From 05476b3ace0505841b00c36195bcb5e30aeb1ba0 Mon Sep 17 00:00:00 2001
From: Ben Lin <linben@google.com>
Date: Fri, 6 Nov 2020 12:47:07 -0800
Subject: [PATCH] Change PiP stash to be based on velocity rather than
 position.

Also only allow stashing if user starts dragging from that edge.

Bug: 165793553
Test: Stash PIP via flinging
Change-Id: Icfd6d8d580cfb96b148f7712d0aedfcee1f30b2d
---
 .../wm/shell/pip/phone/PipMotionHelper.java   |  7 +++---
 .../wm/shell/pip/phone/PipTouchHandler.java   | 25 ++++++++++---------
 2 files changed, 16 insertions(+), 16 deletions(-)

diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/pip/phone/PipMotionHelper.java b/libs/WindowManager/Shell/src/com/android/wm/shell/pip/phone/PipMotionHelper.java
index d211d6570025a..d7b56ae74b38c 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/pip/phone/PipMotionHelper.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/pip/phone/PipMotionHelper.java
@@ -368,12 +368,11 @@ public class PipMotionHelper implements PipAppOpsListener.Callback,
     }
 
     /**
-     * Stash PiP to the closest edge.
+     * Stash PiP to the closest edge. We set velocityY to 0 to limit pure horizontal motion.
      */
-    void stashToEdge(
-            float velocityX, float velocityY, @Nullable Runnable postBoundsUpdateCallback) {
+    void stashToEdge(float velocityX, @Nullable Runnable postBoundsUpdateCallback) {
         mPipBoundsState.setStashed(velocityX < 0 ? STASH_TYPE_LEFT : STASH_TYPE_RIGHT);
-        movetoTarget(velocityX, velocityY, postBoundsUpdateCallback, true /* isStash */);
+        movetoTarget(velocityX, 0 /* velocityY */, postBoundsUpdateCallback, true /* isStash */);
     }
 
     private void movetoTarget(
diff --git a/libs/WindowManager/Shell/src/com/android/wm/shell/pip/phone/PipTouchHandler.java b/libs/WindowManager/Shell/src/com/android/wm/shell/pip/phone/PipTouchHandler.java
index ae1dd3873bded..b8d6b3cab8839 100644
--- a/libs/WindowManager/Shell/src/com/android/wm/shell/pip/phone/PipTouchHandler.java
+++ b/libs/WindowManager/Shell/src/com/android/wm/shell/pip/phone/PipTouchHandler.java
@@ -64,11 +64,7 @@ import java.util.function.Consumer;
 public class PipTouchHandler {
     private static final String TAG = "PipTouchHandler";
 
-    /** Duration of the dismiss scrim fading in/out. */
-    private static final int DISMISS_TRANSITION_DURATION_MS = 200;
-
-    /* The multiplier to apply scale the target size by when applying the magnetic field radius */
-    private static final float MAGNETIC_FIELD_RADIUS_MULTIPLIER = 1.25f;
+    private static final float STASH_MINIMUM_VELOCITY_X = 3000.f;
 
     // Allow PIP to resize to a slightly bigger state upon touch
     private final boolean mEnableResize;
@@ -710,6 +706,7 @@ public class PipTouchHandler {
         private final Point mStartPosition = new Point();
         private final PointF mDelta = new PointF();
         private boolean mShouldHideMenuAfterFling;
+        private float mDownSavedFraction = -1f;
 
         @Override
         public void onDown(PipTouchState touchState) {
@@ -722,6 +719,7 @@ public class PipTouchHandler {
             mStartPosition.set(bounds.left, bounds.top);
             mMovementWithinDismiss = touchState.getDownTouchPosition().y >= mMovementBounds.bottom;
             mMotionHelper.setSpringingToTouch(false);
+            mDownSavedFraction = mPipBoundsHandler.getSnapFraction(mPipBoundsState.getBounds());
 
             // If the menu is still visible then just poke the menu
             // so that it will timeout after the user stops touching it
@@ -790,13 +788,15 @@ public class PipTouchHandler {
 
                 // Reset the touch state on up before the fling settles
                 mTouchState.reset();
-                final Rect animatingBounds = getPossiblyAnimatingBounds();
-                // If User releases the PIP window while it's out of the display bounds, put
-                // PIP into stashed mode.
-                if (mEnableStash
-                        && (animatingBounds.right > mPipBoundsState.getDisplayBounds().right
-                        || animatingBounds.left < mPipBoundsState.getDisplayBounds().left)) {
-                    mMotionHelper.stashToEdge(vel.x, vel.y, this::stashEndAction /* endAction */);
+                // If user flings the PIP window above the minimum velocity, stash PIP.
+                // Only allow stashing to the edge if the user starts dragging the PIP from that
+                // edge.
+                if (mEnableStash && !mPipBoundsState.isStashed()
+                        && ((vel.x > STASH_MINIMUM_VELOCITY_X
+                        && mDownSavedFraction > 1f && mDownSavedFraction < 2f)
+                        || (vel.x < -STASH_MINIMUM_VELOCITY_X
+                        && mDownSavedFraction > 3f && mDownSavedFraction < 4f))) {
+                    mMotionHelper.stashToEdge(vel.x, this::stashEndAction /* endAction */);
                 } else {
                     mMotionHelper.flingToSnapTarget(vel.x, vel.y,
                             this::flingEndAction /* endAction */);
@@ -834,6 +834,7 @@ public class PipTouchHandler {
                     mTouchState.scheduleDoubleTapTimeoutCallback();
                 }
             }
+            mDownSavedFraction = -1f;
             return true;
         }