Merge pull request #791 from gpodder/gnome3-header-bar-csd

Gtk UI: Add support for GtkHeaderBar / GNOME3 CSDs

share/gpodder/ui/gtk/gpodder.ui

@@ -218,6 +218,7 @@
                           <object class="GtkGrid" id="vbox42">
                             <property name="visible">True</property>
                             <property name="orientation">vertical</property>
+                            <property name="hexpand">True</property>
                             <child>
                               <object class="GtkButton" id="btnUpdateFeeds">
                                 <property name="label" translatable="yes">Check for new episodes</property>

src/gpodder/gtkui/app.py

@@ -80,6 +80,10 @@ class gPodderApplication(Gtk.Application):
         action.connect('activate', self.on_check_for_updates_activate)
         self.add_action(action)
 
+        action = Gio.SimpleAction.new('menu', None)
+        action.connect('activate', self.on_menu)
+        self.add_action(action)
+
     def do_startup(self):
         Gtk.Application.do_startup(self)
 
@@ -102,7 +106,29 @@ class gPodderApplication(Gtk.Application):
         self.menu_view_columns = builder.get_object('menuViewColumns')
         self.set_menubar(menubar)
 
-        self.set_app_menu(builder.get_object('app-menu'))
+        # If $XDG_CURRENT_DESKTOP is set then it contains a colon-separated list of strings.
+        # https://specifications.freedesktop.org/desktop-entry-spec/desktop-entry-spec-latest.html
+        # See https://askubuntu.com/a/227669 for a list of values in different environments
+        xdg_current_desktops = os.environ.get('XDG_CURRENT_DESKTOP', '').split(':')
+        # See https://developer.gnome.org/gtk3/stable/gtk-running.html
+        # GTK_CSD=0 is used to disable client side decorations
+        csd_disabled = os.environ.get('GTK_CSD') == '0'
+
+        self.want_headerbar = ('GNOME' in xdg_current_desktops) and not gpodder.ui.osx and not csd_disabled
+
+        self.app_menu = builder.get_object('app-menu')
+        if self.want_headerbar:
+            # Use GtkHeaderBar for client-side decorations on recent GNOME 3 versions
+            self.header_bar_menu_button = Gtk.Button.new_from_icon_name('open-menu-symbolic', Gtk.IconSize.SMALL_TOOLBAR)
+            self.header_bar_menu_button.set_action_name('app.menu')
+
+            self.header_bar_refresh_button = Gtk.Button.new_from_icon_name('view-refresh-symbolic', Gtk.IconSize.SMALL_TOOLBAR)
+            self.header_bar_refresh_button.set_action_name('win.updateChannel')
+
+            self.menu_popover = Gtk.Popover.new_from_model(self.header_bar_menu_button, self.app_menu)
+            self.menu_popover.set_position(Gtk.PositionType.BOTTOM)
+        else:
+            self.set_app_menu(self.app_menu)
 
         Gtk.Window.set_default_icon_name('gpodder')
 
@@ -137,6 +163,9 @@ class gPodderApplication(Gtk.Application):
 
         self.window.gPodder.present()
 
+    def on_menu(self, action, param):
+        self.menu_popover.popup()
+
     def on_about(self, action, param):
         dlg = Gtk.Dialog(_('About gPodder'), self.window.gPodder,
                 Gtk.DialogFlags.MODAL)

src/gpodder/gtkui/main.py

@@ -89,6 +89,18 @@ class gPodder(BuilderWidget, dbus.service.Object):
         BuilderWidget.__init__(self, None, _builder_expose={'app': app})
 
     def new(self):
+        if self.application.want_headerbar:
+            self.header_bar = Gtk.HeaderBar()
+            self.header_bar.pack_end(self.application.header_bar_menu_button)
+            self.header_bar.pack_start(self.application.header_bar_refresh_button)
+            self.header_bar.set_show_close_button(True)
+            self.header_bar.show_all()
+
+            # Tweaks to the UI since we moved the refresh button into the header bar
+            self.vboxChannelNavigator.set_row_spacing(0)
+
+            self.main_window.set_titlebar(self.header_bar)
+
         gpodder.user_extensions.on_ui_object_available('gpodder-gtk', self)
         self.toolbar.set_property('visible', self.config.show_toolbar)
 
@@ -197,7 +209,8 @@ class gPodder(BuilderWidget, dbus.service.Object):
         util.run_in_background(self.user_apps_reader.read)
 
         # Now, update the feed cache, when everything's in place
-        self.btnUpdateFeeds.show()
+        if not self.application.want_headerbar:
+            self.btnUpdateFeeds.show()
         self.feed_cache_update_cancelled = False
         self.update_podcast_list_model()
 
@@ -2523,7 +2536,8 @@ class gPodder(BuilderWidget, dbus.service.Object):
         # Make sure that the buttons for updating feeds
         # appear - this should happen after a feed update
         self.hboxUpdateFeeds.hide()
-        self.btnUpdateFeeds.show()
+        if not self.application.want_headerbar:
+            self.btnUpdateFeeds.show()
         self.update_action.set_enabled(True)
         self.update_channel_action.set_enabled(True)