From 4cd6a2ad2db15ff6d5cc4dd030d30c30460df6a0 Mon Sep 17 00:00:00 2001
From: Jordan Demeulenaere <jdemeulenaere@google.com>
Date: Thu, 7 Oct 2021 15:22:19 +0200
Subject: [PATCH] Fix SysUI crash when locking while showing the Media Output
 Group dialog

This CL fixes a bug introduced by http://ag/15663086: When locking the
phone while showing the Media Output Group dialog, SystemUI would crash
because of a mismatch between MediaOutputAdapter.currentActivePosition
and MediaOutputController.mMediaDevices. That mismatch came from the
sharing of the controller between the 2 dialogs, that are now shown at
the same time (even though one is hidden).

Starting from this CL, both dialogs now use a separate instance of
MediaOutputController to avoid this kind of race condition. This CL also
adds a safeguard in MediaOutputBaseDialog to ensure that we notify an
item change within bounds, which would otherwise throw and crash.

Bug: 200781817
Test: Show media output group dialog then lock phone.
Change-Id: I7749cc963a5e145467b32aa3a9efb1e80009f324
---
 .../media/dialog/MediaOutputBaseDialog.java   |  2 +-
 .../media/dialog/MediaOutputController.java   | 30 +++++--------------
 2 files changed, 8 insertions(+), 24 deletions(-)

diff --git a/packages/SystemUI/src/com/android/systemui/media/dialog/MediaOutputBaseDialog.java b/packages/SystemUI/src/com/android/systemui/media/dialog/MediaOutputBaseDialog.java
index 85d0802012acc..6895ef10fd07e 100644
--- a/packages/SystemUI/src/com/android/systemui/media/dialog/MediaOutputBaseDialog.java
+++ b/packages/SystemUI/src/com/android/systemui/media/dialog/MediaOutputBaseDialog.java
@@ -175,7 +175,7 @@ public abstract class MediaOutputBaseDialog extends SystemUIDialog implements
         }
         if (!mAdapter.isDragging() && !mAdapter.isAnimating()) {
             int currentActivePosition = mAdapter.getCurrentActivePosition();
-            if (currentActivePosition >= 0) {
+            if (currentActivePosition >= 0 && currentActivePosition < mAdapter.getItemCount()) {
                 mAdapter.notifyItemChanged(currentActivePosition);
             } else {
                 mAdapter.notifyDataSetChanged();
diff --git a/packages/SystemUI/src/com/android/systemui/media/dialog/MediaOutputController.java b/packages/SystemUI/src/com/android/systemui/media/dialog/MediaOutputController.java
index 437a0c85a6e01..42dd8862576b7 100644
--- a/packages/SystemUI/src/com/android/systemui/media/dialog/MediaOutputController.java
+++ b/packages/SystemUI/src/com/android/systemui/media/dialog/MediaOutputController.java
@@ -73,6 +73,7 @@ public class MediaOutputController implements LocalMediaManager.DeviceCallback {
     private final String mPackageName;
     private final Context mContext;
     private final MediaSessionManager mMediaSessionManager;
+    private final LocalBluetoothManager mLocalBluetoothManager;
     private final ShadeController mShadeController;
     private final ActivityStarter mActivityStarter;
     private final DialogLaunchAnimator mDialogLaunchAnimator;
@@ -85,7 +86,6 @@ public class MediaOutputController implements LocalMediaManager.DeviceCallback {
     private MediaController mMediaController;
     @VisibleForTesting
     Callback mCallback;
-    Callback mPreviousCallback;
     @VisibleForTesting
     LocalMediaManager mLocalMediaManager;
 
@@ -101,6 +101,7 @@ public class MediaOutputController implements LocalMediaManager.DeviceCallback {
         mContext = context;
         mPackageName = packageName;
         mMediaSessionManager = mediaSessionManager;
+        mLocalBluetoothManager = lbm;
         mShadeController = shadeController;
         mActivityStarter = starter;
         mAboveStatusbar = aboveStatusbar;
@@ -135,19 +136,7 @@ public class MediaOutputController implements LocalMediaManager.DeviceCallback {
             }
             return;
         }
-
-        if (mPreviousCallback != null) {
-            Log.w(TAG,
-                    "Callback started when mPreviousCallback is not null, which is unexpected");
-            mPreviousCallback.dismissDialog();
-        }
-
-        // If we start the output group dialog when the output dialog is shown, we need to keep a
-        // reference to the output dialog to set it back as the callback once we dismiss the output
-        // group dialog.
-        mPreviousCallback = mCallback;
         mCallback = cb;
-
         mLocalMediaManager.unregisterCallback(this);
         mLocalMediaManager.stopScan();
         mLocalMediaManager.registerCallback(this);
@@ -163,15 +152,6 @@ public class MediaOutputController implements LocalMediaManager.DeviceCallback {
             mLocalMediaManager.stopScan();
         }
         mMediaDevices.clear();
-
-        // If there was a previous callback, i.e. we just dismissed the output group dialog and are
-        // now back on the output dialog, then we reset the callback to its previous value.
-        mCallback = null;
-        Callback previous = mPreviousCallback;
-        mPreviousCallback = null;
-        if (previous != null) {
-            start(previous);
-        }
     }
 
     @Override
@@ -480,7 +460,11 @@ public class MediaOutputController implements LocalMediaManager.DeviceCallback {
 
     void launchMediaOutputGroupDialog(View mediaOutputDialog) {
         // We show the output group dialog from the output dialog.
-        MediaOutputGroupDialog dialog = new MediaOutputGroupDialog(mContext, mAboveStatusbar, this);
+        MediaOutputController controller = new MediaOutputController(mContext, mPackageName,
+                mAboveStatusbar, mMediaSessionManager, mLocalBluetoothManager, mShadeController,
+                mActivityStarter, mNotificationEntryManager, mUiEventLogger, mDialogLaunchAnimator);
+        MediaOutputGroupDialog dialog = new MediaOutputGroupDialog(mContext, mAboveStatusbar,
+                controller);
         mDialogLaunchAnimator.showFromView(dialog, mediaOutputDialog);
     }