Handle failed device grabs and retry lock

LockWindow.py

@@ -42,6 +42,7 @@ class LockWindow(Gtk.Window):
 
         self.display = Gdk.Display.get_default()
         self.screen = self.display.get_default_screen()
+        self.devicesGrabbed = False
 
         self.overlay = Gtk.Overlay()
         self.add(self.overlay)
@@ -135,22 +136,33 @@ class LockWindow(Gtk.Window):
     def _grabDevices(self, w, e):
         self.promptEntry.grab_focus()
 
+        if not self.devicesGrabbed:
             for device in self.deviceManager.list_devices(Gdk.DeviceType.MASTER):
-            device.grab(self.get_window(), Gdk.GrabOwnership.APPLICATION, True, Gdk.EventMask.ALL_EVENTS_MASK, None, Gdk.CURRENT_TIME)
+                if device.grab(self.get_window(), Gdk.GrabOwnership.APPLICATION, True, Gdk.EventMask.ALL_EVENTS_MASK, None, Gdk.CURRENT_TIME) != Gdk.GrabStatus.SUCCESS:
+                    self._ungrabDevices()
+                    self.get_window().lower()
+                    return False
 
         self.present()
 
+        self.devicesGrabbed = True
+
         return False
 
     def _ungrabDevices(self):
         for device in self.deviceManager.list_devices(Gdk.DeviceType.MASTER):
             device.ungrab(Gdk.CURRENT_TIME)
+        self.devicesGrabbed = False
 
     def lock(self):
         self.show_all()
+        self.display.sync()
+        self._grabDevices(self, None)
+        return self.devicesGrabbed
 
     def unlock(self):
         self._ungrabDevices()
 
         self.hide()
+
         self.reset(False, True)

Locker.py

@@ -66,7 +66,10 @@ class Locker(object):
     def lock(self):
         if not self.locked:
             self.locked = True
-            self.doLock(self.logoutTimeout)
+            if not self.doLock(self.logoutTimeout):
+                self.locked = False
+                GLib.timeout_add_seconds(1, self._checkLock)
+                return False
 
             if self.doLogout is not None:
                 self.currentLogoutTimeout = self.logoutTimeout
@@ -74,6 +77,8 @@ class Locker(object):
                 if self.currentLogoutTimeout > 0:
                     GLib.timeout_add_seconds(1, self._checkLogout)
 
+        return True
+
     def unlock(self):
         if self.locked:
             self.doUnlock()

pylock.py

@@ -91,7 +91,7 @@ if not Message.acquireSelection(window):
 
 def lock(timeLeft):
     window.updateLockMessage(args.username, timeLeft)
-    window.lock()
+    return window.lock()
 
 def logout():
     try: