fix mixing of messages when changing applications too quickly

gotify_tray/gui/MainApplication.py

@@ -166,16 +166,25 @@ class MainApplication(QtWidgets.QApplication):
         else:
             self.gotify_client.stop(reset_wait=True)
 
-    def application_selection_changed_callback(
+    def abort_get_messages_task(self):
-        self, item: ApplicationModelItem | ApplicationAllMessagesItem
+        """
-    ):
+        Abort any tasks that will result in new messages getting appended to messages_model
+        """
+        aborted_tasks = []
+        for s in ["get_application_messages_task", "get_messages_task"]:
+            if task := getattr(self, s, None):
+                task.abort()
+                aborted_tasks.append(task)
+        
+        for task in aborted_tasks:
+            task.wait()
+
+    def application_selection_changed_callback(self, item: ApplicationModelItem | ApplicationAllMessagesItem):
+        self.abort_get_messages_task()
         self.messages_model.clear()
 
         if isinstance(item, ApplicationModelItem):
-            self.get_application_messages_task = GetApplicationMessagesTask(
+            self.get_application_messages_task = GetApplicationMessagesTask(item.data(ApplicationItemDataRole.ApplicationRole).id, self.gotify_client)
-                item.data(ApplicationItemDataRole.ApplicationRole).id,
-                self.gotify_client,
-            )
             self.get_application_messages_task.message.connect(self.messages_model.append_message)
             self.get_application_messages_task.start()
 

gotify_tray/tasks.py

@@ -26,11 +26,18 @@ class BaseTask(QtCore.QThread):
     def __init__(self):
         super(BaseTask, self).__init__()
         self.running = False
+        self._abort = False
 
     @abc.abstractmethod
     def task(self):
         ...
 
+    def abort(self):
+        self._abort = True
+
+    def abort_requested(self) -> bool:
+        return self._abort
+
     def run(self):
         self.running = True
         try:
@@ -111,6 +118,8 @@ class GetApplicationMessagesTask(BaseTask):
             self.error.emit(result)
         else:
             for message in process_messages(result.messages):
+                if self.abort_requested():
+                    return
                 self.message.emit(message)
                 
                 # Prevent locking up the UI when there are a lot of messages ready at the same time
@@ -133,6 +142,8 @@ class GetMessagesTask(BaseTask):
             self.error.emit(result)
         else:
             for message in process_messages(result.messages):
+                if self.abort_requested():
+                    return
                 self.message.emit(message)
                 time.sleep(0.001)
             self.success.emit(result)