@Override
public boolean onScale(ScaleGestureDetector detector) {
if (ignoreDetectorEvents()) return false;
// It is possible that pinchBegin() was never called when we reach here.
// This happens when webkit handles the 2nd touch down event. That causes
// ContentView to ignore the onScaleBegin() call. And if webkit does not
// handle the touch move events afterwards, we will face a situation
// that pinchBy() is called without any pinchBegin().
// To solve this problem, we call pinchBegin() here if it is never called.
if (!mPinchEventSent) {
mContentViewCore
.getContentViewGestureHandler()
.pinchBegin(
detector.getEventTime(), (int) detector.getFocusX(), (int) detector.getFocusY());
mPinchEventSent = true;
}
mContentViewCore
.getContentViewGestureHandler()
.pinchBy(
detector.getEventTime(),
(int) detector.getFocusX(),
(int) detector.getFocusY(),
detector.getScaleFactor());
return true;
}
public boolean onScale(ScaleGestureDetector detector) {
// the velocity of the pinch in scale factor per ms
float velocity =
(detector.getCurrentSpan() - detector.getPreviousSpan()) / detector.getTimeDelta();
float currentSpan = detector.getCurrentSpanX();
float prevSpan = detector.getPreviousSpanX();
double diff = Math.abs(currentSpan - prevSpan);
/*
* If Shove is in progress do not handle scale
* If previous scale is handled then keep on handling scale
* else give some buffer for shove to be processed
*/
if (mDoubleTapScale
|| mScaleHandled
|| (!mShoveHandled
&& diff
> PINCH_THRESHOLD
* Math.min(displayMetrics.widthPixels, displayMetrics.heightPixels))) {
mScaleHandled = true;
float focusX = mDoubleTapScale ? mapView.getWidth() * 0.5f : detector.getFocusX();
float focusY = mDoubleTapScale ? mapView.getHeight() * 0.5f : detector.getFocusY();
mLastDoubleGestureTime = detector.getEventTime();
handlePinchGesture(focusX, focusY, detector.getScaleFactor(), velocity);
return true;
}
mScaleHandled = false;
return false;
}
@Override
public void onScaleEnd(ScaleGestureDetector detector) {
if (!mPinchEventSent || !mContentViewCore.isAlive()) return;
mContentViewCore.getContentViewGestureHandler().pinchEnd(detector.getEventTime());
mPinchEventSent = false;
}