ImageWorker.java 文件源码

/**
 * Called when the processing is complete and the final drawable should be 
 * set on the ImageView.
 *
 * @param imageView
 * @param drawable
 */
private void setImageDrawable(ImageView imageView, Drawable drawable) {
    if (mFadeInBitmap) {
        // Transition drawable with a transparent drawable and the final drawable
        final TransitionDrawable td =
                new TransitionDrawable(new Drawable[] {
                        new ColorDrawable(android.R.color.transparent),
                        drawable
                });
        // Set background to loading bitmap
        imageView.setBackgroundDrawable(
                new BitmapDrawable(mResources, mLoadingBitmap));

        imageView.setImageDrawable(td);
        td.startTransition(FADE_IN_TIME);
    } else {
        imageView.setImageDrawable(drawable);
    }
}