1 package com.bumptech.glide.load.resource.drawable; 2 3 import android.graphics.drawable.Drawable; 4 5 import com.bumptech.glide.load.engine.Resource; 6 7 /** 8 * Simple wrapper for an Android {@link Drawable} which returns a 9 * {@link android.graphics.drawable.Drawable.ConstantState#newDrawable() new drawable} 10 * based on it's {@link android.graphics.drawable.Drawable.ConstantState state}. 11 * 12 * <b>Suggested usages only include {@code T}s where the new drawable is of the same or descendant class.</b> 13 * 14 * @param <T> type of the wrapped {@link Drawable} 15 */ 16 public abstract class DrawableResource<T extends Drawable> implements Resource<T> { 17 protected final T drawable; 18 private boolean returnedOriginalDrawable; 19 20 public DrawableResource(T drawable) { 21 if (drawable == null) { 22 throw new NullPointerException("Drawable must not be null!"); 23 } 24 this.drawable = drawable; 25 } 26 27 @SuppressWarnings("unchecked") 28 // drawables should always return a copy of the same class 29 @Override 30 public final T get() { 31 if (!returnedOriginalDrawable) { 32 returnedOriginalDrawable = true; 33 return drawable; 34 } else { 35 return (T) drawable.getConstantState().newDrawable(); 36 } 37 } 38 } 39
