Implement Basic FreeDesktop icon support

lib/pystray/_appindicator.py

@@ -35,6 +35,7 @@ def __init__(self, *args, **kwargs):
         super(Icon, self).__init__(*args, **kwargs)
 
         self._appindicator = None
+        self._uses_freedesktop_icon_name = True
 
         if self.icon:
             self._update_icon()
@@ -47,7 +48,7 @@ def _show(self):
             AppIndicator.IndicatorCategory.APPLICATION_STATUS)
 
         self._appindicator.set_status(AppIndicator.IndicatorStatus.ACTIVE)
-        self._appindicator.set_icon(self._icon_path)
+        self._appindicator.set_icon(self._freedesktop_icon_name or self._icon_path)
         self._appindicator.set_menu(
             self._menu_handle or self._create_default_menu())
 
@@ -60,7 +61,7 @@ def _update_icon(self):
         self._remove_fs_icon()
         self._update_fs_icon()
         if self._appindicator:
-            self._appindicator.set_icon(self._icon_path)
+            self._appindicator.set_icon(self._freedesktop_icon_name or self._icon_path)
 
     @mainloop
     def _update_title(self):

lib/pystray/_base.py

@@ -35,6 +35,9 @@ class Icon(object):
     :param icon: The icon to use. If this is specified, it must be a
         :class:`PIL.Image.Image` instance.
 
+    :param str freedesktop_icon_name: An available icon_name as specified by
+    the FreeDesktop Icon Theme specification, used with compatible modules.
+
     :param str title: A short title for the icon.
 
     :param menu: A menu to use as popup menu. This can be either an instance of
@@ -67,13 +70,16 @@ class Icon(object):
     HAS_NOTIFICATION = True
 
     def __init__(
-            self, name, icon=None, title=None, menu=None):
+            self, name, icon=None, freedesktop_icon_name=None, 
+            title=None, menu=None):
         self._name = name
         self._icon = icon or None
+        self._freedesktop_icon_name = freedesktop_icon_name or None
         self._title = title or ''
         self._menu = menu
         self._visible = False
         self._icon_valid = False
+        self._uses_freedesktop_icon_name = False
         self._log = logging.getLogger(__name__)
 
         self._running = False
@@ -114,6 +120,27 @@ def icon(self, value):
             if self.visible:
                 self.visible = False
 
+    @property
+    def freedesktop_icon_name(self):
+        """The current FreeDesktop icon_name.
+
+        Setting this to a falsy value will fall back to `icon` or hide the icon
+        if no `icon` is present. Setting this to an icon_name while the icon 
+        is hidden has no effect until the icon is shown.
+        """
+        return self._freedesktop_icon_name
+
+    @freedesktop_icon_name.setter
+    def freedesktop_icon_name(self, value):
+        self._freedesktop_icon_name = value
+        self._icon_valid = False
+        if value:
+            if self.visible and self._uses_freedesktop_icon_name:
+                self._update_icon()
+        else:
+            if self.visible:
+                self.visible = False
+
     @property
     def title(self):
         """The current icon title.

lib/pystray/_gtk.py

@@ -45,7 +45,10 @@ def _hide(self):
     def _update_icon(self):
         self._remove_fs_icon()
         self._update_fs_icon()
-        self._status_icon.set_from_file(self._icon_path)
+        if self._freedesktop_icon_name:
+            self._status_icon.set_from_icon_name(self.freedesktop_icon_name)
+        else:
+            self._status_icon.set_from_file(self._icon_path)
 
     @mainloop
     def _update_menu(self):