Question

I am using AsyncTask to download images from remote server and show them in a ListView. I am using this blog to accomplish it and everything is working fine.

The only problem in this blog is that a ColorDrawable is being shown while the image is being downloaded. But I want to show a default image while the image is being downloaded. Just like in the attached image below:

Here you can see that:

1. Images for Taylor Loother and Oye Oye have already been downloaded.
2. There is no image for Gopala Govinda on the server , so I am not
   downloading image for him from the server and showing Default image.

3. For Hellboy, the image is still being downloaded , so a color
   background (the thin black line) is showing up against his name. I
   don’t want to show this black line . I want to show the default
   image just like in front of Gopala Govinda until the image is not
   loaded from the server for Hellboy.

   Does anyone have any idea how to do that?

Answer 1

I think what you want to do is to have the DownloadedDrawable class extend BitmapDrawable instead of Drawable and then choose one of the appropriate super constructors to specify your default image bitmap:

/**
 * A fake Drawable that will be attached to the imageView while the download is in progress.
 *
 * Contains a reference to the actual download task, so that a download task can be stopped
 * if a new binding is required, and makes sure that only the last started download process can
 * bind its result, independently of the download finish order.</p>
 */
private static class DownloadedDrawable extends BitmapDrawable {
    private final WeakReference<BitmapDownloaderTask> 
       bitmapDownloaderTaskReference;

    private DownloadedDrawable(BitmapDownloaderTask bitmapDownloaderTask,
       Resources resources, Bitmap bitmap) {
        super(resources, bitmap); // you'll have to provide these
        bitmapDownloaderTaskReference =
            new WeakReference<BitmapDownloaderTask>(bitmapDownloaderTask);
    }

    public BitmapDownloaderTask getBitmapDownloaderTask() {
        return bitmapDownloaderTaskReference.get();
    }
}