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Commit 1f30125c authored by Huahui Wu's avatar Huahui Wu
Browse files

b/3350774 avoid screen jumping when pinching to zoom. 

After the change that sends multi-touch to WebKit first, there is
a chance that the single-touch move event is handled before multi-
touch events are finished and this makes the page jumps.
This change skips those single-touch move events to avoid that.

Change-Id: I03992ef18c1de8e07933bd7cc6c12ffc02c014a8
parent 28f0a53a

core/java/android/webkit/WebView.java

+26 −9
Original line number Diff line number Diff line
@@ -499,6 +499,15 @@ public class WebView extends AbsoluteLayout 
    // if true, multi-touch events will be passed to webkit directly before UI

    private boolean mDeferMultitouch = false;



    // Currently, multi-touch events are sent to WebKit first then back to

    // WebView while single-touch events are handled in WebView first.

    // So there is a chance that a single-touch move event is handled in WebView

    // before multi-touch events are finished.

    // if mIsHandlingMultiTouch is true, which means multi-touch event handling

    // is not finished, then any single-touch move event will be skipped.

    // FIXME: send single-touch events to WebKit first then back to WebView.

    private boolean mIsHandlingMultiTouch = false;



    // to avoid interfering with the current touch events, track them

    // separately. Currently no snapping or fling in the deferred process mode

    private int mDeferTouchMode = TOUCH_DONE_MODE;
@@ -5356,11 +5365,19 @@ public class WebView extends AbsoluteLayout 
            if (DebugFlags.WEB_VIEW) {

                Log.v(LOGTAG, "passing " + ev.getPointerCount() + " points to webkit");

            }

            if (!mIsHandlingMultiTouch) {

                mIsHandlingMultiTouch = true;

            }

            passMultiTouchToWebKit(ev);

            return true;

        } else {

            // Skip ACTION_MOVE for single touch if it's still handling multi-touch.

            if (mIsHandlingMultiTouch && ev.getActionMasked() == MotionEvent.ACTION_MOVE) {

                return false;

            }

        }



        return handleTouchEventCommon(ev, Math.round(ev.getX()), Math.round(ev.getY()));

        return handleTouchEventCommon(ev, ev.getActionMasked(), Math.round(ev.getX()), Math.round(ev.getY()));

    }



    /*
@@ -5368,8 +5385,7 @@ public class WebView extends AbsoluteLayout 
     * (x, y) denotes current focus point, which is the touch point for single touch

     * and the middle point for multi-touch.

     */

    private boolean handleTouchEventCommon(MotionEvent ev, int x, int y) {

        int action = ev.getAction();

    private boolean handleTouchEventCommon(MotionEvent ev, int action, int x, int y) {

        long eventTime = ev.getEventTime();
@@ -5847,7 +5863,7 @@ public class WebView extends AbsoluteLayout 


    private void passMultiTouchToWebKit(MotionEvent ev) {

        TouchEventData ted = new TouchEventData();

        ted.mAction = ev.getAction() & MotionEvent.ACTION_MASK;

        ted.mAction = ev.getActionMasked();

        final int count = ev.getPointerCount();

        ted.mIds = new int[count];

        ted.mPoints = new Point[count];
@@ -5866,7 +5882,7 @@ public class WebView extends AbsoluteLayout 
        mPreventDefault = PREVENT_DEFAULT_IGNORE;

    }



    private boolean handleMultiTouchInWebView(MotionEvent ev) {

    private void handleMultiTouchInWebView(MotionEvent ev) {

        if (DebugFlags.WEB_VIEW) {

            Log.v(LOGTAG, "multi-touch: " + ev + " at " + ev.getEventTime()

                + " mTouchMode=" + mTouchMode
@@ -5879,7 +5895,7 @@ public class WebView extends AbsoluteLayout 


        // A few apps use WebView but don't instantiate gesture detector.

        // We don't need to support multi touch for them.

        if (detector == null) return false;

        if (detector == null) return;



        float x = ev.getX();

        float y = ev.getY();
@@ -5914,7 +5930,7 @@ public class WebView extends AbsoluteLayout 
            cancelLongPress();

            mPrivateHandler.removeMessages(SWITCH_TO_LONGPRESS);

            if (!mZoomManager.supportsPanDuringZoom()) {

                return false;

                return;

            }

            mTouchMode = TOUCH_DRAG_MODE;

            if (mVelocityTracker == null) {
@@ -5930,14 +5946,15 @@ public class WebView extends AbsoluteLayout 
            // set mLastTouchX/Y to the remaining point

            mLastTouchX = Math.round(x);

            mLastTouchY = Math.round(y);

            mIsHandlingMultiTouch = false;

        } else if (action == MotionEvent.ACTION_MOVE) {

            // negative x or y indicate it is on the edge, skip it.

            if (x < 0 || y < 0) {

                return false;

                return;

            }

        }



        return handleTouchEventCommon(ev, Math.round(x), Math.round(y));

        handleTouchEventCommon(ev, action, Math.round(x), Math.round(y));

    }



    private void cancelWebCoreTouchEvent(int x, int y, boolean removeEvents) {