From 746a9259db1f312e4cb34b7ee3e09ee186c9bc7c Mon Sep 17 00:00:00 2001
From: miruka <miruka@disroot.org>
Date: Mon, 11 Nov 2019 09:12:31 -0400
Subject: [PATCH] SignIn: cancel previous task when clicking button

---
 src/python/app.py        |  2 --
 src/python/backend.py    |  2 ++
 src/python/utils.py      | 33 ++++++++++++++++++++++++++++++++-
 src/qml/Base/HBox.qml    | 10 +++++++---
 src/qml/Base/HButton.qml | 10 +++++++++-
 src/qml/Pages/SignIn.qml |  5 ++++-
 6 files changed, 54 insertions(+), 8 deletions(-)

diff --git a/src/python/app.py b/src/python/app.py
index b6a5d109..6db1afb3 100644
--- a/src/python/app.py
+++ b/src/python/app.py
@@ -11,8 +11,6 @@ from typing import Coroutine, Sequence
 import nio
 from appdirs import AppDirs
 
-import pyotherside
-
 from . import __about__
 from .pyotherside_events import CoroutineDone
 
diff --git a/src/python/backend.py b/src/python/backend.py
index 2dd007b7..06917cff 100644
--- a/src/python/backend.py
+++ b/src/python/backend.py
@@ -7,6 +7,7 @@ import hsluv
 
 import nio
 
+from . import utils
 from .app import App
 from .matrix_client import MatrixClient, MatrixError
 from .models.items import Account, Device, Event, Member, Room, Upload
@@ -46,6 +47,7 @@ class Backend:
 
     # Clients management
 
+    @utils.cancel_previous
     async def login_client(self,
         user:       str,
         password:   str,
diff --git a/src/python/utils.py b/src/python/utils.py
index 8c7041d8..0a074c87 100644
--- a/src/python/utils.py
+++ b/src/python/utils.py
@@ -1,17 +1,21 @@
+import asyncio
 import collections
 import html
 import inspect
+import logging as log
 import xml.etree.cElementTree as xml_etree  # FIXME: bandit warning
 from enum import Enum
 from enum import auto as autostr
 from pathlib import Path
 from types import ModuleType
-from typing import IO, Any, Dict, Tuple, Type, Union
+from typing import IO, Any, Callable, Dict, Tuple, Type, Union
 
 import filetype
 
 auto = autostr
 
+CANCELLABLE_FUTURES: Dict[Tuple[Any, Callable], asyncio.Future] = {}
+
 
 class AutoStrEnum(Enum):
     @staticmethod
@@ -83,3 +87,30 @@ def classes_defined_in(module: ModuleType) -> Dict[str, Type]:
         if not m[0].startswith("_") and
         m[1].__module__.startswith(module.__name__)
     }
+
+
+def cancel_previous(async_func):
+    async def wrapper(*args, **kwargs):
+        try:
+            arg0_is_self = inspect.getfullargspec(async_func).args[0] == "self"
+        except IndexError:
+            parent_obj = None
+        else:
+            parent_obj = args[0] if arg0_is_self else None
+
+        previous = CANCELLABLE_FUTURES.get((parent_obj, async_func))
+        if previous:
+            previous.cancel()
+            log.info("Cancelled previous coro: %s", previous)
+
+        future = asyncio.ensure_future(async_func(*args, **kwargs))
+        CANCELLABLE_FUTURES[parent_obj, async_func] = future
+
+        try:
+            result = await future
+            return result
+        finally:
+            # Make sure to do this even if an exception happens
+            del CANCELLABLE_FUTURES[parent_obj, async_func]
+
+    return wrapper
diff --git a/src/qml/Base/HBox.qml b/src/qml/Base/HBox.qml
index 3080a34c..5f4475f5 100644
--- a/src/qml/Base/HBox.qml
+++ b/src/qml/Base/HBox.qml
@@ -98,9 +98,13 @@ Rectangle {
                         theme.icons.colorize
                     )
 
-                    enabled: (modelData.enabled == undefined ?
-                              true : modelData.enabled) &&
-                             ! button.loading
+                    enabled:
+                        modelData.enabled === undefined ?
+                        true : modelData.enabled
+
+                    disableWhileLoading:
+                        modelData.disableWhileLoading === undefined ?
+                        true : modelData.disableWhileLoading
 
                     onClicked: buttonCallbacks[name](button)
 
diff --git a/src/qml/Base/HButton.qml b/src/qml/Base/HButton.qml
index 8f1185a2..1350825c 100644
--- a/src/qml/Base/HButton.qml
+++ b/src/qml/Base/HButton.qml
@@ -12,7 +12,6 @@ Button {
 
     iconItem.svgName: loading ? "hourglass" : icon.name
     icon.color: theme.icons.colorize
-    enabled: ! loading
 
     // Must be explicitely set to display correctly on KDE
     implicitWidth: Math.max(
@@ -32,6 +31,7 @@ Button {
     readonly property alias label: contentItem.label
 
     property color backgroundColor: theme.controls.button.background
+    property bool disableWhileLoading: true
     property bool loading: false
     property bool circle: false
 
@@ -41,6 +41,14 @@ Button {
     }
 
 
+    Binding {
+        when: disableWhileLoading && loading
+        target: button
+        property: "enabled"
+        value: false
+    }
+
+
     background: HButtonBackground {
         button: button
         buttonTheme: theme.controls.button
diff --git a/src/qml/Pages/SignIn.qml b/src/qml/Pages/SignIn.qml
index a9ecd02a..3fb72209 100644
--- a/src/qml/Pages/SignIn.qml
+++ b/src/qml/Pages/SignIn.qml
@@ -19,7 +19,8 @@ HPage {
 
         buttonModel: [
             { name: "register", text: qsTr("Register"), enabled: false },
-            { name: "login", text: qsTr("Login"), enabled: canLogin },
+            { name: "login", text: qsTr("Login"), enabled: canLogin,
+              disableWhileLoading: false },
             { name: "forgot", text: qsTr("Forgot?"), enabled: false },
         ]
 
@@ -52,6 +53,8 @@ HPage {
                         "AccountSettings/AccountSettings", {userId: data}
                     )
                 }, type => {
+                    if (type === "CancelledError") return
+
                     loginTimeout.stop()
                     let txt = qsTr("Invalid request or login type")