[Android] A class to get image from a URL and find the vibrant color.

ImageFromUrl.java

package com.example.app.package; // Your package namespace

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;

import java.io.IOException;
import java.io.InputStream;

import androidx.annotation.ColorInt;
import androidx.palette.graphics.Palette;

@SuppressWarnings("unused")
public class ImageFromUrl extends AsyncTask<Void, Void, Bitmap> {

    private static final int DEFAULT_VIBRANT_COLOR = 0xCCCCCC;

    private GetImageFromUrlListener getImageFromUrlListener;
    private GetVibrantColorListener getVibrantColorListener;
    private Bitmap bitmap;
    private String imageUrl;

    public ImageFromUrl(String imageUrl) {
        this.imageUrl = imageUrl;
    }

    public void setImageUrl(String imageUrl) {
        this.imageUrl = imageUrl;
    }

    public static Bitmap getBitmap(String imageUrl) {
        InputStream in = null;
        try {
            in = new java.net.URL(imageUrl).openStream();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return BitmapFactory.decodeStream(in);
    }

    @Override
    protected Bitmap doInBackground(Void... voids) {
        try {
            InputStream in = new java.net.URL(this.imageUrl).openStream();
            this.bitmap = BitmapFactory.decodeStream(in);
        } catch (Exception e) {
            // I have no idea what to do here. I think it's just fine to do nothing.
        }
        return this.bitmap;
    }

    @Override
    protected void onPostExecute(Bitmap bitmap) {
        super.onPostExecute(bitmap);

        if (getImageFromUrlListener != null) {
            getImageFromUrlListener.onFinishGettingImageFromUrl(bitmap);
        }

        if (getVibrantColorListener != null) {
            Palette.from(bitmap).generate(p -> {
                if (p != null) {
                    getVibrantColorListener.onVibrantColorGenerated(p.getVibrantColor(DEFAULT_VIBRANT_COLOR));
                }
                else {
                    getVibrantColorListener.onVibrantColorGenerated(DEFAULT_VIBRANT_COLOR);
                }
            });
        }
    }

    public void setOnFinishGettingImageFromUrl(GetImageFromUrlListener listener) {
        this.getImageFromUrlListener = listener;
    }

    public interface GetImageFromUrlListener {
        void onFinishGettingImageFromUrl(Bitmap bitmap);
    }

    public void setOnGetVibrantColorListener(GetVibrantColorListener listener) {
        this.getVibrantColorListener = listener;
    }

    public interface GetVibrantColorListener {
        void onVibrantColorGenerated(@ColorInt int vibrantColor);
    }
}

USAGE.txt

// Make sure you're using Java 8.
// Read more: https://developer.android.com/studio/write/java8-support

// Initialize
ImageFromUrl imageFromUrl = new ImageFromUrl("https://example.com/image.jpg"); // "https://example.com/image.jpg" is the image URL.

// Do something when the image has been downloaded.
imageFromUrl.setOnFinishGettingImageFromUrl(bitmap -> {
    imageView.setImageBitmap(bitmap); // Display image to an ImageView.
});

// Do something when the vibrant color has been found.
imageFromUrl.setOnGetVibrantColorListener(vibrantColor -> {
    // ...
});

// Execute this process in the background thread.
imageFromUrl.execute();