Don't pass Python Future objects to QML

Returning a Future doesn't work on Windows for some reason
(thp/pyotherside#116).

Instead of using these objects from QML to cancel running coroutines,
call a Python QMLBridge function that takes a coroutine UUID and will
take care of the cancelling.

TODO.md

@@ -1,5 +1,7 @@
 # TODO
 
+- Encrypted rooms don't show invites in member list after Mirage restart
+- Room display name not updated when someone removes theirs
 - Fix right margin of own `<image url>\n<image url>` messages
 
 - filter > enter > room list is always scrolled to top

src/backend/qml_bridge.py

@@ -21,7 +21,7 @@
 from concurrent.futures import Future
 from operator import attrgetter
 from threading import Thread
-from typing import Coroutine, Sequence
+from typing import Coroutine, Dict, Sequence
 
 import pyotherside
 
@@ -52,6 +52,8 @@ def __init__(self) -> None:
         from .backend import Backend
         self.backend: Backend = Backend()
 
+        self._running_futures: Dict[str, Future] = {}
+
         Thread(target=self._start_asyncio_loop).start()
 
 
@@ -73,7 +75,7 @@ def _start_asyncio_loop(self) -> None:
         self._loop.run_forever()
 
 
-    def _call_coro(self, coro: Coroutine, uuid: str) -> Future:
+    def _call_coro(self, coro: Coroutine, uuid: str) -> None:
         """Schedule a coroutine to run in our thread and return a `Future`."""
 
         def on_done(future: Future) -> None:
@@ -87,27 +89,37 @@ def on_done(future: Future) -> None:
                 trace     = traceback.format_exc().rstrip()
 
             CoroutineDone(uuid, result, exception, trace)
+            del self._running_futures[uuid]
 
         future = asyncio.run_coroutine_threadsafe(coro, self._loop)
+        self._running_futures[uuid] = future
         future.add_done_callback(on_done)
-        return future
 
 
     def call_backend_coro(
         self, name: str, uuid: str, args: Sequence[str] = (),
-    ) -> Future:
-        """Schedule a `Backend` coroutine and return a `Future`."""
+    ) -> None:
+        """Schedule a coroutine from the `QMLBridge.backend` object."""
 
-        return self._call_coro(attrgetter(name)(self.backend)(*args), uuid)
+        self._call_coro(attrgetter(name)(self.backend)(*args), uuid)
 
 
     def call_client_coro(
         self, user_id: str, name: str, uuid: str, args: Sequence[str] = (),
-    ) -> Future:
-        """Schedule a `MatrixClient` coroutine and return a `Future`."""
+    ) -> None:
+        """Schedule a coroutine from a `QMLBridge.backend.clients` client."""
 
         client = self.backend.clients[user_id]
-        return self._call_coro(attrgetter(name)(client)(*args), uuid)
+        self._call_coro(attrgetter(name)(client)(*args), uuid)
+
+
+    def cancel_coro(self, uuid: str) -> None:
+        """Cancel a couroutine scheduled by the `QMLBridge` methods."""
+
+        try:
+            self._running_futures[uuid].cancel()
+        except KeyError:
+            log.warning("Couldn't cancel coroutine %s, future not found", uuid)
 
 
     def pdb(self, additional_data: Sequence = ()) -> None:

src/gui/Base/HMxcImage.qml

@@ -2,7 +2,6 @@
 // SPDX-License-Identifier: LGPL-3.0-or-later
 
 import QtQuick 2.12
-import "../PythonBridge"
 
 HImage {
     id: image
@@ -18,7 +17,7 @@ HImage {
     property bool canUpdate: true
     property bool show: ! canUpdate
 
-    property Future getFuture: null
+    property string getFutureId: ""
 
     readonly property bool isMxc: mxc.startsWith("mxc://")
 
@@ -45,10 +44,11 @@ HImage {
             [clientUserId, image.mxc, image.title, w, h, cryptDict] :
             [clientUserId, image.mxc, image.title, cryptDict]
 
-        getFuture = py.callCoro("media_cache." + method, args, path => {
+        getFutureId = py.callCoro("media_cache." + method, args, path => {
                 if (! image) return
                 if (image.cachedPath !== path) image.cachedPath = path
 
+                getFutureId  = ""
                 image.broken = Qt.binding(() => image.status === Image.Error)
                 image.show   = image.visible
 
@@ -68,5 +68,5 @@ HImage {
     onHeightChanged: Qt.callLater(reload)
     onVisibleChanged: Qt.callLater(reload)
     onMxcChanged: Qt.callLater(reload)
-    Component.onDestruction: if (getFuture) getFuture.cancel()
+    Component.onDestruction: if (getFutureId) py.cancelCoro(getFutureId)
 }

src/gui/Dialogs/ImportKeys.qml

@@ -5,11 +5,10 @@ import QtQuick 2.12
 import QtQuick.Controls 2.12
 import Qt.labs.platform 1.1
 import "../Popups"
-import "../PythonBridge"
 
 HFileDialogOpener {
     property string userId: ""
-    property Future importFuture: null
+    property string importFutureId: ""
 
 
     fill: false
@@ -28,13 +27,13 @@ HFileDialogOpener {
             const call = py.callClientCoro
             const path = file.toString().replace(/^file:\/\//, "")
 
-            importFuture = call(userId, "import_keys", [path, pass], () => {
-                importFuture = null
+            importFutureId = call(userId, "import_keys", [path, pass], () => {
+                importFutureId = ""
                 callback(true)
 
             }, (type, args, error, traceback, uuid) => {
-                let unknown  = false
-                importFuture = null
+                let unknown    = false
+                importFutureId = ""
 
                 callback(
                     type === "EncryptionError" ?
@@ -63,17 +62,17 @@ HFileDialogOpener {
         }
 
         summary.text:
-            importFuture ?
+            importFutureId ?
             qsTr("This might take a while...") :
             qsTr("Passphrase used to protect this file:")
         validateButton.text: qsTr("Import")
         validateButton.icon.name: "import-keys"
 
-        onClosed: if (importFuture) importFuture.cancel()
+        onClosed: if (importFutureId) py.cancelCoro(importFutureId)
 
         Binding on closePolicy {
             value: Popup.CloseOnEscape
-            when: importFuture
+            when: importFutureId
         }
     }
 }

src/gui/MainPane/RoomDelegate.qml

@@ -7,13 +7,12 @@ import Clipboard 0.1
 import ".."
 import "../Base"
 import "../Base/HTile"
-import "../PythonBridge"
 
 HTile {
     id: room
 
-    property Future fetchProfilesFuture: null
-    property Future loadEventsFuture: null
+    property string fetchProfilesFutureId: ""
+    property string loadEventsFutureId: ""
     property bool moreToLoad: true
 
     readonly property bool joined: ! invited && ! parted
@@ -204,8 +203,8 @@ HTile {
     }
 
     Component.onDestruction: {
-        if (fetchProfilesFuture) fetchProfilesFuture.cancel()
-        if (loadEventsFuture) loadEventsFuture.cancel()
+        if (fetchProfilesFutureId) py.cancelCoro(fetchProfilesFutureId)
+        if (loadEventsFutureId) py.cancelCoro(loadEventsFutureId)
     }
 
     Timer {
@@ -217,15 +216,15 @@ HTile {
             ! lastEvent &&
             moreToLoad
 
-        onTriggered: if (! loadEventsFuture) {
-            loadEventsFuture = py.callClientCoro(
+        onTriggered: if (! loadEventsFutureId) {
+            loadEventsFutureId = py.callClientCoro(
                 model.for_account,
                 "load_past_events",
                 [model.id],
                 more => {
                     if (! room) return  // delegate was destroyed
-                    loadEventsFuture = null
-                    moreToLoad       = more
+                    loadEventsFutureId = ""
+                    moreToLoad         = more
                 }
             )
         }
@@ -242,13 +241,13 @@ HTile {
             lastEvent.fetch_profile
 
         onTriggered: {
-            if (fetchProfilesFuture) fetchProfilesFuture.cancel()
+            if (fetchProfilesFutureId) py.cancelCoro(fetchProfilesFutureId)
 
-            fetchProfilesFuture = py.callClientCoro(
+            fetchProfilesFutureId = py.callClientCoro(
                 model.for_account,
                 "get_event_profiles",
                 [model.id, lastEvent.id],
-                () => { if (room) fetchProfilesFuture = null },
+                () => { if (room) fetchProfilesFutureId = "" },
             )
         }
     }

src/gui/Pages/AccountSettings/Sessions.qml

@@ -7,7 +7,6 @@ import QtQuick.Layouts 1.12
 import "../.."
 import "../../Base"
 import "../../Base/Buttons"
-import "../../PythonBridge"
 import "../../ShortcutBundles"
 
 HColumnPage {
@@ -18,19 +17,19 @@ HColumnPage {
     property bool enableFlickShortcuts:
         SwipeView ? SwipeView.isCurrentItem : true
 
-    property Future loadFuture: null
+    property string loadFutureId: ""
 
     function takeFocus() {} // TODO
 
     function loadDevices() {
-        loadFuture = py.callClientCoro(userId, "devices_info", [], devices => {
+        loadFutureId = py.callClientCoro(userId, "devices_info",[],devices => {
             deviceList.uncheckAll()
             deviceList.model.clear()
 
             for (const device of devices)
                 deviceList.model.append(device)
 
-            loadFuture                   = null
+            loadFutureId                 = ""
             deviceList.sectionItemCounts = getSectionItemCounts()
 
             if (page.enabled && ! deviceList.currentItem)
@@ -187,7 +186,7 @@ HColumnPage {
             height: width
 
             source: "../../Base/HBusyIndicator.qml"
-            active: page.loadFuture
+            active: page.loadFutureId
             opacity: active ? 1 : 0
 
             Behavior on opacity { HNumberAnimation { factor: 2 } }

src/gui/Pages/AddAccount/ServerBrowser.qml

@@ -21,26 +21,26 @@ HBox {
     property var saveProperties: ["acceptedUserUrl", "knownHttps"]
     property string loadingIconStep: "server-ping-bad"
 
-    property Future connectFuture: null
-    property Future fetchServersFuture: null
+    property string connectFutureId: ""
+    property string fetchServersFutureId: ""
 
     signal accepted()
 
     function takeFocus() { serverField.item.field.forceActiveFocus() }
 
     function fetchServers() {
-        if (fetchServersFuture) fetchServersFuture.cancel()
+        if (fetchServersFutureId) py.cancelCoro(fetchServersFutureId)
 
-        fetchServersFuture = py.callCoro("fetch_homeservers", [], () => {
-            fetchServersFuture = null
+        fetchServersFutureId = py.callCoro("fetch_homeservers", [], () => {
+            fetchServersFutureId = ""
         }, (type, args, error, traceback) => {
-            fetchServersFuture = null
+            fetchServersFutureId = ""
             print( traceback)  // TODO: display error graphically
         })
     }
 
     function connect() {
-        if (connectFuture) connectFuture.cancel()
+        if (connectFutureId) py.cancelCoro(connectFutureId)
         connectTimeout.restart()
 
         const typedUrl = serverField.item.field.cleanText
@@ -49,10 +49,10 @@ HBox {
         if (box.knownHttps)
             args[0] = args[0].replace(/^(https?:\/\/)?/, "https://")
 
-        connectFuture = py.callCoro("server_info", args, ([url, flows]) => {
+        connectFutureId = py.callCoro("server_info", args, ([url, flows]) => {
             connectTimeout.stop()
             serverField.errorLabel.text = ""
-            connectFuture               = null
+            connectFutureId             = ""
 
             if (! (
                 flows.includes("m.login.password") ||
@@ -75,7 +75,7 @@ HBox {
             console.error(traceback)
 
             connectTimeout.stop()
-            connectFuture = null
+            connectFutureId = ""
 
             let text = qsTr("Unexpected error: %1 [%2]").arg(type).arg(args)
 
@@ -194,7 +194,7 @@ HBox {
                 enabled: field.cleanText && ! field.error
                 icon.name: "server-connect-to-address"
                 icon.color: theme.colors.positiveBackground
-                loading: box.connectFuture !== null
+                loading: box.connectFutureId !== ""
                 disableWhileLoading: false
                 onClicked: box.connect()
 
@@ -209,7 +209,7 @@ HBox {
     onAccepted: window.saveState(this)
 
     Component.onDestruction:
-        if (fetchServersFuture) fetchServersFuture.cancel()
+        if (fetchServersFutureId) py.cancelCoro(fetchServersFutureId)
 
     Timer {
         id: connectTimeout
@@ -230,7 +230,7 @@ HBox {
     Timer {
         interval: 1000
         running:
-            fetchServersFuture === null &&
+            fetchServersFutureId === "" &&
             ModelStore.get("homeservers").count === 0
 
         repeat: true
@@ -292,7 +292,7 @@ HBox {
             height: width
 
             source: "../../Base/HBusyIndicator.qml"
-            active: box.fetchServersFuture && ! serverList.count
+            active: box.fetchServersFutureId && ! serverList.count
             opacity: active ? 1 : 0
 
             Behavior on opacity { HNumberAnimation { factor: 2 } }