Allows Launcher to recover gracefully into OverviewSplitSelect state

When Launcher restarts (as the result of a UiModeChange or something else), it attempts to recover its previous state. However, the OverviewSplitSelect state is unique because it requires some additional information to recover properly (the taskId of the staged task and so on). This change makes it so that the relevant information is passed forward in the recovery bundle. Launcher will now restart in the base Overview state, and then immediately apply the saved data to recover the OverviewSplitSelect state.

Fixes: 233019928
Test: Manual
Change-Id: Ie6123ef9c374be000268f82857b696c49213c541

quickstep/src/com/android/launcher3/BaseQuickstepLauncher.java

@@ -20,6 +20,8 @@ import static com.android.launcher3.AbstractFloatingView.TYPE_HIDE_BACK_BUTTON;
 import static com.android.launcher3.LauncherState.FLAG_HIDE_BACK_BUTTON;
 import static com.android.launcher3.LauncherState.NORMAL;
 import static com.android.launcher3.LauncherState.NO_OFFSET;
+import static com.android.launcher3.LauncherState.OVERVIEW;
+import static com.android.launcher3.LauncherState.OVERVIEW_SPLIT_SELECT;
 import static com.android.launcher3.config.FeatureFlags.ENABLE_QUICKSTEP_LIVE_TILE;
 import static com.android.launcher3.config.FeatureFlags.ENABLE_SPLIT_FROM_WORKSPACE;
 import static com.android.launcher3.model.data.ItemInfo.NO_MATCHING_ID;
@@ -70,6 +72,7 @@ import com.android.launcher3.util.DisplayController;
 import com.android.launcher3.util.DisplayController.NavigationMode;
 import com.android.launcher3.util.IntSet;
 import com.android.launcher3.util.ObjectWrapper;
+import com.android.launcher3.util.PendingSplitSelectInfo;
 import com.android.launcher3.util.RunnableList;
 import com.android.launcher3.util.SplitConfigurationOptions.SplitPositionOption;
 import com.android.launcher3.util.UiThreadHelper;
@@ -91,10 +94,10 @@ import com.android.systemui.shared.system.ActivityOptionsCompat;
 import com.android.systemui.shared.system.RemoteAnimationTargetCompat;
 import com.android.systemui.unfold.UnfoldTransitionFactory;
 import com.android.systemui.unfold.UnfoldTransitionProgressProvider;
+import com.android.systemui.unfold.config.ResourceUnfoldTransitionConfig;
 import com.android.systemui.unfold.config.UnfoldTransitionConfig;
 import com.android.systemui.unfold.system.ActivityManagerActivityTypeProvider;
 import com.android.systemui.unfold.system.DeviceStateManagerFoldProvider;
-import com.android.systemui.unfold.config.ResourceUnfoldTransitionConfig;
 
 import java.io.FileDescriptor;
 import java.io.PrintWriter;
@@ -130,9 +133,19 @@ public abstract class BaseQuickstepLauncher extends Launcher {
     private @Nullable UnfoldTransitionProgressProvider mUnfoldTransitionProgressProvider;
     private @Nullable LauncherUnfoldAnimationController mLauncherUnfoldAnimationController;
 
+    /**
+     * If Launcher restarted while in the middle of an Overview split select, it needs this data to
+     * recover. In all other cases this will remain null.
+     */
+    private PendingSplitSelectInfo mPendingSplitSelectInfo = null;
+
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
+        if (savedInstanceState != null) {
+            mPendingSplitSelectInfo = ObjectWrapper.unwrap(
+                    savedInstanceState.getIBinder(PENDING_SPLIT_SELECT_INFO));
+        }
         addMultiWindowModeChangedListener(mDepthController);
         initUnfoldTransitionProgressProvider();
     }
@@ -643,4 +656,53 @@ public abstract class BaseQuickstepLauncher extends Launcher {
             mDepthController.dump(prefix, writer);
         }
     }
+
+    @Override
+    protected void onSaveInstanceState(Bundle outState) {
+        super.onSaveInstanceState(outState);
+
+        // If Launcher shuts downs during split select, we save some extra data in the recovery
+        // bundle to allow graceful recovery. The normal LauncherState restore mechanism doesn't
+        // work in this case because restoring straight to OverviewSplitSelect without staging data,
+        // or before the tasks themselves have loaded into Overview, causes a crash. So we tell
+        // Launcher to first restore into Overview state, wait for the relevant tasks and icons to
+        // load in, and then proceed to OverviewSplitSelect.
+        if (isInState(OVERVIEW_SPLIT_SELECT)) {
+            SplitSelectStateController splitSelectStateController =
+                    ((RecentsView) getOverviewPanel()).getSplitPlaceholder();
+            // Launcher will restart in Overview and then transition to OverviewSplitSelect.
+            outState.putIBinder(PENDING_SPLIT_SELECT_INFO, ObjectWrapper.wrap(
+                    new PendingSplitSelectInfo(
+                            splitSelectStateController.getInitialTaskId(),
+                            splitSelectStateController.getActiveSplitStagePosition()
+                    )
+            ));
+            outState.putInt(RUNTIME_STATE, OVERVIEW.ordinal);
+        }
+    }
+
+    /**
+     * When Launcher restarts, it sometimes needs to recover to a split selection state.
+     * This function checks if such a recovery is needed.
+     * @return a boolean representing whether the launcher is waiting to recover to
+     * OverviewSplitSelect state.
+     */
+    public boolean hasPendingSplitSelectInfo() {
+        return mPendingSplitSelectInfo != null;
+    }
+
+    /**
+     * See {@link #hasPendingSplitSelectInfo()}
+     */
+    public @Nullable PendingSplitSelectInfo getPendingSplitSelectInfo() {
+        return mPendingSplitSelectInfo;
+    }
+
+    /**
+     * When the launcher has successfully recovered to OverviewSplitSelect state, this function
+     * deletes the recovery data, returning it to a null state.
+     */
+    public void finishSplitSelectRecovery() {
+        mPendingSplitSelectInfo = null;
+    }
 }