Support scrolling divs. (a3ebcc9d) · Commits · e / os / android_frameworks_base

core/java/android/webkit/WebView.java

+124 −29

Original line number	Diff line number	Diff line
		@@ -401,6 +401,10 @@ public class WebView extends AbsoluteLayout
		private float mLastVelX;
		private float mLastVelY;

		// A pointer to the native scrollable layer when dragging layers. Only
		// valid when mTouchMode is TOUCH_DRAG_LAYER_MODE.
		private int mScrollingLayer;

		// only trigger accelerated fling if the new velocity is at least
		// MINIMUM_VELOCITY_RATIO_FOR_ACCELERATION times of the previous velocity
		private static final float MINIMUM_VELOCITY_RATIO_FOR_ACCELERATION = 0.2f;
		@@ -417,6 +421,7 @@ public class WebView extends AbsoluteLayout
		private static final int TOUCH_DOUBLE_TAP_MODE = 6;
		private static final int TOUCH_DONE_MODE = 7;
		private static final int TOUCH_PINCH_DRAG = 8;
		private static final int TOUCH_DRAG_LAYER_MODE = 9;

		// Whether to forward the touch events to WebCore
		private boolean mForwardTouchEvents = false;
		@@ -883,6 +888,9 @@ public class WebView extends AbsoluteLayout
		mNavSlop = (int) (16 * density);
		mZoomManager.init(density);
		mMaximumFling = configuration.getScaledMaximumFlingVelocity();

		// Compute the inverse of the density squared.
		DRAG_LAYER_INVERSE_DENSITY_SQUARED = 1 / (density * density);
		}

		/**
		@@ -4540,6 +4548,25 @@ public class WebView extends AbsoluteLayout
		startTouch(detector.getFocusX(), detector.getFocusY(), mLastTouchTime);
		}

		private void startScrollingLayer(float gestureX, float gestureY) {
		if (mTouchMode != TOUCH_DRAG_LAYER_MODE) {
		int contentX = viewToContentX((int) gestureX + mScrollX);
		int contentY = viewToContentY((int) gestureY + mScrollY);
		mScrollingLayer = nativeScrollableLayer(contentX, contentY);
		if (mScrollingLayer != 0) {
		mTouchMode = TOUCH_DRAG_LAYER_MODE;
		}
		}
		}

		// 1/(density * density) used to compute the distance between points.
		// Computed in init().
		private float DRAG_LAYER_INVERSE_DENSITY_SQUARED;

		// The distance between two points reported in onTouchEvent scaled by the
		// density of the screen.
		private static final int DRAG_LAYER_FINGER_DISTANCE = 20000;

		@Override
		public boolean onTouchEvent(MotionEvent ev) {
		if (mNativeClass == 0 \|\| !isClickable() \|\| !isLongClickable()) {
		@@ -4551,20 +4578,73 @@ public class WebView extends AbsoluteLayout
		+ mTouchMode);
		}

		int action;
		float x, y;
		int action = ev.getAction();
		float x = ev.getX();
		float y = ev.getY();
		long eventTime = ev.getEventTime();

		final ScaleGestureDetector detector =
		mZoomManager.getMultiTouchGestureDetector();
		boolean skipScaleGesture = false;
		// Set to the mid-point of a two-finger gesture used to detect if the
		// user has touched a layer.
		float gestureX = x;
		float gestureY = y;
		if (!detector.isInProgress()) {
		// The gesture for scrolling a layer is two fingers close together.
		// FIXME: we may consider giving WebKit an option to handle
		// multi-touch events later.
		if (ev.getPointerCount() > 1) {
		float dx = ev.getX(1) - ev.getX(0);
		float dy = ev.getY(1) - ev.getY(0);
		float dist = (dx * dx + dy * dy) *
		DRAG_LAYER_INVERSE_DENSITY_SQUARED;
		// Use the approximate center to determine if the gesture is in
		// a layer.
		gestureX = ev.getX(0) + (dx * .5f);
		gestureY = ev.getY(0) + (dy * .5f);
		// Now use a consistent point for tracking movement.
		if (ev.getX(0) < ev.getX(1)) {
		x = ev.getX(0);
		y = ev.getY(0);
		} else {
		x = ev.getX(1);
		y = ev.getY(1);
		}
		action = ev.getActionMasked();
		if (dist < DRAG_LAYER_FINGER_DISTANCE) {
		skipScaleGesture = true;
		} else if (mTouchMode == TOUCH_DRAG_LAYER_MODE) {
		// Fingers moved too far apart while dragging, the user
		// might be trying to zoom.
		mTouchMode = TOUCH_INIT_MODE;
		}
		}
		}

		// FIXME: we may consider to give WebKit an option to handle multi-touch
		// events later.
		if (mZoomManager.supportsMultiTouchZoom() && ev.getPointerCount() > 1) {
		if (mZoomManager.supportsMultiTouchZoom() && ev.getPointerCount() > 1 &&
		mTouchMode != TOUCH_DRAG_LAYER_MODE && !skipScaleGesture) {

		// if the page disallows zoom, then skip multi-pointer action
		// if the page disallows zoom, skip multi-pointer action
		if (mZoomManager.isZoomScaleFixed()) {
		return true;
		}

		ScaleGestureDetector detector = mZoomManager.getMultiTouchGestureDetector();
		if (!detector.isInProgress() &&
		ev.getActionMasked() != MotionEvent.ACTION_POINTER_DOWN) {
		// Insert a fake pointer down event in order to start
		// the zoom scale detector.
		MotionEvent temp = MotionEvent.obtain(ev);
		// Clear the original event and set it to
		// ACTION_POINTER_DOWN.
		temp.setAction(temp.getAction() &
		~MotionEvent.ACTION_MASK \|
		MotionEvent.ACTION_POINTER_DOWN);
		detector.onTouchEvent(temp);
		}

		detector.onTouchEvent(ev);

		if (detector.isInProgress()) {
		@@ -4588,22 +4668,14 @@ public class WebView extends AbsoluteLayout
		return true;
		}
		}
		} else {
		action = ev.getAction();
		x = ev.getX();
		y = ev.getY();
		}

		// Due to the touch screen edge effect, a touch closer to the edge
		// always snapped to the edge. As getViewWidth() can be different from
		// getWidth() due to the scrollbar, adjusting the point to match
		// getViewWidth(). Same applied to the height.
		if (x > getViewWidth() - 1) {
		x = getViewWidth() - 1;
		}
		if (y > getViewHeightWithTitle() - 1) {
		y = getViewHeightWithTitle() - 1;
		}
		x = Math.min(x, getViewWidth() - 1);
		y = Math.min(y, getViewHeightWithTitle() - 1);

		float fDeltaX = mLastTouchX - x;
		float fDeltaY = mLastTouchY - y;
		@@ -4776,7 +4848,9 @@ public class WebView extends AbsoluteLayout
		invalidate();
		break;
		}
		if (mTouchMode != TOUCH_DRAG_MODE) {

		if (mTouchMode != TOUCH_DRAG_MODE &&
		mTouchMode != TOUCH_DRAG_LAYER_MODE) {

		if (!mConfirmMove) {
		break;
		@@ -4808,6 +4882,9 @@ public class WebView extends AbsoluteLayout
		deltaX = 0;
		deltaY = 0;

		if (skipScaleGesture) {
		startScrollingLayer(gestureX, gestureY);
		}
		startDrag();
		}

		@@ -4816,6 +4893,7 @@ public class WebView extends AbsoluteLayout
		}

		// do pan
		if (mTouchMode != TOUCH_DRAG_LAYER_MODE) {
		int newScrollX = pinLocX(mScrollX + deltaX);
		int newDeltaX = newScrollX - mScrollX;
		if (deltaX != newDeltaX) {
		@@ -4828,6 +4906,7 @@ public class WebView extends AbsoluteLayout
		deltaY = newDeltaY;
		fDeltaY = (float) newDeltaY;
		}
		}
		boolean done = false;
		boolean keepScrollBarsVisible = false;
		if (Math.abs(fDeltaX) < 1.0f && Math.abs(fDeltaY) < 1.0f) {
		@@ -4894,7 +4973,9 @@ public class WebView extends AbsoluteLayout

		doDrag(deltaX, deltaY);

		if (keepScrollBarsVisible) {
		// Turn off scrollbars when dragging a layer.
		if (keepScrollBarsVisible &&
		mTouchMode != TOUCH_DRAG_LAYER_MODE) {
		if (mHeldMotionless != MOTIONLESS_TRUE) {
		mHeldMotionless = MOTIONLESS_TRUE;
		invalidate();
		@@ -5021,6 +5102,7 @@ public class WebView extends AbsoluteLayout
		invalidate();
		// fall through
		case TOUCH_DRAG_START_MODE:
		case TOUCH_DRAG_LAYER_MODE:
		// TOUCH_DRAG_START_MODE should not happen for the real
		// device as we almost certain will get a MOVE. But this
		// is possible on emulator.
		@@ -5086,6 +5168,14 @@ public class WebView extends AbsoluteLayout

		private void doDrag(int deltaX, int deltaY) {
		if ((deltaX \| deltaY) != 0) {
		if (mTouchMode == TOUCH_DRAG_LAYER_MODE) {
		deltaX = viewToContentDimension(deltaX);
		deltaY = viewToContentDimension(deltaY);
		if (nativeScrollLayer(mScrollingLayer, deltaX, deltaY)) {
		invalidate();
		}
		return;
		}
		scrollBy(deltaX, deltaY);
		}
		mZoomManager.keepZoomPickerVisible();
		@@ -5115,7 +5205,8 @@ public class WebView extends AbsoluteLayout
		mVelocityTracker.recycle();
		mVelocityTracker = null;
		}
		if (mTouchMode == TOUCH_DRAG_MODE) {
		if (mTouchMode == TOUCH_DRAG_MODE \|\|
		mTouchMode == TOUCH_DRAG_LAYER_MODE) {
		WebViewCore.resumePriority();
		WebViewCore.resumeUpdatePicture(mWebViewCore);
		}
		@@ -7117,4 +7208,8 @@ public class WebView extends AbsoluteLayout
		// return NO_LEFTEDGE means failure.
		static final int NO_LEFTEDGE = -1;
		native int nativeGetBlockLeftEdge(int x, int y, float scale);

		// Returns a pointer to the scrollable LayerAndroid at the given point.
		private native int nativeScrollableLayer(int x, int y);
		private native boolean nativeScrollLayer(int layer, int dx, int dy);
		}