static void removeFromLayers(Shape shape) {
if (!layerOf.containsKey(shape)) return;
int oldLayer = layerOf.get(shape);
layerContents.get(oldLayer).remove(shape);
if (layerContents.get(oldLayer).isEmpty()) {
layerContents.remove(oldLayer);
layers.remove((Integer) oldLayer);
}
layerOf.remove(shape);
}
/**
* Get the layer that the given shape is in. See {@link #setLayer} for more information about
* layers.
*
* @param shape the shape whose layer index will be returned.
* @return the index of the layer that <code>shape</code> is contained in.
* @see #setLayer
*/
static int getLayerOf(Shape shape) {
return layerOf.get(shape);
}