QRCodeEncoder.java

/*
 * Copyright (C) 2008 ZXing authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package utils;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;

import android.graphics.Bitmap;

import java.util.Hashtable;

/** License Apache 2.0
 *
 * @author dswitkin@google.com (Daniel Switkin)
 */
public final class QRCodeEncoder {

  private static final int WHITE = 0xFFFFFFFF;
  private static final int BLACK = 0xFF000000;
	public static Bitmap encodeAsBitmap(String contents, BarcodeFormat format,
			int desiredWidth, int desiredHeight) throws WriterException {
		Hashtable<EncodeHintType, String> hints = null;
		String encoding = guessAppropriateEncoding(contents);
		if (encoding != null) {
			hints = new Hashtable<EncodeHintType, String>(2);
			hints.put(EncodeHintType.CHARACTER_SET, encoding);
		}
		MultiFormatWriter writer = new MultiFormatWriter();
		BitMatrix result = writer.encode(contents, format, desiredWidth, desiredHeight, hints);
		int width = result.getWidth();
		int height = result.getHeight();
		int[] pixels = new int[width * height];
		// All are 0, or black, by default
		for (int y = 0; y < height; y++) {
			int offset = y * width;
			for (int x = 0; x < width; x++) {
				pixels[offset + x] = result.get(x, y) ? BLACK : WHITE;
			}
		}

		Bitmap bitmap = Bitmap.createBitmap(width, height,
				Bitmap.Config.ARGB_8888);
		bitmap.setPixels(pixels, 0, width, 0, 0, width, height);
		return bitmap;
	}


  private static String guessAppropriateEncoding(CharSequence contents) {
    // Very crude at the moment
    for (int i = 0; i < contents.length(); i++) {
      if (contents.charAt(i) > 0xFF) {
        return "ISO-8859-1";
      }
    }
    return null;
  }

}