public void pan(float dx, float dy) {
final float aspectQuotient = mAspectQuotient.get();
mState.setPanX(mState.getPanX() + dx / mState.getZoomX(aspectQuotient));
mState.setPanY(mState.getPanY() + dy / mState.getZoomY(aspectQuotient));
limitPan();
mState.notifyObservers();
}
public void zoom(float f, float x, float y) {
final float aspectQuotient = mAspectQuotient.get();
final float prevZoomX = mState.getZoomX(aspectQuotient);
final float prevZoomY = mState.getZoomY(aspectQuotient);
mState.setZoom(mState.getZoom() * f);
limitZoom();
final float newZoomX = mState.getZoomX(aspectQuotient);
final float newZoomY = mState.getZoomY(aspectQuotient);
mState.setPanX(mState.getPanX() + (x - .5f) * (1f / prevZoomX - 1f / newZoomX));
mState.setPanY(mState.getPanY() + (y - .5f) * (1f / prevZoomY - 1f / newZoomY));
limitPan();
mState.notifyObservers();
}
private void resetZoomState() {
mZoomState.setPanX(0.5f);
mZoomState.setPanY(0.5f);
mZoomState.setZoom(1f);
mZoomState.notifyObservers();
}