Add springs when snapping between pages on the workspace.
- Behind feature flag QUICKSTEP_SPRINGS
- Springs control settling the page and allow for overscroll for the
first/last pages
Bug: 111698021
Change-Id: Ib4a9ef59463cc46e31ac0766bf7705612f6c63c1
diff --git a/src/com/android/launcher3/PagedView.java b/src/com/android/launcher3/PagedView.java
index 9470635..a6b3a19 100644
--- a/src/com/android/launcher3/PagedView.java
+++ b/src/com/android/launcher3/PagedView.java
@@ -18,6 +18,7 @@
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.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 @@
protected boolean mIsPageInTransition = false;
+ protected float mSpringOverScrollX;
+
protected boolean mWasInOverscroll = false;
protected int mUnboundedScrollX;
@@ -349,6 +353,11 @@
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 @@
}
}
+ @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 @@
}
protected void overScroll(int amount) {
+ mSpringOverScrollX = amount;
+ if (mScroller.isSpringing()) {
+ invalidate();
+ return;
+ }
+
if (amount == 0) return;
if (mFreeScroll && !mScroller.isFinished()) {
@@ -1372,7 +1410,12 @@
// 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 @@
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 @@
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();
diff --git a/src/com/android/launcher3/Workspace.java b/src/com/android/launcher3/Workspace.java
index eb26961..3438a26 100644
--- a/src/com/android/launcher3/Workspace.java
+++ b/src/com/android/launcher3/Workspace.java
@@ -996,7 +996,7 @@
@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 &&
diff --git a/src/com/android/launcher3/util/OverScroller.java b/src/com/android/launcher3/util/OverScroller.java
index d697ece..fc8a138 100644
--- a/src/com/android/launcher3/util/OverScroller.java
+++ b/src/com/android/launcher3/util/OverScroller.java
@@ -26,6 +26,11 @@
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 @@
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.
@@ -254,6 +262,22 @@
}
/**
+ * 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.
*
* @param start Starting X coordinate
@@ -354,6 +378,10 @@
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 @@
// 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 @@
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 @@
}
void updateScroll(float q) {
+ if (mState == SPRING) {
+ return;
+ }
mCurrentPosition = mStart + Math.round(q * (mFinal - mStart));
}
@@ -495,6 +542,10 @@
}
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 @@
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 @@
void setFinalPosition(int position) {
mFinal = position;
+ if (mState == SPRING && mSpring != null) {
+ mSpring.animateToFinalPosition(mFinal);
+ }
mSplineDistance = mFinal - mStart;
mFinished = false;
}
@@ -722,6 +795,10 @@
* reached.
*/
boolean update() {
+ if (mState == SPRING) {
+ return mFinished;
+ }
+
final long time = AnimationUtils.currentAnimationTimeMillis();
final long currentTime = time - mStartTime;