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 boolean onScale(ScaleGestureDetector detector) {
float xScale = ((float) detector.getCurrentSpanX()) / detector.getPreviousSpanX();
yAmplifier *= (((float) detector.getCurrentSpanY()) / detector.getPreviousSpanY());
yAmplifier = Math.max(Math.min(yAmplifier, MAX_YAMP), MIN_YAMP);
shownDataAmount /= xScale;
shownDataAmount = Math.min(Math.max(1, (shownDataAmount)), MAXSAMPLEPACKETS);
return true;
}
@Override
public boolean onScale(ScaleGestureDetector scaleGestureDetector) {
float spanX =
scaleGestureDetector.getCurrentSpanX() - scaleGestureDetector.getPreviousSpanX();
float spanY =
scaleGestureDetector.getCurrentSpanY() - scaleGestureDetector.getPreviousSpanY();
LayoutParams lParams = (LayoutParams) getLayoutParams();
float newWidth = lParams.width + spanX;
float newHeight = lParams.height + spanY;
lParams.width = (int) newWidth;
lParams.height = (int) newHeight;
setLayoutParams(lParams);
Log.i("spanX", spanX + "");
Log.i("spanY", spanY + "");
return true;
}
//// TODO: 16/12/15 Still get better method to judge the rotate gesture
private boolean judgeRotate(ScaleGestureDetector detector) {
boolean res = false;
double preDistX = detector.getPreviousSpanX();
double preDistY = detector.getPreviousSpanY();
double curDistX = detector.getCurrentSpanX();
double curDistY = detector.getCurrentSpanY();
double atanPre = Math.atan2(preDistY, preDistX);
double atanCur = Math.atan2(curDistY, curDistX);
rotate = atanCur - atanPre;
if (Math.abs(rotate) > ROTATE_THRESHOLD) {
res = true;
gestureName = GESTURE_ROTATE;
focus_x = detector.getFocusX();
focus_y = detector.getFocusY();
gestureLabel.setText(
gestureName + "\n x:" + focus_x + " y:" + focus_y + "\ndeltaAngel:" + rotate);
}
return res;
}