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;
}
@SuppressWarnings("unused")
@Override
public boolean onScale(ScaleGestureDetector detector) {
float span = detector.getCurrentSpan() - detector.getPreviousSpan();
float targetScale = mCurrentScaleFactor * detector.getScaleFactor();
if (mScaleEnabled) {
targetScale = Math.min(getMaxZoom(), Math.max(targetScale, MIN_ZOOM));
zoomTo(targetScale, detector.getFocusX(), detector.getFocusY());
mCurrentScaleFactor = Math.min(getMaxZoom(), Math.max(targetScale, MIN_ZOOM));
mDoubleTapDirection = 1;
invalidate();
return true;
}
return false;
}
private boolean judgePinch(ScaleGestureDetector detector) {
boolean res = false;
float curDist = detector.getCurrentSpan();
float preDist = detector.getPreviousSpan();
pinch = preDist - curDist;
if ((curDist < preDist) && (pinch > PINCH_THRESHOLD)) {
res = true;
gestureName = GESTURE_PINCH;
focus_x = detector.getFocusX();
focus_y = detector.getFocusY();
gestureLabel.setText(gestureName + "\n x:" + focus_x + " y:" + focus_y + "\npinch:" + pinch);
}
return res;
}