Make icon_name api consistent between the different toolbuttons

As discused in the mailing list [1] the api to set the icon in sugar
ToolButton, RadioToolButton and ToggleToolButton is inconsistent,
and with the port to GTK+ 3 the differences are visible (SL #3849).

This patch changes the API of ToolButton, RadioToolButton and
ToggleToolButton to override the icon-name property and add an
Icon instance with the set_icon_widget method.

Signed-off-by: Gonzalo Odiard <gonzalo@laptop.org>
Acked-by: Simon Schampijer <simon@laptop.org>

[1] http://lists.sugarlabs.org/archive/sugar-devel/2012-September/039624.html

src/sugar3/graphics/radiotoolbutton.py

@@ -36,7 +36,7 @@ class RadioToolButton(Gtk.RadioToolButton):
 
     __gtype_name__ = 'SugarRadioToolButton'
 
-    def __init__(self, **kwargs):
+    def __init__(self, icon_name=None, **kwargs):
         self._accelerator = None
         self._tooltip = None
         self._xo_color = None
@@ -46,6 +46,9 @@ class RadioToolButton(Gtk.RadioToolButton):
 
         self._palette_invoker.attach_tool(self)
 
+        if icon_name:
+            self.set_icon_name(icon_name)
+
         self.connect('destroy', self.__destroy_cb)
 
     def __destroy_cb(self, icon):
@@ -115,21 +118,13 @@ class RadioToolButton(Gtk.RadioToolButton):
     accelerator = GObject.property(type=str, setter=set_accelerator,
             getter=get_accelerator)
 
-    def set_named_icon(self, named_icon):
-        icon = Icon(icon_name=named_icon,
-                    xo_color=self._xo_color,
-                    icon_size=Gtk.IconSize.LARGE_TOOLBAR)
+    def set_icon_name(self, icon_name):
+        icon = Icon(icon_name=icon_name,
+                    xo_color=self._xo_color)
         self.set_icon_widget(icon)
         icon.show()
 
-    def get_named_icon(self):
-        if self.props.icon_widget is not None:
-            return self.props.icon_widget.props.icon_name
-        else:
-            return None
-
-    named_icon = GObject.property(type=str, setter=set_named_icon,
-                                  getter=get_named_icon)
+    icon_name = GObject.property(type=str, setter=set_icon_name)
 
     def set_xo_color(self, xo_color):
         if self._xo_color != xo_color: