Question

I must set the same image to two imageviews in my activity. The image is downloaded from internet and set to the imageview 1 asynchronously by a method that takes as parameter the url of the picture and one imageview.

Can I synchronize the source of the imageview 2 with imageview 1 (i.e. as soon as the picture is set in image 1, it also set it to image 2)?

Answer 1

You can change the download method so that it accepts a list or an array of ImageView or varargs: download(String url, ImageView... imageViews)

Upd: synchronization of ImageViews can be done over subclassing it.

class MyImageView extends ImageView {
    private OnImageChangedListener onImageChangedListener;

    public MyImageView(Context context) {
        super(context);
    }

    // Plus other constructors if needed

    // Call to super method and do callback
    // Override another method if needed
    @Override
    public void setImageBitmap(Bitmap bitmap) {
        super(bitmap);
        if (onImageChangedListener != null) {
            onImageChangedListener.onImageChanged(bitmap);
        }
    }

    public setOnImageChangedListener(OnImageChangedListener listener) {
        this.onImageChangedListener = listener;
    }

    public interface OnImageChangedListener() {
        public void onImageChanged(Bitmap bitmap);
    }
}

And set the listener:

MyImageView imageView1 = ...

imageView1.setOnImageChangedListener(new OnImageChangedListener() {
    @Override
    public void onImageChanged(Bitmap bitmap) {
        imageView2.setImageBitmap(bitmap);
    }
});
download(url, imageView1);