Proper single-time download notifications (bug 1161)

Only show a notification for finished or failed downloads
once, both on the Desktop version and on Maemo 5 by adding
a special function to DownloadTask to keep track whether or
not the notification has already been shown previously.

src/gpodder/download.py

@@ -516,6 +516,14 @@ class DownloadTask(object):
     it from the UI, so that it can carry out any pending clean-up
     actions (e.g. removing the temporary file when the task has not
     finished successfully; i.e. task.status != DownloadTask.DONE).
+
+    The UI can call the method "notify_as_finished()" to determine if
+    this episode still has still to be shown as "finished" download
+    in a notification window. This will return True only the first time
+    it is called when the status is DONE. After returning True once,
+    it will always return False afterwards.
+
+    The same thing works for failed downloads ("notify_as_failed()").
     """
     # Possible states this download task can be in
     STATUS_MESSAGE = (_('Added'), _('Queued'), _('Downloading'),
@@ -582,6 +590,9 @@ def __init__(self, episode, config):
         self.progress = 0.0
         self.error_message = None
 
+        # Have we already shown this task in a notification?
+        self._notification_shown = False
+
         # Variables for speed limit and speed calculation
         self.__start_time = 0
         self.__start_blocks = 0
@@ -604,6 +615,26 @@ def __init__(self, episode, config):
             # files for resuming when the file is queued
             open(self.tempname, 'w').close()
 
+    def notify_as_finished(self):
+        if self.status == DownloadTask.DONE:
+            if self._notification_shown:
+                return False
+            else:
+                self._notification_shown = True
+                return True
+
+        return False
+
+    def notify_as_failed(self):
+        if self.status == DownloadTask.FAILED:
+            if self._notification_shown:
+                return False
+            else:
+                self._notification_shown = True
+                return True
+
+        return False
+
     def add_progress_callback(self, callback):
         self._progress_updated = callback
 
@@ -683,6 +714,7 @@ def run(self):
 
         # We are downloading this file right now
         self.status = DownloadTask.DOWNLOADING
+        self._notification_shown = False
 
         try:
             # Resolve URL and start downloading the episode
@@ -761,7 +793,8 @@ def run(self):
             self.error_message = _('HTTP Error %(code)s: %(message)s') % d
         except Exception, e:
             self.status = DownloadTask.FAILED
-            self.error_message = _('Error: %s') % (e.message,)
+            log('Download error: %s', str(e), traceback=True, sender=self)
+            self.error_message = _('Error: %s') % (str(e),)
 
         if self.status == DownloadTask.DOWNLOADING:
             # Everything went well - we're done

src/gpodder/gui.py

@@ -1321,7 +1321,6 @@ def update_downloads_list(self, can_call_cleanup=True):
             if model is None:
                 model = ()
 
-            failed_downloads = []
             for row in model:
                 self.download_status_model.request_update(row.iter)
 
@@ -1345,7 +1344,6 @@ def update_downloads_list(self, can_call_cleanup=True):
                     downloading += 1
                     total_speed += speed
                 elif status == download.DownloadTask.FAILED:
-                    failed_downloads.append(task)
                     failed += 1
                 elif status == download.DownloadTask.DONE:
                     finished += 1
@@ -1424,10 +1422,11 @@ def update_downloads_list(self, can_call_cleanup=True):
                 if self.config.cmd_all_downloads_complete:
                     util.run_external_command(self.config.cmd_all_downloads_complete)
 
-                if gpodder.ui.fremantle and failed:
+                if gpodder.ui.fremantle:
                     message = '\n'.join(['%s: %s' % (str(task), \
-                            task.error_message) for task in failed_downloads])
-                    self.show_message(message, _('Downloads failed'), important=True)
+                            task.error_message) for task in self.download_tasks_seen if task.notify_as_failed()])
+                    if message:
+                        self.show_message(message, _('Downloads failed'), important=True)
 
                 # Remove finished episodes
                 if self.config.auto_cleanup_downloads and can_call_cleanup:
@@ -1645,9 +1644,8 @@ def downloads_list_get_selection(self, model=None, paths=None):
         return selected_tasks, can_queue, can_cancel, can_pause, can_remove, can_force
 
     def downloads_finished(self, download_tasks_seen):
-        # FIXME: Filter all tasks that have already been reported
-        finished_downloads = [str(task) for task in download_tasks_seen if task.status == task.DONE]
-        failed_downloads = [str(task)+' ('+task.error_message+')' for task in download_tasks_seen if task.status == task.FAILED]
+        finished_downloads = [str(task) for task in download_tasks_seen if task.notify_as_finished()]
+        failed_downloads = [str(task)+' ('+task.error_message+')' for task in download_tasks_seen if task.notify_as_failed()]
 
         if finished_downloads and failed_downloads:
             message = self.format_episode_list(finished_downloads, 5)