void updateHandles() {
bounds = new Rect(roi.getBoundsX(), roi.getBoundsY(), roi.getBoundsWidth(), roi.getBoundsHeight());
handles.get(TOP_LEFT).setLocation(bounds.getMinX(), bounds.getMinY());
handles.get(TOP_CENTER).setLocation(bounds.getCenterX(), bounds.getMinY());
handles.get(TOP_RIGHT).setLocation(bounds.getMaxX(), bounds.getMinY());
handles.get(CENTER_RIGHT).setLocation(bounds.getMaxX(), bounds.getCenterY());
handles.get(BOTTOM_RIGHT).setLocation(bounds.getMaxX(), bounds.getMaxY());
handles.get(BOTTOM_CENTER).setLocation(bounds.getCenterX(), bounds.getMaxY());
handles.get(BOTTOM_LEFT).setLocation(bounds.getMinX(), bounds.getMaxY());
handles.get(CENTER_LEFT).setLocation(bounds.getMinX(), bounds.getCenterY());
}