exception when click on listview before image loads

Question

There is a custom listview which displays image and text. I am using Glide image library to load the image. So when i search the image and text displays in listview but before image loads if i click on it Java Null Pointer exception is seen. How to avoid making click before image loads or any change is required to done on the itemclick listener.

ItemClick:

@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

    descusers du = dusers.get(position);

    final String Limage = du.image;


    if (!Limage.isEmpty()) {
    final ImageView imageView1 = (ImageView) view.findViewById(R.id.imageList);
    final GlideBitmapDrawable bitmapDrawable = (GlideBitmapDrawable) imageView1.getDrawable();
    final Bitmap yourBitmap = bitmapDrawable.getBitmap();

    Dialog builder = new Dialog(this);
    builder.requestWindowFeature(Window.FEATURE_NO_TITLE);
    builder.getWindow().setBackgroundDrawable(
            new ColorDrawable(android.graphics.Color.TRANSPARENT));
    builder.setOnDismissListener(new DialogInterface.OnDismissListener() {
        @Override
        public void onDismiss(DialogInterface dialogInterface) {
            //nothing;
        }
    });

    ImageView imageView = new ImageView(this);
    imageView.setImageBitmap(yourBitmap);
    p=new PhotoViewAttacher(imageView);


    builder.addContentView(imageView, new RelativeLayout.LayoutParams(
            ViewGroup.LayoutParams.MATCH_PARENT,
            ViewGroup.LayoutParams.MATCH_PARENT));
    builder.show();

    }
}

I am checking if there is image url then fetch the image after loading using Glide, but exception when i click before image loads. any suggestion?

Answer:

Created Onclicklistener in Adapter passing display activity.

viewholder.iview.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Dialog builder = new Dialog(listdisplay);
                builder.requestWindowFeature(Window.FEATURE_NO_TITLE);
                builder.getWindow().setBackgroundDrawable(
                        new ColorDrawable(android.graphics.Color.TRANSPARENT));
                builder.setOnDismissListener(new DialogInterface.OnDismissListener() {
                    @Override
                    public void onDismiss(DialogInterface dialogInterface) {
                        //nothing;
                    }
                });
                ImageView imageView = new ImageView(listdisplay);

                final GlideBitmapDrawable bitmapDrawable = (GlideBitmapDrawable) finalViewholder.iview.getDrawable();
                final Bitmap yourBitmap = bitmapDrawable.getBitmap();
                imageView.setImageBitmap(yourBitmap);
                p=new PhotoViewAttacher(imageView);


                builder.addContentView(imageView, new RelativeLayout.LayoutParams(
                        ViewGroup.LayoutParams.MATCH_PARENT,
                        ViewGroup.LayoutParams.MATCH_PARENT));
                builder.show();
            }
        });

Adapter constructor:

private Activity listdisplay;
public DescAdapter(listdisplay ds, ArrayList<descusers> dusers,Activity listdisplay) {
    this.ds = ds;
    this.dusers = dusers;
    this.listdisplay = listdisplay;

}

java.lang.NullPointerException: Attempt to invoke virtual method 'android.graphics.Bitmap com.bumptech.glide.load.resource.bitmap.GlideBitmapDrawable.getBitmap()' on a null object reference — user2269164, May 12 '16 at 08:51
as error suggested you have null reference to your imageView1 @user2269164 — KDeogharkar, May 12 '16 at 08:58
Edit your message and add properly your logcat, nobody will read your messages, and second, show us your layout. We need 0s and 1s not guesses. — Andrei T, May 12 '16 at 09:04
you are getting NPE because you are trying to read image drawable which is really not downloaded or downloading. — Bharatesh, May 12 '16 at 12:18

score 0 · Answer 1 · answered May 12 '16 at 08:59

Try with this code on your getView()

@Override public View getView(int position, View convertView, ViewGroup parent) {
final T item = getItem(position);
....
Glide.with(getContext())
    .load(UIUtils.getThumbnailImageUrl(item.images))
    .placeholder(R.drawable.default_thumbnail_picture)
    .crossFade()
    .listener(new RequestListener<String, GlideDrawable>() {
        @Override
        public boolean onException(Exception e, String model, Target<GlideDrawable> target, boolean isFirstResource) {
            return false;
        }

        @Override
        public boolean onResourceReady(GlideDrawable resource, String model, Target<GlideDrawable> target, boolean isFromMemoryCache, boolean isFirstResource) {
            return false;
        }
    })
    .into(viewHolder.mExerciseImageView);
return convertView;
}

This may helps you.

score 0 · Answer 2 · answered May 12 '16 at 09:01

you can check if the image is null or not. may be there will be callbacks in the library you are using(i'm not sure)

final Bitmap yourBitmap = bitmapDrawable.getBitmap();
if(yourBitmap==null){
 image.setEnabled(false);
}

so you can avoid the click if the image is not loaded. or you can setEnabled(false) by default and when the image loaded use setEnabled(true)

exception when click on listview before image loads

2 Answers2