use cache for async tracker images

deluge/tracker_icons.py

@@ -89,16 +89,22 @@ class TrackerIcons(object):
             gobject.idle_add(callback, filename)
 
     def get_async(self, tracker_host, callback):
-        threading.Thread(
-            target=self. _fetch_icon_thread,
-            args=(tracker_host, callback)).start()
+        if tracker_host in self.images:
+            if callback:
+                callback(self.images[tracker_host])
+        else:
+            threading.Thread(target=self. _fetch_icon_thread,
+                args=(tracker_host, callback)).start()
 
     def  get(self, tracker_host):
         """
         returns None if the icon is not fetched(yet) or not fond.
         """
-        if not tracker_host in self.images:
+        if tracker_host in self.images:
+            return self.images[tracker_host]
+        else:
             self.images[tracker_host] = None
             self.get_async(tracker_host, None)
-        return self.images[tracker_host]
+            return None
+
 

deluge/ui/gtkui/filtertreeview.py

@@ -193,6 +193,10 @@ class FilterTreeView(component.Component):
                 label = _(value)
             row = self.treestore.append(self.cat_nodes[cat],[cat, value, label, count , pix, True])
             self.filters[(cat, value)] = row
+
+            if cat == "tracker_host":
+                self.tracker_icons.get_async(value, lambda filename: self.set_row_image(cat, value, filename))
+
         self.treestore.set_value(row, FILTER_COLUMN, True)
         return row
 
@@ -230,9 +234,6 @@ class FilterTreeView(component.Component):
             pix = STATE_PIX.get(value, "dht")
             return gtk.gdk.pixbuf_new_from_file(deluge.common.get_pixmap("%s16.png" % pix))
 
-        elif cat == "tracker_host":
-            self.tracker_icons.get_async(value, lambda filename: self.set_row_image(cat, value, filename))
-
         return None
 
     def set_row_image(self, cat, value, filename):