/* * @(#)DitherTest.java	1.17 06/02/22 *  * Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved. *  * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: *  * -Redistribution of source code must retain the above copyright notice, this *  list of conditions and the following disclaimer. *  * -Redistribution in binary form must reproduce the above copyright notice,  *  this list of conditions and the following disclaimer in the documentation *  and/or other materials provided with the distribution. *  * Neither the name of Sun Microsystems, Inc. or the names of contributors may  * be used to endorse or promote products derived from this software without  * specific prior written permission. *  * This software is provided "AS IS," without a warranty of any kind. ALL  * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN") * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST  * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,  * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY  * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,  * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. *  * You acknowledge that this software is not designed, licensed or intended * for use in the design, construction, operation or maintenance of any * nuclear facility. *//* * @(#)DitherTest.java	1.17 06/02/22 */import java.applet.Applet;import java.awt.event.*;import java.awt.*;import java.awt.image.ColorModel;import java.awt.image.MemoryImageSource;public class DitherTest extends Applet implements Runnable {    final private static int NOOP = 0;    final private static int RED = 1;    final private static int GREEN = 2;    final private static int BLUE = 3;    final private static int ALPHA = 4;    final private static int SATURATION = 5;    private Thread runner;    private DitherControls XControls;    private DitherControls YControls;    private DitherCanvas canvas;    public static void main(String args[]) {        Frame f = new Frame("DitherTest");        DitherTest ditherTest = new DitherTest();        ditherTest.init();        f.add("Center", ditherTest);        f.pack();        f.setVisible(true);        ditherTest.start();    }    public void init() {        String xspec = null, yspec = null;        int xvals[] = new int[2];        int yvals[] = new int[2];                try {            xspec = getParameter("xaxis");            yspec = getParameter("yaxis");        } catch (NullPointerException npe) {            //only occurs if run as application        }                if (xspec == null) {            xspec = "red";        }        if (yspec == null) {            yspec = "blue";        }        int xmethod = colormethod(xspec, xvals);        int ymethod = colormethod(yspec, yvals);        setLayout(new BorderLayout());        XControls = new DitherControls(this, xvals[0], xvals[1],                                       xmethod, false);        YControls = new DitherControls(this, yvals[0], yvals[1],                                       ymethod, true);        YControls.addRenderButton();        add("North", XControls);        add("South", YControls);        add("Center", canvas = new DitherCanvas());    }    private int colormethod(String s, int vals[]) {        int method = NOOP;        if (s == null) {            s = "";        }        String lower = s.toLowerCase();        int len = 0;        if (lower.startsWith("red")) {            method = RED;            lower = lower.substring(3);        } else if (lower.startsWith("green")) {            method = GREEN;            lower = lower.substring(5);        } else if (lower.startsWith("blue")) {            method = BLUE;            lower = lower.substring(4);        } else if (lower.startsWith("alpha")) {            method = ALPHA;            lower = lower.substring(5);        } else if (lower.startsWith("saturation")) {            method = SATURATION;            lower = lower.substring(10);        }        if (method == NOOP) {            vals[0] = 0;            vals[1] = 0;            return method;        }        int begval = 0;        int endval = 255;        try {            int dash = lower.indexOf('-');            if (dash < 0) {                endval = Integer.parseInt(lower);            } else {                begval = Integer.parseInt(lower.substring(0, dash));                endval = Integer.parseInt(lower.substring(dash + 1));            }        } catch (NumberFormatException nfe) {        }        if (begval < 0) {            begval = 0;        } else if (begval > 255) {            begval = 255;        }                if (endval < 0) {            endval = 0;        } else if (endval > 255) {            endval = 255;        }        vals[0] = begval;        vals[1] = endval;        return method;    }    /**     * Calculates and returns the image.  Halts the calculation and returns     * null if the Applet is stopped during the calculation.     */    private Image calculateImage() {        Thread me = Thread.currentThread();                int width = canvas.getSize().width;        int height = canvas.getSize().height;        int xvals[] = new int[2];        int yvals[] = new int[2];        int xmethod = XControls.getParams(xvals);        int ymethod = YControls.getParams(yvals);        int pixels[] = new int[width * height];        int c[] = new int[4];   //temporarily holds R,G,B,A information        int index = 0;        for (int j = 0; j < height; j++) {            for (int i = 0; i < width; i++) {                c[0] = c[1] = c[2] = 0;                c[3] = 255;                if (xmethod < ymethod) {                    applymethod(c, xmethod, i, width, xvals);                    applymethod(c, ymethod, j, height, yvals);                } else {                    applymethod(c, ymethod, j, height, yvals);                    applymethod(c, xmethod, i, width, xvals);                }                pixels[index++] = ((c[3] << 24) |                                   (c[0] << 16) |                                   (c[1] << 8) |                                   c[2]);            }            // Poll once per row to see if we've been told to stop.            if (runner != me) {                return null;            }        }        return createImage(new MemoryImageSource(width, height,                            ColorModel.getRGBdefault(), pixels, 0, width));    }    private void applymethod(int c[], int method, int step,                              int total, int vals[]) {        if (method == NOOP) {            return;        }        int val = ((total < 2)                   ? vals[0]                   : vals[0] + ((vals[1] - vals[0]) * step / (total - 1)));        switch (method) {        case RED:            c[0] = val;            break;        case GREEN:            c[1] = val;            break;        case BLUE:            c[2] = val;            break;        case ALPHA:            c[3] = val;            break;        case SATURATION:            int max = Math.max(Math.max(c[0], c[1]), c[2]);            int min = max * (255 - val) / 255;            if (c[0] == 0) {                c[0] = min;            }            if (c[1] == 0) {                c[1] = min;            }            if (c[2] == 0) {                c[2] = min;            }            break;        }    }    public void start() {        runner = new Thread(this);        runner.start();    }    public void run() {        canvas.setImage(null);  // Wipe previous image        Image img = calculateImage();        if (img != null && runner == Thread.currentThread()) {            canvas.setImage(img);        }    }    public void stop() {        runner = null;    }    public void destroy() {        remove(XControls);        remove(YControls);        remove(canvas);    }    public String getAppletInfo() {        return "An interactive demonstration of dithering.";    }    public String[][] getParameterInfo() {        String[][] info = {            {"xaxis", "{RED, GREEN, BLUE, ALPHA, SATURATION}",             "The color of the Y axis.  Default is RED."},            {"yaxis", "{RED, GREEN, BLUE, ALPHA, SATURATION}",              "The color of the X axis.  Default is BLUE."}        };        return info;    }}class DitherCanvas extends Canvas {    private Image img;    private static String calcString = "Calculating...";    public void paint(Graphics g) {        int w = getSize().width;        int h = getSize().height;        if (img == null) {            super.paint(g);            g.setColor(Color.black);            FontMetrics fm = g.getFontMetrics();            int x = (w - fm.stringWidth(calcString)) / 2;            int y = h / 2;            g.drawString(calcString, x, y);        } else {            g.drawImage(img, 0, 0, w, h, this);        }    }    public void update(Graphics g) {        paint(g);    }    public Dimension getMinimumSize() {        return new Dimension(20, 20);    }    public Dimension getPreferredSize() {        return new Dimension(200, 200);    }    public Image getImage() {        return img;    }    public void setImage(Image img) {        this.img = img;        repaint();    }}class DitherControls extends Panel implements ActionListener {    private CardinalTextField start;    private CardinalTextField end;    private Button button;    private Choice choice;    private DitherTest applet;    private static LayoutManager dcLayout = new FlowLayout(FlowLayout.CENTER,                                                           10, 5);    public DitherControls(DitherTest app, int s, int e, int type,                          boolean vertical) {        applet = app;        setLayout(dcLayout);        add(new Label(vertical ? "Vertical" : "Horizontal"));        add(choice = new Choice());        choice.addItem("Noop");        choice.addItem("Red");        choice.addItem("Green");        choice.addItem("Blue");        choice.addItem("Alpha");        choice.addItem("Saturation");        choice.select(type);        add(start = new CardinalTextField(Integer.toString(s), 4));        add(end = new CardinalTextField(Integer.toString(e), 4));    }    /* puts on the button */    public void addRenderButton() {        add(button = new Button("New Image"));        button.addActionListener(this);    }    /* retrieves data from the user input fields */    public int getParams(int vals[]) {        try {            vals[0] = scale(Integer.parseInt(start.getText()));        } catch (NumberFormatException nfe) {            vals[0] = 0;        }        try {            vals[1] = scale(Integer.parseInt(end.getText()));        } catch (NumberFormatException nfe) {            vals[1] = 255;        }        return choice.getSelectedIndex();    }        /* fits the number between 0 and 255 inclusive */    private int scale(int number) {        if (number < 0) {            number = 0;        } else if (number > 255) {            number = 255;        }        return number;    }    /* called when user clicks the button */    public void actionPerformed(ActionEvent e) {        if (e.getSource() == button) {            applet.start();        }    }}class CardinalTextField extends TextField {    String oldText = null;    public CardinalTextField(String text, int columns) {         super(text, columns);        enableEvents(AWTEvent.KEY_EVENT_MASK | AWTEvent.TEXT_EVENT_MASK);        oldText = getText();    }    // Consume non-digit KeyTyped events    // Note that processTextEvent kind of eliminates the need for this     // function, but this is neater, since ideally, it would prevent     // the text from appearing at all.  Sigh.  See bugid 4100317/4114565.     //    protected void processEvent(AWTEvent evt) {        int id = evt.getID();        if (id != KeyEvent.KEY_TYPED) {            super.processEvent(evt);            return;        }        KeyEvent kevt = (KeyEvent) evt;        char c = kevt.getKeyChar();        // Digits, backspace, and delete are okay         // Note that the minus sign is not allowed (neither is decimal)        if (Character.isDigit(c) || (c == '\b') || (c == '\u007f')) {            super.processEvent(evt);            return;        }        Toolkit.getDefaultToolkit().beep();        kevt.consume();    }    // Should consume TextEvents for non-integer Strings    // Store away the text in the tf for every TextEvent    // so we can revert to it on a TextEvent (paste, or     // legal key in the wrong location) with bad text    //    // Note: it would be easy to extend this to an eight-bit     // TextField (range 0-255), but I'll leave it as-is.      //    protected void processTextEvent(TextEvent te) {         // The empty string is okay, too         String newText = getText();        if (newText.equals("") || textIsCardinal(newText)) {            oldText = newText;            super.processTextEvent(te);            return;        }        Toolkit.getDefaultToolkit().beep();        setText(oldText);    }    // Returns true for Cardinal (non-negative) numbers    // Note that the empty string is not allowed    private boolean textIsCardinal(String textToCheck) {        int value = -1;        try {             value = Integer.parseInt(textToCheck, 10);             return (value >= 0);        } catch (NumberFormatException nfe) {             return false;         }    }}