picasso: how to cancel all image requests made in an adapter

Question

as usual we use an adapter to populate a listView. in the adapter we use picasso to load the images. i see that as rows are recycled when loading an image into an target (imageV

Answer 1

This answer may come a bit late, but maybe someone still needs it...

Define a ViewHolder which provides a cleanup method:

static class ImageHolder extends RecyclerView.ViewHolder {
    public final ImageView image;

    public ImageHolder(final View itemView) {
        super(itemView);
        image = (ImageView) itemView.findViewById(R.id.image);
    }

    public void cleanup() {
        Picasso.with(image.getContext())
            .cancelRequest(image);
        image.setImageDrawable(null);
    }
}

Implement onViewRecycled() in your adapter:

static class ImageAdapter extends RecyclerView.Adapter {

    // ...

    @Override
    public void onViewRecycled(final ImageHolder holder) {
        holder.cleanup();
    }
}

Cancel the Picasso requests when your Fragment's view is destroyed (or whenever you wish):

public class MyFragment extends Fragment {
    private RecyclerView recycler;

    // ...

    @Override
    public void onDestroyView() {
        super.onDestroyView();
        recycler.setAdapter(null); // will trigger the recycling in the adapter
    }
}

RecyclerView.setAdapter(null) will detach all currently added Views and their associated ViewHolders will be recycled.