package com.google.zxing.qrcode;
import com.google.zxing.BarcodeFormat;
+import com.google.zxing.EncodeHintType;
import com.google.zxing.Writer;
-import com.google.zxing.common.ByteMatrix;
-import com.google.zxing.qrcode.encoder.ByteArray;
+import com.google.zxing.WriterException;
+import com.google.zxing.common.BitMatrix;
+import com.google.zxing.qrcode.encoder.ByteMatrix;
+import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import com.google.zxing.qrcode.encoder.Encoder;
import com.google.zxing.qrcode.encoder.QRCode;
import java.util.Hashtable;
+/**
+ * This object renders a QR Code as a BitMatrix 2D array of greyscale values.
+ *
+ * @author dswitkin@google.com (Daniel Switkin)
+ */
public final class QRCodeWriter implements Writer {
- public ByteMatrix encode(byte[] contents, BarcodeFormat format, int width,
- int height) throws Exception {
+ private static final int QUIET_ZONE_SIZE = 4;
+
+ public BitMatrix encode(String contents, BarcodeFormat format, int width, int height)
+ throws WriterException {
return encode(contents, format, width, height, null);
}
- public ByteMatrix encode(byte[] contents, BarcodeFormat format, int width, int height,
- Hashtable hints) throws Exception {
+ public BitMatrix encode(String contents, BarcodeFormat format, int width, int height,
+ Hashtable hints) throws WriterException {
- if (contents == null || contents.length == 0) {
+ if (contents == null || contents.length() == 0) {
throw new IllegalArgumentException("Found empty contents");
}
}
if (width < 0 || height < 0) {
- throw new IllegalArgumentException("Requested dimensions are too small: " + width + "x" +
+ throw new IllegalArgumentException("Requested dimensions are too small: " + width + 'x' +
height);
}
- // TODO: Check hints for error correction level instead of hardcoding
- int errorCorrectionLevel = QRCode.EC_LEVEL_L;
- QRCode code = new QRCode();
- if (Encoder.Encode(new ByteArray(contents), errorCorrectionLevel, code)) {
- return renderResult(code, width, height);
- } else {
- throw new IllegalStateException("Could not generate a QR Code");
+ ErrorCorrectionLevel errorCorrectionLevel = ErrorCorrectionLevel.L;
+ if (hints != null) {
+ ErrorCorrectionLevel requestedECLevel = (ErrorCorrectionLevel) hints.get(EncodeHintType.ERROR_CORRECTION);
+ if (requestedECLevel != null) {
+ errorCorrectionLevel = requestedECLevel;
+ }
}
+
+ QRCode code = new QRCode();
+ Encoder.encode(contents, errorCorrectionLevel, hints, code);
+ return renderResult(code, width, height);
}
// Note that the input matrix uses 0 == white, 1 == black, while the output matrix uses
// 0 == black, 255 == white (i.e. an 8 bit greyscale bitmap).
- private ByteMatrix renderResult(QRCode code, final int width, final int height) {
- ByteMatrix input = code.matrix();
- int inputWidth = input.width();
- int inputHeight = input.height();
- int outputWidth = Math.max(width, inputWidth);
- int outputHeight = Math.max(height, inputHeight);
-
- int multiple = Math.min(outputWidth / inputWidth, outputHeight / inputHeight);
+ private static BitMatrix renderResult(QRCode code, int width, int height) {
+ ByteMatrix input = code.getMatrix();
+ int inputWidth = input.getWidth();
+ int inputHeight = input.getHeight();
+ int qrWidth = inputWidth + (QUIET_ZONE_SIZE << 1);
+ int qrHeight = inputHeight + (QUIET_ZONE_SIZE << 1);
+ int outputWidth = Math.max(width, qrWidth);
+ int outputHeight = Math.max(height, qrHeight);
+
+ int multiple = Math.min(outputWidth / qrWidth, outputHeight / qrHeight);
+ // Padding includes both the quiet zone and the extra white pixels to accommodate the requested
+ // dimensions. For example, if input is 25x25 the QR will be 33x33 including the quiet zone.
+ // If the requested size is 200x160, the multiple will be 4, for a QR of 132x132. These will
+ // handle all the padding from 100x100 (the actual QR) up to 200x160.
int leftPadding = (outputWidth - (inputWidth * multiple)) / 2;
int topPadding = (outputHeight - (inputHeight * multiple)) / 2;
- ByteMatrix output = new ByteMatrix(outputHeight, outputWidth);
- byte[][] outputArray = output.getArray();
-
- // We could be tricky and use the first row in each set of multiple as the temporary storage,
- // instead of allocating this separate array.
- byte[] row = new byte[outputWidth];
+ BitMatrix output = new BitMatrix(outputWidth, outputHeight);
- // 1. Write the white lines at the top
- for (int y = 0; y < topPadding; y++) {
- setRowColor(outputArray[y], (byte) 255);
- }
-
- // 2. Expand the QR image to the multiple
- final byte[][] inputArray = input.getArray();
- for (int y = 0; y < inputHeight; y++) {
- // a. Write the white pixels at the left of each row
- for (int x = 0; x < leftPadding; x++) {
- row[x] = (byte) 255;
- }
-
- // b. Write the contents of this row of the barcode
- int offset = leftPadding;
- for (int x = 0; x < inputWidth; x++) {
- byte value = (inputArray[y][x] == 1) ? 0 : (byte) 255;
- for (int z = 0; z < multiple; z++) {
- row[offset + z] = value;
+ for (int inputY = 0, outputY = topPadding; inputY < inputHeight; inputY++, outputY += multiple) {
+ // Write the contents of this row of the barcode
+ for (int inputX = 0, outputX = leftPadding; inputX < inputWidth; inputX++, outputX += multiple) {
+ if (input.get(inputX, inputY) == 1) {
+ output.setRegion(outputX, outputY, multiple, multiple);
}
- offset += multiple;
- }
-
- // c. Write the white pixels at the right of each row
- offset = leftPadding + (inputWidth * multiple);
- for (int x = offset; x < outputWidth; x++) {
- row[x] = (byte) 255;
- }
-
- // d. Write the completed row multiple times
- offset = topPadding + (y * multiple);
- for (int z = 0; z < multiple; z++) {
- System.arraycopy(row, 0, outputArray[offset + z], 0, outputWidth);
}
}
- // 3. Write the white lines at the bottom
- int offset = topPadding + (inputHeight * multiple);
- for (int y = offset; y < outputHeight; y++) {
- setRowColor(outputArray[y], (byte) 255);
- }
-
return output;
}
- private static void setRowColor(byte[] row, byte value) {
- for (int x = 0; x < row.length; x++) {
- row[x] = value;
- }
- }
-
}