fi.jasoft.qrcode.QRCode.java Source code

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/*
 * Copyright 2013 John Ahlroos
 *
 * 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 fi.jasoft.qrcode;

import java.awt.Color;
import java.awt.image.BufferedImage;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.UUID;
import java.util.logging.Level;
import java.util.logging.Logger;

import javax.imageio.ImageIO;

import com.vaadin.server.StreamResource;
import com.vaadin.ui.AbstractField;

import fi.jasoft.qrcode.client.ui.QRCodeConnector;
import fi.jasoft.qrcode.client.ui.SizeListener;
import fi.jasoft.qrcode.zxing.ByteMatrix;
import fi.jasoft.qrcode.zxing.Encoder;
import fi.jasoft.qrcode.zxing.ErrorCorrectionLevel;
import fi.jasoft.qrcode.zxing.WriterException;
import fi.jasoft.qrcode.zxing.ZXingQRCode;

/**
 * A component for encoding values into QR coded images and embedding them into
 * Vaadin applications.
 * 
 * @author John Ahlroos (www.jasoft.fi)
 */
@SuppressWarnings("serial")
public class QRCode extends AbstractField<String> implements SizeListener {

    private final ZXingQRCode qrcode = new ZXingQRCode();

    private static final Logger logger = Logger.getLogger(QRCode.class.getName());

    private int pixelWidth = -1;
    private int pixelHeight = -1;

    private Color fgColor = Color.BLACK;
    private Color bgColor = Color.WHITE;

    private String value;

    private ErrorCorrectionLevel ecl = ErrorCorrectionLevel.L;

    /**
     * Constructs an empty <code>QRCode</code> with no caption.
     */
    public QRCode() {
        doSetValue("");
        registerRpc(this, SizeListener.class);
    }

    /**
     * Constructs an empty <code>QRCode</code> with given caption.
     * 
     * @param caption
     *            the caption <code>String</code> for the editor.
     */
    public QRCode(String caption) {
        this();
        setCaption(caption);
    }

    /**
     * Constructs a new <code>QRCode</code> with the given caption and initial
     * text contents. The editor constructed this way will not be bound to a
     * Property unless
     * {@link com.vaadin.data.Property.Viewer#setPropertyDataSource(Property)}
     * is called to bind it.
     * 
     * @param caption
     *            the caption <code>String</code> for the editor.
     * @param text
     *            the initial text content of the editor.
     */
    public QRCode(String caption, String value) {
        doSetValue(value);
        setCaption(caption);
        registerRpc(this, SizeListener.class);
    }

    @Override
    public void setWidth(float width, Unit unit) {
        super.setWidth(width, unit);
        generateQRCode();
    }

    @Override
    public void setHeight(float height, Unit unit) {
        super.setHeight(height, unit);
        generateQRCode();
    }

    @Override
    protected boolean setValue(String value, boolean userOriginated) {
        boolean result = super.setValue(value, userOriginated);
        if (result) {
            generateQRCode();
        }
        return result;
    }

    private void generateQRCode() {

        if (pixelHeight < 0 || pixelWidth < 0) {
            return;
        }

        String value = getValue();
        if (value == null) {
            value = "";
        }

        // Try to encode
        try {
            Encoder.encode(value, ecl, qrcode);
        } catch (WriterException e1) {
            logger.log(Level.SEVERE, "Could not encode QR Code for '" + value + "'", e1);
            return;
        }

        /*
         * Generate a unique filename for this qrcode relative to the value of
         * the qrcode and the width
         */
        String hash = value + pixelWidth + "x" + pixelHeight + fgColor.getRGB() + bgColor.getRGB();
        String filename = "qrcode-" + UUID.nameUUIDFromBytes(hash.getBytes()).toString() + ".png";

        // Create a image resource
        setResource(QRCodeConnector.RESOURCE_KEY, new StreamResource(new StreamResource.StreamSource() {
            public InputStream getStream() {
                ByteMatrix matrix = renderResult(qrcode, pixelWidth, pixelHeight);
                BufferedImage image = toBufferedImage(matrix, fgColor.getRGB(), bgColor.getRGB());
                ByteArrayOutputStream imagebuffer = new ByteArrayOutputStream();

                try {
                    ImageIO.write(image, "png", imagebuffer);
                    return new ByteArrayInputStream(imagebuffer.toByteArray());
                } catch (IOException e) {
                    logger.log(Level.SEVERE, "Could not create QRCode image file", e);
                }
                return null;
            }
        }, filename));
    }

    /**
     * Copy&Paste from com.google.zxing.qrcode.QRCodeWriter.java
     * 
     * http://zxing.googlecode.com/svn-history/r800/trunk/core/src/com/google/
     * zxing/qrcode/QRCodeWriter.java
     * 
     */
    private static final int QUIET_ZONE_SIZE = 4;

    private static ByteMatrix renderResult(ZXingQRCode 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);
        int leftPadding = (outputWidth - (inputWidth * multiple)) / 2;
        int topPadding = (outputHeight - (inputHeight * multiple)) / 2;

        ByteMatrix output = new ByteMatrix(outputWidth, outputHeight);
        byte[][] outputArray = output.getArray();
        byte[] row = new byte[outputWidth];

        // 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
        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;
                }
                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;
    }

    /**
     * Copy & Paste from com.google.zxing.qrcode.QRCodeWriter.java
     * 
     * http://zxing.googlecode.com/svn-history/r800/trunk/core/src/com/google/
     * zxing/qrcode/QRCodeWriter.java
     * 
     */
    private static void setRowColor(byte[] row, byte value) {
        for (int x = 0; x < row.length; x++) {
            row[x] = value;
        }
    }

    /**
     * Copy & Paste from com.google.zxing.client.j2se.MatrixToImageWriter.java
     * 
     * http://zxing.googlecode.com/svn-history/r1028/trunk/javase/src/com/google
     * /zxing/client/j2se/MatrixToImageWriter.java
     */
    protected static BufferedImage toBufferedImage(ByteMatrix matrix, int fgColor, int bgColor) {
        int width = matrix.getWidth();
        int height = matrix.getHeight();
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB);
        for (int x = 0; x < width; x++) {
            for (int y = 0; y < height; y++) {
                image.setRGB(x, y, matrix.get(x, y) == 0 ? fgColor : bgColor);
            }
        }
        return image;
    }

    /**
     * Set the color which will be the primary color of the QR Code. By default
     * this is black. This color should be darker than the secondary color.
     * 
     * @param color
     *            The color to use as the primary color
     */
    public void setPrimaryColor(Color color) {
        if (color == null) {
            fgColor = Color.BLACK;
        } else {
            fgColor = color;
        }
        generateQRCode();
    }

    /**
     * Get the color which will be the primary color of the QR Code. By default
     * this is black.
     */
    public Color getPrimaryColor() {
        return fgColor;
    }

    /**
     * Set the color which wll be the secondary, or background color, of the QR
     * Code. By default this is white. THis color should be lighter than the
     * primary color.
     * 
     * @param color
     *            The color to use as the secondary color
     */
    public void setSecondaryColor(Color color) {
        if (color == null) {
            bgColor = Color.WHITE;
        } else {
            bgColor = color;
        }
        generateQRCode();
    }

    /**
     * Returns the error correction level. Default is
     * {@link ErrorCorrectionLevel#L}
     * 
     * @return
     */
    protected ErrorCorrectionLevel getEcl() {
        return ecl;
    }

    /**
     * Set the error correction level. Default is {@link ErrorCorrectionLevel#L}
     * 
     * @param ecl
     *            The error correction level to use.
     */
    protected void setEcl(ErrorCorrectionLevel ecl) {
        this.ecl = ecl;
        generateQRCode();
    }

    @Override
    public void sizeChanged(int width, int height) {
        pixelWidth = width;
        pixelHeight = height;
        generateQRCode();
    }

    @Override
    public String getValue() {
        return value;
    }

    @Override
    protected void doSetValue(String value) {
        this.value = value;
        generateQRCode();
    }
}