[geary/wip/766133-gnotification: 8/15] Allow Notifications.Desktop to cancel its async tasks

[Michael Gratton <mjog src gnome org>]

commit 3701aa0c302e58af91b3ee531a5e7fad67a21055
Author: Michael Gratton <mike vee net>
Date:   Sat Apr 13 11:45:02 2019 +1000

    Allow Notifications.Desktop to cancel its async tasks
    
    Pass a cancellable when constructed and use that for async tasks.

 src/client/application/geary-controller.vala      |  3 ++-
 src/client/notification/notification-desktop.vala | 20 +++++++++++++-------
 2 files changed, 15 insertions(+), 8 deletions(-)
---
diff --git a/src/client/application/geary-controller.vala b/src/client/application/geary-controller.vala
index 7ff8f29b..cf75af46 100644
--- a/src/client/application/geary-controller.vala
+++ b/src/client/application/geary-controller.vala
@@ -331,7 +331,8 @@ public class GearyController : Geary.BaseObject {
 
         this.notifications = new Notification.Desktop(
             this.new_messages_monitor,
-            this.application
+            this.application,
+            this.open_cancellable
         );
 
         this.main_window.conversation_list_view.grab_focus();
diff --git a/src/client/notification/notification-desktop.vala 
b/src/client/notification/notification-desktop.vala
index fa8580d7..1dfc9713 100644
--- a/src/client/notification/notification-desktop.vala
+++ b/src/client/notification/notification-desktop.vala
@@ -31,12 +31,15 @@ public class Notification.Desktop : Geary.BaseObject {
     private GLib.Notification? error_notification = null;
     private Geary.Folder? folder = null;
     private Geary.Email? email = null;
+    private GLib.Cancellable load_cancellable;
 
 
     public Desktop(NewMessagesMonitor monitor,
-                   GearyApplication application) {
+                   GearyApplication application,
+                   GLib.Cancellable load_cancellable) {
         this.monitor = monitor;
         this.application = application;
+        this.load_cancellable = load_cancellable;
         init_sound();
 
         this.monitor.add_required_fields(REQUIRED_FIELDS);
@@ -44,6 +47,7 @@ public class Notification.Desktop : Geary.BaseObject {
     }
 
     ~Desktop() {
+        this.load_cancellable.cancel();
         this.monitor.new_messages_arrived.disconnect(on_new_messages_arrived);
     }
 
@@ -79,12 +83,13 @@ public class Notification.Desktop : Geary.BaseObject {
     private void on_new_messages_arrived(Geary.Folder folder,
                                          int total,
                                          int added) {
-        if (added == 1 && monitor.last_new_message_folder != null &&
+        if (added == 1 &&
+            monitor.last_new_message_folder != null &&
             monitor.last_new_message != null) {
-            notify_one_message_async.begin(
+            this.notify_one_message.begin(
                 monitor.last_new_message_folder,
                 monitor.last_new_message,
-                null
+                this.load_cancellable
             );
         } else if (added > 0) {
             notify_new_mail(folder, added);
@@ -120,9 +125,10 @@ public class Notification.Desktop : Geary.BaseObject {
         }
     }
 
-    private async void notify_one_message_async(Geary.Folder folder,
-                                                Geary.Email email,
-                                                GLib.Cancellable? cancellable) throws GLib.Error {
+    private async void notify_one_message(Geary.Folder folder,
+                                          Geary.Email email,
+                                          GLib.Cancellable? cancellable)
+        throws GLib.Error {
         // used if notification is invoked
         this.folder = folder;
         this.email = email;