Adding mouse scroll wheel support to StackView (a8a7c92b) · Commits · e / os / android_frameworks_base

core/java/android/widget/StackView.java

+36 −0

Original line number	Diff line number	Diff line
		@@ -33,6 +33,7 @@ import android.graphics.Region;
		import android.graphics.TableMaskFilter;
		import android.util.AttributeSet;
		import android.util.Log;
		import android.view.InputDevice;
		import android.view.MotionEvent;
		import android.view.VelocityTracker;
		import android.view.View;
		@@ -114,6 +115,8 @@ public class StackView extends AdapterViewAnimator {

		private static final int MIN_TIME_BETWEEN_INTERACTION_AND_AUTOADVANCE = 5000;

		private static long MIN_TIME_BETWEEN_SCROLLS = 100;

		/**
		* These variables are all related to the current state of touch interaction
		* with the stack
		@@ -137,6 +140,7 @@ public class StackView extends AdapterViewAnimator {
		private StackSlider mStackSlider;
		private boolean mFirstLayoutHappened = false;
		private long mLastInteractionTime = 0;
		private long mLastScrollTime;
		private int mStackMode;
		private int mFramePadding;
		private final Rect stackInvalidateRect = new Rect();
		@@ -565,6 +569,38 @@ public class StackView extends AdapterViewAnimator {
		}
		}

		@Override
		public boolean onGenericMotionEvent(MotionEvent event) {
		if ((event.getSource() & InputDevice.SOURCE_CLASS_POINTER) != 0) {
		switch (event.getAction()) {
		case MotionEvent.ACTION_SCROLL: {
		final float vscroll = event.getAxisValue(MotionEvent.AXIS_VSCROLL);
		if (vscroll < 0) {
		pacedScroll(false);
		return true;
		} else if (vscroll > 0) {
		pacedScroll(true);
		return true;
		}
		}
		}
		}
		return super.onGenericMotionEvent(event);
		}

		// This ensures that the frequency of stack flips caused by scrolls is capped
		private void pacedScroll(boolean up) {
		long timeSinceLastScroll = System.currentTimeMillis() - mLastScrollTime;
		if (timeSinceLastScroll > MIN_TIME_BETWEEN_SCROLLS) {
		if (up) {
		showPrevious();
		} else {
		showNext();
		}
		mLastScrollTime = System.currentTimeMillis();
		}
		}

		/**
		* {@inheritDoc}
		*/