Added basic system tray icon and associated functionality

Application is not closed when the main window's X button is clicked, it's hidden instead, it can be displayed
again by clicking in the system tray icon or choosing 'Show' from the context menu.

This functionality is only available if the system tray is available (as reported by Qt) and if
the desktop environment is not Unity, since the system tray replacement it ships with doesn't work.

blink/__init__.py

@@ -108,6 +108,10 @@ class Blink(QApplication):
         self.log_manager = LogManager()
         self.presence_manager = PresenceManager()
 
+        # Prevent application from exiting after last window is closed if system tray was initialized
+        if self.main_window.system_tray_icon:
+            self.setQuitOnLastWindowClosed(False)
+
         self.update_manager = UpdateManager()
         self.main_window.check_for_updates_action.triggered.connect(self.update_manager.check_for_updates)
         self.main_window.check_for_updates_action.setVisible(self.update_manager != Null)

blink/mainwindow.py

@@ -10,8 +10,8 @@ from functools import partial
 
 from PyQt4 import uic
 from PyQt4.QtCore import Qt, QSettings, QUrl
-from PyQt4.QtGui  import QAction, QActionGroup, QDesktopServices, QShortcut
-from PyQt4.QtGui  import QFileDialog, QIcon, QStyle, QStyleOptionComboBox, QStyleOptionFrameV2
+from PyQt4.QtGui  import QAction, QActionGroup, QDesktopServices, QMenu, QShortcut
+from PyQt4.QtGui  import QFileDialog, QIcon, QStyle, QStyleOptionComboBox, QStyleOptionFrameV2, QSystemTrayIcon
 
 from application.notification import IObserver, NotificationCenter
 from application.python import Null, limit
@@ -86,6 +86,18 @@ class MainWindow(base_class, ui_class):
         self.contacts_view.setCurrentWidget(self.contact_list_panel)
         self.search_view.setCurrentWidget(self.search_list_panel)
 
+        # System tray
+        if QSystemTrayIcon.isSystemTrayAvailable() and not os.getenv('XDG_CURRENT_DESKTOP', '').lower().startswith('unity'):
+            self.system_tray_icon = QSystemTrayIcon(QIcon(Resources.get('icons/blink.png')), self)
+            self.system_tray_icon.activated.connect(self._SH_SystemTrayIconActivated)
+            menu = QMenu(self)
+            menu.addAction(QAction("Show", self, triggered=self._AH_SystemTrayShowWindow))
+            menu.addAction(QAction(QIcon(Resources.get('icons/application-exit.png')), "Quit", self, triggered=self._AH_QuitActionTriggered))
+            self.system_tray_icon.setContextMenu(menu)
+            self.system_tray_icon.show()
+        else:
+            self.system_tray_icon = None
+
         # Accounts
         self.account_model = AccountModel(self)
         self.enabled_account_model = ActiveAccountModel(self.account_model, self)
@@ -160,7 +172,7 @@ class MainWindow(base_class, ui_class):
         self.auto_accept_chat_action.triggered.connect(self._AH_AutoAcceptChatTriggered)
         self.auto_accept_files_action.triggered.connect(self._AH_AutoAcceptFilesTriggered)
         self.release_notes_action.triggered.connect(partial(QDesktopServices.openUrl, QUrl(u'http://icanblink.com/changelog-qt.phtml')))
-        self.quit_action.triggered.connect(self.close)
+        self.quit_action.triggered.connect(self._AH_QuitActionTriggered)
 
         # Call menu actions
         self.redial_action.triggered.connect(self._AH_RedialActionTriggered)
@@ -367,6 +379,19 @@ class MainWindow(base_class, ui_class):
             account = None
         session_manager.start_call(None, action.entry.target_uri, account=account)
 
+    def _AH_SystemTrayShowWindow(self, checked):
+        self.show()
+        self.raise_()
+        self.activateWindow()
+
+    def _AH_QuitActionTriggered(self, checked):
+        self.close()
+        if self.system_tray_icon is not None:
+            self.system_tray_icon.hide()
+            from blink import Blink
+            blink = Blink()
+            blink.quit()
+
     def _SH_AccountStateChanged(self):
         self.activity_note.setText(self.account_state.note)
         if self.account_state.state is AccountState.Invisible:
@@ -592,6 +617,12 @@ class MainWindow(base_class, ui_class):
     def _SH_PendingWatcherDialogFinished(self, dialog, code):
         self.pending_watcher_dialogs.remove(dialog)
 
+    def _SH_SystemTrayIconActivated(self, reason):
+        if reason == QSystemTrayIcon.Trigger:
+            self.show()
+            self.raise_()
+            self.activateWindow()
+
     @run_in_gui_thread
     def handle_notification(self, notification):
         handler = getattr(self, '_NH_%s' % notification.name, Null)