[gimp] app: start an infrastructure where the shell keeps around its canvas items

[Michael Natterer <mitch src gnome org>]

commit 7edfa2ca543739fb86c9e2e277470d8f3df5ee45
Author: Michael Natterer <mitch gimp org>
Date:   Wed Sep 29 22:12:01 2010 +0200

    app: start an infrastructure where the shell keeps around its canvas items
    
    - Invalidate the proper area when an item gets added or removed.
    - Draw the kept canvas items instead of calling a draw tool function.
    - The draw tool now sets its item on the shell.

 app/display/Makefile.am                  |    2 +
 app/display/gimpdisplayshell-callbacks.c |   15 ++------
 app/display/gimpdisplayshell-items.c     |   55 ++++++++++++++++++++++++++++++
 app/display/gimpdisplayshell-items.h     |   31 +++++++++++++++++
 app/display/gimpdisplayshell.c           |    9 +++++
 app/display/gimpdisplayshell.h           |    2 +
 app/tools/gimpdrawtool.c                 |   49 +++++++++------------------
 app/tools/gimpdrawtool.h                 |    3 --
 8 files changed, 119 insertions(+), 47 deletions(-)
---
diff --git a/app/display/Makefile.am b/app/display/Makefile.am
index 3b82f4a..ab093df 100644
--- a/app/display/Makefile.am
+++ b/app/display/Makefile.am
@@ -79,6 +79,8 @@ libappdisplay_a_sources = \
 	gimpdisplayshell-layer-select.h		\
 	gimpdisplayshell-icon.c			\
 	gimpdisplayshell-icon.h			\
+	gimpdisplayshell-items.c		\
+	gimpdisplayshell-items.h		\
 	gimpdisplayshell-preview.c		\
 	gimpdisplayshell-preview.h		\
 	gimpdisplayshell-progress.c		\
diff --git a/app/display/gimpdisplayshell-callbacks.c b/app/display/gimpdisplayshell-callbacks.c
index d1261bc..835acec 100644
--- a/app/display/gimpdisplayshell-callbacks.c
+++ b/app/display/gimpdisplayshell-callbacks.c
@@ -60,6 +60,7 @@
 #include "widgets/gimpuimanager.h"
 
 #include "gimpcanvas.h"
+#include "gimpcanvasitem.h"
 #include "gimpdisplay.h"
 #include "gimpdisplayshell.h"
 #include "gimpdisplayshell-appearance.h"
@@ -2350,17 +2351,9 @@ gimp_display_shell_canvas_expose_image (GimpDisplayShell *shell,
   cairo_restore (cr);
 
   /* draw tool items */
-  {
-    GimpTool *tool = tool_manager_get_active (shell->display->gimp);
-
-    if (GIMP_IS_DRAW_TOOL (tool) &&
-        GIMP_DRAW_TOOL (tool)->display == shell->display)
-      {
-        cairo_save (cr);
-        gimp_draw_tool_draw_items (GIMP_DRAW_TOOL (tool), cr);
-        cairo_restore (cr);
-      }
-  }
+  cairo_save (cr);
+  gimp_canvas_item_draw (shell->canvas_item, shell, cr);
+  cairo_restore (cr);
 
   /* and the cursor (if we have a software cursor) */
   cairo_save (cr);
diff --git a/app/display/gimpdisplayshell-items.c b/app/display/gimpdisplayshell-items.c
new file mode 100644
index 0000000..d98e1ae
--- /dev/null
+++ b/app/display/gimpdisplayshell-items.c
@@ -0,0 +1,55 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpdisplayshell-items.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 <gtk/gtk.h>
+
+#include "display-types.h"
+
+#include "gimpcanvasgroup.h"
+#include "gimpdisplayshell.h"
+#include "gimpdisplayshell-expose.h"
+#include "gimpdisplayshell-items.h"
+
+
+void
+gimp_display_shell_add_item (GimpDisplayShell *shell,
+                             GimpCanvasItem   *item)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  gimp_canvas_group_add_item (GIMP_CANVAS_GROUP (shell->canvas_item), item);
+
+  gimp_display_shell_expose_item (shell, item);
+}
+
+void
+gimp_display_shell_remove_item (GimpDisplayShell *shell,
+                                GimpCanvasItem   *item)
+{
+  g_return_if_fail (GIMP_IS_DISPLAY_SHELL (shell));
+  g_return_if_fail (GIMP_IS_CANVAS_ITEM (item));
+
+  gimp_display_shell_expose_item (shell, item);
+
+  gimp_canvas_group_remove_item (GIMP_CANVAS_GROUP (shell->canvas_item), item);
+}
diff --git a/app/display/gimpdisplayshell-items.h b/app/display/gimpdisplayshell-items.h
new file mode 100644
index 0000000..59b040f
--- /dev/null
+++ b/app/display/gimpdisplayshell-items.h
@@ -0,0 +1,31 @@
+/* GIMP - The GNU Image Manipulation Program
+ * Copyright (C) 1995 Spencer Kimball and Peter Mattis
+ *
+ * gimpdisplayshell-items.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_DISPLAY_SHELL_ITEMS_H__
+#define __GIMP_DISPLAY_SHELL_ITEMS_H__
+
+
+void   gimp_display_shell_add_item    (GimpDisplayShell *shell,
+                                       GimpCanvasItem   *item);
+void   gimp_display_shell_remove_item (GimpDisplayShell *shell,
+                                       GimpCanvasItem   *item);
+
+
+#endif /* __GIMP_DISPLAY_SHELL_ITEMS_H__ */
diff --git a/app/display/gimpdisplayshell.c b/app/display/gimpdisplayshell.c
index f349495..3402f73 100644
--- a/app/display/gimpdisplayshell.c
+++ b/app/display/gimpdisplayshell.c
@@ -53,6 +53,7 @@
 #include "tools/tool_manager.h"
 
 #include "gimpcanvas.h"
+#include "gimpcanvasgroup.h"
 #include "gimpdisplay.h"
 #include "gimpdisplayshell.h"
 #include "gimpdisplayshell-appearance.h"
@@ -290,6 +291,8 @@ gimp_display_shell_init (GimpDisplayShell *shell)
                                                       GIMP_DISPLAY_RENDER_BUF_WIDTH,
                                                       GIMP_DISPLAY_RENDER_BUF_HEIGHT);
 
+  shell->canvas_item = gimp_canvas_group_new ();
+
   shell->icon_size  = 32;
 
   shell->cursor_format   = GIMP_CURSOR_FORMAT_BITMAP;
@@ -793,6 +796,12 @@ gimp_display_shell_dispose (GObject *object)
       shell->mask = NULL;
     }
 
+  if (shell->canvas_item)
+    {
+      g_object_unref (shell->canvas_item);
+      shell->canvas_item = NULL;
+    }
+
   if (shell->event_history)
     {
       g_array_free (shell->event_history, TRUE);
diff --git a/app/display/gimpdisplayshell.h b/app/display/gimpdisplayshell.h
index a6eb26d..eefbcf9 100644
--- a/app/display/gimpdisplayshell.h
+++ b/app/display/gimpdisplayshell.h
@@ -135,6 +135,8 @@ struct _GimpDisplayShell
   cairo_surface_t   *mask_surface;     /*  buffer for rendering the mask      */
   cairo_pattern_t   *checkerboard;     /*  checkerboard pattern               */
 
+  GimpCanvasItem    *canvas_item;      /*  items drawn on the canvas          */
+
   guint              title_idle_id;    /*  title update idle ID               */
   gchar             *title;            /*  current title                      */
   gchar             *status;           /*  current default statusbar content  */
diff --git a/app/tools/gimpdrawtool.c b/app/tools/gimpdrawtool.c
index 285482f..7e99785 100644
--- a/app/tools/gimpdrawtool.c
+++ b/app/tools/gimpdrawtool.c
@@ -46,6 +46,7 @@
 #include "display/gimpdisplay.h"
 #include "display/gimpdisplayshell.h"
 #include "display/gimpdisplayshell-expose.h"
+#include "display/gimpdisplayshell-items.h"
 #include "display/gimpdisplayshell-transform.h"
 
 #include "gimpdrawtool.h"
@@ -181,36 +182,35 @@ gimp_draw_tool_clear_items (GimpDrawTool *draw_tool)
 }
 
 static void
-gimp_draw_tool_invalidate_items (GimpDrawTool *draw_tool)
-{
-  if (draw_tool->item)
-    {
-      GimpDisplayShell *shell = gimp_display_get_shell (draw_tool->display);
-
-      gimp_display_shell_expose_item (shell, draw_tool->item);
-    }
-}
-
-static void
 gimp_draw_tool_draw (GimpDrawTool *draw_tool)
 {
   if (draw_tool->display && draw_tool->paused_count == 0)
     {
-      gimp_draw_tool_invalidate_items (draw_tool);
-      gimp_draw_tool_clear_items (draw_tool);
+      GimpDisplayShell *shell = gimp_display_get_shell (draw_tool->display);
+
+      if (draw_tool->item)
+        {
+          gimp_display_shell_remove_item (shell, draw_tool->item);
+          gimp_draw_tool_clear_items (draw_tool);
+        }
 
       GIMP_DRAW_TOOL_GET_CLASS (draw_tool)->draw (draw_tool);
 
-      gimp_draw_tool_invalidate_items (draw_tool);
+      if (draw_tool->item)
+        {
+          gimp_display_shell_add_item (shell, draw_tool->item);
+        }
     }
 }
 
 static void
 gimp_draw_tool_undraw (GimpDrawTool *draw_tool)
 {
-  if (draw_tool->display)
+  if (draw_tool->display && draw_tool->item)
     {
-      gimp_draw_tool_invalidate_items (draw_tool);
+      GimpDisplayShell *shell = gimp_display_get_shell (draw_tool->display);
+
+      gimp_display_shell_remove_item (shell, draw_tool->item);
       gimp_draw_tool_clear_items (draw_tool);
     }
 }
@@ -272,23 +272,6 @@ gimp_draw_tool_resume (GimpDrawTool *draw_tool)
   gimp_draw_tool_draw (draw_tool);
 }
 
-void
-gimp_draw_tool_draw_items (GimpDrawTool *draw_tool,
-                           cairo_t      *cr)
-{
-  g_return_if_fail (GIMP_IS_DRAW_TOOL (draw_tool));
-  g_return_if_fail (cr != NULL);
-
-  if (draw_tool->item                      &&
-      gimp_draw_tool_is_active (draw_tool) &&
-      draw_tool->paused_count == 0)
-    {
-      GimpDisplayShell *shell = gimp_display_get_shell (draw_tool->display);
-
-      gimp_canvas_item_draw (draw_tool->item, shell, cr);
-    }
-}
-
 /**
  * gimp_draw_tool_calc_distance:
  * @draw_tool: a #GimpDrawTool
diff --git a/app/tools/gimpdrawtool.h b/app/tools/gimpdrawtool.h
index 4b43489..d5279b7 100644
--- a/app/tools/gimpdrawtool.h
+++ b/app/tools/gimpdrawtool.h
@@ -66,9 +66,6 @@ gboolean         gimp_draw_tool_is_active            (GimpDrawTool     *draw_too
 void             gimp_draw_tool_pause                (GimpDrawTool     *draw_tool);
 void             gimp_draw_tool_resume               (GimpDrawTool     *draw_tool);
 
-void             gimp_draw_tool_draw_items           (GimpDrawTool     *draw_tool,
-                                                      cairo_t          *cr);
-
 gdouble          gimp_draw_tool_calc_distance        (GimpDrawTool     *draw_tool,
                                                       GimpDisplay      *display,
                                                       gdouble           x1,