From c779ae54cefbfcb26258ab3067ce36ce7d18abbd Mon Sep 17 00:00:00 2001
From: Jeremy Sim <jeremysim@google.com>
Date: Tue, 31 Jan 2023 10:54:19 +0800
Subject: [PATCH] Fix bug with trying to split an app with itself

This patch fixes the following user flow:
1) App is already running
2) User initiates splitscreen from Home with that app
3) User selects the same app from Taskbar or AllApps

Previously, this caused a crash because the split-from-home initiation removed the corresponding app tile, causing a null pointer exception when the same task ID was used as a split target.

Fixed by adding a null check: if the target TaskView can't be found for any reason, fall back to launching the second app via Intent instead. If the app doesn't support multi-instance, the UI will now show an attempted split, followed by the message "This app can only be opened in 1 window."

Fixes: 263041522
Fixes: 266218404
Test: Manual
Change-Id: I39ed60c9ac758ac215391f0618f44f7fcee4f32c
---
 .../taskbar/TaskbarUIController.java          | 42 +++++++++++--------
 1 file changed, 25 insertions(+), 17 deletions(-)

diff --git a/quickstep/src/com/android/launcher3/taskbar/TaskbarUIController.java b/quickstep/src/com/android/launcher3/taskbar/TaskbarUIController.java
index ebb37a88fc..2d47616594 100644
--- a/quickstep/src/com/android/launcher3/taskbar/TaskbarUIController.java
+++ b/quickstep/src/com/android/launcher3/taskbar/TaskbarUIController.java
@@ -175,24 +175,32 @@ public class TaskbarUIController {
                 (Consumer<Task>) foundTask -> {
                     if (foundTask != null) {
                         TaskView foundTaskView = recents.getTaskViewByTaskId(foundTask.key.id);
-                        // There is already a running app of this type, use that as second app.
-                        recents.confirmSplitSelect(
-                                foundTaskView,
-                                foundTaskView.getTask(),
-                                foundTaskView.getIconView().getDrawable(),
-                                foundTaskView.getThumbnail(),
-                                foundTaskView.getThumbnail().getThumbnail(),
-                                null /* intent */);
-                    } else {
-                        // No running app of that type, create a new instance as second app.
-                        recents.confirmSplitSelect(
-                                null /* containerTaskView */,
-                                null /* task */,
-                                new BitmapDrawable(info.bitmap.icon),
-                                startingView,
-                                null /* thumbnail */,
-                                intent);
+                        // TODO (b/266482558): This additional null check is needed because there
+                        // are times when our Tasks list doesn't match our TaskViews list (like when
+                        // a tile is removed during {@link RecentsView#applyLoadPlan()}. A clearer
+                        // state management system is in the works so that we don't need to rely on
+                        // null checks as much. See comments at ag/21152798.
+                        if (foundTaskView != null) {
+                            // There is already a running app of this type, use that as second app.
+                            recents.confirmSplitSelect(
+                                    foundTaskView,
+                                    foundTaskView.getTask(),
+                                    foundTaskView.getIconView().getDrawable(),
+                                    foundTaskView.getThumbnail(),
+                                    foundTaskView.getThumbnail().getThumbnail(),
+                                    null /* intent */);
+                            return;
+                        }
                     }
+
+                    // No running app of that type, create a new instance as second app.
+                    recents.confirmSplitSelect(
+                            null /* containerTaskView */,
+                            null /* task */,
+                            new BitmapDrawable(info.bitmap.icon),
+                            startingView,
+                            null /* thumbnail */,
+                            intent);
                 }
         );
     }