DrawableResource.java 文件源码

@SuppressWarnings("unchecked")
@Override
public final T get() {
  @Nullable ConstantState state = drawable.getConstantState();
  if (state == null) {
    return drawable;
  }
  // Drawables contain temporary state related to how they're being displayed
  // (alpha, color filter etc), so return a new copy each time.
  // If we ever return the original drawable, it's temporary state may be changed
  // and subsequent copies may end up with that temporary state. See #276.
  return (T) state.newDrawable();
}