Found a solution myself, maybe someone else could need it:
I created a SimpleOnScaleGestureListener:
Code:
public class PDFSimpleOnScaleGestureListener extends
SimpleOnScaleGestureListener {
@Override
public boolean onScale(ScaleGestureDetector detector) {
return true;
}
@Override
public boolean onScaleBegin(ScaleGestureDetector detector) {
mActivityViewScaleCallback.onPDFViewScaleCallback();
return false;
}
@Override
public void onScaleEnd(ScaleGestureDetector detector) {
}
}
//With an Interface for callback:
/**
* Callback for PDFViewerActivity
*/
public interface OnPDFViewScaleCallback {
/**
* Callback when user starts to zoom pdf view
*/
public void onPDFViewScaleCallback();
}
//i use pdfview in a fragment so my activty implements the interface and to set the callback
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
mActivityViewScaleCallback = (OnPDFViewScaleCallback) activity;
scaleGestureDetector = new ScaleGestureDetector(activity, new PDFSimpleOnScaleGestureListener());
}
//and then i set the scaleGestureDetector to readercontroller (when view is drawn)
mPdfView.setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
scaleGestureDetector.onTouchEvent(event);
return false;
}
});
}
//and in my activity I implement the interface and every time the user starts to scale the callback method is called
@Override
public void onPDFViewScaleCallback() {
//TODO -> Your stuff
}
