Merge "Adjustments to PIP position while flinging" into oc-dr1-dev

am: 176f2533a1

Change-Id: Ic5d38c862c155ac025884e53d688826b57829529

5 files changed, 109 insertions, 24 deletions

diff --git a/core/java/com/android/internal/policy/PipSnapAlgorithm.java b/core/java/com/android/internal/policy/PipSnapAlgorithm.java
index 95d714f1c3c7..749d00c136ec 100644
--- a/core/java/com/android/internal/policy/PipSnapAlgorithm.java
+++ b/core/java/com/android/internal/policy/PipSnapAlgorithm.java
@@ -49,9 +49,6 @@ public class PipSnapAlgorithm {
     // Allows snapping on the long edge in each orientation and magnets towards corners
     private static final int SNAP_MODE_LONG_EDGE_MAGNET_CORNERS = 4;
 
-    // The friction multiplier to control how slippery the PIP is when flung
-    private static final float SCROLL_FRICTION_MULTIPLIER = 8f;
-
     // Threshold to magnet to a corner
     private static final float CORNER_MAGNET_THRESHOLD = 0.3f;
 
@@ -64,8 +61,8 @@ public class PipSnapAlgorithm {
     private final float mDefaultSizePercent;
     private final float mMinAspectRatioForMinSize;
     private final float mMaxAspectRatioForMinSize;
+    private final int mFlingDeceleration;
 
-    private Scroller mScroller;
     private int mOrientation = Configuration.ORIENTATION_UNDEFINED;
 
     private final int mMinimizedVisibleSize;
@@ -81,6 +78,8 @@ public class PipSnapAlgorithm {
         mMaxAspectRatioForMinSize = res.getFloat(
                 com.android.internal.R.dimen.config_pictureInPictureAspectRatioLimitForMinSize);
         mMinAspectRatioForMinSize = 1f / mMaxAspectRatioForMinSize;
+        mFlingDeceleration = mContext.getResources().getDimensionPixelSize(
+                com.android.internal.R.dimen.pip_fling_deceleration);
         onConfigurationChanged();
     }
 
@@ -107,20 +106,97 @@ public class PipSnapAlgorithm {
      * those for the given {@param stackBounds}.
      */
     public Rect findClosestSnapBounds(Rect movementBounds, Rect stackBounds, float velocityX,
-            float velocityY) {
-        final Rect finalStackBounds = new Rect(stackBounds);
-        if (mScroller == null) {
-            final ViewConfiguration viewConfig = ViewConfiguration.get(mContext);
-            mScroller = new Scroller(mContext);
-            mScroller.setFriction(viewConfig.getScrollFriction() * SCROLL_FRICTION_MULTIPLIER);
+            float velocityY, Point dragStartPosition) {
+        final Rect intersectStackBounds = new Rect(stackBounds);
+        final Point intersect = getEdgeIntersect(stackBounds, movementBounds, velocityX, velocityY,
+                dragStartPosition);
+        intersectStackBounds.offsetTo(intersect.x, intersect.y);
+        return findClosestSnapBounds(movementBounds, intersectStackBounds);
+    }
+
+    /**
+     * @return The point along the {@param movementBounds} that the PIP would intersect with based
+     *         on the provided {@param velX}, {@param velY} along with the position of the PIP when
+     *         the gesture started, {@param dragStartPosition}.
+     */
+    public Point getEdgeIntersect(Rect stackBounds, Rect movementBounds, float velX, float velY,
+            Point dragStartPosition) {
+        final boolean isLandscape = mOrientation == Configuration.ORIENTATION_LANDSCAPE;
+        final int x = stackBounds.left;
+        final int y = stackBounds.top;
+
+        // Find the line of movement the PIP is on. Line defined by: y = slope * x + yIntercept
+        final float slope = velY / velX; // slope = rise / run
+        final float yIntercept = y - slope * x; // rearrange line equation for yIntercept
+        // The PIP can have two intercept points:
+        // 1) Where the line intersects with one of the edges of the screen (vertical line)
+        Point vertPoint = new Point();
+        // 2) Where the line intersects with the top or bottom of the screen (horizontal line)
+        Point horizPoint = new Point();
+
+        // Find the vertical line intersection, x will be one of the edges
+        vertPoint.x = velX > 0 ? movementBounds.right : movementBounds.left;
+        // Sub in x in our line equation to determine y position
+        vertPoint.y = findY(slope, yIntercept, vertPoint.x);
+
+        // Find the horizontal line intersection, y will be the top or bottom of the screen
+        horizPoint.y = velY > 0 ? movementBounds.bottom : movementBounds.top;
+        // Sub in y in our line equation to determine x position
+        horizPoint.x = findX(slope, yIntercept, horizPoint.y);
+
+        // Now pick one of these points -- first determine if we're flinging along the current edge.
+        // Only fling along current edge if it's a direction with space for the PIP to move to
+        int maxDistance;
+        if (isLandscape) {
+            maxDistance = velX > 0
+                    ? movementBounds.right - stackBounds.left
+                    : stackBounds.left - movementBounds.left;
+        } else {
+            maxDistance = velY > 0
+                    ? movementBounds.bottom - stackBounds.top
+                    : stackBounds.top - movementBounds.top;
         }
-        mScroller.fling(stackBounds.left, stackBounds.top,
-                (int) velocityX, (int) velocityY,
-                movementBounds.left, movementBounds.right,
-                movementBounds.top, movementBounds.bottom);
-        finalStackBounds.offsetTo(mScroller.getFinalX(), mScroller.getFinalY());
-        mScroller.abortAnimation();
-        return findClosestSnapBounds(movementBounds, finalStackBounds);
+        if (maxDistance > 0) {
+            // Only fling along the current edge if the start and end point are on the same side
+            final int startPoint = isLandscape ? dragStartPosition.y : dragStartPosition.x;
+            final int endPoint = isLandscape ? horizPoint.y : horizPoint.x;
+            final int center = movementBounds.centerX();
+            if ((startPoint < center && endPoint < center)
+                    || (startPoint > center && endPoint > center)) {
+                // We are flinging along the current edge, figure out how far it should travel
+                // based on velocity and assumed deceleration.
+                int distance = (int) (0 - Math.pow(isLandscape ? velX : velY, 2))
+                        / (2 * mFlingDeceleration);
+                distance = Math.min(distance, maxDistance);
+                // Adjust the point for the distance
+                if (isLandscape) {
+                    horizPoint.x = stackBounds.left + (velX > 0 ? distance : -distance);
+                } else {
+                    horizPoint.y = stackBounds.top + (velY > 0 ? distance : -distance);
+                }
+                return horizPoint;
+            }
+        }
+        // If we're not flinging along the current edge, find the closest point instead.
+        final double distanceVert = Math.hypot(vertPoint.x - x, vertPoint.y - y);
+        final double distanceHoriz = Math.hypot(horizPoint.x - x, horizPoint.y - y);
+        // Ensure that we're actually going somewhere
+        if (distanceVert == 0) {
+            return horizPoint;
+        }
+        if (distanceHoriz == 0) {
+            return vertPoint;
+        }
+        // Otherwise use the closest point
+        return Math.abs(distanceVert) > Math.abs(distanceHoriz) ? horizPoint : vertPoint;
+    }
+
+    private int findY(float slope, float yIntercept, float x) {
+        return (int) ((slope * x) + yIntercept);
+    }
+
+    private int findX(float slope, float yIntercept, float y) {
+        return (int) ((y - yIntercept) / slope);
     }
 
     /**
diff --git a/core/res/res/values/dimens.xml b/core/res/res/values/dimens.xml
index 5e2334d20da1..fa33d567983e 100644
--- a/core/res/res/values/dimens.xml
+++ b/core/res/res/values/dimens.xml
@@ -67,6 +67,9 @@
     <!-- The amount to leave on-screen when the PIP is minimized. -->
     <dimen name="pip_minimized_visible_size">48dp</dimen>
 
+    <!-- The the PIP decelerates at while moving from a fling. -->
+    <dimen name="pip_fling_deceleration">-3000dp</dimen>
+
     <!-- Min width for a tablet device -->
     <dimen name="min_xlarge_screen_width">800dp</dimen>
 
diff --git a/core/res/res/values/symbols.xml b/core/res/res/values/symbols.xml
index f39c24985b17..885f0a3a9ecc 100644
--- a/core/res/res/values/symbols.xml
+++ b/core/res/res/values/symbols.xml
@@ -1581,6 +1581,7 @@
   <java-symbol type="dimen" name="docked_stack_divider_insets" />
   <java-symbol type="dimen" name="docked_stack_minimize_thickness" />
   <java-symbol type="dimen" name="pip_minimized_visible_size" />
+  <java-symbol type="dimen" name="pip_fling_deceleration" />
   <java-symbol type="integer" name="config_dockedStackDividerSnapMode" />
   <java-symbol type="integer" name="config_pictureInPictureSnapMode" />
   <java-symbol type="fraction" name="docked_stack_divider_fixed_ratio" />
diff --git a/packages/SystemUI/src/com/android/systemui/pip/phone/PipMotionHelper.java b/packages/SystemUI/src/com/android/systemui/pip/phone/PipMotionHelper.java
index b8771d7e0fb6..cebb22f07aaf 100644
--- a/packages/SystemUI/src/com/android/systemui/pip/phone/PipMotionHelper.java
+++ b/packages/SystemUI/src/com/android/systemui/pip/phone/PipMotionHelper.java
@@ -241,14 +241,14 @@ public class PipMotionHelper implements Handler.Callback {
     /**
      * Flings the minimized PiP to the closest minimized snap target.
      */
-    Rect flingToMinimizedState(float velocityY, Rect movementBounds) {
+    Rect flingToMinimizedState(float velocityY, Rect movementBounds, Point dragStartPosition) {
         cancelAnimations();
         // We currently only allow flinging the minimized stack up and down, so just lock the
         // movement bounds to the current stack bounds horizontally
         movementBounds = new Rect(mBounds.left, movementBounds.top, mBounds.left,
                 movementBounds.bottom);
         Rect toBounds = mSnapAlgorithm.findClosestSnapBounds(movementBounds, mBounds,
-                0 /* velocityX */, velocityY);
+                0 /* velocityX */, velocityY, dragStartPosition);
         if (!mBounds.equals(toBounds)) {
             mBoundsAnimator = createAnimationToBounds(mBounds, toBounds, 0, FAST_OUT_SLOW_IN);
             mFlingAnimationUtils.apply(mBoundsAnimator, 0,
@@ -281,10 +281,11 @@ public class PipMotionHelper implements Handler.Callback {
      * Flings the PiP to the closest snap target.
      */
     Rect flingToSnapTarget(float velocity, float velocityX, float velocityY, Rect movementBounds,
-            AnimatorUpdateListener updateListener, AnimatorListener listener) {
+            AnimatorUpdateListener updateListener, AnimatorListener listener,
+            Point startPosition) {
         cancelAnimations();
         Rect toBounds = mSnapAlgorithm.findClosestSnapBounds(movementBounds, mBounds,
-                velocityX, velocityY);
+                velocityX, velocityY, startPosition);
         if (!mBounds.equals(toBounds)) {
             mBoundsAnimator = createAnimationToBounds(mBounds, toBounds, 0, FAST_OUT_SLOW_IN);
             mFlingAnimationUtils.apply(mBoundsAnimator, 0,
diff --git a/packages/SystemUI/src/com/android/systemui/pip/phone/PipTouchHandler.java b/packages/SystemUI/src/com/android/systemui/pip/phone/PipTouchHandler.java
index 3682ae655f7c..9588b03b53bd 100644
--- a/packages/SystemUI/src/com/android/systemui/pip/phone/PipTouchHandler.java
+++ b/packages/SystemUI/src/com/android/systemui/pip/phone/PipTouchHandler.java
@@ -185,7 +185,7 @@ public class PipTouchHandler {
         mDismissViewController = new PipDismissViewController(context);
         mSnapAlgorithm = new PipSnapAlgorithm(mContext);
         mTouchState = new PipTouchState(mViewConfig);
-        mFlingAnimationUtils = new FlingAnimationUtils(context, 2f);
+        mFlingAnimationUtils = new FlingAnimationUtils(context, 2.5f);
         mGestures = new PipTouchGesture[] {
                 mDefaultMovementGesture
         };
@@ -534,6 +534,7 @@ public class PipTouchHandler {
     private PipTouchGesture mDefaultMovementGesture = new PipTouchGesture() {
         // Whether the PiP was on the left side of the screen at the start of the gesture
         private boolean mStartedOnLeft;
+        private Point mStartPosition;
 
         @Override
         public void onDown(PipTouchState touchState) {
@@ -541,7 +542,9 @@ public class PipTouchHandler {
                 return;
             }
 
-            mStartedOnLeft = mMotionHelper.getBounds().left < mMovementBounds.centerX();
+            Rect bounds = mMotionHelper.getBounds();
+            mStartPosition = new Point(bounds.left, bounds.top);
+            mStartedOnLeft = bounds.left < mMovementBounds.centerX();
             mMovementWithinMinimize = true;
             mMovementWithinDismiss = touchState.getDownTouchPosition().y >= mMovementBounds.bottom;
 
@@ -687,7 +690,8 @@ public class PipTouchHandler {
 
                 if (isFling) {
                     mMotionHelper.flingToSnapTarget(velocity, vel.x, vel.y, mMovementBounds,
-                            mUpdateScrimListener, postAnimationCallback);
+                            mUpdateScrimListener, postAnimationCallback,
+                            mStartPosition);
                 } else {
                     mMotionHelper.animateToClosestSnapTarget(mMovementBounds, mUpdateScrimListener,
                             postAnimationCallback);