle, NULL, constraint, FALSE);

      g_object_thaw_notify (G_OBJECT (rectangle));

      gimp_tool_rectangle_change_complete (rectangle);
    }
}

GimpRectangleConstraint
gimp_tool_rectangle_get_constraint (GimpToolRectangle *rectangle)
{
  g_return_val_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle), 0);

  return rectangle->private->constraint;
}

/**
 * gimp_tool_rectangle_get_public_rect:
 * @rectangle:
 * @x1:
 * @y1:
 * @x2:
 * @y2:
 *
 * This function returns the rectangle as it appears to be publicly
 * (based on integer or double precision-mode).
 **/
void
gimp_tool_rectangle_get_public_rect (GimpToolRectangle *rectangle,
                                     gdouble           *x1,
                                     gdouble           *y1,
                                     gdouble           *x2,
                                     gdouble           *y2)
{
  GimpToolRectanglePrivate *priv;

  g_return_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle));
  g_return_if_fail (x1 != NULL);
  g_return_if_fail (y1 != NULL);
  g_return_if_fail (x2 != NULL);
  g_return_if_fail (y2 != NULL);

  priv = rectangle->private;

  switch (priv->precision)
    {
    case GIMP_RECTANGLE_PRECISION_INT:
      *x1 = priv->x1_int;
      *y1 = priv->y1_int;
      *x2 = priv->x1_int + priv->width_int;
      *y2 = priv->y1_int + priv->height_int;
      break;

    case GIMP_RECTANGLE_PRECISION_DOUBLE:
    default:
      *x1 = priv->x1;
      *y1 = priv->y1;
      *x2 = priv->x2;
      *y2 = priv->y2;
      break;
    }
}

/**
 * gimp_tool_rectangle_pending_size_set:
 * @width_property:  Option property to set to pending rectangle width.
 * @height_property: Option property to set to pending rectangle height.
 *
 * Sets specified rectangle tool options properties to the width and
 * height of the current pending rectangle.
 */
void
gimp_tool_rectangle_pending_size_set (GimpToolRectangle *rectangle,
                                      GObject           *object,
                                      const gchar       *width_property,
                                      const gchar       *height_property)
{
  GimpToolRectanglePrivate *private;

  g_return_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle));
  g_return_if_fail (width_property  != NULL);
  g_return_if_fail (height_property != NULL);

  private = rectangle->private;

  g_object_set (object,
                width_property,  MAX (private->x2 - private->x1, 1.0),
                height_property, MAX (private->y2 - private->y1, 1.0),
                NULL);
}

/**
 * gimp_tool_rectangle_constraint_size_set:
 * @width_property:  Option property to set to current constraint width.
 * @height_property: Option property to set to current constraint height.
 *
 * Sets specified rectangle tool options properties to the width and
 * height of the current constraint size.
 */
void
gimp_tool_rectangle_constraint_size_set (GimpToolRectangle *rectangle,
                                         GObject           *object,
                                         const gchar       *width_property,
                                         const gchar       *height_property)
{
  GimpDisplayShell *shell;
  GimpContext      *context;
  GimpImage        *image;
  gdouble           width;
  gdouble           height;

  g_return_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle));

  shell   = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (rectangle));
  context = gimp_get_user_context (shell->display->gimp);
  image   = gimp_context_get_image (context);

  if (! image)
    {
      width  = 1.0;
      height = 1.0;
    }
  else
    {
      GimpRectangleConstraint constraint;

      constraint = gimp_tool_rectangle_get_constraint (rectangle);

      switch (constraint)
        {
        case GIMP_RECTANGLE_CONSTRAIN_DRAWABLE:
          {
            GList *items = gimp_image_get_selected_layers (image);
            GList *iter;

            width  = 0.0;
            height = 0.0;
            for (iter = items; iter; iter = iter->next)
              {
                if (width == 0.0 || height == 0.0)
                  {
                    width  = gimp_item_get_width  (iter->data);
                    height = gimp_item_get_height (iter->data);
                  }
                else if (width  != gimp_item_get_width  (iter->data) ||
                         height != gimp_item_get_height (iter->data))
                  {
                    width  = 0.0;
                    height = 0.0;
                    break;
                  }
              }

            /* Set constraint to the selected layers' dimensions if all
             * selected layers have the same dimension. Otherwise set to
             * image dimensions.
             */
            if (width == 0.0 || height == 0.0)
              {
                width  = gimp_image_get_width  (image);
                height = gimp_image_get_height (image);
              }
          }
          break;

        case GIMP_RECTANGLE_CONSTRAIN_IMAGE:
        default:
          {
            width  = gimp_image_get_width  (image);
            height = gimp_image_get_height (image);
          }
          break;
        }
    }

  g_object_set (object,
                width_property,  width,
                height_property, height,
                NULL);
}

/**
 * gimp_tool_rectangle_rectangle_is_first:
 * @rectangle:
 *
 * Returns: %TRUE if the user is creating the first rectangle with
 * this instance from scratch, %FALSE if modifying an existing
 * rectangle, or creating a new rectangle, discarding the existing
 * one. This function is only meaningful in _motion and
 * _button_release.
 */
gboolean
gimp_tool_rectangle_rectangle_is_first (GimpToolRectangle *rectangle)
{
  g_return_val_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle), FALSE);

  return rectangle->private->is_first;
}

/**
 * gimp_tool_rectangle_rectangle_is_new:
 * @rectangle:
 *
 * Returns: %TRUE if the user is creating a new rectangle from
 * scratch, %FALSE if modifying n previously existing rectangle. This
 * function is only meaningful in _motion and _button_release.
 */
gboolean
gimp_tool_rectangle_rectangle_is_new (GimpToolRectangle *rectangle)
{
  g_return_val_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle), FALSE);

  return rectangle->private->is_new;
}

/**
 * gimp_tool_rectangle_point_in_rectangle:
 * @rectangle:
 * @x:         X-coord of point to test (in image coordinates)
 * @y:         Y-coord of point to test (in image coordinates)
 *
 * Returns: %TRUE if the passed point was within the rectangle
 **/
gboolean
gimp_tool_rectangle_point_in_rectangle (GimpToolRectangle *rectangle,
                                        gdouble            x,
                                        gdouble            y)
{
  gdouble  x1, y1, x2, y2;

  g_return_val_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle), FALSE);

  gimp_tool_rectangle_get_public_rect (rectangle, &x1, &y1, &x2, &y2);

  return (x >= x1 && x <= x2 &&
          y >= y1 && y <= y2);
}

/**
 * gimp_tool_rectangle_frame_item:
 * @rectangle: a #GimpToolRectangle interface
 * @item:      a #GimpItem attached to the image on which a
 *             rectangle is being shown.
 *
 * Convenience function to set the corners of the rectangle to
 * match the bounds of the specified item.  The rectangle interface
 * must be active (i.e., showing a rectangle), and the item must be
 * attached to the image on which the rectangle is active.
 **/
void
gimp_tool_rectangle_frame_item (GimpToolRectangle *rectangle,
                                GimpItem          *item)
{
  GimpDisplayShell *shell;
  gint              offset_x;
  gint              offset_y;
  gint              width;
  gint              height;

  g_return_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle));
  g_return_if_fail (GIMP_IS_ITEM (item));
  g_return_if_fail (gimp_item_is_attached (item));

  shell = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (rectangle));

  g_return_if_fail (gimp_display_get_image (shell->display) ==
                    gimp_item_get_image (item));

  width  = gimp_item_get_width  (item);
  height = gimp_item_get_height (item);

  gimp_item_get_offset (item, &offset_x, &offset_y);

  gimp_tool_rectangle_set_function (rectangle, GIMP_TOOL_RECTANGLE_CREATING);

  g_object_set (rectangle,
                "x1", (gdouble) offset_x,
                "y1", (gdouble) offset_y,
                "x2", (gdouble) (offset_x + width),
                "y2", (gdouble) (offset_y + height),
                NULL);

  /* kludge to force handle sizes to update.  This call may be harmful
   * if this function is ever moved out of the text tool code.
   */
  gimp_tool_rectangle_set_constraint (rectangle, GIMP_RECTANGLE_CONSTRAIN_NONE);
}

void
gimp_tool_rectangle_auto_shrink (GimpToolRectangle *rectangle,
                                 gboolean           shrink_merged)
{
  GimpToolRectanglePrivate *private;
  GimpDisplayShell         *shell;
  GimpImage                *image;
  GList                    *pickables = NULL;
  GList                    *iter;
  gdouble                   new_x1, new_y1;
  gdouble                   new_x2, new_y2;

  g_return_if_fail (GIMP_IS_TOOL_RECTANGLE (rectangle));

  private = rectangle->private;

  shell = gimp_tool_widget_get_shell (GIMP_TOOL_WIDGET (rectangle));
  image = gimp_display_get_image (shell->display);

  if (shrink_merged)
    pickables = g_list_prepend (NULL, image);
  else
    pickables = gimp_image_get_selected_drawables (image);

  if (! pickables)
    return;

  new_x1 = new_y1 = G_MAXINT;
  new_x2 = new_y2 = G_MININT;
  for (iter = pickables; iter; iter = iter->next)
    {
      gint x1, y1;
      gint x2, y2;
      gint offset_x = 0;
      gint offset_y = 0;
      gint shrunk_x;
      gint shrunk_y;
      gint shrunk_width;
      gint shrunk_height;

      if (GIMP_IS_IMAGE (iter->data))
        {
          x1 = private->x1;
          y1 = private->y1;
          x2 = private->x2;
          y2 = private->y2;
        }
      else
        {
          gimp_item_get_offset (GIMP_ITEM (iter->data), &offset_x, &offset_y);

          x1 = private->x1 - offset_x;
          y1 = private->y1 - offset_y;
          x2 = private->x2 - offset_x;
          y2 = private->y2 - offset_y;
        }

      switch (gimp_pickable_auto_shrink (iter->data,
                                         x1, y1, x2 - x1, y2 - y1,
                                         &shrunk_x,
                                         &shrunk_y,
                                         &shrunk_width,
                                         &shrunk_height))
        {
        case GIMP_AUTO_SHRINK_SHRINK:
            {
              new_x1 = MIN (new_x1, offset_x + shrunk_x);
              new_y1 = MIN (new_y1, offset_y + shrunk_y);
              new_x2 = MAX (new_x2, offset_x + shrunk_x + shrunk_width);
              new_y2 = MAX (new_y2, offset_y + shrunk_y + shrunk_height);
            }
          break;

        default:
          break;
        }
    }

  if (new_x1 != G_MAXINT && new_y1 != G_MAXINT &&
      new_x2 != G_MININT && new_y2 != G_MININT)
    {
      GimpRectangleFunction original_function = private->function;

      private->function = GIMP_TOOL_RECTANGLE_AUTO_SHRINK;

      private->x1 = new_x1;
      private->y1 = new_y1;
      private->x2 = new_x2;
      private->y2 = new_y2;

      gimp_tool_rectangle_update_int_rect (rectangle);

      gimp_tool_rectangle_change_complete (rectangle);

      private->function = original_function;

      gimp_tool_rectangle_update_options (rectangle);
    }

  g_list_free (pickables);
}
