Added an option to set the background color of CanvasIcon. Then a RGB cache can be used.

src/sugar/graphics/icon.py

@@ -83,6 +83,7 @@ class _IconBuffer(object):
         self.icon_size = None
         self.file_name = None
         self.fill_color = None
+        self.background_color = None
         self.stroke_color = None
         self.badge_name = None
         self.width = None
@@ -91,9 +92,14 @@ class _IconBuffer(object):
         self.scale = 1.0
 
     def _get_cache_key(self, sensitive):
+        if self.background_color is None:
+            color = None
+        else:
+            color = (self.background_color.red, self.background_color.green,
+                     self.background_color.blue)
         return (self.icon_name, self.file_name, self.fill_color,
                 self.stroke_color, self.badge_name, self.width, self.height,
-                sensitive)
+                color, sensitive)
 
     def _load_svg(self, file_name):
         entities = {}
@@ -260,9 +266,16 @@ class _IconBuffer(object):
 
         padding = badge_info.icon_padding
         width, height = self._get_size(icon_width, icon_height, padding)
+        if self.background_color is None:
             surface = cairo.ImageSurface(cairo.FORMAT_ARGB32, width, height)
-
             context = cairo.Context(surface)
+        else:
+            surface = cairo.ImageSurface(cairo.FORMAT_RGB24, width, height)
+            context = cairo.Context(surface)
+            context = gtk.gdk.CairoContext(context)
+            context.set_source_color(self.background_color)
+            context.paint()
+
         context.scale(float(width) / (icon_width + padding * 2),
                       float(height) / (icon_height + padding * 2))
         context.save()
@@ -499,6 +512,18 @@ class CanvasIcon(hippo.CanvasBox, hippo.CanvasItem):
 
         self.connect('destroy', self.__destroy_cb)
 
+    def _emit_paint_needed_icon_area(self):
+        surface = self._buffer.get_surface()
+        if surface:
+            width, height = self.get_allocation()
+            s_width = surface.get_width()
+            s_height = surface.get_height()
+
+            x = (width - s_width) / 2
+            y = (height - s_height) / 2
+
+            self.emit_paint_needed(x, y, s_width, s_height)
+
     def __destroy_cb(self, icon):
         if self._palette_invoker is not None:
             self._palette_invoker.detach()
@@ -580,7 +605,7 @@ class CanvasIcon(hippo.CanvasBox, hippo.CanvasItem):
         """
         if self._buffer.xo_color != value:
             self._buffer.xo_color = value
-            self.emit_paint_needed(0, 0, -1, -1)
+            self._emit_paint_needed_icon_area()
 
     xo_color = gobject.property(
         type=object, getter=None, setter=set_xo_color)
@@ -598,7 +623,7 @@ class CanvasIcon(hippo.CanvasBox, hippo.CanvasItem):
         """
         if self._buffer.fill_color != value:
             self._buffer.fill_color = value
-            self.emit_paint_needed(0, 0, -1, -1)
+            self._emit_paint_needed_icon_area()
 
     def get_fill_color(self):
         """
@@ -629,7 +654,7 @@ class CanvasIcon(hippo.CanvasBox, hippo.CanvasItem):
         """
         if self._buffer.stroke_color != value:
             self._buffer.stroke_color = value
-            self.emit_paint_needed(0, 0, -1, -1)
+            self._emit_paint_needed_icon_area()
 
     def get_stroke_color(self):
         """
@@ -647,6 +672,37 @@ class CanvasIcon(hippo.CanvasBox, hippo.CanvasItem):
     stroke_color = gobject.property(
         type=object, getter=get_stroke_color, setter=set_stroke_color)
 
+    def set_background_color(self, value):
+        """
+        Parameters
+        ----------
+        value:
+
+        Returns
+        -------
+        None
+
+        """
+        if self._buffer.background_color != value:
+            self._buffer.background_color = value
+            self.emit_paint_needed(0, 0, -1, -1)
+
+    def get_background_color(self):
+        """
+        Parameters
+        ----------
+        None
+
+        Returns
+        -------
+        fill color :
+
+        """
+        return self._buffer.background_color
+
+    background_color = gobject.property(
+        type=object, getter=get_background_color, setter=set_background_color)
+
     def set_size(self, value):
         """
         Parameters