AsciiArtInterceptor.java

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Color;
import java.io.IOException;
import okhttp3.Interceptor;
import okhttp3.Response;
import okio.Buffer;
import okio.BufferedSource;

final class AsciiArtInterceptor implements Interceptor {
  private static String convertToAscii(Buffer buffer, int targetWidth, int targetHeight) {
    BitmapFactory.Options options = new BitmapFactory.Options();
    options.inJustDecodeBounds = true;
    BitmapFactory.decodeStream(buffer.clone().inputStream(), null, options);
    int decodedWidth = options.outWidth;
    if (decodedWidth == -1) {
      return null;
    }
    int decodedHeight = options.outHeight;
    int scaleFactor = Math.min(decodedWidth / targetWidth, decodedHeight / targetHeight);
    options.inJustDecodeBounds = false;
    options.inSampleSize = scaleFactor;
    Bitmap image = BitmapFactory.decodeStream(buffer.clone().inputStream(), null, options);
    int imageHeight = image.getHeight();
    int imageWidth = image.getWidth();
    if (imageHeight == 0 || imageWidth == 0) {
      return "";
    }
    StringBuilder builder = new StringBuilder(imageHeight * imageWidth + imageHeight - 1);
    for (int i = 0; i != imageHeight; i++) {
      if (i != 0) {
        builder.append('\n');
      }
      for (int j = 0; j != imageWidth; j++) {
        int pixel = image.getPixel(j, i);
        double value =
            (((Color.red(pixel) * 0.30) + (Color.blue(pixel) * 0.59) + (Color.green(pixel)
                * 0.11)));
        builder.append(strChar(value));
      }
    }
    return builder.toString();
  }

  private static char strChar(double g) {
    if (g >= 240) {
      return ' ';
    }
    if (g >= 210) {
      return '.';
    }
    if (g >= 190) {
      return '*';
    }
    if (g >= 170) {
      return '+';
    }
    if (g >= 120) {
      return '^';
    }
    if (g >= 110) {
      return '&';
    }
    if (g >= 80) {
      return '8';
    }
    if (g >= 60) {
      return '#';
    }
    return '@';
  }

  @Override public Response intercept(Chain chain) throws IOException {
    Response response = chain.proceed(chain.request());
    BufferedSource source = response.body().source();
    source.request(Long.MAX_VALUE);
    android.util.Log.d("Image (" + response.request().url() + ")",
        String.valueOf(convertToAscii(source.buffer(), 50, 50)));
    return response;
  }
}