[gnome-control-center] Replace Gdk drawing with Cairo

[Benjamin Otte <otte src gnome org>]

commit 7ea3249a4a0fa9a176a120257355a4ca75593386
Author: Benjamin Otte <otte redhat com>
Date:   Sun Jul 25 14:31:49 2010 +0200

    Replace Gdk drawing with Cairo
    
    https://bugzilla.gnome.org/show_bug.cgi?id=626870

 font-viewer/font-view.c         |   27 ++++++++++------
 panels/display/scrollarea.c     |   67 ++++++++++++++++++++-------------------
 typing-break/drw-break-window.c |   41 +++++++++++-------------
 typing-break/drw-utils.c        |   17 +++-------
 4 files changed, 75 insertions(+), 77 deletions(-)
---
diff --git a/font-viewer/font-view.c b/font-viewer/font-view.c
index 56c557a..b68b382 100644
--- a/font-viewer/font-view.c
+++ b/font-viewer/font-view.c
@@ -112,6 +112,7 @@ create_text_pixmap(GtkWidget *drawing_area, FT_Face face)
     XftFont *font;
     gint *sizes = NULL, n_sizes, alpha_size;
     FcCharSet *charset = NULL;
+    cairo_t *cr;
     GdkWindow *window = gtk_widget_get_window (drawing_area);
 
     text = pango_language_get_sample_string(NULL);
@@ -192,8 +193,11 @@ create_text_pixmap(GtkWidget *drawing_area, FT_Face face)
 			    pixmap_width, pixmap_height, -1);
     if (!pixmap)
 	goto end;
-    gdk_draw_rectangle(pixmap, gtk_widget_get_style(drawing_area)->white_gc,
-		       TRUE, 0, 0, pixmap_width, pixmap_height);
+    
+    cr = gdk_cairo_create (pixmap);
+    cairo_set_source_rgb (cr, 1, 1, 1);
+    cairo_paint (cr);
+    cairo_destroy (cr);
 
     xdrawable = GDK_DRAWABLE_XID(pixmap);
     draw = XftDrawCreate(xdisplay, xdrawable, xvisual, xcolormap);
@@ -376,12 +380,16 @@ add_face_info(GtkWidget *table, gint *row_p, const gchar *uri, FT_Face face)
 static gboolean
 expose_event(GtkWidget *widget, GdkEventExpose *event, GdkPixmap *pixmap)
 {
-    gdk_draw_drawable(gtk_widget_get_window (widget),
-		      gtk_widget_get_style (widget)->fg_gc[gtk_widget_get_state (widget)],
-		      pixmap,
-		      event->area.x, event->area.y,
-		      event->area.x, event->area.y,
-		      event->area.width, event->area.height);
+    cairo_t *cr;
+
+    cr = gdk_cairo_create (gtk_widget_get_window (widget));
+
+    gdk_cairo_set_source_pixmap (cr, pixmap, 0, 0);
+    gdk_cairo_region (cr, event->region);
+    cairo_fill (cr);
+
+    cairo_destroy (cr);
+
     return FALSE;
 }
 
@@ -505,7 +513,6 @@ main(int argc, char **argv)
     gchar *font_file, *title;
     gint row;
     GtkWidget *window, *hbox, *table, *swin, *drawing_area;
-    GdkPixmap *pixmap;
     GdkColor white = { 0, 0xffff, 0xffff, 0xffff };
     GtkWidget *button, *align;
 
@@ -567,7 +574,7 @@ main(int argc, char **argv)
     gtk_widget_modify_bg(drawing_area, GTK_STATE_NORMAL, &white);
     gtk_scrolled_window_add_with_viewport(GTK_SCROLLED_WINDOW(swin),
 					  drawing_area);
-    g_signal_connect (drawing_area, "realize", create_text_pixmap, face);
+    g_signal_connect (drawing_area, "realize", G_CALLBACK (create_text_pixmap), face);
 
     /* set the minimum size on the scrolled window to prevent
      * unnecessary scrolling */
diff --git a/panels/display/scrollarea.c b/panels/display/scrollarea.c
index 26b7d84..eab52d6 100644
--- a/panels/display/scrollarea.c
+++ b/panels/display/scrollarea.c
@@ -486,23 +486,6 @@ clip_to_region (cairo_t *cr, cairo_region_t *region)
     cairo_clip (cr);
 }
 
-static void
-simple_draw_drawable (GdkDrawable *dst,
-		      GdkDrawable *src,
-		      int	   src_x,
-		      int	   src_y,
-		      int          dst_x,
-		      int          dst_y,
-		      int          width,
-		      int          height)
-{
-    GdkGC *gc = gdk_gc_new (dst);
-
-    gdk_draw_drawable (dst, gc, src, src_x, src_y, dst_x, dst_y, width, height);
-
-    g_object_unref (gc);
-}
-
 static gboolean
 foo_scroll_area_expose (GtkWidget *widget,
 			GdkEventExpose *expose)
@@ -512,7 +495,6 @@ foo_scroll_area_expose (GtkWidget *widget,
     GdkRectangle extents;
     cairo_region_t *region;
     int x_offset, y_offset;
-    GdkGC *gc;
     GtkAllocation widget_allocation;
     GdkWindow *window = gtk_widget_get_window (widget);
 
@@ -563,17 +545,16 @@ foo_scroll_area_expose (GtkWidget *widget,
     scroll_area->priv->expose_region = NULL;
     scroll_area->priv->current_input = NULL;
 
-    /* Finally draw the backing pixmap */
-    gc = gdk_gc_new (window);
-
-    gdk_gc_set_clip_region (gc, expose->region);
-
     gtk_widget_get_allocation (widget, &widget_allocation);
-    gdk_draw_drawable (window, gc, scroll_area->priv->pixmap,
-		       0, 0, widget_allocation.x, widget_allocation.y,
-		       widget_allocation.width, widget_allocation.height);
 
-    g_object_unref (gc);
+    /* Finally draw the backing pixmap */
+    cr = gdk_cairo_create (window);
+    gdk_cairo_set_source_pixmap (cr, scroll_area->priv->pixmap,
+                                 widget_allocation.x, widget_allocation.y);
+    gdk_cairo_region (cr, expose->region);
+    cairo_fill (cr);
+    cairo_destroy (cr);
+
     cairo_region_destroy (region);
     
     return TRUE;
@@ -727,6 +708,7 @@ create_new_pixmap (GtkWidget *widget,
 {
     GtkAllocation widget_allocation;
     GdkPixmap *new;
+    cairo_t *cr;
 
     gtk_widget_get_allocation (widget, &widget_allocation);
     new = gdk_pixmap_new (gtk_widget_get_window (widget),
@@ -741,7 +723,11 @@ create_new_pixmap (GtkWidget *widget,
      * That might just work, actually. We need to make sure metacity uses
      * static gravity for the window before this will be useful.
      */
-    simple_draw_drawable (new, old, 0, 0, 0, 0, -1, -1);
+    cr = gdk_cairo_create (new);
+    cairo_set_operator (cr, CAIRO_OPERATOR_SOURCE);
+    gdk_cairo_set_source_pixmap (cr, old, 0, 0);
+    cairo_paint (cr);
+    cairo_destroy (cr);
 
     return new;
 }
@@ -1150,6 +1136,7 @@ foo_scroll_area_scroll (FooScrollArea *area,
     if (gdk_rectangle_intersect (&allocation, &src_area, &move_area))
     {
 	cairo_region_t *move_region;
+        cairo_t *cr;
 
 #if 0
 	g_print ("scrolling %d %d %d %d (%d %d)\n",
@@ -1157,11 +1144,25 @@ foo_scroll_area_scroll (FooScrollArea *area,
 		 move_area.width, move_area.height,
 		 dx, dy);
 #endif
-	
-	simple_draw_drawable (area->priv->pixmap, area->priv->pixmap,
-			      move_area.x, move_area.y,
-			      move_area.x + dx, move_area.y + dy,
-			      move_area.width, move_area.height);
+	cr = gdk_cairo_create (area->priv->pixmap);
+
+        /* Cairo doesn't allow self-copies, so we do this little trick instead:
+         * 1) Clip so the group size is small.
+         * 2) Call push_group() which creates a temporary pixmap as a workaround
+         */
+        gdk_cairo_rectangle (cr, &move_area);
+        cairo_clip (cr);
+        cairo_push_group (cr);
+        
+        gdk_cairo_set_source_pixmap (cr, area->priv->pixmap, dx, dy);
+        gdk_cairo_rectangle (cr, &move_area);
+        cairo_fill (cr);
+
+        cairo_pop_group_to_source (cr);
+        cairo_paint (cr);
+
+        cairo_destroy (cr);
+
 	gtk_widget_queue_draw (GTK_WIDGET (area));
 	
 	move_region = cairo_region_create_rectangle (&move_area);
diff --git a/typing-break/drw-break-window.c b/typing-break/drw-break-window.c
index 8372c4d..aaebf74 100644
--- a/typing-break/drw-break-window.c
+++ b/typing-break/drw-break-window.c
@@ -588,34 +588,31 @@ label_expose_event_cb (GtkLabel       *label,
 		       GdkEventExpose *event,
 		       gpointer        user_data)
 {
-	gint       x, y;
-	GdkColor   color;
-	GtkWidget *widget;
-	GdkWindow *window;
-	GdkGC     *gc;
-
-	color.red = 0;
-	color.green = 0;
-	color.blue = 0;
-	color.pixel = 0;
+	gint             x, y;
+	GtkWidget       *widget;
+	GdkWindow       *window;
+        cairo_t         *cr;
 
 	get_layout_location (label, &x, &y);
 
 	widget = GTK_WIDGET (label);
 	window = gtk_widget_get_window (widget);
 
-	gc = gdk_gc_new (window);
-	gdk_gc_set_rgb_fg_color (gc, &color);
-	gdk_gc_set_clip_rectangle (gc, &event->area);
-
-	gdk_draw_layout_with_colors (window,
-				     gc,
-				     x + 1,
-				     y + 1,
-				     gtk_label_get_layout (label),
-				     &color,
-				     NULL);
-	g_object_unref (gc);
+        cr = gdk_cairo_create (window);
+
+        gdk_cairo_rectangle (cr, &event->area);
+        cairo_clip (cr);
+
+        cairo_set_source_rgb (cr, 0, 0, 0);
+
+        /* Can't use pango_cairo_show_layout() here as we need to override
+         * the layout's colors with our shadow color.
+         */
+        cairo_move_to (cr, x + 1, y + 1);
+        pango_cairo_layout_path (cr, gtk_label_get_layout (label));
+        cairo_fill (cr);
+
+        cairo_destroy (cr);
 
 	gtk_paint_layout (gtk_widget_get_style (widget),
 			  window,
diff --git a/typing-break/drw-utils.c b/typing-break/drw-utils.c
index ff19f74..73eee36 100644
--- a/typing-break/drw-utils.c
+++ b/typing-break/drw-utils.c
@@ -150,6 +150,7 @@ set_pixmap_background (GtkWidget *window)
 	GdkRectangle  rect;
 	GdkColor      color;
 	gint          width, height;
+        cairo_t      *cr;
 
 	gtk_widget_realize (window);
 
@@ -205,18 +206,10 @@ set_pixmap_background (GtkWidget *window)
 				 height,
 				 -1);
 
-	gdk_draw_pixbuf (pixmap,
-                         NULL, 
-                         tmp_pixbuf,
-                         0,
-                         0,
-                         0,
-                         0,
-                         width,
-                         height,
-                         GDK_RGB_DITHER_NONE,
-                         0,
-                         0);
+        cr = gdk_cairo_create (pixmap);
+        gdk_cairo_set_source_pixbuf (cr, tmp_pixbuf, 0, 0);
+        cairo_paint (cr);
+        cairo_destroy (cr);
 
 	g_object_unref (tmp_pixbuf);