package your.package;

import android.graphics.Bitmap;
import android.support.annotation.NonNull;
import android.support.v7.graphics.Palette;
import android.widget.ImageView;

import com.squareup.picasso.Callback;

import java.lang.ref.WeakReference;

/**
 * A {@link Callback} that receives {@link Palette} information in its callback.
 *
 * @see Callback
 */
public abstract class PaletteCallback<T extends ImageView> implements Callback {
    private WeakReference<T> mImageView;

    public PaletteCallback(@NonNull T imageView) {
        mImageView = new WeakReference<>(imageView);
    }

    protected abstract void onSuccess(Palette palette);    

    @Override public final void onSuccess() {
        if (getImageView() == null) {
            return;
        }
        final Bitmap bitmap = getBitmap(); // Ew!
        final Palette palette = PaletteTransformation.getPalette(bitmap);
        onSuccess(palette);
    }

    @Override public void onError() {
        if (onError != null) {
            onError.call();
        }
    }

    protected abstract Bitmap getBitmap();

    protected T getImageView() {
        return mImageView.get();
    }

}