Android - How to cancel the image request when preloading images with the Glide library?

Question

Note: This question is different from this question as no answers given for the question explain how to cancel the image request which we make for preloaded image.

I have an infinite list(RecyclerView). I need to preload images of next 'x'(read 3) items from the last bound item of the RecyclerView. Also, when a particular Viewholder is detached from the window, I need to cancel the preload image request if it is already not successful.

I have achieved it in the following way.

Map<Integer, SimpleTarget> simpleTargetMap = new HashMap<>();

public void preloadImage(int position, Context context, String imageUrl) {
    SimpleTarget simpleTarget = new SimpleTarget() {
      @Override
      public void onResourceReady(@NonNull Object resource, @Nullable Transition transition) {
        simpleTargetMap.remove(position);
      }
    };
    Glide.with(context)asBitmap().load(imageUrl).into(simpleTarget);
    simpleTargetMap.put(position, simpleTarget);
}


  @Override
public void onViewDetachedFromWindow(RecyclerView.ViewHolder holder) {
    super.onViewDetachedFromWindow(holder);
    SimpleTarget simpleTarget = simpleTargetMap.get(holder.getAdapterPosition());
    Glide.with(context).clear(simpleTarget);
    simpleTargetMap.remove(holder.getAdapterPosition());
}

I am able to achieve the desired result. But I am facing memory issues with this approach. If I don't use the preloading, my memory usage is between 150-200 mb. But if I start using the preload, the memory usage jumps to 250-300 mb. After taking a heap dump, I see a lot of Bitmap objects which are not there(not as many) if I don't use preload.

So what is the best way to preload an image in Glide where I can also cancel the image request in the future? And if I don't use SimpleTarget, is there any way of cancelling an image request based only of the imageUrl?

Answer 1

Load images into memory cache using preload method:

Glide.with(context)
        .load(url)
        .preload(500, 500);

You can later use the cached images using:

Glide.with(yourFragment)
    .load(yourUrl)
    .into(yourView);