1 /*
2  * Copyright (C) 2018 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License
15  */
16 
17 package com.android.settings.wifi.qrcode;
18 
19 import android.graphics.Bitmap;
20 import android.graphics.Color;
21 
22 import com.google.zxing.BarcodeFormat;
23 import com.google.zxing.EncodeHintType;
24 import com.google.zxing.MultiFormatWriter;
25 import com.google.zxing.WriterException;
26 import com.google.zxing.common.BitMatrix;
27 
28 import java.nio.charset.CharsetEncoder;
29 import java.nio.charset.StandardCharsets;
30 import java.util.HashMap;
31 import java.util.Map;
32 
33 public final class QrCodeGenerator {
34     /**
35      * Generates a barcode image with {@code contents}.
36      *
37      * @param contents The contents to encode in the barcode
38      * @param size     The preferred image size in pixels
39      * @return Barcode bitmap
40      */
encodeQrCode(String contents, int size)41     public static Bitmap encodeQrCode(String contents, int size)
42             throws WriterException, IllegalArgumentException {
43         final Map<EncodeHintType, Object> hints = new HashMap<>();
44         if (!isIso88591(contents)) {
45             hints.put(EncodeHintType.CHARACTER_SET, StandardCharsets.UTF_8.name());
46         }
47 
48         final BitMatrix qrBits = new MultiFormatWriter().encode(contents, BarcodeFormat.QR_CODE,
49                 size, size, hints);
50         final Bitmap bitmap = Bitmap.createBitmap(size, size, Bitmap.Config.RGB_565);
51         for (int x = 0; x < size; x++) {
52             for (int y = 0; y < size; y++) {
53                 bitmap.setPixel(x, y, qrBits.get(x, y) ? Color.BLACK : Color.WHITE);
54             }
55         }
56         return bitmap;
57     }
58 
isIso88591(String contents)59     private static boolean isIso88591(String contents) {
60         CharsetEncoder encoder = StandardCharsets.ISO_8859_1.newEncoder();
61         return encoder.canEncode(contents);
62     }
63 }
64