app: add a software cursor canvas item

and use it to draw the sw cursor. Almost every aspect of the old code
was ugly and hard to read, this is so much nicer...

app/display/Makefile.am

@@ -25,6 +25,8 @@ libappdisplay_a_sources = \
 	gimpcanvasboundary.h			\
 	gimpcanvascorner.c			\
 	gimpcanvascorner.h			\
+	gimpcanvascursor.c			\
+	gimpcanvascursor.h			\
 	gimpcanvasgrid.c			\
 	gimpcanvasgrid.h			\
 	gimpcanvasgroup.c			\

app/display/gimpcanvascursor.c

+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvascursor.c
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <gegl.h>
+#include <gtk/gtk.h>
+
+#include "libgimpbase/gimpbase.h"
+#include "libgimpmath/gimpmath.h"
+
+#include "display-types.h"
+
+#include "widgets/gimpcairo.h"
+
+#include "gimpcanvascursor.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-transform.h"
+
+
+#define GIMP_CURSOR_SIZE 7
+
+
+enum
+{
+  PROP_0,
+  PROP_X,
+  PROP_Y
+};
+
+
+typedef struct _GimpCanvasCursorPrivate GimpCanvasCursorPrivate;
+
+struct _GimpCanvasCursorPrivate
+{
+  gdouble x;
+  gdouble y;
+};
+
+#define GET_PRIVATE(cursor) \
+        G_TYPE_INSTANCE_GET_PRIVATE (cursor, \
+                                     GIMP_TYPE_CANVAS_CURSOR, \
+                                     GimpCanvasCursorPrivate)
+
+
+/*  local function prototypes  */
+
+static void        gimp_canvas_cursor_set_property (GObject          *object,
+                                                    guint             property_id,
+                                                    const GValue     *value,
+                                                    GParamSpec       *pspec);
+static void        gimp_canvas_cursor_get_property (GObject          *object,
+                                                    guint             property_id,
+                                                    GValue           *value,
+                                                    GParamSpec       *pspec);
+static void        gimp_canvas_cursor_draw         (GimpCanvasItem   *item,
+                                                    GimpDisplayShell *shell,
+                                                    cairo_t          *cr);
+static GdkRegion * gimp_canvas_cursor_get_extents  (GimpCanvasItem   *item,
+                                                    GimpDisplayShell *shell);
+
+
+G_DEFINE_TYPE (GimpCanvasCursor, gimp_canvas_cursor,
+               GIMP_TYPE_CANVAS_ITEM)
+
+#define parent_class gimp_canvas_cursor_parent_class
+
+
+static void
+gimp_canvas_cursor_class_init (GimpCanvasCursorClass *klass)
+{
+  GObjectClass        *object_class = G_OBJECT_CLASS (klass);
+  GimpCanvasItemClass *item_class   = GIMP_CANVAS_ITEM_CLASS (klass);
+
+  object_class->set_property = gimp_canvas_cursor_set_property;
+  object_class->get_property = gimp_canvas_cursor_get_property;
+
+  item_class->draw           = gimp_canvas_cursor_draw;
+  item_class->get_extents    = gimp_canvas_cursor_get_extents;
+
+  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,
+                                                        GIMP_PARAM_READWRITE));
+
+  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,
+                                                        GIMP_PARAM_READWRITE));
+
+  g_type_class_add_private (klass, sizeof (GimpCanvasCursorPrivate));
+}
+
+static void
+gimp_canvas_cursor_init (GimpCanvasCursor *cursor)
+{
+  gimp_canvas_item_set_line_cap (GIMP_CANVAS_ITEM (cursor),
+                                 CAIRO_LINE_CAP_SQUARE);
+}
+
+static void
+gimp_canvas_cursor_set_property (GObject      *object,
+                                 guint         property_id,
+                                 const GValue *value,
+                                 GParamSpec   *pspec)
+{
+  GimpCanvasCursorPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_X:
+      private->x = g_value_get_double (value);
+      break;
+    case PROP_Y:
+      private->y = g_value_get_double (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_cursor_get_property (GObject    *object,
+                                 guint       property_id,
+                                 GValue     *value,
+                                 GParamSpec *pspec)
+{
+  GimpCanvasCursorPrivate *private = GET_PRIVATE (object);
+
+  switch (property_id)
+    {
+    case PROP_X:
+      g_value_set_double (value, private->x);
+      break;
+    case PROP_Y:
+      g_value_set_double (value, private->y);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
+      break;
+    }
+}
+
+static void
+gimp_canvas_cursor_draw (GimpCanvasItem   *item,
+                         GimpDisplayShell *shell,
+                         cairo_t          *cr)
+{
+  GimpCanvasCursorPrivate *private = GET_PRIVATE (item);
+  gdouble                  x, y;
+
+  x = floor (private->x) + 0.5;
+  y = floor (private->y) + 0.5;
+
+  cairo_move_to (cr, x - GIMP_CURSOR_SIZE, y);
+  cairo_line_to (cr, x + GIMP_CURSOR_SIZE, y);
+
+  cairo_move_to (cr, x, y - GIMP_CURSOR_SIZE);
+  cairo_line_to (cr, x, y + GIMP_CURSOR_SIZE);
+
+  _gimp_canvas_item_stroke (item, cr);
+}
+
+static GdkRegion *
+gimp_canvas_cursor_get_extents (GimpCanvasItem   *item,
+                                GimpDisplayShell *shell)
+{
+  GimpCanvasCursorPrivate *private = GET_PRIVATE (item);
+  GdkRectangle             rectangle;
+  gdouble                  x, y;
+
+  x = floor (private->x) + 0.5;
+  y = floor (private->y) + 0.5;
+
+  rectangle.x      = floor (x - GIMP_CURSOR_SIZE - 1.5);
+  rectangle.y      = floor (y - GIMP_CURSOR_SIZE - 1.5);
+  rectangle.width  = ceil (x + GIMP_CURSOR_SIZE + 1.5) - rectangle.x;
+  rectangle.height = ceil (y + GIMP_CURSOR_SIZE + 1.5) - rectangle.y;
+
+  return gdk_region_rectangle (&rectangle);
+}
+
+GimpCanvasItem *
+gimp_canvas_cursor_new (GimpDisplayShell *shell)
+{
+  g_return_val_if_fail (GIMP_IS_DISPLAY_SHELL (shell), NULL);
+
+  return g_object_new (GIMP_TYPE_CANVAS_CURSOR,
+                       "shell", shell,
+                       NULL);
+}
+
+void
+gimp_canvas_cursor_set_coords (GimpCanvasCursor *cursor,
+                               gdouble           x,
+                               gdouble           y)
+{
+  GimpCanvasCursorPrivate *private;
+
+  g_return_if_fail (GIMP_IS_CANVAS_CURSOR (cursor));
+
+  private = GET_PRIVATE (cursor);
+
+  if (private->x != x || private->y != y)
+    {
+      gimp_canvas_item_begin_change (GIMP_CANVAS_ITEM (cursor));
+      g_object_set (cursor,
+                    "x", x,
+                    "y", y,
+                    NULL);
+      gimp_canvas_item_end_change (GIMP_CANVAS_ITEM (cursor));
+    }
+}

app/display/gimpcanvascursor.h

+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpcanvascursor.h
+ * Copyright (C) 2010 Michael Natterer <mitch@gimp.org>
+ *
+ * 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 <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __GIMP_CANVAS_CURSOR_H__
+#define __GIMP_CANVAS_CURSOR_H__
+
+
+#include "gimpcanvasitem.h"
+
+
+#define GIMP_TYPE_CANVAS_CURSOR            (gimp_canvas_cursor_get_type ())
+#define GIMP_CANVAS_CURSOR(obj)            (G_TYPE_CHECK_INSTANCE_CAST ((obj), GIMP_TYPE_CANVAS_CURSOR, GimpCanvasCursor))
+#define GIMP_CANVAS_CURSOR_CLASS(klass)    (G_TYPE_CHECK_CLASS_CAST ((klass), GIMP_TYPE_CANVAS_CURSOR, GimpCanvasCursorClass))
+#define GIMP_IS_CANVAS_CURSOR(obj)         (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GIMP_TYPE_CANVAS_CURSOR))
+#define GIMP_IS_CANVAS_CURSOR_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GIMP_TYPE_CANVAS_CURSOR))
+#define GIMP_CANVAS_CURSOR_GET_CLASS(obj)  (G_TYPE_INSTANCE_GET_CLASS ((obj), GIMP_TYPE_CANVAS_CURSOR, GimpCanvasCursorClass))
+
+
+typedef struct _GimpCanvasCursor      GimpCanvasCursor;
+typedef struct _GimpCanvasCursorClass GimpCanvasCursorClass;
+
+struct _GimpCanvasCursor
+{
+  GimpCanvasItem  parent_instance;
+};
+
+struct _GimpCanvasCursorClass
+{
+  GimpCanvasItemClass  parent_class;
+};
+
+
+GType            gimp_canvas_cursor_get_type   (void) G_GNUC_CONST;
+
+GimpCanvasItem * gimp_canvas_cursor_new        (GimpDisplayShell *shell);
+
+void             gimp_canvas_cursor_set_coords (GimpCanvasCursor *cursor,
+                                                gdouble           x,
+                                                gdouble           y);
+
+
+#endif /* __GIMP_CANVAS_CURSOR_H__ */

app/display/gimpdisplayshell-callbacks.c

@@ -2340,11 +2340,6 @@ gimp_display_shell_canvas_expose_image (GimpDisplayShell *shell,
   gimp_canvas_item_draw (shell->canvas_item, cr);
   cairo_restore (cr);
 
-  /* and the cursor (if we have a software cursor) */
-  cairo_save (cr);
-  gimp_display_shell_draw_cursor (shell, cr);
-  cairo_restore (cr);
-
   /* restart (and recalculate) the selection boundaries */
   gimp_display_shell_selection_control (shell, GIMP_SELECTION_ON);
 }

app/display/gimpdisplayshell-cursor.c

@@ -31,11 +31,11 @@
 #include "widgets/gimpdialogfactory.h"
 #include "widgets/gimpsessioninfo.h"
 
+#include "gimpcanvascursor.h"
 #include "gimpdisplay.h"
 #include "gimpcursorview.h"
 #include "gimpdisplayshell.h"
 #include "gimpdisplayshell-cursor.h"
-#include "gimpdisplayshell-expose.h"
 #include "gimpdisplayshell-transform.h"
 #include "gimpstatusbar.h"
 
@@ -125,44 +125,31 @@ gimp_display_shell_update_cursor (GimpDisplayShell    *shell,
                                   gdouble              image_x,
                                   gdouble              image_y)
 {
-  GimpStatusbar     *statusbar;
-  GimpSessionInfo   *session_info;
-  GimpImage         *image;
-  gboolean           new_cursor;
+  GimpStatusbar   *statusbar;
+  GimpSessionInfo *session_info;
+  GimpImage       *image;
 
   g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
 
   image = gimp_display_get_image (shell->display);
 
-  new_cursor = (shell->draw_cursor &&
-                shell->proximity   &&
-                display_x >= 0     &&
-                display_y >= 0);
-
-  /* Erase old cursor, if necessary */
-
-  if (shell->have_cursor && (! new_cursor                 ||
-                             display_x != shell->cursor_x ||
-                             display_y != shell->cursor_y))
+  if (shell->draw_cursor &&
+      shell->proximity   &&
+      display_x >= 0     &&
+      display_y >= 0)
     {
-      gimp_display_shell_expose_area (shell,
-                                      shell->cursor_x - GIMP_CURSOR_SIZE,
-                                      shell->cursor_y - GIMP_CURSOR_SIZE,
-                                      2 * GIMP_CURSOR_SIZE + 1,
-                                      2 * GIMP_CURSOR_SIZE + 1);
-    }
+      gimp_canvas_item_begin_change (shell->cursor);
 
-  shell->have_cursor = new_cursor;
-  shell->cursor_x    = display_x;
-  shell->cursor_y    = display_y;
+      gimp_canvas_cursor_set_coords (GIMP_CANVAS_CURSOR (shell->cursor),
+                                     display_x,
+                                     display_y);
+      gimp_canvas_item_set_visible (shell->cursor, TRUE);
 
-  if (shell->have_cursor)
+      gimp_canvas_item_end_change (shell->cursor);
+    }
+  else
     {
-      gimp_display_shell_expose_area (shell,
-                                      shell->cursor_x - GIMP_CURSOR_SIZE,
-                                      shell->cursor_y - GIMP_CURSOR_SIZE,
-                                      2 * GIMP_CURSOR_SIZE + 1,
-                                      2 * GIMP_CURSOR_SIZE + 1);
+      gimp_canvas_item_set_visible (shell->cursor, FALSE);
     }
 
   /*  use the passed image_coords for the statusbar because they are
@@ -205,6 +192,8 @@ gimp_display_shell_clear_cursor (GimpDisplayShell *shell)
 
   g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
 
+  gimp_canvas_item_set_visible (shell->cursor, FALSE);
+
   statusbar = gimp_display_shell_get_statusbar (shell);
 
   gimp_statusbar_clear_cursor (statusbar);

app/display/gimpdisplayshell-cursor.h

@@ -19,9 +19,6 @@
 #define __GIMP_DISPLAY_SHELL_CURSOR_H__
 
 
-#define GIMP_CURSOR_SIZE 7
-
-
 void   gimp_display_shell_set_cursor            (GimpDisplayShell    *shell,
                                                  GimpCursorType       cursor_type,
                                                  GimpToolCursorType   tool_cursor,

app/display/gimpdisplayshell-draw.c

@@ -44,7 +44,6 @@
 #include "gimpdisplay.h"
 #include "gimpdisplayshell.h"
 #include "gimpdisplayshell-appearance.h"
-#include "gimpdisplayshell-cursor.h"
 #include "gimpdisplayshell-draw.h"
 #include "gimpdisplayshell-render.h"
 #include "gimpdisplayshell-scale.h"
@@ -289,54 +288,6 @@ gimp_display_shell_draw_vectors (GimpDisplayShell *shell,
     }
 }
 
-void
-gimp_display_shell_draw_cursor (GimpDisplayShell *shell,
-                                cairo_t          *cr)
-{
-  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
-  g_return_if_fail (cr != NULL);
-
-  if (shell->have_cursor)
-    {
-      gimp_display_shell_set_cursor_style (shell, cr);
-      cairo_translate (cr, 0.5, 0.5);
-
-      cairo_set_source_rgb (cr, 1.0, 1.0, 1.0);
-
-      cairo_move_to (cr,
-                     shell->cursor_x - GIMP_CURSOR_SIZE, shell->cursor_y - 1);
-      cairo_line_to (cr,
-                     shell->cursor_x + GIMP_CURSOR_SIZE, shell->cursor_y - 1);
-
-      cairo_move_to (cr,
-                     shell->cursor_x - GIMP_CURSOR_SIZE, shell->cursor_y + 1);
-      cairo_line_to (cr,
-                     shell->cursor_x + GIMP_CURSOR_SIZE, shell->cursor_y + 1);
-
-      cairo_move_to (cr,
-                     shell->cursor_x - 1, shell->cursor_y - GIMP_CURSOR_SIZE);
-      cairo_line_to (cr,
-                     shell->cursor_x - 1, shell->cursor_y + GIMP_CURSOR_SIZE);
-
-      cairo_move_to (cr,
-                     shell->cursor_x + 1, shell->cursor_y - GIMP_CURSOR_SIZE);
-      cairo_line_to (cr,
-                     shell->cursor_x + 1, shell->cursor_y + GIMP_CURSOR_SIZE);
-
-      cairo_stroke (cr);
-
-      cairo_set_source_rgb (cr, 0.0, 0.0, 0.0);
-
-      cairo_move_to (cr, shell->cursor_x - GIMP_CURSOR_SIZE, shell->cursor_y);
-      cairo_line_to (cr, shell->cursor_x + GIMP_CURSOR_SIZE, shell->cursor_y);
-
-      cairo_move_to (cr, shell->cursor_x, shell->cursor_y - GIMP_CURSOR_SIZE);
-      cairo_line_to (cr, shell->cursor_x, shell->cursor_y + GIMP_CURSOR_SIZE);
-
-      cairo_stroke (cr);
-    }
-}
-
 void
 gimp_display_shell_draw_image (GimpDisplayShell *shell,
                                cairo_t          *cr,

app/display/gimpdisplayshell-draw.h

@@ -50,8 +50,6 @@ void   gimp_display_shell_draw_selection_in          (GimpDisplayShell   *shell,
                                                       gint                index);
 void   gimp_display_shell_draw_vectors               (GimpDisplayShell   *shell,
                                                       cairo_t            *cr);
-void   gimp_display_shell_draw_cursor                (GimpDisplayShell   *shell,
-                                                      cairo_t            *cr);
 void   gimp_display_shell_draw_image                 (GimpDisplayShell   *shell,
                                                       cairo_t            *cr,
                                                       gint                x,

app/display/gimpdisplayshell-items.c

@@ -24,6 +24,7 @@
 
 #include "display-types.h"
 
+#include "gimpcanvascursor.h"
 #include "gimpcanvasgrid.h"
 #include "gimpcanvasproxygroup.h"
 #include "gimpdisplayshell.h"
@@ -60,6 +61,11 @@ gimp_display_shell_items_init (GimpDisplayShell *shell)
   gimp_display_shell_add_item (shell, shell->sample_points);
   g_object_unref (shell->sample_points);
 
+  shell->cursor = gimp_canvas_cursor_new (shell);
+  gimp_canvas_item_set_visible (shell->cursor, FALSE);
+  gimp_display_shell_add_item (shell, shell->cursor);
+  g_object_unref (shell->cursor);
+
   g_signal_connect (shell->canvas_item, "update",
                     G_CALLBACK (gimp_display_shell_item_update),
                     shell);
@@ -82,6 +88,7 @@ gimp_display_shell_items_free (GimpDisplayShell *shell)
       shell->grid          = NULL;
       shell->guides        = NULL;
       shell->sample_points = NULL;
+      shell->cursor        = NULL;
     }
 }
 

app/display/gimpdisplayshell.h

@@ -139,6 +139,7 @@ struct _GimpDisplayShell
   GimpCanvasItem    *grid;             /*  item proxy of the grid             */
   GimpCanvasItem    *guides;           /*  item proxies of guides             */
   GimpCanvasItem    *sample_points;    /*  item proxies of sample points      */
+  GimpCanvasItem    *cursor;           /*  item for the software cursor       */
 
   guint              title_idle_id;    /*  title update idle ID               */
   gchar             *title;            /*  current title                      */
@@ -158,9 +159,6 @@ struct _GimpDisplayShell
   GimpCursorType     override_cursor;  /*  Overriding cursor                 */
   gboolean           using_override_cursor;
   gboolean           draw_cursor;      /* should we draw software cursor ?    */
-  gboolean           have_cursor;      /* is cursor currently drawn ?         */
-  gint               cursor_x;         /* software cursor X value             */
-  gint               cursor_y;         /* software cursor Y value             */
 
   GtkWidget         *close_dialog;     /*  close dialog                       */
   GtkWidget         *scale_dialog;     /*  scale (zoom) dialog                */