class BitmapWorkerTask extends AsyncTask<Integer, Void, Bitmap> {  private final WeakReference<ImageView> imageViewReference;  private int data = 0;  public BitmapWorkerTask(ImageView imageView) {    // Use a WeakReference to ensure the ImageView can be garbage collected    imageViewReference = new WeakReference<ImageView>(imageView);  }  // Decode image in background.  @Override  protected Bitmap doInBackground(Integer... params) {    data = params[0];    return decodeSampledBitmapFromResource(getResources(), data, 100, 100));  }  // Once complete, see if ImageView is still around and set bitmap.  @Override  protected void onPostExecute(Bitmap bitmap) {    if (imageViewReference != null && bitmap != null) {      final ImageView imageView = imageViewReference.get();      if (imageView != null) {        imageView.setImageBitmap(bitmap);      }    }  }}

public void loadBitmap(int resId, ImageView imageView) {  BitmapWorkerTask task = new BitmapWorkerTask(imageView);  task.execute(resId);}

static class AsyncDrawable extends BitmapDrawable {  private final WeakReference<BitmapWorkerTask> bitmapWorkerTaskReference;  public AsyncDrawable(Resources res, Bitmap bitmap,      BitmapWorkerTask bitmapWorkerTask) {    super(res, bitmap);    bitmapWorkerTaskReference =      new WeakReference<BitmapWorkerTask>(bitmapWorkerTask);  }  public BitmapWorkerTask getBitmapWorkerTask() {    return bitmapWorkerTaskReference.get();  }}

public void loadBitmap(int resId, ImageView imageView) {  if (cancelPotentialWork(resId, imageView)) {    final BitmapWorkerTask task = new BitmapWorkerTask(imageView);    final AsyncDrawable asyncDrawable =        new AsyncDrawable(getResources(), mPlaceHolderBitmap, task);    imageView.setImageDrawable(asyncDrawable);    task.execute(resId);  }}

public static boolean cancelPotentialWork(int data, ImageView imageView) {  final BitmapWorkerTask bitmapWorkerTask = getBitmapWorkerTask(imageView);  if (bitmapWorkerTask != null) {    final int bitmapData = bitmapWorkerTask.data;    // If bitmapData is not yet set or it differs from the new data    if (bitmapData == 0 || bitmapData != data) {      // Cancel previous task      bitmapWorkerTask.cancel(true);    } else {      // The same work is already in progress      return false;    }  }  // No task associated with the ImageView, or an existing task was cancelled  return true;}

private static BitmapWorkerTask getBitmapWorkerTask(ImageView imageView) {  if (imageView != null) {    final Drawable drawable = imageView.getDrawable();    if (drawable instanceof AsyncDrawable) {      final AsyncDrawable asyncDrawable = (AsyncDrawable) drawable;      return asyncDrawable.getBitmapWorkerTask();    }  }  return null;}