notification: keep track of shown notifications

Currently notifications shown so far are not tracked, thus often it
happens that multiple notifications regarding the same topic appear,
where only one should be shown. The change adds tracking of
notifications being shown within the Notification class.

Notifications cleared by user will be re-shown if device pushes them
again.

src/notification.vala

@@ -17,17 +17,20 @@
  * AUTHORS
  * Maciek Borzecki <maciek.borzecki (at] gmail.com>
  */
+using Gee;
 
 class NotificationHandler : Object, PacketHandlerInterface {
 
 	private const string  NOTIFICATION = "kdeconnect.notification";
 
+	private HashMap<string, Notify.Notification> _pending_notifications;
+
 	public string get_pkt_type() {
 		return NOTIFICATION;
 	}
 
 	private NotificationHandler() {
-
+		_pending_notifications = new HashMap<string, Notify.Notification>();
 	}
 
 	public static NotificationHandler instance() {
@@ -52,15 +55,41 @@ class NotificationHandler : Object, PacketHandlerInterface {
 		if (id.match_string("com.android.dialer", false) == true)
 			return;
 
-		// other notifications
-		if (pkt.body.has_member("appName") == false ||
-			pkt.body.has_member("ticker") == false)
-			return;
-
 		// maybe it's a notification about a notification being
 		// cancelled
 		if (pkt.body.has_member("isCancel") == true &&
 			pkt.body.get_boolean_member("isCancel") == true)
+		{
+			debug("message cancels notification %s", id);
+			if (_pending_notifications.has_key(id) == true)
+			{
+				// cancel out pending notifications
+				Notify.Notification notif = _pending_notifications.@get(id);
+				if (notif != null)
+				{
+					_pending_notifications.unset(id);
+					try {
+						notif.close();
+					} catch (Error e) {
+						critical("error closing notification: %s", e.message);
+					}
+				}
+			}
+			return;
+		}
+
+		// check if notification is already known, if so don't show
+		// anything
+		if (_pending_notifications.has_key(id) == true)
+		{
+			debug("notification %s is known, ignore", id);
+			return;
+		}
+		debug("new notification %s", id);
+
+		// other notifications
+		if (pkt.body.has_member("appName") == false ||
+			pkt.body.has_member("ticker") == false)
 			return;
 
 		string app = pkt.body.get_string_member("appName");
@@ -81,6 +110,8 @@ class NotificationHandler : Object, PacketHandlerInterface {
 		} else {
 			time = new DateTime.now_local();
 		}
+		// format the body of notification, so that a time information
+		// is included
 		if (time != null)
 			ticker = "%s %s".printf(time.format("%X"),
 									ticker);
@@ -90,9 +121,22 @@ class NotificationHandler : Object, PacketHandlerInterface {
 		var notif = new Notify.Notification(app, ticker,
 											"phone");
 		try {
+			// react to closed signal
+			notif.closed.connect((n) => {
+					this.handle_closed_notification(id);
+				});
 			notif.show();
+			_pending_notifications.@set(id, notif);
 		} catch (Error e) {
 			critical("failed to show notification: %s", e.message);
 		}
 	}
+
+	private void handle_closed_notification(string id) {
+		debug("notification %s closed by user", id);
+		if (_pending_notifications.has_key(id) == true)
+		{
+			_pending_notifications.unset(id);
+		}
+	}
 }