XML attribute for overscrolling behavior (c9fbaabc) · Commits · e / os / android_frameworks_base

api/current.xml

+11 −0

Original line number	Diff line number	Diff line
		@@ -5960,6 +5960,17 @@
		visibility="public"
		>
		</field>
		<field name="overscrollMode"
		type="int"
		transient="false"
		volatile="false"
		value="16843450"
		static="true"
		final="true"
		deprecated="not deprecated"
		visibility="public"
		>
		</field>
		<field name="padding"
		type="int"
		transient="false"

core/java/android/view/View.java

+79 −35

Original line number	Diff line number	Diff line
		@@ -1505,6 +1505,31 @@ public class View implements Drawable.Callback, KeyEvent.Callback, Accessibility
		*/
		private static final int PREPRESSED = 0x02000000;

		/**
		* Always allow a user to overscroll this view, provided it is a
		* view that can scroll.
		*/
		private static final int OVERSCROLL_ALWAYS = 0;

		/**
		* Allow a user to overscroll this view only if the content is large
		* enough to meaningfully scroll, provided it is a view that can scroll.
		*/
		private static final int OVERSCROLL_IF_CONTENT_SCROLLS = 1;

		/**
		* Never allow a user to overscroll this view.
		*/
		private static final int OVERSCROLL_NEVER = 2;

		/**
		* Controls the overscroll mode for this view.
		* See {@link #overscrollBy(int, int, int, int, int, int, int, int)},
		* {@link #OVERSCROLL_ALWAYS}, {@link #OVERSCROLL_IF_CONTENT_SCROLLS},
		* and {@link #OVERSCROLL_NEVER}.
		*/
		private int mOverscrollMode = OVERSCROLL_ALWAYS;

		/**
		* The parent this view is attached to.
		* {@hide}
		@@ -2053,6 +2078,9 @@ public class View implements Drawable.Callback, KeyEvent.Callback, Accessibility
		});
		}
		break;
		case R.styleable.View_overscrollMode:
		mOverscrollMode = a.getInt(attr, OVERSCROLL_ALWAYS);
		break;
		}
		}

		@@ -8573,16 +8601,26 @@ public class View implements Drawable.Callback, KeyEvent.Callback, Accessibility
		int scrollX, int scrollY,
		int scrollRangeX, int scrollRangeY,
		int maxOverscrollX, int maxOverscrollY) {
		final int overscrollMode = mOverscrollMode;
		final boolean canScrollHorizontal =
		computeHorizontalScrollRange() > computeHorizontalScrollExtent();
		final boolean canScrollVertical =
		computeVerticalScrollRange() > computeVerticalScrollExtent();
		final boolean overscrollHorizontal = overscrollMode == OVERSCROLL_ALWAYS \|\|
		(overscrollMode == OVERSCROLL_IF_CONTENT_SCROLLS && canScrollHorizontal);
		final boolean overscrollVertical = overscrollMode == OVERSCROLL_ALWAYS \|\|
		(overscrollMode == OVERSCROLL_IF_CONTENT_SCROLLS && canScrollVertical);

		int newScrollX = scrollX + deltaX;
		if (overscrollHorizontal) {
		// 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;
		@@ -8591,16 +8629,19 @@ public class View implements Drawable.Callback, KeyEvent.Callback, Accessibility
		newScrollX = dropoffLeft + extra / 2;
		}
		}
		} else {
		maxOverscrollX = 0;
		}

		int newScrollY = scrollY + deltaY;
		if (overscrollVertical) {
		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;
		@@ -8609,6 +8650,9 @@ public class View implements Drawable.Callback, KeyEvent.Callback, Accessibility
		newScrollY = dropoffTop + extra / 2;
		}
		}
		} else {
		maxOverscrollY = 0;
		}

		// Clamp values if at the limits and record
		final int left = -maxOverscrollX;
		@@ -8636,8 +8680,8 @@ public class View implements Drawable.Callback, KeyEvent.Callback, Accessibility

		// 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)) {
		if ((overscrollHorizontal && clampedX && scrollX != left && scrollX != right) \|\|
		(overscrollVertical && clampedY && scrollY != top && scrollY != bottom)) {
		performHapticFeedback(HapticFeedbackConstants.SCROLL_BARRIER);
		}

core/java/android/widget/AbsListView.java

+2 −1

Original line number	Diff line number	Diff line
		@@ -2589,7 +2589,8 @@ public abstract class AbsListView extends AdapterView<ListAdapter> implements Te
		if (trackMotionScroll(delta, delta)) {
		if (motionView != null) {
		// Tweak the scroll for how far we overshot
		mScrollY -= delta - (motionView.getTop() - oldTop);
		int overshoot = -(delta - (motionView.getTop() - oldTop));
		overscrollBy(0, overshoot, 0, mScrollY, 0, 0, 0, getOverscrollMax());
		}
		float vel = scroller.getCurrVelocity();
		if (delta > 0) {

core/res/res/values/attrs.xml

+13 −0

Original line number	Diff line number	Diff line
		@@ -1307,6 +1307,19 @@
		<code>public void sayHello(View v)</code> method of your context
		(typically, your Activity). -->
		<attr name="onClick" format="string" />

		<!-- Defines overscrolling behavior. This property is used only if the
		View is scrollable. Overscrolling is the ability for the user to
		scroll a View beyond its content boundaries into empty space. -->
		<attr name="overscrollMode">
		<!-- Always allow the user to overscroll the content. -->
		<enum name="always" value="0" />
		<!-- Only allow the user to overscroll content if the content is large
		enough to meaningfully scroll. -->
		<enum name="ifContentScrolls" value="1" />
		<!-- Never overscroll. -->
		<enum name="never" value="2" />
		</attr>
		</declare-styleable>

		<!-- Attributes that can be used with a {@link android.view.ViewGroup} or any

core/res/res/values/public.xml

+1 −0

Original line number	Diff line number	Diff line
		@@ -1230,6 +1230,7 @@
		<public type="attr" name="installLocation" id="0x010102b7" />
		<public type="attr" name="safeMode" id="0x010102b8" />
		<public type="attr" name="webTextViewStyle" id="0x010102b9" />
		<public type="attr" name="overscrollMode" id="0x010102ba" />

		<public type="anim" name="cycle_interpolator" id="0x010a000c" />