public boolean canMove(Layer layer) {
final Layer parentLayer = layer.getParent();
if (parentLayer == null) {
return false;
}
final int layerIndex = parentLayer.getChildIndex(layer.getId());
return layerIndex > 0;
}
void moveUp(Layer layer) {
if (canMove(layer)) {
final Layer parentLayer = layer.getParent();
final int layerIndex = layer.getParent().getChildIndex(layer.getId());
parentLayer.getChildren().remove(layer);
parentLayer.getChildren().add(layerIndex - 1, layer);
}
}