private void limitPan() {
final float aspectQuotient = mAspectQuotient.get();
final float zoomX = mState.getZoomX(aspectQuotient);
final float zoomY = mState.getZoomY(aspectQuotient);
final float panMinX = .5f - getMaxPanDelta(zoomX);
final float panMaxX = .5f + getMaxPanDelta(zoomX);
final float panMinY = .5f - getMaxPanDelta(zoomY);
final float panMaxY = .5f + getMaxPanDelta(zoomY);
if (mState.getPanX() > panMaxX) {
mState.setPanX(panMaxX);
}
if (mState.getPanX() < panMinX) {
mState.setPanX(panMinX);
}
if (mState.getPanY() > panMaxY) {
mState.setPanY(panMaxY);
}
if (mState.getPanY() < panMinY) {
mState.setPanY(panMinY);
}
}
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();
}