From 3974edc46a7f6c027f051e03e8e998b2e23c8a3d Mon Sep 17 00:00:00 2001
From: Tony Wickham <twickham@google.com>
Date: Mon, 16 Aug 2021 17:39:12 -0700
Subject: [PATCH] Don't draw taskbar background during gestures

In this case, the ScrimView for BackgroundAppState will handle drawing behind the whole screen, and prevents taskbar from drawing the rounded corners on top of TaskViews.

Added a hack to defer resuming last task by a frame to ensure taskbar is drawing first.

Test: Quick switch to an app, ensure it isn't covered by the taskbar's rounded corner
Bug: 196257194
Change-Id: Ibc81d80bc3bf1d908e6912b179cbcafbdcc56c0f
---
 .../taskbar/LauncherTaskbarUIController.java  |  7 ++++-
 .../android/quickstep/AbsSwipeUpHandler.java  | 20 +++++++++++---
 .../quickstep/BaseActivityInterface.java      | 10 +++++++
 .../quickstep/LauncherActivityInterface.java  | 26 +++++++++++++++++++
 4 files changed, 59 insertions(+), 4 deletions(-)

diff --git a/quickstep/src/com/android/launcher3/taskbar/LauncherTaskbarUIController.java b/quickstep/src/com/android/launcher3/taskbar/LauncherTaskbarUIController.java
index 4c96fbae9d..da10bfb0fa 100644
--- a/quickstep/src/com/android/launcher3/taskbar/LauncherTaskbarUIController.java
+++ b/quickstep/src/com/android/launcher3/taskbar/LauncherTaskbarUIController.java
@@ -23,6 +23,7 @@ import android.animation.AnimatorListenerAdapter;
 import android.animation.ObjectAnimator;
 import android.graphics.Rect;
 import android.view.MotionEvent;
+import android.view.View;
 
 import androidx.annotation.NonNull;
 
@@ -241,7 +242,11 @@ public class LauncherTaskbarUIController extends TaskbarUIController {
         return mContext.getDragController().isDragging();
     }
 
-    void setTaskbarViewVisible(boolean isVisible) {
+    public View getRootView() {
+        return mTaskbarDragLayer;
+    }
+
+    private void setTaskbarViewVisible(boolean isVisible) {
         mIconAlphaForHome.setValue(isVisible ? 1 : 0);
         mLauncher.getHotseat().setIconsAlpha(isVisible ? 0f : 1f);
     }
diff --git a/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java b/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java
index 42c89fd006..6797fbb032 100644
--- a/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java
+++ b/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java
@@ -655,8 +655,13 @@ public abstract class AbsSwipeUpHandler<T extends StatefulActivity<S>,
 
     private void onAnimatorPlaybackControllerCreated(AnimatorControllerWithResistance anim) {
         mLauncherTransitionController = anim;
-        mLauncherTransitionController.getNormalController().dispatchOnStart();
-        updateLauncherTransitionProgress();
+        mStateCallback.runOnceAtState(STATE_GESTURE_STARTED, () -> {
+            // Wait until the gesture is started (touch slop was passed) to start in sync with
+            // mWindowTransitionController. This ensures we don't hide the taskbar background when
+            // long pressing to stash it, for instance.
+            mLauncherTransitionController.getNormalController().dispatchOnStart();
+            updateLauncherTransitionProgress();
+        });
     }
 
     public Intent getLaunchIntent() {
@@ -885,6 +890,9 @@ public abstract class AbsSwipeUpHandler<T extends StatefulActivity<S>,
         // Fast-finish the attaching animation if it's still running.
         maybeUpdateRecentsAttachedState(false);
         final GestureEndTarget endTarget = mGestureState.getEndTarget();
+        // Wait until the given View (if supplied) draws before resuming the last task.
+        View postResumeLastTask = mActivityInterface.onSettledOnEndTarget(endTarget);
+
         if (endTarget != NEW_TASK) {
             InteractionJankMonitorWrapper.cancel(
                     InteractionJankMonitorWrapper.CUJ_QUICK_SWITCH);
@@ -893,6 +901,7 @@ public abstract class AbsSwipeUpHandler<T extends StatefulActivity<S>,
             InteractionJankMonitorWrapper.cancel(
                     InteractionJankMonitorWrapper.CUJ_APP_CLOSE_TO_HOME);
         }
+
         switch (endTarget) {
             case HOME:
                 mStateCallback.setState(STATE_SCALED_CONTROLLER_HOME | STATE_CAPTURE_SCREENSHOT);
@@ -907,7 +916,12 @@ public abstract class AbsSwipeUpHandler<T extends StatefulActivity<S>,
                 mStateCallback.setState(STATE_START_NEW_TASK | STATE_CAPTURE_SCREENSHOT);
                 break;
             case LAST_TASK:
-                mStateCallback.setState(STATE_RESUME_LAST_TASK);
+                if (postResumeLastTask != null) {
+                    ViewUtils.postFrameDrawn(postResumeLastTask,
+                            () -> mStateCallback.setState(STATE_RESUME_LAST_TASK));
+                } else {
+                    mStateCallback.setState(STATE_RESUME_LAST_TASK);
+                }
                 TaskViewUtils.setDividerBarShown(mRecentsAnimationTargets.nonApps, true);
                 break;
         }
diff --git a/quickstep/src/com/android/quickstep/BaseActivityInterface.java b/quickstep/src/com/android/quickstep/BaseActivityInterface.java
index 571ffc23e5..29a069c354 100644
--- a/quickstep/src/com/android/quickstep/BaseActivityInterface.java
+++ b/quickstep/src/com/android/quickstep/BaseActivityInterface.java
@@ -40,6 +40,7 @@ import android.graphics.Rect;
 import android.os.Build;
 import android.view.Gravity;
 import android.view.MotionEvent;
+import android.view.View;
 
 import androidx.annotation.Nullable;
 import androidx.annotation.UiThread;
@@ -385,6 +386,15 @@ public abstract class BaseActivityInterface<STATE_TYPE extends BaseState<STATE_T
      */
     public abstract STATE_TYPE stateFromGestureEndTarget(GestureState.GestureEndTarget endTarget);
 
+    /**
+     * Called when the animation to the target has finished, but right before updating the state.
+     * @return A View that needs to draw before ending the recents animation to LAST_TASK.
+     * (This is a hack to ensure Taskbar draws its background first to avoid flickering.)
+     */
+    public @Nullable View onSettledOnEndTarget(GestureState.GestureEndTarget endTarget) {
+        return null;
+    }
+
     public interface AnimationFactory {
 
         void createActivityInterface(long transitionLength);
diff --git a/quickstep/src/com/android/quickstep/LauncherActivityInterface.java b/quickstep/src/com/android/quickstep/LauncherActivityInterface.java
index f84f377913..1b796e998c 100644
--- a/quickstep/src/com/android/quickstep/LauncherActivityInterface.java
+++ b/quickstep/src/com/android/quickstep/LauncherActivityInterface.java
@@ -25,10 +25,12 @@ import static com.android.launcher3.config.FeatureFlags.ENABLE_QUICKSTEP_LIVE_TI
 import static com.android.launcher3.util.Executors.MAIN_EXECUTOR;
 
 import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
 import android.animation.AnimatorSet;
 import android.content.Context;
 import android.graphics.Rect;
 import android.view.MotionEvent;
+import android.view.View;
 
 import androidx.annotation.Nullable;
 import androidx.annotation.UiThread;
@@ -131,6 +133,18 @@ public final class LauncherActivityInterface extends
                         new ClampedDepthProperty(fromDepthRatio, toDepthRatio),
                         fromDepthRatio, toDepthRatio, LINEAR);
 
+                pa.addListener(new AnimatorListenerAdapter() {
+                    @Override
+                    public void onAnimationStart(Animator animation) {
+                        LauncherTaskbarUIController taskbarUIController =
+                                activity.getTaskbarUIController();
+                        if (taskbarUIController != null) {
+                            // Launcher's ScrimView will draw the background throughout the gesture.
+                            taskbarUIController.forceHideBackground(true);
+                        }
+                    }
+                });
+
             }
         };
 
@@ -358,4 +372,16 @@ public final class LauncherActivityInterface extends
                 return NORMAL;
         }
     }
+
+    @Override
+    public View onSettledOnEndTarget(@Nullable GestureEndTarget endTarget) {
+        View superRet = super.onSettledOnEndTarget(endTarget);
+        LauncherTaskbarUIController taskbarUIController = getTaskbarController();
+        if (taskbarUIController != null) {
+            // Start drawing taskbar's background again since launcher might stop drawing.
+            taskbarUIController.forceHideBackground(false);
+            return taskbarUIController.getRootView();
+        }
+        return superRet;
+    }
 }