Revert "Adding overscroll effect in recents list"

This reverts commit 4d6b1a95a13fd6f5b293ba97051bc645fab95334.

Bug: 110279118

Change-Id: I794b2c7af076d63901f2286fd2ff3d06c6e39fee

3 files changed, 61 insertions, 13 deletions

diff --git a/quickstep/src/com/android/quickstep/views/RecentsView.java b/quickstep/src/com/android/quickstep/views/RecentsView.java
index f7f496fef..1650b53a8 100644
--- a/quickstep/src/com/android/quickstep/views/RecentsView.java
+++ b/quickstep/src/com/android/quickstep/views/RecentsView.java
@@ -259,8 +259,8 @@ public abstract class RecentsView<T extends BaseActivity> extends PagedView impl
     public RecentsView(Context context, AttributeSet attrs, int defStyleAttr) {
         super(context, attrs, defStyleAttr);
         setPageSpacing(getResources().getDimensionPixelSize(R.dimen.recents_page_spacing));
-        setEnableFreeScroll(true);
-        setEnableOverscroll(true);
+        enableFreeScroll(true);
+        setClipToOutline(true);
 
         mFastFlingVelocity = getResources()
                 .getDimensionPixelSize(R.dimen.recents_fast_fling_velocity);
diff --git a/src/com/android/launcher3/LauncherScroller.java b/src/com/android/launcher3/LauncherScroller.java
index af87550ea..a9b49556b 100644
--- a/src/com/android/launcher3/LauncherScroller.java
+++ b/src/com/android/launcher3/LauncherScroller.java
@@ -459,13 +459,13 @@ public class LauncherScroller  {
         return Math.log(INFLEXION * Math.abs(velocity) / (mFlingFriction * mPhysicalCoeff));
     }
 
-    public int getSplineFlingDuration(float velocity) {
+    private int getSplineFlingDuration(float velocity) {
         final double l = getSplineDeceleration(velocity);
         final double decelMinusOne = DECELERATION_RATE - 1.0;
         return (int) (1000.0 * Math.exp(l / decelMinusOne));
     }
 
-    public double getSplineFlingDistance(float velocity) {
+    private double getSplineFlingDistance(float velocity) {
         final double l = getSplineDeceleration(velocity);
         final double decelMinusOne = DECELERATION_RATE - 1.0;
         return mFlingFriction * mPhysicalCoeff * Math.exp(DECELERATION_RATE / decelMinusOne * l);
diff --git a/src/com/android/launcher3/PagedView.java b/src/com/android/launcher3/PagedView.java
index 0cb653900..db5dc6635 100644
--- a/src/com/android/launcher3/PagedView.java
+++ b/src/com/android/launcher3/PagedView.java
@@ -63,6 +63,7 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
     protected static final ComputePageScrollsLogic SIMPLE_SCROLL_LOGIC = (v) -> v.getVisibility() != GONE;
 
     public static final int PAGE_SNAP_ANIMATION_DURATION = 750;
+    public static final int SLOW_PAGE_SNAP_ANIMATION_DURATION = 950;
 
     // OverScroll constants
     private final static int OVERSCROLL_PAGE_SNAP_ANIMATION_DURATION = 270;
@@ -82,6 +83,7 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
     public static final int INVALID_RESTORE_PAGE = -1001;
 
     private boolean mFreeScroll = false;
+    private boolean mSettleOnPageInFreeScroll = false;
 
     protected int mFlingThresholdVelocity;
     protected int mMinFlingVelocity;
@@ -354,6 +356,17 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
 
     @Override
     public void scrollTo(int x, int y) {
+        // In free scroll mode, we clamp the scrollX
+        if (mFreeScroll) {
+            // If the scroller is trying to move to a location beyond the maximum allowed
+            // in the free scroll mode, we make sure to end the scroll operation.
+            if (!mScroller.isFinished() && (x > mMaxScrollX || x < 0)) {
+                forceFinishScroller(false);
+            }
+
+            x = Utilities.boundToRange(x, 0, mMaxScrollX);
+        }
+
         mUnboundedScrollX = x;
 
         boolean isXBeforeFirstPage = mIsRtl ? (x > mMaxScrollX) : (x < 0);
@@ -1013,7 +1026,13 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
         dampedOverScroll(amount);
     }
 
-    protected void setEnableFreeScroll(boolean freeScroll) {
+
+    protected void enableFreeScroll(boolean settleOnPageInFreeScroll) {
+        setEnableFreeScroll(true);
+        mSettleOnPageInFreeScroll = settleOnPageInFreeScroll;
+    }
+
+    private void setEnableFreeScroll(boolean freeScroll) {
         boolean wasFreeScroll = mFreeScroll;
         mFreeScroll = freeScroll;
 
@@ -1022,6 +1041,8 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
         } else if (wasFreeScroll) {
             snapToPage(getNextPage());
         }
+
+        setEnableOverscroll(!freeScroll);
     }
 
     protected void setEnableOverscroll(boolean enable) {
@@ -1134,15 +1155,42 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
                         snapToDestination();
                     }
                 } else {
-                    int unscaledScrollX = getScrollX() - (int) Math.round(
-                            mScroller.getSplineFlingDistance(velocityX) * Math.signum(velocityX));
-                    int duration = mScroller.getSplineFlingDuration(velocityX);
-                    int finalPage = getPageNearestToCenterOfScreen(unscaledScrollX);
-                    if ((isFling || isSignificantMove) && (finalPage != mCurrentPage)) {
-                        snapToPage(finalPage, duration);
-                    } else {
-                        snapToDestination();
+                    if (!mScroller.isFinished()) {
+                        abortScrollerAnimation(true);
+                    }
+
+                    float scaleX = getScaleX();
+                    int vX = (int) (-velocityX * scaleX);
+                    int initialScrollX = (int) (getScrollX() * scaleX);
+
+                    mScroller.setInterpolator(mDefaultInterpolator);
+                    mScroller.fling(initialScrollX,
+                            getScrollY(), vX, 0, Integer.MIN_VALUE, Integer.MAX_VALUE, 0, 0);
+                    int unscaledScrollX = (int) (mScroller.getFinalX() / scaleX);
+                    mNextPage = getPageNearestToCenterOfScreen(unscaledScrollX);
+                    int firstPageScroll = getScrollForPage(!mIsRtl ? 0 : getPageCount() - 1);
+                    int lastPageScroll = getScrollForPage(!mIsRtl ? getPageCount() - 1 : 0);
+                    if (mSettleOnPageInFreeScroll && unscaledScrollX > 0
+                            && unscaledScrollX < mMaxScrollX) {
+                        // If scrolling ends in the half of the added space that is closer to the
+                        // end, settle to the end. Otherwise snap to the nearest page.
+                        // If flinging past one of the ends, don't change the velocity as it will
+                        // get stopped at the end anyway.
+                        final int finalX = unscaledScrollX < firstPageScroll / 2 ?
+                                0 :
+                                unscaledScrollX > (lastPageScroll + mMaxScrollX) / 2 ?
+                                        mMaxScrollX :
+                                        getScrollForPage(mNextPage);
+
+                        mScroller.setFinalX((int) (finalX * getScaleX()));
+                        // Ensure the scroll/snap doesn't happen too fast;
+                        int extraScrollDuration = OVERSCROLL_PAGE_SNAP_ANIMATION_DURATION
+                                - mScroller.getDuration();
+                        if (extraScrollDuration > 0) {
+                            mScroller.extendDuration(extraScrollDuration);
+                        }
                     }
+                    invalidate();
                 }
                 onScrollInteractionEnd();
             } else if (mTouchState == TOUCH_STATE_PREV_PAGE) {