Use Picasso to get a callback with a Bitmap

Steve M picture Steve M · Nov 24, 2013 · Viewed 97.6k times · Source

I'm using Picasso to download images for my app.

I'm in a situation where I need to access the Bitmap first before it's loaded into the ImageView. The presence of the Downloader.Response class seems to suggest this is possible, but I can't find any use examples. I don't want to write a bunch more code to asynchronously handle this one particular case if it's possible to do with Picasso.

Can anyone show me how to do it?

Answer

Steve M picture Steve M · Nov 24, 2013

Found the answer on github in case anyone is wondering:

private Target target = new Target() {
      @Override
      public void onBitmapLoaded(Bitmap bitmap, Picasso.LoadedFrom from) {
      }

      @Override
      public void onBitmapFailed(Drawable errorDrawable) {
      }

      @Override
      public void onPrepareLoad(Drawable placeHolderDrawable) {
      }
}

private void someMethod() {
   Picasso.with(this).load("url").into(target);
}

@Override 
public void onDestroy() {  // could be in onPause or onStop
   Picasso.with(this).cancelRequest(target);
   super.onDestroy();
}

The post recommends not using an anonymous callback, and instead using an instance variable for target.