From cad1f13d2740d26d6e9b9f01bef1edbc64558355 Mon Sep 17 00:00:00 2001
From: Fengjiang Li <fengjial@google.com>
Date: Thu, 29 Feb 2024 10:24:37 -0800
Subject: [PATCH] [Predictive Back] Fix predictive back swipe on task bar all
 apps [1/n]

For taskbar all apps, the background scrim is child view of AbstractSlideInView, thus scaling AbstracSlideInView during PB swipe will scale down background scrim. There is no need to re-apply scale effect on background scrim separately.

Bug: 327490078
Flag: aconfig com.android.launcher3.enable_predictive_back_gesture TEAMFOOD
Test: manual
Change-Id: I125670d14bc788664a1371008589e4106496ae2e
---
 .../allapps/TaskbarAllAppsSlideInView.java    |  8 +++++++-
 .../allapps/ActivityAllAppsContainerView.java |  6 ++++--
 .../android/launcher3/views/ScrimView.java    | 19 +++++++++++++++----
 3 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/quickstep/src/com/android/launcher3/taskbar/allapps/TaskbarAllAppsSlideInView.java b/quickstep/src/com/android/launcher3/taskbar/allapps/TaskbarAllAppsSlideInView.java
index 5424fcf013..70d25b9753 100644
--- a/quickstep/src/com/android/launcher3/taskbar/allapps/TaskbarAllAppsSlideInView.java
+++ b/quickstep/src/com/android/launcher3/taskbar/allapps/TaskbarAllAppsSlideInView.java
@@ -196,7 +196,13 @@ public class TaskbarAllAppsSlideInView extends AbstractSlideInView<TaskbarOverla
 
     @Override
     protected void dispatchDraw(Canvas canvas) {
-        mAppsView.drawOnScrimWithScale(canvas, mSlideInViewScale.value);
+        // We should call drawOnScrimWithBottomOffset() rather than drawOnScrimWithScale(). Because
+        // for taskbar all apps, the scrim view is a child view of AbstractSlideInView. Thus scaling
+        // down in AbstractSlideInView#onScaleProgressChanged() with SCALE_PROPERTY has already
+        // done the job - there is no need to re-apply scale effect here. But it also means we need
+        // to pass extra bottom offset to background scrim to fill the bottom gap during predictive
+        // back swipe.
+        mAppsView.drawOnScrimWithBottomOffset(canvas, getBottomOffsetPx());
         super.dispatchDraw(canvas);
     }
 
diff --git a/src/com/android/launcher3/allapps/ActivityAllAppsContainerView.java b/src/com/android/launcher3/allapps/ActivityAllAppsContainerView.java
index 6acfcd0f11..01ea9fb240 100644
--- a/src/com/android/launcher3/allapps/ActivityAllAppsContainerView.java
+++ b/src/com/android/launcher3/allapps/ActivityAllAppsContainerView.java
@@ -1372,7 +1372,8 @@ public class ActivityAllAppsContainerView<T extends Context & ActivityContext>
     }
 
     @Override
-    public void drawOnScrimWithScale(Canvas canvas, float scale) {
+    public void drawOnScrimWithScaleAndBottomOffset(
+            Canvas canvas, float scale, @Px int bottomOffsetPx) {
         final View panel = mBottomSheetBackground;
         final boolean hasBottomSheet = panel.getVisibility() == VISIBLE;
         final float translationY = ((View) panel.getParent()).getTranslationY();
@@ -1384,6 +1385,7 @@ public class ActivityAllAppsContainerView<T extends Context & ActivityContext>
         final float topWithScale = topNoScale + verticalScaleOffset;
         final float leftWithScale = panel.getLeft() + horizontalScaleOffset;
         final float rightWithScale = panel.getRight() - horizontalScaleOffset;
+        final float bottomWithOffset = panel.getBottom() + bottomOffsetPx;
         // Draw full background panel for tablets.
         if (hasBottomSheet) {
             mHeaderPaint.setColor(mBottomSheetBackgroundColor);
@@ -1393,7 +1395,7 @@ public class ActivityAllAppsContainerView<T extends Context & ActivityContext>
                     leftWithScale,
                     topWithScale,
                     rightWithScale,
-                    panel.getBottom());
+                    bottomWithOffset);
             mTmpPath.reset();
             mTmpPath.addRoundRect(mTmpRectF, mBottomSheetCornerRadii, Direction.CW);
             canvas.drawPath(mTmpPath, mHeaderPaint);
diff --git a/src/com/android/launcher3/views/ScrimView.java b/src/com/android/launcher3/views/ScrimView.java
index ca80c516f0..f6c49847de 100644
--- a/src/com/android/launcher3/views/ScrimView.java
+++ b/src/com/android/launcher3/views/ScrimView.java
@@ -26,6 +26,7 @@ import android.util.AttributeSet;
 import android.view.View;
 
 import androidx.annotation.NonNull;
+import androidx.annotation.Px;
 import androidx.core.graphics.ColorUtils;
 
 import com.android.launcher3.BaseActivity;
@@ -187,9 +188,19 @@ public class ScrimView extends View implements Insettable {
      * A Utility interface allowing for other surfaces to draw on ScrimView
      */
     public interface ScrimDrawingController {
-        /**
-         * Called inside ScrimView#OnDraw
-         */
-        void drawOnScrimWithScale(Canvas canvas, float scale);
+
+        /** Draw scrim view on canvas with scale. */
+        default void drawOnScrimWithScale(Canvas canvas, float scale) {
+            drawOnScrimWithScaleAndBottomOffset(canvas, scale, 0);
+        }
+
+        /** Draw scrim view on canvas with bottomOffset. */
+        default void drawOnScrimWithBottomOffset(Canvas canvas, @Px int bottomOffsetPx) {
+            drawOnScrimWithScaleAndBottomOffset(canvas, 1f, bottomOffsetPx);
+        }
+
+        /** Draw scrim view on canvas with scale and bottomOffset. */
+        void drawOnScrimWithScaleAndBottomOffset(
+                Canvas canvas, float scale, @Px int bottomOffsetPx);
     }
 }