Rewrite mailcap handling.

Add a class that encapsulates the handler and is responsible for
managing the temporary file, if one is needed.

Use this class for both rendering inline content and displaying
attachments externally.

External attachments are now wrapped in an asyncio task that is added to
a pool of tasks managed by ui.

1 files changed, 14 insertions, 0 deletions

diff --git a/alot/ui.py b/alot/ui.py
index 9a2d59fd..69c9cda3 100644
--- a/alot/ui.py
+++ b/alot/ui.py
@@ -104,6 +104,8 @@ class UI:
     # running asyncio event loop
     _loop             = None
 
+    _pending_tasks    = None
+
     def __init__(self, loop, dbman, initialcmdline):
         """
         :param dbman: :class:`~alot.db.DBManager`
@@ -133,6 +135,8 @@ class UI:
 
         self._loop = loop
 
+        self._pending_tasks = set()
+
         # define empty notification pile
         self._notification_bar = urwid.Pile([])
         self._footer_wgt       = urwid.Pile([self._notification_bar])
@@ -758,8 +762,18 @@ class UI:
         self._save_history_to_file(self.recipienthistory,
                                    self._recipients_hist_file, size=size)
 
+        logging.info('cancelling pending tasks: %s', self._pending_tasks)
+        for t in self._pending_tasks:
+            t.cancel()
+        await asyncio.gather(*self._pending_tasks)
+
         await self.dbman.shutdown()
 
+    def run_task(self, coro):
+        task = self._loop.create_task(coro)
+        self._pending_tasks.add(task)
+        task.add_done_callback(self._pending_tasks.discard)
+
     @staticmethod
     def _load_history_from_file(path, size=-1):
         """Load a history list from a file and split it into lines.