Convert the imagebox to the new layout system

Signed-off-by: Uli Schlachter <psychon@znc.in>

lib/wibox/widget/imagebox.lua

@@ -20,8 +20,6 @@ function imagebox:draw(context, cr, width, height)
     if not self._image then return end
     if width == 0 or height == 0 then return end
 
-    cr:save()
-
     if not self.resize_forbidden then
         -- Let's scale the image so that it fits into (width, height)
         local w = self._image:get_width()
@@ -34,8 +32,6 @@ function imagebox:draw(context, cr, width, height)
     end
     cr:set_source_surface(self._image, 0, 0)
     cr:paint()
-
-    cr:restore()
 end
 
 --- Fit the imagebox into the given geometry
@@ -101,7 +97,8 @@ function imagebox:set_image(image)
 
     self._image = image
 
-    self:emit_signal("widget::updated")
+    self:emit_signal("widget::redraw_needed")
+    self:emit_signal("widget::layout_changed")
     return true
 end
 
@@ -110,7 +107,8 @@ end
 --                to fit into the available space.
 function imagebox:set_resize(allowed)
     self.resize_forbidden = not allowed
-    self:emit_signal("widget::updated")
+    self:emit_signal("widget::redraw_needed")
+    self:emit_signal("widget::layout_changed")
 end
 
 --- Returns a new imagebox