Scale recents during quick switch for large screens.

Test: manual
Fix: 192470757
Change-Id: I4522455e488213a6f461549a31e78edef35aac21
diff --git a/quickstep/res/values/dimens.xml b/quickstep/res/values/dimens.xml
index 1febc88..f54070e 100644
--- a/quickstep/res/values/dimens.xml
+++ b/quickstep/res/values/dimens.xml
@@ -70,6 +70,8 @@
     <item name="content_scale" format="float" type="dimen">0.97</item>
     <dimen name="closing_window_trans_y">115dp</dimen>
 
+    <dimen name="quick_switch_scaling_scroll_threshold">100dp</dimen>
+
     <dimen name="recents_empty_message_text_size">16sp</dimen>
     <dimen name="recents_empty_message_text_padding">16dp</dimen>
 
diff --git a/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java b/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java
index 9180bd0..830b7fa 100644
--- a/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java
+++ b/quickstep/src/com/android/quickstep/AbsSwipeUpHandler.java
@@ -212,6 +212,8 @@
 
     public static final long RECENTS_ATTACH_DURATION = 300;
 
+    private static final float MAX_QUICK_SWITCH_RECENTS_SCALE_PROGRESS = 0.07f;
+
     /**
      * Used as the page index for logging when we return to the last task at the end of the gesture.
      */
@@ -252,6 +254,9 @@
     private SwipePipToHomeAnimator mSwipePipToHomeAnimator;
     protected boolean mIsSwipingPipToHome;
 
+    // Interpolate RecentsView scale from start of quick switch scroll until this scroll threshold
+    private final float mQuickSwitchScaleScrollThreshold;
+
     public AbsSwipeUpHandler(Context context, RecentsAnimationDeviceState deviceState,
             TaskAnimationManager taskAnimationManager, GestureState gestureState,
             long touchTimeMs, boolean continuingLastGesture,
@@ -267,6 +272,8 @@
         mTaskAnimationManager = taskAnimationManager;
         mTouchTimeMs = touchTimeMs;
         mContinuingLastGesture = continuingLastGesture;
+        mQuickSwitchScaleScrollThreshold = context.getResources().getDimension(
+                R.dimen.quick_switch_scaling_scroll_threshold);
 
         initAfterSubclassConstructor();
         initStateCallbacks();
@@ -669,7 +676,8 @@
                 || !canCreateNewOrUpdateExistingLauncherTransitionController()) {
             return;
         }
-        mLauncherTransitionController.setProgress(mCurrentShift.value, mDragLengthFactor);
+        mLauncherTransitionController.setProgress(
+                Math.max(mCurrentShift.value, getScaleProgressDueToScroll()), mDragLengthFactor);
     }
 
     /**
@@ -1784,7 +1792,9 @@
      */
     protected void applyWindowTransform() {
         if (mWindowTransitionController != null) {
-            mWindowTransitionController.setProgress(mCurrentShift.value, mDragLengthFactor);
+            mWindowTransitionController.setProgress(
+                    Math.max(mCurrentShift.value, getScaleProgressDueToScroll()),
+                    mDragLengthFactor);
         }
         // No need to apply any transform if there is ongoing swipe-pip-to-home animator since
         // that animator handles the leash solely.
@@ -1797,6 +1807,35 @@
         ProtoTracer.INSTANCE.get(mContext).scheduleFrameUpdate();
     }
 
+    // Scaling of RecentsView during quick switch based on amount of recents scroll
+    private float getScaleProgressDueToScroll() {
+        if (!mActivity.getDeviceProfile().isTablet || mRecentsView == null
+                || !mRecentsViewScrollLinked) {
+            return 0;
+        }
+
+        float scrollOffset = Math.abs(mRecentsView.getScrollOffset(mRecentsView.getCurrentPage()));
+        int maxScrollOffset = mRecentsView.getPagedOrientationHandler().getPrimaryValue(
+                mRecentsView.getLastComputedTaskSize().width(),
+                mRecentsView.getLastComputedTaskSize().height());
+        maxScrollOffset += mRecentsView.getPageSpacing();
+
+        float maxScaleProgress =
+                MAX_QUICK_SWITCH_RECENTS_SCALE_PROGRESS * mRecentsView.getMaxScaleForFullScreen();
+        float scaleProgress = maxScaleProgress;
+
+        if (scrollOffset < mQuickSwitchScaleScrollThreshold) {
+            scaleProgress = Utilities.mapToRange(scrollOffset, 0, mQuickSwitchScaleScrollThreshold,
+                    0, maxScaleProgress, ACCEL_DEACCEL);
+        } else if (scrollOffset > (maxScrollOffset - mQuickSwitchScaleScrollThreshold)) {
+            scaleProgress = Utilities.mapToRange(scrollOffset,
+                    (maxScrollOffset - mQuickSwitchScaleScrollThreshold), maxScrollOffset,
+                    maxScaleProgress, 0, ACCEL_DEACCEL);
+        }
+
+        return scaleProgress;
+    }
+
     /**
      * Used for winscope tracing, see launcher_trace.proto
      * @see com.android.systemui.shared.tracing.ProtoTraceable#writeToProto