Add tweaks to smooth out swipe to dismiss. (ddc6e0b7) · Commits · e / os / android_frameworks_base

core/java/com/android/internal/widget/SwipeDismissLayout.java

+27 −9

Original line number	Diff line number	Diff line
		@@ -43,7 +43,8 @@ import android.widget.FrameLayout;
		public class SwipeDismissLayout extends FrameLayout {
		private static final String TAG = "SwipeDismissLayout";

		private static final float DISMISS_MIN_DRAG_WIDTH_RATIO = .33f;
		private static final float MAX_DIST_THRESHOLD = .33f;
		private static final float MIN_DIST_THRESHOLD = .1f;

		public interface OnDismissedListener {
		void onDismissed(SwipeDismissLayout layout);
		@@ -73,6 +74,7 @@ public class SwipeDismissLayout extends FrameLayout {
		private int mActiveTouchId;
		private float mDownX;
		private float mDownY;
		private float mLastX;
		private boolean mSwiping;
		private boolean mDismissed;
		private boolean mDiscardIntercept;
		@@ -105,7 +107,6 @@ public class SwipeDismissLayout extends FrameLayout {
		};
		private IntentFilter mScreenOffFilter = new IntentFilter(Intent.ACTION_SCREEN_OFF);

		private float mLastX;

		private boolean mDismissable = true;

		@@ -174,7 +175,7 @@ public class SwipeDismissLayout extends FrameLayout {
		mDownX = ev.getRawX();
		mDownY = ev.getRawY();
		mActiveTouchId = ev.getPointerId(0);
		mVelocityTracker = VelocityTracker.obtain();
		mVelocityTracker = VelocityTracker.obtain("int1");
		mVelocityTracker.addMovement(ev);
		break;

		@@ -238,7 +239,10 @@ public class SwipeDismissLayout extends FrameLayout {
		updateDismiss(ev);
		if (mDismissed) {
		mDismissAnimator.animateDismissal(ev.getRawX() - mDownX);
		} else if (mSwiping) {
		} else if (mSwiping
		// Only trigger animation if we had a MOVE event that would shift the
		// underlying view, otherwise the animation would be janky.
		&& mLastX != Integer.MIN_VALUE) {
		mDismissAnimator.animateRecovery(ev.getRawX() - mDownX);
		}
		resetMembers();
		@@ -298,6 +302,7 @@ public class SwipeDismissLayout extends FrameLayout {
		mVelocityTracker = null;
		mTranslationX = 0;
		mDownX = 0;
		mLastX = Integer.MIN_VALUE;
		mDownY = 0;
		mSwiping = false;
		mDismissed = false;
		@@ -329,19 +334,32 @@ public class SwipeDismissLayout extends FrameLayout {

		private void updateDismiss(MotionEvent ev) {
		float deltaX = ev.getRawX() - mDownX;
		mVelocityTracker.addMovement(ev);
		// Don't add the motion event as an UP event would clear the velocity tracker
		mVelocityTracker.computeCurrentVelocity(1000);
		float xVelocity = mVelocityTracker.getXVelocity();
		if (mLastX == Integer.MIN_VALUE) {
		// If there's no changes to mLastX, we have only one point of data, and therefore no
		// velocity. Estimate velocity from just the up and down event in that case.
		xVelocity = deltaX / ((ev.getEventTime() - ev.getDownTime()) / 1000);
		}
		if (!mDismissed) {
		if ((deltaX > (getWidth() * DISMISS_MIN_DRAG_WIDTH_RATIO) &&
		ev.getRawX() >= mLastX)
		\|\| mVelocityTracker.getXVelocity() >= mMinFlingVelocity) {
		// Adjust the distance threshold linearly between the min and max threshold based on the
		// x-velocity scaled with the the fling threshold speed
		float distanceThreshold = getWidth() * Math.max(
		Math.min((MIN_DIST_THRESHOLD - MAX_DIST_THRESHOLD)
		* xVelocity / mMinFlingVelocity // scale x-velocity with fling velocity
		+ MAX_DIST_THRESHOLD, // offset to start at max threshold
		MAX_DIST_THRESHOLD), // cap at max threshold
		MIN_DIST_THRESHOLD); // bottom out at min threshold
		if ((deltaX > distanceThreshold && ev.getRawX() >= mLastX)
		\|\| xVelocity >= mMinFlingVelocity) {
		mDismissed = true;
		}
		}
		// Check if the user tried to undo this.
		if (mDismissed && mSwiping) {
		// Check if the user's finger is actually flinging back to left
		if (mVelocityTracker.getXVelocity() < -mMinFlingVelocity) {
		if (xVelocity < -mMinFlingVelocity) {
		mDismissed = false;
		}
		}