From 77e70f3550464df79eedf8ac5b68e69933a3556f Mon Sep 17 00:00:00 2001
From: Michael Natterer <mitch@gimp.org>
Date: Sun, 28 Apr 2013 14:51:57 +0200
Subject: [PATCH] app: remove the manual double buffering from the canvas

It is messing with overlay widgets. Is was effectively disabled since
cairo tool drawing was introduced, but not completely.
---
 app/display/gimpdisplayshell-callbacks.c | 50 ------------------------
 app/display/gimpdisplayshell-callbacks.h |  3 --
 app/display/gimpdisplayshell.c           |  9 -----
 3 files changed, 62 deletions(-)

diff --git a/app/display/gimpdisplayshell-callbacks.c b/app/display/gimpdisplayshell-callbacks.c
index 7f14f111c0..16e2cdf10e 100644
--- a/app/display/gimpdisplayshell-callbacks.c
+++ b/app/display/gimpdisplayshell-callbacks.c
@@ -210,25 +210,6 @@ gimp_display_shell_canvas_size_allocate (GtkWidget        *widget,
     }
 }
 
-static gboolean
-gimp_display_shell_is_double_buffered (GimpDisplayShell *shell)
-{
-  return TRUE; /* FIXME: repair this after cairo tool drawing is done */
-
-  /*  always double-buffer if there are overlay children or a
-   *  transform preview, or they will flicker badly. Also double
-   *  buffer when we are editing paths.
-   */
-#if 0
-  if (GIMP_OVERLAY_BOX (shell->canvas)->children    ||
-      gimp_display_shell_get_show_transform (shell) ||
-      GIMP_IS_VECTOR_TOOL (tool_manager_get_active (shell->display->gimp)))
-    return TRUE;
-#endif
-
-  return FALSE;
-}
-
 gboolean
 gimp_display_shell_canvas_expose (GtkWidget        *widget,
                                   GdkEventExpose   *eevent,
@@ -243,15 +224,6 @@ gimp_display_shell_canvas_expose (GtkWidget        *widget,
     {
       cairo_t *cr;
 
-      if (gimp_display_get_image (shell->display))
-        {
-          if (gimp_display_shell_is_double_buffered (shell))
-            gdk_window_begin_paint_region (eevent->window, eevent->region);
-        }
-
-      /*  create the cairo_t after enabling double buffering, or we
-       *  will get the wrong window destination surface
-       */
       cr = gdk_cairo_create (gtk_widget_get_window (shell->canvas));
       gdk_cairo_region (cr, eevent->region);
       cairo_clip (cr);
@@ -271,28 +243,6 @@ gimp_display_shell_canvas_expose (GtkWidget        *widget,
   return FALSE;
 }
 
-gboolean
-gimp_display_shell_canvas_expose_after (GtkWidget        *widget,
-                                        GdkEventExpose   *eevent,
-                                        GimpDisplayShell *shell)
-{
-  /*  are we in destruction?  */
-  if (! shell->display || ! gimp_display_get_shell (shell->display))
-    return TRUE;
-
-  /*  ignore events on overlays  */
-  if (eevent->window == gtk_widget_get_window (widget))
-    {
-      if (gimp_display_get_image (shell->display))
-        {
-          if (gimp_display_shell_is_double_buffered (shell))
-            gdk_window_end_paint (eevent->window);
-        }
-    }
-
-  return FALSE;
-}
-
 gboolean
 gimp_display_shell_origin_button_press (GtkWidget        *widget,
                                         GdkEventButton   *event,
diff --git a/app/display/gimpdisplayshell-callbacks.h b/app/display/gimpdisplayshell-callbacks.h
index c81630c18c..2fca4e5ff7 100644
--- a/app/display/gimpdisplayshell-callbacks.h
+++ b/app/display/gimpdisplayshell-callbacks.h
@@ -27,9 +27,6 @@ void       gimp_display_shell_canvas_size_allocate    (GtkWidget        *widget,
 gboolean   gimp_display_shell_canvas_expose           (GtkWidget        *widget,
                                                        GdkEventExpose   *eevent,
                                                        GimpDisplayShell *shell);
-gboolean   gimp_display_shell_canvas_expose_after     (GtkWidget        *widget,
-                                                       GdkEventExpose   *eevent,
-                                                       GimpDisplayShell *shell);
 
 gboolean   gimp_display_shell_origin_button_press     (GtkWidget        *widget,
                                                        GdkEventButton   *bevent,
diff --git a/app/display/gimpdisplayshell.c b/app/display/gimpdisplayshell.c
index b1e9a7978e..c0e1915a19 100644
--- a/app/display/gimpdisplayshell.c
+++ b/app/display/gimpdisplayshell.c
@@ -574,9 +574,6 @@ gimp_display_shell_constructed (GObject *object)
   g_signal_connect (shell->canvas, "expose-event",
                     G_CALLBACK (gimp_display_shell_canvas_expose),
                     shell);
-  g_signal_connect_after (shell->canvas, "expose-event",
-                          G_CALLBACK (gimp_display_shell_canvas_expose_after),
-                          shell);
 
   g_signal_connect (shell->canvas, "enter-notify-event",
                     G_CALLBACK (gimp_display_shell_canvas_tool_events),
@@ -1355,9 +1352,6 @@ gimp_display_shell_empty (GimpDisplayShell *shell)
 
   gimp_statusbar_empty (GIMP_STATUSBAR (shell->statusbar));
 
-  /*  so wilber doesn't flicker  */
-  gtk_widget_set_double_buffered (shell->canvas, TRUE);
-
   shell->rotate_angle = 0.0;
   gimp_display_shell_rotate_update_transform (shell);
 
@@ -1416,9 +1410,6 @@ gimp_display_shell_fill (GimpDisplayShell *shell,
                                                                 TRUE,
                                                                 TRUE);
 
-  /*  we double buffer image drawing manually  */
-  gtk_widget_set_double_buffered (shell->canvas, FALSE);
-
   shell->fill_idle_id =
     g_idle_add_full (GIMP_DISPLAY_SHELL_FILL_IDLE_PRIORITY,
                      (GSourceFunc) gimp_display_shell_fill_idle, shell,