How to avoid flickering while updating gridview?

Question

I have a gridview. Im displaying images from the array of 10 images. After 1 minute i'm adding 5 more images. To update the gridview i'm using the following code.

aImgAdapterL.notifyDataSetChanged();  

aImgAdapterL is my ImgaeAdapter. The new images are getting displayed.
My problem is when updating the gridview one flickering or blinking happening during the image updation. Is it possible to hide that flickering?

Answer 1

I had the same issue and was able to solve it like this:

In fact it was due to my ListAdapter which didn't managed properly the case when the whole list is refreshed. If so, what you want to do is keeping the items already displayed on the screen as-is.

To do so, in the method getView of the Adapter when you get a recycled item, you must check if it's not already the one you want to display. If it's the case, just return it directly.

@Override
public View getView(int position, View convertView, ViewGroup container) {
    ImageView imageView;
    String src = this.getItem(position).getSrcThumbnail();
    if (convertView == null) {
        imageView = new ImageView(getContext());
        imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);

        int height = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 120, getResources().getDisplayMetrics());

        imageView.setLayoutParams(new GridView.LayoutParams(GridView.LayoutParams.MATCH_PARENT, height));

    } else {
        imageView = (ImageView) convertView;

        // When you get a recycled item, check if it's not already the one you want to display.
        String newSrc = (String) imageView.getTag();

        if(newSrc.equals(src)){
            // If so, return it directly.
            return imageView;
        }
    }

    loadBitmap(this.getItem(position).getSrcThumbnail(), imageView);

    // Here you set the unique tag that allow to identify this item.
    imageView.setTag(src);

    return imageView;
}

Answer 2

If your adapter has stable ids, override hasStableIds to return true.

Grep the android.GridView source code here, it allows the grid view to reuse a view for the same data rather than do a full redraw. This might help in the OP's case, because by default hasStableIds returns false.