Overscrolling modifications. Overscroll will not allow the user to (0b8bb428) · Commits · e / os / android_frameworks_base

api/current.xml

+57 −0

Original line number	Diff line number	Diff line
		@@ -164726,6 +164726,17 @@
		visibility="public"
		>
		</field>
		<field name="SCROLL_BARRIER"
		type="int"
		transient="false"
		volatile="false"
		value="2"
		static="true"
		final="true"
		deprecated="not deprecated"
		visibility="public"
		>
		</field>
		<field name="VIRTUAL_KEY"
		type="int"
		transient="false"
		@@ -173140,6 +173151,25 @@
		<parameter name="heightMeasureSpec" type="int">
		</parameter>
		</method>
		<method name="onOverscrolled"
		return="void"
		abstract="false"
		native="false"
		synchronized="false"
		static="false"
		final="false"
		deprecated="not deprecated"
		visibility="protected"
		>
		<parameter name="scrollX" type="int">
		</parameter>
		<parameter name="scrollY" type="int">
		</parameter>
		<parameter name="clampedX" type="boolean">
		</parameter>
		<parameter name="clampedY" type="boolean">
		</parameter>
		</method>
		<method name="onRestoreInstanceState"
		return="void"
		abstract="false"
		@@ -173293,6 +173323,33 @@
		<parameter name="visibility" type="int">
		</parameter>
		</method>
		<method name="overscrollBy"
		return="boolean"
		abstract="false"
		native="false"
		synchronized="false"
		static="false"
		final="false"
		deprecated="not deprecated"
		visibility="protected"
		>
		<parameter name="deltaX" type="int">
		</parameter>
		<parameter name="deltaY" type="int">
		</parameter>
		<parameter name="scrollX" type="int">
		</parameter>
		<parameter name="scrollY" type="int">
		</parameter>
		<parameter name="scrollRangeX" type="int">
		</parameter>
		<parameter name="scrollRangeY" type="int">
		</parameter>
		<parameter name="maxOverscrollX" type="int">
		</parameter>
		<parameter name="maxOverscrollY" type="int">
		</parameter>
		</method>
		<method name="performClick"
		return="boolean"
		abstract="false"

core/java/android/view/HapticFeedbackConstants.java

+5 −0

Original line number	Diff line number	Diff line
		@@ -35,6 +35,11 @@ public class HapticFeedbackConstants {
		*/
		public static final int VIRTUAL_KEY = 1;

		/**
		* The user has hit the barrier point while scrolling a view.
		*/
		public static final int SCROLL_BARRIER = 2;

		/**
		* This is a private constant. Feel free to renumber as desired.
		* @hide

core/java/android/view/View.java

+112 −0

Original line number	Diff line number	Diff line
		@@ -8548,6 +8548,118 @@ public class View implements Drawable.Callback, KeyEvent.Callback, Accessibility
		return factory.inflate(resource, root);
		}

		/**
		* Scroll the view with standard behavior for scrolling beyond the normal
		* content boundaries. Views that call this method should override
		* {@link #onOverscrolled()} to respond to the results of an overscroll
		* operation.
		*
		* Views can use this method to handle any touch or fling-based scrolling.
		*
		* @param deltaX Change in X in pixels
		* @param deltaY Change in Y in pixels
		* @param scrollX Current X scroll value in pixels before applying deltaX
		* @param scrollY Current Y scroll value in pixels before applying deltaY
		* @param scrollRangeX Maximum content scroll range along the X axis
		* @param scrollRangeY Maximum content scroll range along the Y axis
		* @param maxOverscrollX Number of pixels to overscroll by in either direction
		* along the X axis.
		* @param maxOverscrollY Number of pixels to overscroll by in either direction
		* along the Y axis.
		* @return true if scrolling was clamped to an overscroll boundary along either
		* axis, false otherwise.
		*/
		protected boolean overscrollBy(int deltaX, int deltaY,
		int scrollX, int scrollY,
		int scrollRangeX, int scrollRangeY,
		int maxOverscrollX, int maxOverscrollY) {
		// Scale the scroll amount if we're in the dropoff zone
		final int dropoffX = maxOverscrollX / 2;
		final int dropoffLeft = -dropoffX;
		final int dropoffRight = dropoffX + scrollRangeX;
		int newScrollX;
		if ((scrollX < dropoffLeft && deltaX < 0) \|\|
		(scrollX > dropoffRight && deltaX > 0)) {
		newScrollX = scrollX + deltaX / 2;
		} else {
		newScrollX = scrollX + deltaX;
		if (newScrollX > dropoffRight && deltaX > 0) {
		int extra = newScrollX - dropoffRight;
		newScrollX = dropoffRight + extra / 2;
		} else if (newScrollX < dropoffLeft && deltaX < 0) {
		int extra = newScrollX - dropoffLeft;
		newScrollX = dropoffLeft + extra / 2;
		}
		}

		final int dropoffY = maxOverscrollY / 2;
		final int dropoffTop = -dropoffY;
		final int dropoffBottom = dropoffY + scrollRangeY;
		int newScrollY;
		if ((scrollY < dropoffTop && deltaY < 0) \|\|
		(scrollY > dropoffBottom && deltaY > 0)) {
		newScrollY = scrollY + deltaY / 2;
		} else {
		newScrollY = scrollY + deltaY;
		if (newScrollY > dropoffBottom && deltaY > 0) {
		int extra = newScrollY - dropoffBottom;
		newScrollY = dropoffBottom + extra / 2;
		} else if (newScrollY < dropoffTop && deltaY < 0) {
		int extra = newScrollY - dropoffTop;
		newScrollY = dropoffTop + extra / 2;
		}
		}

		// Clamp values if at the limits and record
		final int left = -maxOverscrollX;
		final int right = maxOverscrollX + scrollRangeX;
		final int top = -maxOverscrollY;
		final int bottom = maxOverscrollY + scrollRangeY;

		boolean clampedX = false;
		if (newScrollX > right) {
		newScrollX = right;
		clampedX = true;
		} else if (newScrollX < left) {
		newScrollX = left;
		clampedX = true;
		}

		boolean clampedY = false;
		if (newScrollY > bottom) {
		newScrollY = bottom;
		clampedY = true;
		} else if (newScrollY < top) {
		newScrollY = top;
		clampedY = true;
		}

		// Bump the device with some haptic feedback if we're at the edge
		// and didn't start there.
		if ((clampedX && scrollX != left && scrollX != right) \|\|
		(clampedY && scrollY != top && scrollY != bottom)) {
		performHapticFeedback(HapticFeedbackConstants.SCROLL_BARRIER);
		}

		onOverscrolled(newScrollX, newScrollY, clampedX, clampedY);

		return clampedX \|\| clampedY;
		}

		/**
		* Called by {@link #overscrollBy(int, int, int, int, int, int, int, int)} to
		* respond to the results of an overscroll operation.
		*
		* @param scrollX New X scroll value in pixels
		* @param scrollY New Y scroll value in pixels
		* @param clampedX True if scrollX was clamped to an overscroll boundary
		* @param clampedY True if scrollY was clamped to an overscroll boundary
		*/
		protected void onOverscrolled(int scrollX, int scrollY,
		boolean clampedX, boolean clampedY) {
		// Intentionally empty.
		}

		/**
		* A MeasureSpec encapsulates the layout requirements passed from parent to child.
		* Each MeasureSpec represents a requirement for either the width or the height.

core/java/android/widget/AbsListView.java

+81 −20

Original line number	Diff line number	Diff line
		@@ -378,6 +378,16 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te

		private ContextMenuInfo mContextMenuInfo = null;

		/**
		* Maximum distance to overscroll by
		*/
		private int mOverscrollMax;

		/**
		* Content height divided by this is the overscroll limit.
		*/
		private static final int OVERSCROLL_LIMIT_DIVISOR = 3;

		/**
		* Used to request a layout when we changed touch mode
		*/
		@@ -1048,7 +1058,8 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		final int top = view.getTop();
		int height = view.getHeight();
		if (height > 0) {
		return Math.max(firstPosition * 100 - (top * 100) / height, 0);
		return Math.max(firstPosition * 100 - (top * 100) / height +
		(int)((float)mScrollY / getHeight() * mItemCount * 100), 0);
		}
		} else {
		int index;
		@@ -1068,7 +1079,17 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te

		@Override
		protected int computeVerticalScrollRange() {
		return mSmoothScrollbarEnabled ? Math.max(mItemCount * 100, 0) : mItemCount;
		int result;
		if (mSmoothScrollbarEnabled) {
		result = Math.max(mItemCount * 100, 0);
		if (mScrollY != 0) {
		// Compensate for overscroll
		result += Math.abs((int) ((float) mScrollY / getHeight() * mItemCount * 100));
		}
		} else {
		result = mItemCount;
		}
		return result;
		}

		@Override
		@@ -1129,6 +1150,8 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		mInLayout = true;
		layoutChildren();
		mInLayout = false;

		mOverscrollMax = (b - t) / OVERSCROLL_LIMIT_DIVISOR;
		}

		/**
		@@ -2078,11 +2101,13 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		// Check if the top of the motion view is where it is
		// supposed to be
		final int motionViewRealTop = motionView.getTop();
		final int motionViewNewTop = mMotionViewNewTop;
		if (atEdge) {
		// Apply overscroll

		mScrollY -= incrementalDeltaY - (motionViewRealTop - motionViewPrevTop);
		int overscroll = -incrementalDeltaY -
		(motionViewRealTop - motionViewPrevTop);
		overscrollBy(0, overscroll, 0, mScrollY, 0, 0,
		0, getOverscrollMax());
		mTouchMode = TOUCH_MODE_OVERSCROLL;
		invalidate();
		}
		@@ -2126,7 +2151,8 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		mMotionPosition = motionPosition;
		}
		} else {
		mScrollY -= incrementalDeltaY;
		overscrollBy(0, -incrementalDeltaY, 0, mScrollY, 0, 0,
		0, getOverscrollMax());
		invalidate();
		}
		mLastY = y;
		@@ -2312,6 +2338,28 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		return true;
		}

		@Override
		protected void onOverscrolled(int scrollX, int scrollY,
		boolean clampedX, boolean clampedY) {
		mScrollY = scrollY;
		if (clampedY) {
		// Velocity is broken by hitting the limit; don't start a fling off of this.
		if (mVelocityTracker != null) {
		mVelocityTracker.clear();
		}
		}
		}

		private int getOverscrollMax() {
		final int childCount = getChildCount();
		if (childCount > 0) {
		return Math.min(mOverscrollMax,
		getChildAt(childCount - 1).getBottom() / OVERSCROLL_LIMIT_DIVISOR);
		} else {
		return mOverscrollMax;
		}
		}

		@Override
		public void draw(Canvas canvas) {
		super.draw(canvas);
		@@ -2532,15 +2580,17 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		delta = Math.max(-(getHeight() - mPaddingBottom - mPaddingTop - 1), delta);
		}

		// Do something different on overscroll - offsetChildrenTopAndBottom()
		trackMotionScroll(delta, delta);

		// Check to see if we have bumped into the scroll limit
		View motionView = getChildAt(mMotionPosition - mFirstPosition);
		int oldTop = 0;
		if (motionView != null) {
		// Check if the top of the motion view is where it is
		// supposed to be
		if (motionView.getTop() != mMotionViewNewTop) {
		oldTop = motionView.getTop();
		}
		if (trackMotionScroll(delta, delta)) {
		if (motionView != null) {
		// Tweak the scroll for how far we overshot
		mScrollY -= delta - (motionView.getTop() - oldTop);
		}
		float vel = scroller.getCurrVelocity();
		if (delta > 0) {
		vel = -vel;
		@@ -2548,7 +2598,6 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		startOverfling(Math.round(vel));
		break;
		}
		}

		if (more) {
		invalidate();
		@@ -2570,9 +2619,14 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		case TOUCH_MODE_OVERFLING: {
		final OverScroller scroller = mScroller;
		if (scroller.computeScrollOffset()) {
		mScrollY = scroller.getCurrY();
		final int scrollY = mScrollY;
		final int deltaY = scroller.getCurrY() - scrollY;
		if (overscrollBy(0, deltaY, 0, scrollY, 0, 0, 0, getOverscrollMax())) {
		startSpringback();
		} else {
		invalidate();
		post(this);
		}
		} else {
		endFling();
		}
		@@ -2703,6 +2757,10 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		final int lastViewIndex = getChildCount() - 1;
		final int lastPos = firstPos + lastViewIndex;

		if (lastViewIndex < 0) {
		return;
		}

		if (lastPos == mLastSeenPos) {
		// No new views, let things keep going.
		post(this);
		@@ -2764,6 +2822,9 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		}

		final View firstView = getChildAt(0);
		if (firstView == null) {
		return;
		}
		final int firstViewTop = firstView.getTop();

		smoothScrollBy(firstViewTop - mExtraScroll, mScrollDuration);

core/java/android/widget/HorizontalScrollView.java

+60 −9

Original line number	Diff line number	Diff line
		@@ -461,7 +461,8 @@ public class HorizontalScrollView extends FrameLayout {
		final int deltaX = (int) (mLastMotionX - x);
		mLastMotionX = x;

		super.scrollTo(mScrollX + deltaX, mScrollY);
		overscrollBy(deltaX, 0, mScrollX, 0, getScrollRange(), 0,
		getOverscrollMax(), 0);
		break;
		case MotionEvent.ACTION_UP:
		final VelocityTracker velocityTracker = mVelocityTracker;
		@@ -472,8 +473,7 @@ public class HorizontalScrollView extends FrameLayout {
		if ((Math.abs(initialVelocity) > mMinimumVelocity)) {
		fling(-initialVelocity);
		} else {
		final int right = Math.max(0, getChildAt(0).getHeight() -
		(getHeight() - mPaddingRight - mPaddingLeft));
		final int right = getScrollRange();
		if (mScroller.springback(mScrollX, mScrollY, 0, 0, right, 0)) {
		invalidate();
		}
		@@ -488,6 +488,41 @@ public class HorizontalScrollView extends FrameLayout {
		return true;
		}

		@Override
		protected void onOverscrolled(int scrollX, int scrollY,
		boolean clampedX, boolean clampedY) {
		// Treat animating scrolls differently; see #computeScroll() for why.
		if (!mScroller.isFinished()) {
		mScrollX = scrollX;
		mScrollY = scrollY;
		if (clampedX) {
		mScroller.springback(mScrollX, mScrollY, 0, getScrollRange(), 0, 0);
		}
		} else {
		super.scrollTo(scrollX, scrollY);
		}
		}

		private int getOverscrollMax() {
		int childCount = getChildCount();
		int containerOverscroll = (getWidth() - mPaddingLeft - mPaddingRight) / 3;
		if (childCount > 0) {
		return Math.min(containerOverscroll, getChildAt(0).getWidth() / 3);
		} else {
		return containerOverscroll;
		}
		}

		private int getScrollRange() {
		int scrollRange = 0;
		if (getChildCount() > 0) {
		View child = getChildAt(0);
		scrollRange = Math.max(0,
		child.getWidth() - getWidth() - mPaddingLeft - mPaddingRight);
		}
		return scrollRange;
		}

		/**
		* <p>
		* Finds the next focusable component that fits in this View's bounds
		@@ -856,9 +891,26 @@ public class HorizontalScrollView extends FrameLayout {
		@Override
		protected int computeHorizontalScrollRange() {
		int count = getChildCount();
		return count == 0 ? getWidth() : getChildAt(0).getRight();
		if (count == 0) {
		return getWidth();
		}

		int scrollRange = getChildAt(0).getRight();
		int scrollX = mScrollX;
		int overscrollRight = scrollRange - getWidth() - mPaddingLeft - mPaddingRight;
		if (scrollX < 0) {
		scrollRange -= scrollX;
		} else if (scrollX > overscrollRight) {
		scrollRange += scrollX - overscrollRight;
		}

		return scrollRange;
		}

		@Override
		protected int computeHorizontalScrollOffset() {
		return Math.max(0, super.computeHorizontalScrollOffset());
		}

		@Override
		protected void measureChild(View child, int parentWidthMeasureSpec, int parentHeightMeasureSpec) {
		@@ -913,10 +965,9 @@ public class HorizontalScrollView extends FrameLayout {
		int x = mScroller.getCurrX();
		int y = mScroller.getCurrY();

		mScrollX = x;
		mScrollY = y;

		if (oldX != mScrollX \|\| oldY != mScrollY) {
		if (oldX != x \|\| oldY != y) {
		overscrollBy(x - oldX, y - oldY, oldX, oldY, getScrollRange(), 0,
		getOverscrollMax(), 0);
		onScrollChanged(mScrollX, mScrollY, oldX, oldY);
		}