Add carousel curve effect to RecentsView.
Pages scale down and tuck underneath the centermost page.
Change-Id: I12686cd72634f758ef71828033eb4e22339ef185
diff --git a/quickstep/src/com/android/quickstep/RecentsView.java b/quickstep/src/com/android/quickstep/RecentsView.java
index 675f456..ba88f99 100644
--- a/quickstep/src/com/android/quickstep/RecentsView.java
+++ b/quickstep/src/com/android/quickstep/RecentsView.java
@@ -16,10 +16,12 @@
package com.android.quickstep;
+import android.animation.TimeInterpolator;
import android.content.Context;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.LayoutInflater;
+import android.view.View;
import com.android.launcher3.DeviceProfile;
import com.android.launcher3.Launcher;
@@ -41,6 +43,12 @@
*/
public class RecentsView extends PagedView {
+ /** Designates how "curvy" the carousel is from 0 to 1, where 0 is a straight line. */
+ private static final float CURVE_FACTOR = 0.25f;
+ /** A circular curve of x from 0 to 1, where 0 is the center of the screen and 1 is the edge. */
+ private static final TimeInterpolator CURVE_INTERPOLATOR
+ = x -> (float) (1 - Math.sqrt(1 - Math.pow(x, 2)));
+
private boolean mOverviewStateEnabled;
private boolean mTaskStackListenerRegistered;
@@ -69,6 +77,7 @@
super(context, attrs, defStyleAttr);
setWillNotDraw(false);
setPageSpacing((int) getResources().getDimension(R.dimen.recents_page_spacing));
+ enableFreeScroll(true);
}
@Override
@@ -170,4 +179,39 @@
padding.left = padding.right = (int) ((profile.availableWidthPx - overviewWidth) / 2);
return padding;
}
+
+ @Override
+ public void scrollTo(int x, int y) {
+ super.scrollTo(x, y);
+ updateCurveProperties();
+ }
+
+ /**
+ * Scales and adjusts translation of adjacent pages as if on a curved carousel.
+ */
+ private void updateCurveProperties() {
+ if (getPageCount() == 0 || getPageAt(0).getMeasuredWidth() == 0) {
+ return;
+ }
+ final int halfScreenWidth = getMeasuredWidth() / 2;
+ final int screenCenter = halfScreenWidth + getScrollX();
+ final int pageSpacing = getResources().getDimensionPixelSize(R.dimen.recents_page_spacing);
+ final int pageCount = getPageCount();
+ for (int i = 0; i < pageCount; i++) {
+ View page = getPageAt(i);
+ int pageWidth = page.getMeasuredWidth();
+ int halfPageWidth = pageWidth / 2;
+ int pageCenter = page.getLeft() + halfPageWidth;
+ float distanceFromScreenCenter = Math.abs(pageCenter - screenCenter);
+ float distanceToReachEdge = halfScreenWidth + halfPageWidth + pageSpacing;
+ float linearInterpolation = Math.min(1, distanceFromScreenCenter / distanceToReachEdge);
+ float curveInterpolation = CURVE_INTERPOLATOR.getInterpolation(linearInterpolation);
+ float scale = 1 - curveInterpolation * CURVE_FACTOR;
+ page.setScaleX(scale);
+ page.setScaleY(scale);
+ // Make sure the biggest card (i.e. the one in front) shows on top of the adjacent ones.
+ page.setTranslationZ(scale);
+ page.setTranslationX((screenCenter - pageCenter) * curveInterpolation * CURVE_FACTOR);
+ }
+ }
}
diff --git a/src/com/android/launcher3/PagedView.java b/src/com/android/launcher3/PagedView.java
index 6c22474..9f6efb3 100644
--- a/src/com/android/launcher3/PagedView.java
+++ b/src/com/android/launcher3/PagedView.java
@@ -30,7 +30,6 @@
import android.os.Parcel;
import android.os.Parcelable;
import android.util.AttributeSet;
-import android.util.DisplayMetrics;
import android.util.Log;
import android.view.InputDevice;
import android.view.KeyEvent;
@@ -87,6 +86,7 @@
public static final int INVALID_RESTORE_PAGE = -1001;
private boolean mFreeScroll = false;
+ private boolean mSettleOnPageInFreeScroll = false;
protected int mFlingThresholdVelocity;
protected int mMinFlingVelocity;
@@ -1170,7 +1170,12 @@
* return true if freescroll has been enabled, false otherwise
*/
protected void enableFreeScroll() {
+ enableFreeScroll(false);
+ }
+
+ protected void enableFreeScroll(boolean settleOnPageInFreeScroll) {
setEnableFreeScroll(true);
+ mSettleOnPageInFreeScroll = settleOnPageInFreeScroll;
}
protected void disableFreeScroll() {
@@ -1414,7 +1419,22 @@
mScroller.setInterpolator(mDefaultInterpolator);
mScroller.fling(initialScrollX,
getScrollY(), vX, 0, Integer.MIN_VALUE, Integer.MAX_VALUE, 0, 0);
- mNextPage = getPageNearestToCenterOfScreen((int) (mScroller.getFinalX() / scaleX));
+ 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 > firstPageScroll
+ && unscaledScrollX < lastPageScroll) {
+ // Make sure we land directly on a page. If flinging past one of the ends,
+ // don't change the velocity as it will get stopped at the end anyway.
+ mScroller.setFinalX((int) (getScrollForPage(mNextPage) * 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();