/**
* As {@code setCurrent}, but without invalidating a drawable. Subclasses are responsible to call
* {@code invalidateSelf} on their own.
*
* @param newDelegate
* @return the previous delegate
*/
protected Drawable setCurrentWithoutInvalidate(Drawable newDelegate) {
Drawable previousDelegate = mCurrentDelegate;
DrawableUtils.setCallbacks(previousDelegate, null, null);
DrawableUtils.setCallbacks(newDelegate, null, null);
DrawableUtils.setDrawableProperties(newDelegate, mDrawableProperties);
DrawableUtils.copyProperties(newDelegate, previousDelegate);
DrawableUtils.setCallbacks(newDelegate, this, this);
mCurrentDelegate = newDelegate;
return previousDelegate;
}
/**
* Constructs a new layer drawable.
*
* @param layers the layers that this drawable displays
*/
public ArrayDrawable(Drawable[] layers) {
Preconditions.checkNotNull(layers);
mLayers = layers;
for (int i = 0; i < mLayers.length; i++) {
DrawableUtils.setCallbacks(mLayers[i], this, this);
}
mDrawableParents = new DrawableParent[mLayers.length];
}
/** Sets a new drawable at the specified index, and return the previous drawable, if any. */
@Nullable
public Drawable setDrawable(int index, @Nullable Drawable drawable) {
Preconditions.checkArgument(index >= 0);
Preconditions.checkArgument(index < mLayers.length);
final Drawable oldDrawable = mLayers[index];
if (drawable != oldDrawable) {
if (drawable != null && mIsMutated) {
drawable.mutate();
}
DrawableUtils.setCallbacks(mLayers[index], null, null);
DrawableUtils.setCallbacks(drawable, null, null);
DrawableUtils.setDrawableProperties(drawable, mDrawableProperties);
DrawableUtils.copyProperties(drawable, this);
DrawableUtils.setCallbacks(drawable, this, this);
mIsStatefulCalculated = false;
mLayers[index] = drawable;
invalidateSelf();
}
return oldDrawable;
}
/**
* Constructs a new forwarding drawable.
*
* @param drawable drawable that this forwarding drawable will forward to
*/
public ForwardingDrawable(Drawable drawable) {
mCurrentDelegate = drawable;
DrawableUtils.setCallbacks(mCurrentDelegate, this, this);
}