Merge "Add springs when snapping between pages on the workspace." into ub-launcher3-master

src/com/android/launcher3/PagedView.java

@@ -18,6 +18,7 @@ package com.android.launcher3;
 
 import static com.android.launcher3.compat.AccessibilityManagerCompat.isAccessibilityEnabled;
 import static com.android.launcher3.compat.AccessibilityManagerCompat.isObservedEventType;
+import static com.android.launcher3.config.FeatureFlags.QUICKSTEP_SPRINGS;
 import static com.android.launcher3.touch.OverScroll.OVERSCROLL_DAMP_FACTOR;
 
 import android.animation.LayoutTransition;
@@ -25,6 +26,7 @@ import android.animation.TimeInterpolator;
 import android.annotation.SuppressLint;
 import android.content.Context;
 import android.content.res.TypedArray;
+import android.graphics.Canvas;
 import android.graphics.Rect;
 import android.os.Bundle;
 import android.provider.Settings;
@@ -121,6 +123,8 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
 
     protected boolean mIsPageInTransition = false;
 
+    protected float mSpringOverScrollX;
+
     protected boolean mWasInOverscroll = false;
 
     protected int mUnboundedScrollX;
@@ -349,6 +353,11 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
 
         boolean isXBeforeFirstPage = mIsRtl ? (x > mMaxScrollX) : (x < 0);
         boolean isXAfterLastPage = mIsRtl ? (x < 0) : (x > mMaxScrollX);
+
+        if (!isXBeforeFirstPage && !isXAfterLastPage) {
+            mSpringOverScrollX = 0;
+        }
+
         if (isXBeforeFirstPage) {
             super.scrollTo(mIsRtl ? mMaxScrollX : 0, y);
             if (mAllowOverScroll) {
@@ -988,12 +997,35 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
         }
     }
 
+    @Override
+    protected void dispatchDraw(Canvas canvas) {
+        if (mScroller.isSpringing() && mSpringOverScrollX != 0) {
+            int saveCount = canvas.save();
+
+            canvas.translate(-mSpringOverScrollX, 0);
+            super.dispatchDraw(canvas);
+
+            canvas.restoreToCount(saveCount);
+        } else {
+            super.dispatchDraw(canvas);
+        }
+    }
+
     protected void dampedOverScroll(int amount) {
-        if (amount == 0) return;
+        mSpringOverScrollX = amount;
+        if (amount == 0) {
+            return;
+        }
 
         int overScrollAmount = OverScroll.dampedScroll(amount, getMeasuredWidth());
+        mSpringOverScrollX = overScrollAmount;
+        if (mScroller.isSpringing()) {
+            invalidate();
+            return;
+        }
+
         if (amount < 0) {
-            super.scrollTo(overScrollAmount, getScrollY());
+            super.scrollTo(amount, getScrollY());
         } else {
             super.scrollTo(mMaxScrollX + overScrollAmount, getScrollY());
         }
@@ -1001,6 +1033,12 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
     }
 
     protected void overScroll(int amount) {
+        mSpringOverScrollX = amount;
+        if (mScroller.isSpringing()) {
+            invalidate();
+            return;
+        }
+
         if (amount == 0) return;
 
         if (mFreeScroll && !mScroller.isFinished()) {
@@ -1372,7 +1410,12 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
         // interpolator at zero, ie. 5. We use 4 to make it a little slower.
         duration = 4 * Math.round(1000 * Math.abs(distance / velocity));
 
-        return snapToPage(whichPage, delta, duration);
+        if (QUICKSTEP_SPRINGS.get()) {
+            return snapToPage(whichPage, delta, duration, false, null,
+                    velocity * Math.signum(newX - getUnboundedScrollX()), true);
+        } else {
+            return snapToPage(whichPage, delta, duration);
+        }
     }
 
     public boolean snapToPage(int whichPage) {
@@ -1397,15 +1440,15 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
 
         int newX = getScrollForPage(whichPage);
         final int delta = newX - getUnboundedScrollX();
-        return snapToPage(whichPage, delta, duration, immediate, interpolator);
+        return snapToPage(whichPage, delta, duration, immediate, interpolator, 0, false);
     }
 
     protected boolean snapToPage(int whichPage, int delta, int duration) {
-        return snapToPage(whichPage, delta, duration, false, null);
+        return snapToPage(whichPage, delta, duration, false, null, 0, false);
     }
 
     protected boolean snapToPage(int whichPage, int delta, int duration, boolean immediate,
-            TimeInterpolator interpolator) {
+            TimeInterpolator interpolator, float velocity, boolean spring) {
         if (mFirstLayout) {
             setCurrentPage(whichPage);
             return false;
@@ -1441,7 +1484,11 @@ public abstract class PagedView<T extends View & PageIndicator> extends ViewGrou
             mScroller.setInterpolator(mDefaultInterpolator);
         }
 
-        mScroller.startScroll(getUnboundedScrollX(), delta, duration);
+        if (spring && QUICKSTEP_SPRINGS.get()) {
+            mScroller.startScrollSpring(getUnboundedScrollX(), delta, duration, velocity);
+        } else {
+            mScroller.startScroll(getUnboundedScrollX(), delta, duration);
+        }
 
         updatePageIndicator();
 

src/com/android/launcher3/Workspace.java

@@ -996,7 +996,7 @@ public class Workspace extends PagedView<WorkspacePageIndicator>
 
     @Override
     protected void overScroll(int amount) {
-        boolean shouldScrollOverlay = mLauncherOverlay != null &&
+        boolean shouldScrollOverlay = mLauncherOverlay != null && !mScroller.isSpringing() &&
                 ((amount <= 0 && !mIsRtl) || (amount >= 0 && mIsRtl));
 
         boolean shouldZeroOverlay = mLauncherOverlay != null && mLastOverlayScroll != 0 &&

src/com/android/launcher3/util/OverScroller.java

@@ -26,6 +26,11 @@ import android.view.ViewConfiguration;
 import android.view.animation.AnimationUtils;
 import android.view.animation.Interpolator;
 
+import androidx.dynamicanimation.animation.DynamicAnimation;
+import androidx.dynamicanimation.animation.FloatPropertyCompat;
+import androidx.dynamicanimation.animation.SpringAnimation;
+import androidx.dynamicanimation.animation.SpringForce;
+
 /**
  * Based on {@link android.widget.OverScroller} supporting only 1-d scrolling and with more
  * customization options.
@@ -196,6 +201,9 @@ public class OverScroller {
 
         switch (mMode) {
             case SCROLL_MODE:
+                if (isSpringing()) {
+                    return true;
+                }
                 long time = AnimationUtils.currentAnimationTimeMillis();
                 // Any scroller can be used for time, since they were started
                 // together in scroll mode. We use X here.
@@ -253,6 +261,22 @@ public class OverScroller {
         mScroller.startScroll(start, delta, duration);
     }
 
+    /**
+     * Start scrolling using a spring by providing a starting point and the distance to travel.
+     *
+     * @param start Starting scroll offset in pixels. Positive
+     *        numbers will scroll the content to the left.
+     * @param delta Distance to travel. Positive numbers will scroll the
+     *        content to the left.
+     * @param duration Duration of the scroll in milliseconds.
+     * @param velocity The starting velocity for the spring in px per ms.
+     */
+    public void startScrollSpring(int start, int delta, int duration, float velocity) {
+        mMode = SCROLL_MODE;
+        mScroller.mState = mScroller.SPRING;
+        mScroller.startScroll(start, delta, duration, velocity);
+    }
+
     /**
      * Call this when you want to 'spring back' into a valid coordinate range.
      *
@@ -354,6 +378,10 @@ public class OverScroller {
         return (int) (time - mScroller.mStartTime);
     }
 
+    public boolean isSpringing() {
+        return mScroller.mState == SplineOverScroller.SPRING && !isFinished();
+    }
+
     static class SplineOverScroller {
         // Initial position
         private int mStart;
@@ -397,6 +425,8 @@ public class OverScroller {
         // Current state of the animation.
         private int mState = SPLINE;
 
+        private SpringAnimation mSpring;
+
         // Constant gravity value, used in the deceleration phase.
         private static final float GRAVITY = 2000.0f;
 
@@ -417,6 +447,20 @@ public class OverScroller {
         private static final int SPLINE = 0;
         private static final int CUBIC = 1;
         private static final int BALLISTIC = 2;
+        private static final int SPRING = 3;
+
+        private static final FloatPropertyCompat<SplineOverScroller> SPRING_PROPERTY =
+                new FloatPropertyCompat<SplineOverScroller>("splineOverScrollerSpring") {
+                    @Override
+                    public float getValue(SplineOverScroller scroller) {
+                        return scroller.mCurrentPosition;
+                    }
+
+                    @Override
+                    public void setValue(SplineOverScroller scroller, float value) {
+                        scroller.mCurrentPosition = (int) value;
+                    }
+                };
 
         static {
             float x_min = 0.0f;
@@ -465,6 +509,9 @@ public class OverScroller {
         }
 
         void updateScroll(float q) {
+            if (mState == SPRING) {
+                return;
+            }
             mCurrentPosition = mStart + Math.round(q * (mFinal - mStart));
         }
 
@@ -495,6 +542,10 @@ public class OverScroller {
         }
 
         void startScroll(int start, int distance, int duration) {
+            startScroll(start, distance, duration, 0);
+        }
+
+        void startScroll(int start, int distance, int duration, float velocity) {
             mFinished = false;
 
             mCurrentPosition = mStart = start;
@@ -503,12 +554,31 @@ public class OverScroller {
             mStartTime = AnimationUtils.currentAnimationTimeMillis();
             mDuration = duration;
 
+            if (mState == SPRING) {
+                if (mSpring != null) {
+                    mSpring.cancel();
+                }
+                mSpring = new SpringAnimation(this, SPRING_PROPERTY);
+
+                mSpring.setSpring(new SpringForce(mFinal)
+                        .setStiffness(SpringForce.STIFFNESS_LOW)
+                        .setDampingRatio(SpringForce.DAMPING_RATIO_LOW_BOUNCY));
+                mSpring.setStartVelocity(velocity);
+                mSpring.animateToFinalPosition(mFinal);
+                mSpring.addEndListener((animation, canceled, value, velocity1) -> {
+                    finish();
+                    mState = SPLINE;
+                    mSpring = null;
+                });
+            }
             // Unused
             mDeceleration = 0.0f;
             mVelocity = 0;
         }
 
         void finish() {
+            if (mSpring != null && mSpring.isRunning()) mSpring.cancel();
+
             mCurrentPosition = mFinal;
             // Not reset since WebView relies on this value for fast fling.
             // TODO: restore when WebView uses the fast fling implemented in this class.
@@ -518,6 +588,9 @@ public class OverScroller {
 
         void setFinalPosition(int position) {
             mFinal = position;
+            if (mState == SPRING && mSpring != null) {
+                mSpring.animateToFinalPosition(mFinal);
+            }
             mSplineDistance = mFinal - mStart;
             mFinished = false;
         }
@@ -722,6 +795,10 @@ public class OverScroller {
          * reached.
          */
         boolean update() {
+            if (mState == SPRING) {
+                return mFinished;
+            }
+
             final long time = AnimationUtils.currentAnimationTimeMillis();
             final long currentTime = time - mStartTime;