[gtk+] API: Add gdk_window_get_background_pattern()

[Benjamin Otte <otte src gnome org>]

commit 2944561ba301e0317fe7a1f39892df553d5f4e67
Author: Benjamin Otte <otte redhat com>
Date:   Sun Aug 15 23:50:02 2010 +0200

    API: Add gdk_window_get_background_pattern()
    
    This is the suggested way for GTK3 to store a Window's background so it
    makes sense to use the same function today already.

 docs/reference/gdk/gdk3-sections.txt |    3 +-
 gdk/gdk.symbols                      |    1 +
 gdk/gdkinternals.h                   |    1 +
 gdk/gdkwindow.c                      |   68 ++++++++++++++++++++++++++++++++++
 gdk/gdkwindow.h                      |    2 +
 5 files changed, 73 insertions(+), 2 deletions(-)
---
diff --git a/docs/reference/gdk/gdk3-sections.txt b/docs/reference/gdk/gdk3-sections.txt
index eb3bf36..de08736 100644
--- a/docs/reference/gdk/gdk3-sections.txt
+++ b/docs/reference/gdk/gdk3-sections.txt
@@ -477,9 +477,8 @@ gdk_window_merge_child_input_shapes
 gdk_window_set_static_gravities
 gdk_window_set_title
 gdk_window_set_background
-gdk_window_get_background
 gdk_window_set_back_pixmap
-gdk_window_get_back_pixmap
+gdk_window_get_background_pattern
 GDK_PARENT_RELATIVE
 gdk_window_set_cursor
 gdk_window_get_cursor
diff --git a/gdk/gdk.symbols b/gdk/gdk.symbols
index 8a58243..27f8f6a 100644
--- a/gdk/gdk.symbols
+++ b/gdk/gdk.symbols
@@ -579,6 +579,7 @@ gdk_window_move_resize
 gdk_window_scroll
 gdk_window_move_region
 gdk_window_get_accept_focus
+gdk_window_get_background_pattern
 gdk_window_get_composited
 gdk_window_get_cursor
 gdk_window_get_focus_on_map
diff --git a/gdk/gdkinternals.h b/gdk/gdkinternals.h
index 694391d..dcd6e12 100644
--- a/gdk/gdkinternals.h
+++ b/gdk/gdkinternals.h
@@ -209,6 +209,7 @@ struct _GdkWindowObject
 
   GdkColor bg_color;
   GdkPixmap *bg_pixmap;
+  cairo_pattern_t *background;
   
   GSList *paint_stack;
   
diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index d5bc413..e7380c6 100644
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -2067,6 +2067,12 @@ _gdk_window_destroy_hierarchy (GdkWindow *window,
 	      private->bg_pixmap = NULL;
 	    }
 
+          if (private->background)
+            {
+              cairo_pattern_destroy (private->background);
+              private->background = NULL;
+            }
+
 	  if (private->window_type == GDK_WINDOW_FOREIGN)
 	    g_assert (private->children == NULL);
 	  else
@@ -7085,6 +7091,12 @@ gdk_window_set_background (GdkWindow      *window,
 
   private->bg_pixmap = NULL;
 
+  if (private->background)
+    {
+      cairo_pattern_destroy (private->background);
+      private->background = NULL;
+    }
+
   if (!GDK_WINDOW_DESTROYED (window) &&
       gdk_window_has_impl (private) &&
       !private->input_only)
@@ -7145,6 +7157,12 @@ gdk_window_set_back_pixmap (GdkWindow *window,
       private->bg_pixmap != GDK_NO_BG)
     g_object_unref (private->bg_pixmap);
 
+  if (private->background)
+    {
+      cairo_pattern_destroy (private->background);
+      private->background = NULL;
+    }
+
   if (parent_relative)
     private->bg_pixmap = GDK_PARENT_RELATIVE_BG;
   else if (pixmap)
@@ -7161,6 +7179,56 @@ gdk_window_set_back_pixmap (GdkWindow *window,
     }
 }
 
+/**
+ * gdk_window_get_background_pattern:
+ * @window: a window
+ *
+ * Gets the pattern used to clear the background on @window. If @window
+ * does not have its own background and reuses the parent's, %NULL is
+ * returned and you'll have to query it yourself.
+ *
+ * Returns: The pattern to use for the background or %NULL to use the
+ * parent's background.
+ *
+ * Since: 2.22
+ **/
+cairo_pattern_t *
+gdk_window_get_background_pattern (GdkWindow *window)
+{
+  GdkWindowObject *private = (GdkWindowObject *) window;
+
+  g_return_val_if_fail (GDK_IS_WINDOW (window), NULL);
+
+  if (private->background == NULL)
+    {
+      if (private->bg_pixmap == GDK_PARENT_RELATIVE_BG)
+        private->background = NULL;
+      else if (private->bg_pixmap != GDK_NO_BG &&
+               private->bg_pixmap != NULL)
+        {
+          static cairo_user_data_key_t key;
+          cairo_surface_t *surface;
+
+          surface = _gdk_drawable_ref_cairo_surface (private->bg_pixmap);
+          private->background = cairo_pattern_create_for_surface (surface);
+          cairo_surface_destroy (surface);
+
+          cairo_pattern_set_extend (private->background, CAIRO_EXTEND_REPEAT);
+          cairo_pattern_set_user_data (private->background,
+                                       &key,
+                                       g_object_ref (private->bg_pixmap),
+                                       g_object_unref);
+        }
+      else
+        private->background =
+            cairo_pattern_create_rgb (private->bg_color.red   / 65535.,
+                                      private->bg_color.green / 65535.,
+                                      private->bg_color.blue / 65535.);
+    }   
+
+  return private->background;
+}
+
 static void
 update_cursor_foreach (GdkDisplay           *display,
                        GdkDevice            *device,
diff --git a/gdk/gdkwindow.h b/gdk/gdkwindow.h
index 77523c4..dcc42ac 100644
--- a/gdk/gdkwindow.h
+++ b/gdk/gdkwindow.h
@@ -693,6 +693,8 @@ void	      gdk_window_set_background	 (GdkWindow	  *window,
 void	      gdk_window_set_back_pixmap (GdkWindow	  *window,
 					  GdkPixmap	  *pixmap,
 					  gboolean	   parent_relative);
+cairo_pattern_t *gdk_window_get_background_pattern (GdkWindow     *window);
+
 void	      gdk_window_set_cursor	 (GdkWindow	  *window,
 					  GdkCursor	  *cursor);
 GdkCursor    *gdk_window_get_cursor      (GdkWindow       *window);