package gradient;  

import java.awt.Color;

import java.awt.Dimension;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.awt.Insets;

import java.awt.LinearGradientPaint;

import java.awt.MultipleGradientPaint;

import java.awt.Paint;

import java.awt.RadialGradientPaint;

import java.awt.RenderingHints;

import java.awt.event.KeyAdapter;

import java.awt.event.KeyEvent;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

import java.awt.event.MouseMotionAdapter;

import java.awt.geom.Ellipse2D;

import java.awt.geom.GeneralPath;

import java.awt.geom.Point2D;

import java.awt.geom.Rectangle2D;

import java.util.ArrayList;

import java.util.LinkedList;

import java.util.List;  

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.event.ChangeEvent;

import javax.swing.event.ChangeListener;  

/*

 使用方法:

 渐变窗体:

 a. 左键双击顶点的linear gradient 渐变区，改变渐变超出范围的重复绘制模式.

 b. 左键双击fractions小按钮区，创建添加一个新的fraction按钮.

 c. 左键双击fractions小按钮，弹出窗口选择窗口选择颜色.

 d. 右键双击fractions小按钮，删除此fraction按钮.

 e. 按住fractions小按钮可以拖动它，修改fractions的位置.

 f. 左键双击辐射渐变区，改变辐射渐变的焦点(focus)到点击位置.

 g. 在辐射渐变区按住左键拖动，改变辐射渐变的焦点.

 h. 按下f，显示辐射渐变的圆周，为了方便看到更清楚的数据，默认这圆周是隐藏的.

 i. 按下c，恢复辐射渐变的焦点到辐射渐变的圆心，焦点默认是与圆心重合.  

 颜色选择窗体:

 a. 单击某一个颜色，则选中此颜色，并在底部的预览区显示出来.但颜色选择窗口不消失.

 b. 双击某一个颜色，则选中此颜色，返回给调用者，颜色选择窗口消失.

 c. 按下回车键，返回选中的颜色，颜色选择窗口消失.

 d. 按下ESC键，返回传给颜色选择窗体的默认色，颜色选择窗口消失.

 e. 下部的JSlider依次调节被选中颜色的red, green, blue, alpha，拖动并实时的在预览区显示出调整后颜色.  

 第三方程序集成使用方法: 在第三方程序中创建一个GradientGenerator对象，并添加到组件的某一部分，

 并给此gradientGenerator添加上change listener:

 gradientGenerator.addChangeListener(new ChangedListener() {

 public void stateChanged(ChangeEvent e) {

 float[] fractions = gradientGenerator.getFractons();

 Color[] colors = gradientGenerator.getColors();

 Point2D focus = gradientGenerator.calculateFocus(center, radius);

 repaint(); // 使用这里得到的fractions, colors, focus等去绘制第三方程序中的渐变图形

 });

 这样，当gradient generator中的数据发生变化时，第三方程序里也会即时的反映出来.  

 1. 提示，现在Swing支持合建不规则窗体。

 2. 此程序中，除了JSlider，其他的部分都是使用Java2D手动计算绘制出来的。

 基于上面两点，可以自己创建一个统一的JSlider风格，

 然后就可以把整个程序的外观风格做得在所有平台下都是一个样。

 */

/**

 * *^o^*，本程序一惯还是一惯的作风，LGPL协议，什么版权的废话就不整了，希望修改得效果好的朋友给大家分享一下心得，在此权当扔出块板砖，

 * 希望能砸出块暖玉来，嗷呜嗷呜嗷呜.

 */

@SuppressWarnings("serial")

public class GradientGenerator extends JPanel {

    private int width = 400; // 整个Panel的宽度

    private int height = 400; // 整个Panel的高度

    private Insets padding = new Insets(10, 10, 10, 10); // 边距  

    private int thumbRectHeight = 20; // Fraction按钮区的高度

    private int linearRectHeight = 40; // 线性渐变区域的高度

    private int radialRectHeight = 310; // 辐射渐变区域的高度  

    private Ellipse2D radialCircle = new Ellipse2D.Float(); // 辐射渐变的圆周

    private Point2D focusPoint = new Point2D.Float(); // 辐射渐变的焦点

    private Point2D pressedPoint = new Point2D.Float(); // 鼠标按下时的点

    private Rectangle2D linearRect = new Rectangle2D.Float(); // 线性渐变区域

    private Rectangle2D thumbsRect = new Rectangle2D.Float(); // Fractions按钮区域

    private Rectangle2D radialRect = new Rectangle2D.Float(); // 辐射渐变区域  

    private Thumb selectedThumb = null; // 被选中的Fraction按钮

    private List<Thumb> thumbs = new ArrayList<Thumb>(); // Fractions按钮  

    private boolean showCircle = false; // 显示辐射渐变的圆周

    private List<ChangeListener> changeListeners = new LinkedList<ChangeListener>();

    private MultipleGradientPaint.CycleMethod cycleMethod = MultipleGradientPaint.CycleMethod.REFLECT;  

    /**

     * 返回渐变的fractions数组

     *

     * @return

     */

    public float[] getGradientFractions() {

        float[] fractions = new float[thumbs.size()];

        int i = 0;

        for (Thumb t : thumbs) {

            fractions[i] = (float) ((t.getX() - padding.left) / linearRect.getWidth());

            ++i;

        }

        return fractions;

    }  

    /**

     * 返回渐变的colors数组

     *

     * @return

     */

    public Color[] getGradientColors() {

        Color[] colors = new Color[thumbs.size()];

        int i = 0;

        for (Thumb t : thumbs) {

            colors[i] = t.getColor();

            ++i;

        }  

        return colors;

    }  

    /**

     * 利用指定圆的圆心和半径和当前的辐射渐变数据，计算相对于指定圆的焦点

     *

     * @param center

     *        圆心

     * @param radius

     *        半径

     * @return 返回相对于指定圆的焦点

     */

    public Point2D calculateFocus(Point2D center, double radius) {

        Point2D curCenter = new Point2D.Double(radialCircle.getCenterX(), radialCircle.getCenterY());

        double curRadius = radialCircle.getWidth() / 2;

        double curFocusLen = GeometryUtil.distanceOfPoints(curCenter, focusPoint);  

        double newFocusLen = radius * curFocusLen / curRadius;

        Point2D newFocusPoint = GeometryUtil.extentPoint(curCenter, focusPoint, newFocusLen);

        // 先移回原点，再移动到center的位置

        newFocusPoint.setLocation(center.getX() - curCenter.getX(),

            center.getY() - curCenter.getY());  

        return newFocusPoint;

    }  

    public GradientGenerator() {

        setFocusable(true); // 为了能接收键盘按键事件

        afterResized();

        resetThumbs(new float[] { 0.0f, 0.5f, 1.0f }, new Color[] { Color.BLACK, Color.BLUE,

                new Color(255, 255, 255, 220) });

        handleEvents();  

        setBackground(Color.DARK_GRAY);

    }  

    // 事件处理

    private void handleEvents() {

        this.addMouseListener(new MouseAdapter() {

            @Override

            public void mousePressed(MouseEvent e) {

                int x = e.getX();

                int y = e.getY();

                pressedPoint.setLocation(x, y);  

                // 得到被选中的Thumb

                for (Thumb t : thumbs) {

                    if (t.contains(x, y)) {

                        t.setSelected(true);

                        selectedThumb = t;

                        break;

                    }

                }

                repaint();

            }  

            @Override

            public void mouseReleased(MouseEvent e) {

                for (Thumb t : thumbs) {

                    t.setSelected(false);

                    selectedThumb = null;

                }

                repaint();

            }  

            @Override

            public void mouseClicked(MouseEvent e) {

                int x = e.getX();

                int y = e.getY();

                // 左键双击

                if (e.getButton() == MouseEvent.BUTTON1 && e.getClickCount() == 2) {

                    // 如果在thumbs里面，则弹出颜色选择器

                    for (Thumb t : thumbs) {

                        if (t.contains(x, y)) {

                            changeThumbColor(t);

                            repaint();

                            return;

                        }

                    }  

                    // 如果不在thumbs里，而在thumbs的区域里，则增加一个thumb

                    if (thumbsRect.contains(x, y)) {

                        insertThumbAt(x);

                        repaint();

                        return;

                    }  

                    // 修改focus的位置

                    if (radialRect.contains(x, y)) {

                        changeFocusPoint(new Point2D.Float(x, y));

                        repaint();

                        return;

                    }  

                    // 在Linear rect里面，修改cycle method

                    if (linearRect.contains(x, y)) {

                        changeCycleMethod();

                        repaint();

                        return;

                    }

                } else if (e.getButton() == MouseEvent.BUTTON3 && e.getClickCount() == 2) {

                    // 右键双击

                    removeThumbAt(x, y);

                    return;

                }

            }

        });  

        this.addMouseMotionListener(new MouseMotionAdapter() {

            @Override

            public void mouseDragged(MouseEvent e) {

                // 拖动滑块

                if (selectedThumb != null) {

                    int deltaX = e.getX() - (int) (selectedThumb.getX());

                    int x = selectedThumb.getX() + deltaX;  

                    // 不能超过边界

                    int maxRight = (int) (padding.left + linearRect.getWidth());

                    if (x < padding.left || x > maxRight) { return; }  

                    int index = thumbs.indexOf(selectedThumb);

                    int prevX = Integer.MIN_VALUE;

                    int nextX = Integer.MAX_VALUE;

                    // 只能在前一个和后一个之间移动

                    if (index - 1 >= 0) {

                        prevX = (int) (thumbs.get(index - 1).getX());

                    }  

                    if (index + 1 < thumbs.size()) {

                        nextX = (int) (thumbs.get(index + 1).getX());

                    }  

                    if (x > prevX && x < nextX) {

                        selectedThumb.setX(x);

                        repaint();

                    }

                    return;

                } else if (radialRect.contains(e.getX(), e.getY())) {

                    int deltaX = (int) (e.getX() - pressedPoint.getX());

                    int deltaY = (int) (e.getY() - pressedPoint.getY());

                    focusPoint.setLocation(focusPoint.getX() + deltaX, focusPoint.getY() + deltaY);

                    pressedPoint.setLocation(e.getX(), e.getY());

                    repaint();

                }  

            }

        });  

        this.addKeyListener(new KeyAdapter() {

            @Override

            public void keyReleased(KeyEvent e) {

                switch (e.getKeyCode()) {

                case KeyEvent.VK_F:

                    showCircle = !showCircle;

                    break;

                case KeyEvent.VK_C:

                    changeFocusPoint(radialCircle.getCenterX(), radialCircle.getCenterY());

                    break;

                }

                repaint();

            }

        });

    }  

    // 执行监听器的事件

    public void fireChangeEvent() {

        for (ChangeListener l : changeListeners) {

            l.stateChanged(new ChangeEvent(this));

        }

    }  

    // 改变超出渐变区的颜色渐变方式

    public void changeCycleMethod() {

        changeCycleMethod(cycleMethod);

    }  

    public void changeCycleMethod(MultipleGradientPaint.CycleMethod cycleMethod) {

        switch (cycleMethod) {

        case NO_CYCLE:

            this.cycleMethod = MultipleGradientPaint.CycleMethod.REFLECT;

            break;

        case REFLECT:

            this.cycleMethod = MultipleGradientPaint.CycleMethod.REPEAT;

            break;

        case REPEAT:

            this.cycleMethod = MultipleGradientPaint.CycleMethod.NO_CYCLE;

            break;

        }

    }  

    @Override

    protected void paintComponent(Graphics g) {

        super.paintComponent(g);

        Graphics2D g2d = (Graphics2D) g;

        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);  

        drawLinearRect(g2d);

        drawThumbsRect(g2d);

        drawRadialRect(g2d);

    }  

    // 绘制fraction按钮所在区域

    private void drawThumbsRect(Graphics2D g2d) {

        g2d.setColor(new Color(255, 255, 255, 40));

        g2d.fill(thumbsRect);  

        // 绘制fraction按钮

        for (Thumb t : thumbs) {

            t.paint(g2d);

        }

    }  

    private void drawLinearRect(Graphics2D g2d) {

        // 绘制线性渐变区域

        float sx = (float) linearRect.getX();

        float sy = (float) linearRect.getY();

        float ex = (int) (sx + linearRect.getWidth());

        float ey = sy;

        float[] fractions = getGradientFractions();

        Color[] colors = getGradientColors();

        Paint p = new LinearGradientPaint(sx, sy, ex, ey, fractions, colors, cycleMethod);  

        TransparentPainter.paint(g2d, linearRect);

        g2d.setPaint(p);

        g2d.fill(linearRect);

    }  

    // 绘制辐射渐变区

    private void drawRadialRect(Graphics2D g2d) {

        float cx = (float) radialCircle.getCenterX();

        float cy = (float) radialCircle.getCenterY();

        float fx = (float) focusPoint.getX();

        float fy = (float) focusPoint.getY();

        float radius = (float) radialCircle.getWidth() / 2;

        float[] fractions = getGradientFractions();

        Color[] colors = getGradientColors();  

        TransparentPainter.paint(g2d, radialRect);  

        Paint p = new RadialGradientPaint(cx, cy, radius, fx, fy, fractions, colors, cycleMethod);

        g2d.setPaint(p);

        g2d.fill(radialRect);  

        if (showCircle) {

            // 绘制辐射渐变的圆

            g2d.setPaint(Color.BLACK);

            g2d.draw(radialCircle);

        }

    }  

    // 最少需要两个渐变值，所以开始就创建两个fraction

    public void resetThumbs(float[] fractions, Color[] colors) {

        if (fractions == null || colors == null) { throw new NullPointerException(); }

        if (fractions.length != colors.length) { throw new IllegalArgumentException(

            "Fractions 和 Colors 参数个数不等"); }  

        int x = (int) thumbsRect.getX();

        int w = (int) thumbsRect.getWidth();

        for (int i = 0; i < fractions.length; ++i) {

            insertThumbAt(x + (int) (w * fractions[i]), colors[i]);

        }

    }  

    // 在指定的水平位置插入Fraction按钮

    private void insertThumbAt(int x) {

        insertThumbAt(x, Color.BLUE);

    }  

    private void insertThumbAt(int x, Color color) {

        int index = 0;

        for (Thumb t : thumbs) {

            if (x > t.getX()) {

                index++;

            }

        }  

        int y = (int) (padding.top + linearRect.getHeight());

        thumbs.add(index, new Thumb(x, y, color));  

        fireChangeEvent();

    }  

    public void removeThumbAt(int x, int y) {

        for (Thumb t : thumbs) {

            if (t.contains(x, y)) {

                if (thumbs.size() > 2) {

                    thumbs.remove(t);

                    fireChangeEvent();

                    break;

                }

            }

        }

    }  

    private void changeThumbColor(Thumb thumb) {

        // 弹出颜色选择器

        Color newColor = ColorChooser.chooseColor(this, thumb.getColor());

        if (newColor != null) {

            thumb.setColor(newColor);

            fireChangeEvent();

        }

    }  

    // 改变焦点的位置

    public void changeFocusPoint(double x, double y) {

        focusPoint.setLocation(x, y);

        fireChangeEvent();

    }  

    private void changeFocusPoint(Point2D focusPoint) {

        changeFocusPoint(focusPoint.getX(), focusPoint.getY());

    }  

    // 当panel的大小改变时，再次调用此函数更新显示区域

    private void afterResized() {

        // ////////////////////////////////////////

        // padding-top

        // linear gradient area

        // thumbs area

        // padding = padding top

        // radial gradient area

        // padding-bottom

        // ///////////////////////////////////////  

        // 线性渐变显示区域

        int x = padding.left;

        int y = padding.top;

        int w = width - padding.left - padding.right;

        int h = linearRectHeight;

        linearRect.setRect(x, y, w, h);  

        // Fraction按钮所在区域

        y += linearRectHeight;

        h = thumbRectHeight;

        thumbsRect.setRect(x, y, w, h);  

        // 辐射渐变显示区域

        y = padding.top + linearRectHeight + thumbRectHeight + padding.top;

        h = radialRectHeight;

        h = Math.min(w, h);

        x = (width - w) / 2;

        radialRect.setRect(x, y, w, h);  

        // 中心点和焦点

        int cx = x + w / 2;

        int cy = y + h / 2;

        int radius = 100;

        focusPoint.setLocation(cx, cy);

        radialCircle.setFrame(cx - radius, cy - radius, radius + radius, radius + radius);  

        repaint();

    }  

    @Override

    public Dimension getMinimumSize() {

        return new Dimension(width, height);

    }  

    @Override

    public Dimension getMaximumSize() {

        return new Dimension(width, height);

    }  

    @Override

    public Dimension getPreferredSize() {

        return new Dimension(width, height);

    }  

    private static void createGuiAndShow() {

        JFrame frame = new JFrame("Gradient Generator");

        JPanel panel = new JPanel();

        panel.add(new GradientGenerator());

        frame.setContentPane(new GradientGenerator());  

        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        frame.pack(); // 使用此函数后always on top就不起作用了

        frame.setResizable(false);

        frame.setLocationRelativeTo(null);

        frame.setAlwaysOnTop(true);

        frame.setVisible(true);

    }  

    public static void main(String[] args) {

        createGuiAndShow();

    }

}  

class Thumb {

    private int x;

    private int y;

    private int width = 16;

    private int height = 20;

    private Color color;

    private boolean selected;  

    private GeneralPath outerPath;

    private GeneralPath innerPath;  

    public Thumb(int x, int y, Color color) {

        setXY(x, y);

        this.color = color;

    }  

    public int getX() {

        return x;

    }  

    public void setX(int x) {

        setXY(x, y);

    }  

    public int getY() {

        return y;

    }  

    public void setY(int y) {

        setXY(x, y);

    }  

    public int getWidth() {

        return width;

    }  

    public void setWidth(int width) {

        setWidthHeight(width, height);

    }  

    public int getHeight() {

        return height;

    }  

    public void setHeight(int height) {

        setWidthHeight(width, height);

    }  

    public Color getColor() {

        return color;

    }  

    public void setColor(Color color) {

        this.color = color;

    }  

    public boolean isSelected() {

        return selected;

    }  

    public void setSelected(boolean selected) {

        this.selected = selected;

    }  

    public boolean contains(int x, int y) {

        return outerPath.contains(x, y);

    }  

    public void setXY(int x, int y) {

        this.x = x;

        this.y = y;

        createPaths();

    }  

    public void setWidthHeight(int width, int height) {

        this.width = width;

        this.height = height;

        createPaths();

    }  

    private float[] fractions = new float[] { 0.0f, 0.5f, 1.0f };

    private Color[] colors = new Color[] { Color.ORANGE, Color.BLACK, Color.ORANGE.brighter() };  

    public void paint(Graphics2D g2d) {

        // 绘制大三角形按钮

        // Paint p = new GradientPaint(x, y, selected ? color.darker() : color,

        // x, y + height, Color.ORANGE);

        Paint p = new LinearGradientPaint(x - width, y, x + width / 4, y, fractions, colors);

        g2d.setPaint(p);

        g2d.fill(outerPath);  

        // 绘制小三角形按钮

        g2d.setColor(color);

        g2d.fill(innerPath);

    }  

    // 创建按钮的形状

    private void createPaths() {

        outerPath = new GeneralPath();

        outerPath.moveTo(x, y);

        outerPath.lineTo(x + width / 2, y + height);

        outerPath.lineTo(x - width / 2, y + height);

        outerPath.closePath();  

        innerPath = new GeneralPath();

        innerPath.moveTo(x, y + height / 2);

        innerPath.lineTo(x + width / 4, y + height);

        innerPath.lineTo(x - width / 4, y + height);

        innerPath.closePath();

    }

}  

[html] view plain copy

package gradient;  

import java.awt.AWTEvent;

import java.awt.BorderLayout;

import java.awt.Color;

import java.awt.Component;

import java.awt.Dimension;

import java.awt.Graphics;

import java.awt.Graphics2D;

import java.awt.Insets;

import java.awt.RenderingHints;

import java.awt.Toolkit;

import java.awt.event.AWTEventListener;

import java.awt.event.KeyEvent;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

import java.awt.event.WindowAdapter;

import java.awt.event.WindowEvent;

import java.awt.geom.Rectangle2D;

import java.awt.image.BufferedImage;

import java.io.File;

import java.io.FileNotFoundException;

import java.util.ArrayList;

import java.util.List;

import java.util.Scanner;  

import javax.swing.JComponent;

import javax.swing.JDialog;

import javax.swing.JPanel;

import javax.swing.JSlider;

import javax.swing.event.ChangeEvent;

import javax.swing.event.ChangeListener;  

/**

 * 创建一个模态的颜色选择对话框，可以加载用户预先定义存储好的颜色.

 *

 * @author Biao

 *

 */

@SuppressWarnings("serial")

public class ColorChooser extends JDialog {

    private static ColorChooser instance = new ColorChooser();

    private ColorPanel colorPanel = new ColorPanel();

    private Color color;  

    public static Color chooseColor(JComponent ower, Color defaultColor) {

        instance.color = defaultColor;

        instance.colorPanel.startSelect(defaultColor);  

        instance.pack();

        instance.setLocationRelativeTo(ower);

        instance.setVisible(true);  

        return instance.color;

    }  

    private ColorChooser() {

        setTitle("Choose a color");

        setModal(true);

        setResizable(false);

        setBackground(Color.DARK_GRAY);

        getContentPane().add(colorPanel, BorderLayout.CENTER);  

        this.addWindowListener(new WindowAdapter() {

            @Override

            public void windowClosing(WindowEvent e) {

                gotoHell(color);

            }

        });  

        colorPanel.addChangeListener(new ChangeListener() {

            @Override

            public void stateChanged(ChangeEvent e) {

                Color c = colorPanel.getColor();

                if (colorPanel.isDoubleClickSelection()) {

                    gotoHell(c);

                }  

                int r = c.getRed();

                int g = c.getGreen();

                int b = c.getBlue();

                int a = c.getAlpha();  

                String hex = ColorPanel.colorToHexString(new Color(r, g, b, a));

                String title = String.format("RGBA(%d,%d,%d,%d) Hex(%s)", r, g, b, a, hex);

                setTitle(title);

            }

        });  

        // 处理JDialog所有子组件的按键事件

        // 按下回车使用选择的颜色，按下Esc返回默认传进来的颜色

        Toolkit.getDefaultToolkit().addAWTEventListener(new AWTEventListener() {

            @Override

            public void eventDispatched(AWTEvent event) {

                KeyEvent ke = (KeyEvent) event;  

                if (ke.getID() == KeyEvent.KEY_PRESSED) {

                    if (event.getSource() instanceof Component) {

                        Component com = (Component) event.getSource();

                        if (ke.getKeyCode() == KeyEvent.VK_ESCAPE && hasChild(com)) {

                            gotoHell(color); // 取消时返回默认的颜色

                        } else if (ke.getKeyCode() == KeyEvent.VK_ENTER && hasChild(com)) {

                            gotoHell(colorPanel.getColor());

                        }

                    }

                }

            }

        }, AWTEvent.KEY_EVENT_MASK);

    }  

    // 是否包含了组件

    public boolean hasChild(Component c) {

        for (Component parent = c; parent != null; parent = parent.getParent()) {

            if (parent == this) { return true; }

        }

        return false;

    }  

    // 隐藏颜色选择对话框

    public void gotoHell(Color c) {

        color = (c == null) ? color : c;

        setVisible(false);

    }

}  

@SuppressWarnings("serial")

class ColorPanel extends JPanel {

    final static private int columnSize = 21; // 每行最多显示21个颜色

    final static private int sliderHeight = 20; // Slider的高度

    final static private int previewHeight = 20; // 预览区的高度

    final static private int colorRectWidth = 20; // 颜色小方块的宽度

    final static private int colorRectHeight = 20;// 颜色小方块的高度  

    private int width = 520; // Color panel的尺寸

    private int height = 340;

    private Insets padding = new Insets(10, 10, 0, 10); // 边距  

    private int margin = padding.top;

    private Color color = Color.WHITE;

    private List<Color> storedColors = new ArrayList<Color>(); // 用户存储的颜色

    private List<Color> defaultColors = new ArrayList<Color>(); // 使用算法生成的默认颜色

    private Rectangle2D previewRect = new Rectangle2D.Float(); // 预览区域

    private Rectangle2D colorsImageRect = new Rectangle2D.Double(); // 显示颜色的区域

    private BufferedImage colorsImage; // 需要使用颜色信息来创建确定大小  

    // 调节rgba的slider

    private JSlider redSlider = new JSlider(0, 255, 255);

    private JSlider greenSlider = new JSlider(0, 255, 255);

    private JSlider blueSlider = new JSlider(0, 255, 255);

    private JSlider alphaSlider = new JSlider(0, 255, 255);  

    // 双击时如果选中颜色，则选择完成

    private boolean doubleClickSelection = false;

    private List<ChangeListener> changeListeners = new ArrayList<ChangeListener>();  

    public ColorPanel() {

        // 创建颜色和显示颜色的小方块缓冲图像

        prepareColors();

        prepareColorsImage();

        // 窗口的大小需要用color buffer image的大小来确定，所以必须在这里调用

        prepareSize();  

        preparePreview();

        prepareSliders();  

        this.addMouseListener(new MouseAdapter() {

            @Override

            public void mouseClicked(MouseEvent e) {

                int x = e.getX();

                int y = e.getY();

                Color c = getColorAt(x, y);  

                if (e.getButton() == MouseEvent.BUTTON1 && e.getClickCount() == 1) {

                    // 单击时设置选中的颜色

                    if (c != null) {

                        setColor(c);

                        fireStateChanged();

                    }

                } else if (e.getButton() == MouseEvent.BUTTON1 && e.getClickCount() == 2) {

                    // 双击时返回选中的颜色，隐藏颜色选取窗口

                    if (c != null || previewRect.contains(x, y)) {

                        setDoubleClickSelection(true);

                        fireStateChanged();

                    }

                }

            }

        });  

        redSlider.addChangeListener(new ChangeListener() {

            @Override

            public void stateChanged(ChangeEvent e) {

                setR(redSlider.getValue());

                fireStateChanged();

            }

        });  

        greenSlider.addChangeListener(new ChangeListener() {

            @Override

            public void stateChanged(ChangeEvent e) {

                setG(greenSlider.getValue());

                fireStateChanged();

            }

        });  

        blueSlider.addChangeListener(new ChangeListener() {

            @Override

            public void stateChanged(ChangeEvent e) {

                setB(blueSlider.getValue());

                fireStateChanged();

            }

        });  

        alphaSlider.addChangeListener(new ChangeListener() {

            @Override

            public void stateChanged(ChangeEvent e) {

                setA(alphaSlider.getValue());

                fireStateChanged();

            }

        });

    }  

    @Override

    protected void paintComponent(Graphics g) {

        super.paintComponent(g);

        setBackground(Color.DARK_GRAY);

        Graphics2D g2d = (Graphics2D) g;

        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);  

        // 绘制颜色方块的缓冲图片

        int x = (int) colorsImageRect.getX();

        int y = (int) colorsImageRect.getY();

        int w = (int) colorsImageRect.getWidth();

        int h = (int) colorsImageRect.getHeight();

        g2d.drawImage(colorsImage, x, y, w, h, null);  

        // 绘制颜色预览

        TransparentPainter.paint(g2d, previewRect);

        g2d.setPaint(color);

        g2d.fill(previewRect);

    }  

    public void startSelect(Color color) {

        setColor(color);

        setDoubleClickSelection(false);

    }  

    public boolean isDoubleClickSelection() {

        return doubleClickSelection;

    }  

    protected void setDoubleClickSelection(boolean doubleClickSelection) {

        this.doubleClickSelection = doubleClickSelection;

    }  

    // 当属性改变事件发生时，调用监听器并且重绘

    public void fireStateChanged() {

        for (ChangeListener l : changeListeners) {

            l.stateChanged(new ChangeEvent(this));

        }

        repaint();

    }  

    public void addChangeListener(ChangeListener l) {

        changeListeners.add(l);

    }  

    public void removeChangeListener(ChangeListener l) {

        changeListeners.remove(l);

    }  

    // 选得鼠标选中的颜色

    public Color getColorAt(int x, int y) {

        // 如果不在显示颜色的图片中，则返回null

        if (!colorsImageRect.contains(x, y)) { return null; }  

        // 以图片的左上角为原点

        x -= colorsImageRect.getX();

        y -= colorsImageRect.getY();  

        if (y <= getHeightOfColorsRect(storedColors)) {

            int i = y / colorRectHeight * columnSize + x / colorRectWidth;

            return i >= storedColors.size() ? null : storedColors.get(i);

        } else {

            y -= getHeightOfColorsRect(storedColors) + margin;

            int i = y / colorRectHeight * columnSize + x / colorRectWidth;

            return i >= defaultColors.size() ? null : defaultColors.get(i);

        }

    }  

    // 返回当前选中的颜色

    public Color getColor() {

        return color;

    }  

    // 设置当前颜色

    public void setColor(Color color) {

        this.color = (color == null) ? Color.WHITE : color;

        setSliderValues(color.getRed(), color.getGreen(), color.getBlue(), color.getAlpha());

    }  

    public void setColor(int r, int g, int b) {

        this.color = new Color(r, g, b, 255);

        setSliderValues(r, g, b, 255);

    }  

    public void setColor(int r, int g, int b, int a) {

        r = clamp(r);

        g = clamp(g);

        b = clamp(b);

        a = clamp(a);

        this.color = new Color(r, g, b, a);

        setSliderValues(r, g, b, a);

    }  

    public void setR(int r) {

        setColor(r, color.getGreen(), color.getBlue(), color.getAlpha());

    }  

    public void setG(int g) {

        setColor(color.getRed(), g, color.getBlue(), color.getAlpha());

    }  

    public void setB(int b) {

        setColor(color.getRed(), color.getGreen(), b, color.getAlpha());

    }  

    public void setA(int a) {

        setColor(color.getRed(), color.getGreen(), color.getBlue(), a);

    }  

    public int clamp(int val) {

        val = val < 0 ? 0 : val;

        val = val > 255 ? 255 : val;

        return val;

    }  

    // 设置slier的值

    private void setSliderValues(int r, int g, int b, int a) {

        redSlider.setValue(r);

        greenSlider.setValue(g);

        blueSlider.setValue(b);

        alphaSlider.setValue(a);  

        fireStateChanged();

    }  

    /**

     * 把16进制模式的字符串转化成颜色.

     *

     * @param hex

     *        表示颜色的16进制字符串，格式为#rgb, #rrggbb, #aarrggbb

     * @return 返回字符串的颜色，如果字符串格式不对，返回null

     */

    public static Color parseColorHex(String hex) {

        // #rgb, #rrggbb, #aarrggbb

        // 检查长度

        if (hex == null || hex.length() != 4 && hex.length() != 7 && hex.length() != 9

                && hex.charAt(0) != '#') { return null; }  

        // 检查字符是否有效

        for (int i = 1; i < hex.length(); ++i) {

            char aChar = hex.charAt(i);

            if (!('0' <= aChar && aChar <= '9') && !('a' <= aChar && aChar <= 'f')

                    && !('A' <= aChar && aChar <= 'F')) { return null; }

        }  

        if (hex.length() == 4) {

            // #rgb

            int r = Integer.valueOf(hex.charAt(1) + "" + hex.charAt(1), 16);

            int g = Integer.valueOf(hex.charAt(2) + "" + hex.charAt(2), 16);

            int b = Integer.valueOf(hex.charAt(3) + "" + hex.charAt(3), 16);

            return new Color(r, g, b);

        } else if (hex.length() == 7) {

            // #rrggbb

            int r = Integer.valueOf(hex.substring(1, 3), 16);

            int g = Integer.valueOf(hex.substring(3, 5), 16);

            int b = Integer.valueOf(hex.substring(5, 7), 16);

            return new Color(r, g, b);

        } else if (hex.length() == 9) {

            // #aarrggbb

            int a = Integer.valueOf(hex.substring(1, 3), 16);

            int r = Integer.valueOf(hex.substring(3, 5), 16);

            int g = Integer.valueOf(hex.substring(5, 7), 16);

            int b = Integer.valueOf(hex.substring(7, 9), 16);

            return new Color(r, g, b, a);

        }  

        return null;

    }  

    public static char[] hexDight = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B',

            'C', 'D', 'E', 'F' };  

    /**

     * 把颜色的表示转换为16进制表示#rrggbbaa

     *

     * @param color

     * @return 返回颜色的16进制字符串

     */

    public static String colorToHexString(Color color) {

        if (color == null) { return "null"; }

        int r = color.getRed();

        int g = color.getGreen();

        int b = color.getBlue();

        int a = color.getAlpha();  

        StringBuilder sb = new StringBuilder("#");

        sb.append(hexDight[a >> 4 & 0xF]);

        sb.append(hexDight[a & 0xF]);

        sb.append(hexDight[r >> 4 & 0xF]);

        sb.append(hexDight[r & 0xF]);

        sb.append(hexDight[g >> 4 & 0xF]);

        sb.append(hexDight[g & 0xF]);

        sb.append(hexDight[b >> 4 & 0xF]);

        sb.append(hexDight[b & 0xF]);  

        return sb.toString();

    }  

    private void prepareColors() {

        // 从文件中读取颜色

        try {

            Scanner scanner = new Scanner(new File("resources/colors.txt"));

            while (scanner.hasNextLine()) {

                try {

                    Color c = parseColorHex(scanner.nextLine().trim());

                    if (c != null) {

                        storedColors.add(c);

                    }

                } catch (Exception e) {

                }

            }

        } catch (FileNotFoundException e) {

            e.printStackTrace();

        }  

        // 创建一些默认的颜色

        final float delta = 0.2f;

        for (float r = 0; r <= 1.0; r += delta) {

            for (float g = 0; g <= 1.0; g += delta) {

                for (float b = 0; b <= 1.0; b += delta) {

                    defaultColors.add(new Color(r, g, b));

                }

            }

        }

    }  

    private int getHeightOfColorsRect(List<Color> li) {

        int row = (int) Math.ceil(li.size() / (float) columnSize);  

        return row * colorRectWidth;

    }  

    private void prepareColorsImage() {

        margin = padding.top;

        int w = columnSize * colorRectWidth;

        int h = getHeightOfColorsRect(storedColors) + getHeightOfColorsRect(defaultColors) + margin;

        int x = 0;

        int y = 0;  

        colorsImageRect.setRect(padding.top, padding.top, w, h);

        colorsImage = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);

        Graphics2D g2d = colorsImage.createGraphics();  

        // 绘制用户存储的颜色

        for (int i = 0; i < storedColors.size(); ++i) {

            g2d.setPaint(storedColors.get(i));

            g2d.fillRect(x, y, colorRectWidth, colorRectHeight);  

            x += colorRectWidth;  

            if ((i + 1) % columnSize == 0) {

                x = 0;

                y += colorRectHeight;

            }

        }  

        x = 0;

        y = getHeightOfColorsRect(storedColors) + margin;  

        // 绘制默认的颜色

        for (int i = 0; i < defaultColors.size(); ++i) {

            g2d.setPaint(defaultColors.get(i));

            g2d.fillRect(x, y, colorRectWidth, colorRectHeight);  

            x += colorRectWidth;  

            if ((i + 1) % columnSize == 0) {

                x = 0;

                y += colorRectHeight;

            }

        }

    }  

    private void prepareSize() {

        width = padding.left + colorsImage.getWidth() + padding.right;

        height = padding.top + colorsImage.getHeight() + padding.top + previewHeight + sliderHeight;

    }  

    private void preparePreview() {

        int x = padding.left;

        int y = height - sliderHeight - previewHeight;

        int w = width - padding.left - padding.right;

        previewRect.setRect(x, y, w, previewHeight);

    }  

    private void prepareSliders() {

        setLayout(null);

        int margin = 0; // slider之间的间隔，实际没必须

        int h = sliderHeight;

        int w = (width - padding.left - padding.right) / 4;

        int x = padding.left;

        int y = height - h + 2;  

        redSlider.setBounds(x, y, w, h);

        x += w + margin;

        greenSlider.setBounds(x, y, w, h);

        x += w + margin;

        blueSlider.setBounds(x, y, w, h);

        x += w + margin;

        alphaSlider.setBounds(x, y, w, h);  

        add(redSlider);

        add(greenSlider);

        add(blueSlider);

        add(alphaSlider);

    }  

    @Override

    public Dimension getMinimumSize() {

        return new Dimension(width, height);

    }  

    @Override

    public Dimension getMaximumSize() {

        return new Dimension(width, height);

    }  

    @Override

    public Dimension getPreferredSize() {

        return new Dimension(width, height);

    }

}  

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package gradient;  

import java.awt.Color;

import java.awt.Graphics2D;

import java.awt.geom.Rectangle2D;  

/**

 * 绘制Photoshop中透明色的效果.

 *

 * @author Biao

 *

 */

public class TransparentPainter {

    public static void paint(Graphics2D g2d, Rectangle2D rect) {

        g2d.setClip(rect);

        int sx = (int) rect.getX();

        int sy = (int) rect.getY();

        int w = (int) rect.getWidth();

        int h = (int) rect.getHeight();  

        Color color = Color.WHITE;

        Color color1 = Color.WHITE;

        Color color2 = Color.LIGHT_GRAY;

        int delta = 10;

        boolean odd = false;

        for (int y = sy; y <= h + sy; y += delta) {

            color = (odd) ? color1 : color2;

            for (int x = sx; x <= w + sx; x += delta) {

                g2d.setPaint(color);

                g2d.fillRect(x, y, w, h);  

                color = (color == color1) ? color2 : color1;

            }  

            odd = !odd;

        }

        g2d.setClip(null);

    }

}  

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package gradient;

import java.awt.geom.Point2D;  

public class GeometryUtil {

    // 两点之间的距离

    public static double distanceOfPoints(Point2D p1, Point2D p2) {

        double disX = p2.getX() - p1.getX();

        double disY = p2.getY() - p1.getY();

        double dis = Math.sqrt(disX * disX + disY * disY);  

        return dis;

    }  

    // 两点的中点

    public static Point2D middlePoint(Point2D p1, Point2D p2) {

        double x = (p1.getX() + p2.getX()) / 2;

        double y = (p1.getY() + p2.getY()) / 2;  

        return new Point2D.Double(x, y);

    }  

    // 在两点所在直线上，以从startPoint到endPoint为方向，离startPoint的距离disToStartPoint的点

    public static Point2D extentPoint(Point2D startPoint, Point2D endPoint, double disToStartPoint) {

        double disX = endPoint.getX() - startPoint.getX();

        double disY = endPoint.getY() - startPoint.getY();

        double dis = Math.sqrt(disX * disX + disY * disY);

        double sin = (endPoint.getY() - startPoint.getY()) / dis;

        double cos = (endPoint.getX() - startPoint.getX()) / dis;

        double deltaX = disToStartPoint * cos;

        double deltaY = disToStartPoint * sin;  

        return new Point2D.Double(startPoint.getX() + deltaX, startPoint.getY() + deltaY);

    }

}  

1. package gradient;
2. import java.awt.Color;
3. import java.awt.Dimension;
4. import java.awt.Graphics;
5. import java.awt.Graphics2D;
6. import java.awt.Insets;
7. import java.awt.LinearGradientPaint;
8. import java.awt.MultipleGradientPaint;
9. import java.awt.Paint;
10. import java.awt.RadialGradientPaint;
11. import java.awt.RenderingHints;
12. import java.awt.event.KeyAdapter;
13. import java.awt.event.KeyEvent;
14. import java.awt.event.MouseAdapter;
15. import java.awt.event.MouseEvent;
16. import java.awt.event.MouseMotionAdapter;
17. import java.awt.geom.Ellipse2D;
18. import java.awt.geom.GeneralPath;
19. import java.awt.geom.Point2D;
20. import java.awt.geom.Rectangle2D;
21. import java.util.ArrayList;
22. import java.util.LinkedList;
23. import java.util.List;
24. import javax.swing.JFrame;
25. import javax.swing.JPanel;
26. import javax.swing.event.ChangeEvent;
27. import javax.swing.event.ChangeListener;
28. /*
29. 使用方法:
30. 渐变窗体:
31. a. 左键双击顶点的linear gradient 渐变区，改变渐变超出范围的重复绘制模式.
32. b. 左键双击fractions小按钮区，创建添加一个新的fraction按钮.
33. c. 左键双击fractions小按钮，弹出窗口选择窗口选择颜色.
34. d. 右键双击fractions小按钮，删除此fraction按钮.
35. e. 按住fractions小按钮可以拖动它，修改fractions的位置.
36. f. 左键双击辐射渐变区，改变辐射渐变的焦点(focus)到点击位置.
37. g. 在辐射渐变区按住左键拖动，改变辐射渐变的焦点.
38. h. 按下f，显示辐射渐变的圆周，为了方便看到更清楚的数据，默认这圆周是隐藏的.
39. i. 按下c，恢复辐射渐变的焦点到辐射渐变的圆心，焦点默认是与圆心重合.
40. 颜色选择窗体:
41. a. 单击某一个颜色，则选中此颜色，并在底部的预览区显示出来.但颜色选择窗口不消失.
42. b. 双击某一个颜色，则选中此颜色，返回给调用者，颜色选择窗口消失.
43. c. 按下回车键，返回选中的颜色，颜色选择窗口消失.
44. d. 按下ESC键，返回传给颜色选择窗体的默认色，颜色选择窗口消失.
45. e. 下部的JSlider依次调节被选中颜色的red, green, blue, alpha，拖动并实时的在预览区显示出调整后颜色.
46. 第三方程序集成使用方法: 在第三方程序中创建一个GradientGenerator对象，并添加到组件的某一部分，
47. 并给此gradientGenerator添加上change listener:
48. gradientGenerator.addChangeListener(new ChangedListener() {
49. public void stateChanged(ChangeEvent e) {
50. float[] fractions = gradientGenerator.getFractons();
51. Color[] colors = gradientGenerator.getColors();
52. Point2D focus = gradientGenerator.calculateFocus(center, radius);
53. repaint(); // 使用这里得到的fractions, colors, focus等去绘制第三方程序中的渐变图形
54. });
55. 这样，当gradient generator中的数据发生变化时，第三方程序里也会即时的反映出来.
56. 1. 提示，现在Swing支持合建不规则窗体。
57. 2. 此程序中，除了JSlider，其他的部分都是使用Java2D手动计算绘制出来的。
58. 基于上面两点，可以自己创建一个统一的JSlider风格，
59. 然后就可以把整个程序的外观风格做得在所有平台下都是一个样。
60. */
61. /**
62. * *^o^*，本程序一惯还是一惯的作风，LGPL协议，什么版权的废话就不整了，希望修改得效果好的朋友给大家分享一下心得，在此权当扔出块板砖，
63. * 希望能砸出块暖玉来，嗷呜嗷呜嗷呜.
64. */
65. @SuppressWarnings("serial")
66. public class GradientGenerator extends JPanel {
67. private int width = 400; // 整个Panel的宽度
68. private int height = 400; // 整个Panel的高度
69. private Insets padding = new Insets(10, 10, 10, 10); // 边距
70. private int thumbRectHeight = 20; // Fraction按钮区的高度
71. private int linearRectHeight = 40; // 线性渐变区域的高度
72. private int radialRectHeight = 310; // 辐射渐变区域的高度
73. private Ellipse2D radialCircle = new Ellipse2D.Float(); // 辐射渐变的圆周
74. private Point2D focusPoint = new Point2D.Float(); // 辐射渐变的焦点
75. private Point2D pressedPoint = new Point2D.Float(); // 鼠标按下时的点
76. private Rectangle2D linearRect = new Rectangle2D.Float(); // 线性渐变区域
77. private Rectangle2D thumbsRect = new Rectangle2D.Float(); // Fractions按钮区域
78. private Rectangle2D radialRect = new Rectangle2D.Float(); // 辐射渐变区域
79. private Thumb selectedThumb = null; // 被选中的Fraction按钮
80. private List<Thumb> thumbs = new ArrayList<Thumb>(); // Fractions按钮
81. private boolean showCircle = false; // 显示辐射渐变的圆周
82. private List<ChangeListener> changeListeners = new LinkedList<ChangeListener>();
83. private MultipleGradientPaint.CycleMethod cycleMethod = MultipleGradientPaint.CycleMethod.REFLECT;
84. /**
85. * 返回渐变的fractions数组
86. *
87. * @return
88. */
89. public float[] getGradientFractions() {
90. float[] fractions = new float[thumbs.size()];
91. int i = 0;
92. for (Thumb t : thumbs) {
93. fractions[i] = (float) ((t.getX() - padding.left) / linearRect.getWidth());
94. ++i;
95. }
96. return fractions;
97. }
98. /**
99. * 返回渐变的colors数组
100. *
101. * @return
102. */
103. public Color[] getGradientColors() {
104. Color[] colors = new Color[thumbs.size()];
105. int i = 0;
106. for (Thumb t : thumbs) {
107. colors[i] = t.getColor();
108. ++i;
109. }
110. return colors;
111. }
112. /**
113. * 利用指定圆的圆心和半径和当前的辐射渐变数据，计算相对于指定圆的焦点
114. *
115. * @param center
116. *        圆心
117. * @param radius
118. *        半径
119. * @return 返回相对于指定圆的焦点
120. */
121. public Point2D calculateFocus(Point2D center, double radius) {
122. Point2D curCenter = new Point2D.Double(radialCircle.getCenterX(), radialCircle.getCenterY());
123. double curRadius = radialCircle.getWidth() / 2;
124. double curFocusLen = GeometryUtil.distanceOfPoints(curCenter, focusPoint);
125. double newFocusLen = radius * curFocusLen / curRadius;
126. Point2D newFocusPoint = GeometryUtil.extentPoint(curCenter, focusPoint, newFocusLen);
127. // 先移回原点，再移动到center的位置
128. newFocusPoint.setLocation(center.getX() - curCenter.getX(),
129. center.getY() - curCenter.getY());
130. return newFocusPoint;
131. }
132. public GradientGenerator() {
133. setFocusable(true); // 为了能接收键盘按键事件
134. afterResized();
135. resetThumbs(new float[] { 0.0f, 0.5f, 1.0f }, new Color[] { Color.BLACK, Color.BLUE,
136. new Color(255, 255, 255, 220) });
137. handleEvents();
138. setBackground(Color.DARK_GRAY);
139. }
140. // 事件处理
141. private void handleEvents() {
142. this.addMouseListener(new MouseAdapter() {
143. @Override
144. public void mousePressed(MouseEvent e) {
145. int x = e.getX();
146. int y = e.getY();
147. pressedPoint.setLocation(x, y);
148. // 得到被选中的Thumb
149. for (Thumb t : thumbs) {
150. if (t.contains(x, y)) {
151. t.setSelected(true);
152. selectedThumb = t;
153. break;
154. }
155. }
156. repaint();
157. }
158. @Override
159. public void mouseReleased(MouseEvent e) {
160. for (Thumb t : thumbs) {
161. t.setSelected(false);
162. selectedThumb = null;
163. }
164. repaint();
165. }
166. @Override
167. public void mouseClicked(MouseEvent e) {
168. int x = e.getX();
169. int y = e.getY();
170. // 左键双击
171. if (e.getButton() == MouseEvent.BUTTON1 && e.getClickCount() == 2) {
172. // 如果在thumbs里面，则弹出颜色选择器
173. for (Thumb t : thumbs) {
174. if (t.contains(x, y)) {
175. changeThumbColor(t);
176. repaint();
177. return;
178. }
179. }
180. // 如果不在thumbs里，而在thumbs的区域里，则增加一个thumb
181. if (thumbsRect.contains(x, y)) {
182. insertThumbAt(x);
183. repaint();
184. return;
185. }
186. // 修改focus的位置
187. if (radialRect.contains(x, y)) {
188. changeFocusPoint(new Point2D.Float(x, y));
189. repaint();
190. return;
191. }
192. // 在Linear rect里面，修改cycle method
193. if (linearRect.contains(x, y)) {
194. changeCycleMethod();
195. repaint();
196. return;
197. }
198. } else if (e.getButton() == MouseEvent.BUTTON3 && e.getClickCount() == 2) {
199. // 右键双击
200. removeThumbAt(x, y);
201. return;
202. }
203. }
204. });
205. this.addMouseMotionListener(new MouseMotionAdapter() {
206. @Override
207. public void mouseDragged(MouseEvent e) {
208. // 拖动滑块
209. if (selectedThumb != null) {
210. int deltaX = e.getX() - (int) (selectedThumb.getX());
211. int x = selectedThumb.getX() + deltaX;
212. // 不能超过边界
213. int maxRight = (int) (padding.left + linearRect.getWidth());
214. if (x < padding.left || x > maxRight) { return; }
215. int index = thumbs.indexOf(selectedThumb);
216. int prevX = Integer.MIN_VALUE;
217. int nextX = Integer.MAX_VALUE;
218. // 只能在前一个和后一个之间移动
219. if (index - 1 >= 0) {
220. prevX = (int) (thumbs.get(index - 1).getX());
221. }
222. if (index + 1 < thumbs.size()) {
223. nextX = (int) (thumbs.get(index + 1).getX());
224. }
225. if (x > prevX && x < nextX) {
226. selectedThumb.setX(x);
227. repaint();
228. }
229. return;
230. } else if (radialRect.contains(e.getX(), e.getY())) {
231. int deltaX = (int) (e.getX() - pressedPoint.getX());
232. int deltaY = (int) (e.getY() - pressedPoint.getY());
233. focusPoint.setLocation(focusPoint.getX() + deltaX, focusPoint.getY() + deltaY);
234. pressedPoint.setLocation(e.getX(), e.getY());
235. repaint();
236. }
237. }
238. });
239. this.addKeyListener(new KeyAdapter() {
240. @Override
241. public void keyReleased(KeyEvent e) {
242. switch (e.getKeyCode()) {
243. case KeyEvent.VK_F:
244. showCircle = !showCircle;
245. break;
246. case KeyEvent.VK_C:
247. changeFocusPoint(radialCircle.getCenterX(), radialCircle.getCenterY());
248. break;
249. }
250. repaint();
251. }
252. });
253. }
254. // 执行监听器的事件
255. public void fireChangeEvent() {
256. for (ChangeListener l : changeListeners) {
257. l.stateChanged(new ChangeEvent(this));
258. }
259. }
260. // 改变超出渐变区的颜色渐变方式
261. public void changeCycleMethod() {
262. changeCycleMethod(cycleMethod);
263. }
264. public void changeCycleMethod(MultipleGradientPaint.CycleMethod cycleMethod) {
265. switch (cycleMethod) {
266. case NO_CYCLE:
267. this.cycleMethod = MultipleGradientPaint.CycleMethod.REFLECT;
268. break;
269. case REFLECT:
270. this.cycleMethod = MultipleGradientPaint.CycleMethod.REPEAT;
271. break;
272. case REPEAT:
273. this.cycleMethod = MultipleGradientPaint.CycleMethod.NO_CYCLE;
274. break;
275. }
276. }
277. @Override
278. protected void paintComponent(Graphics g) {
279. super.paintComponent(g);
280. Graphics2D g2d = (Graphics2D) g;
281. g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
282. drawLinearRect(g2d);
283. drawThumbsRect(g2d);
284. drawRadialRect(g2d);
285. }
286. // 绘制fraction按钮所在区域
287. private void drawThumbsRect(Graphics2D g2d) {
288. g2d.setColor(new Color(255, 255, 255, 40));
289. g2d.fill(thumbsRect);
290. // 绘制fraction按钮
291. for (Thumb t : thumbs) {
292. t.paint(g2d);
293. }
294. }
295. private void drawLinearRect(Graphics2D g2d) {
296. // 绘制线性渐变区域
297. float sx = (float) linearRect.getX();
298. float sy = (float) linearRect.getY();
299. float ex = (int) (sx + linearRect.getWidth());
300. float ey = sy;
301. float[] fractions = getGradientFractions();
302. Color[] colors = getGradientColors();
303. Paint p = new LinearGradientPaint(sx, sy, ex, ey, fractions, colors, cycleMethod);
304. TransparentPainter.paint(g2d, linearRect);
305. g2d.setPaint(p);
306. g2d.fill(linearRect);
307. }
308. // 绘制辐射渐变区
309. private void drawRadialRect(Graphics2D g2d) {
310. float cx = (float) radialCircle.getCenterX();
311. float cy = (float) radialCircle.getCenterY();
312. float fx = (float) focusPoint.getX();
313. float fy = (float) focusPoint.getY();
314. float radius = (float) radialCircle.getWidth() / 2;
315. float[] fractions = getGradientFractions();
316. Color[] colors = getGradientColors();
317. TransparentPainter.paint(g2d, radialRect);
318. Paint p = new RadialGradientPaint(cx, cy, radius, fx, fy, fractions, colors, cycleMethod);
319. g2d.setPaint(p);
320. g2d.fill(radialRect);
321. if (showCircle) {
322. // 绘制辐射渐变的圆
323. g2d.setPaint(Color.BLACK);
324. g2d.draw(radialCircle);
325. }
326. }
327. // 最少需要两个渐变值，所以开始就创建两个fraction
328. public void resetThumbs(float[] fractions, Color[] colors) {
329. if (fractions == null || colors == null) { throw new NullPointerException(); }
330. if (fractions.length != colors.length) { throw new IllegalArgumentException(
331. "Fractions 和 Colors 参数个数不等"); }
332. int x = (int) thumbsRect.getX();
333. int w = (int) thumbsRect.getWidth();
334. for (int i = 0; i < fractions.length; ++i) {
335. insertThumbAt(x + (int) (w * fractions[i]), colors[i]);
336. }
337. }
338. // 在指定的水平位置插入Fraction按钮
339. private void insertThumbAt(int x) {
340. insertThumbAt(x, Color.BLUE);
341. }
342. private void insertThumbAt(int x, Color color) {
343. int index = 0;
344. for (Thumb t : thumbs) {
345. if (x > t.getX()) {
346. index++;
347. }
348. }
349. int y = (int) (padding.top + linearRect.getHeight());
350. thumbs.add(index, new Thumb(x, y, color));
351. fireChangeEvent();
352. }
353. public void removeThumbAt(int x, int y) {
354. for (Thumb t : thumbs) {
355. if (t.contains(x, y)) {
356. if (thumbs.size() > 2) {
357. thumbs.remove(t);
358. fireChangeEvent();
359. break;
360. }
361. }
362. }
363. }
364. private void changeThumbColor(Thumb thumb) {
365. // 弹出颜色选择器
366. Color newColor = ColorChooser.chooseColor(this, thumb.getColor());
367. if (newColor != null) {
368. thumb.setColor(newColor);
369. fireChangeEvent();
370. }
371. }
372. // 改变焦点的位置
373. public void changeFocusPoint(double x, double y) {
374. focusPoint.setLocation(x, y);
375. fireChangeEvent();
376. }
377. private void changeFocusPoint(Point2D focusPoint) {
378. changeFocusPoint(focusPoint.getX(), focusPoint.getY());
379. }
380. // 当panel的大小改变时，再次调用此函数更新显示区域
381. private void afterResized() {
382. // ////////////////////////////////////////
383. // padding-top
384. // linear gradient area
385. // thumbs area
386. // padding = padding top
387. // radial gradient area
388. // padding-bottom
389. // ///////////////////////////////////////
390. // 线性渐变显示区域
391. int x = padding.left;
392. int y = padding.top;
393. int w = width - padding.left - padding.right;
394. int h = linearRectHeight;
395. linearRect.setRect(x, y, w, h);
396. // Fraction按钮所在区域
397. y += linearRectHeight;
398. h = thumbRectHeight;
399. thumbsRect.setRect(x, y, w, h);
400. // 辐射渐变显示区域
401. y = padding.top + linearRectHeight + thumbRectHeight + padding.top;
402. h = radialRectHeight;
403. h = Math.min(w, h);
404. x = (width - w) / 2;
405. radialRect.setRect(x, y, w, h);
406. // 中心点和焦点
407. int cx = x + w / 2;
408. int cy = y + h / 2;
409. int radius = 100;
410. focusPoint.setLocation(cx, cy);
411. radialCircle.setFrame(cx - radius, cy - radius, radius + radius, radius + radius);
412. repaint();
413. }
414. @Override
415. public Dimension getMinimumSize() {
416. return new Dimension(width, height);
417. }
418. @Override
419. public Dimension getMaximumSize() {
420. return new Dimension(width, height);
421. }
422. @Override
423. public Dimension getPreferredSize() {
424. return new Dimension(width, height);
425. }
426. private static void createGuiAndShow() {
427. JFrame frame = new JFrame("Gradient Generator");
428. JPanel panel = new JPanel();
429. panel.add(new GradientGenerator());
430. frame.setContentPane(new GradientGenerator());
431. frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
432. frame.pack(); // 使用此函数后always on top就不起作用了
433. frame.setResizable(false);
434. frame.setLocationRelativeTo(null);
435. frame.setAlwaysOnTop(true);
436. frame.setVisible(true);
437. }
438. public static void main(String[] args) {
439. createGuiAndShow();
440. }
441. }
442. class Thumb {
443. private int x;
444. private int y;
445. private int width = 16;
446. private int height = 20;
447. private Color color;
448. private boolean selected;
449. private GeneralPath outerPath;
450. private GeneralPath innerPath;
451. public Thumb(int x, int y, Color color) {
452. setXY(x, y);
453. this.color = color;
454. }
455. public int getX() {
456. return x;
457. }
458. public void setX(int x) {
459. setXY(x, y);
460. }
461. public int getY() {
462. return y;
463. }
464. public void setY(int y) {
465. setXY(x, y);
466. }
467. public int getWidth() {
468. return width;
469. }
470. public void setWidth(int width) {
471. setWidthHeight(width, height);
472. }
473. public int getHeight() {
474. return height;
475. }
476. public void setHeight(int height) {
477. setWidthHeight(width, height);
478. }
479. public Color getColor() {
480. return color;
481. }
482. public void setColor(Color color) {
483. this.color = color;
484. }
485. public boolean isSelected() {
486. return selected;
487. }
488. public void setSelected(boolean selected) {
489. this.selected = selected;
490. }
491. public boolean contains(int x, int y) {
492. return outerPath.contains(x, y);
493. }
494. public void setXY(int x, int y) {
495. this.x = x;
496. this.y = y;
497. createPaths();
498. }
499. public void setWidthHeight(int width, int height) {
500. this.width = width;
501. this.height = height;
502. createPaths();
503. }
504. private float[] fractions = new float[] { 0.0f, 0.5f, 1.0f };
505. private Color[] colors = new Color[] { Color.ORANGE, Color.BLACK, Color.ORANGE.brighter() };
506. public void paint(Graphics2D g2d) {
507. // 绘制大三角形按钮
508. // Paint p = new GradientPaint(x, y, selected ? color.darker() : color,
509. // x, y + height, Color.ORANGE);
510. Paint p = new LinearGradientPaint(x - width, y, x + width / 4, y, fractions, colors);
511. g2d.setPaint(p);
512. g2d.fill(outerPath);
513. // 绘制小三角形按钮
514. g2d.setColor(color);
515. g2d.fill(innerPath);
516. }
517. // 创建按钮的形状
518. private void createPaths() {
519. outerPath = new GeneralPath();
520. outerPath.moveTo(x, y);
521. outerPath.lineTo(x + width / 2, y + height);
522. outerPath.lineTo(x - width / 2, y + height);
523. outerPath.closePath();
524. innerPath = new GeneralPath();
525. innerPath.moveTo(x, y + height / 2);
526. innerPath.lineTo(x + width / 4, y + height);
527. innerPath.lineTo(x - width / 4, y + height);
528. innerPath.closePath();
529. }
530. }

1. package gradient;
2. import java.awt.AWTEvent;
3. import java.awt.BorderLayout;
4. import java.awt.Color;
5. import java.awt.Component;
6. import java.awt.Dimension;
7. import java.awt.Graphics;
8. import java.awt.Graphics2D;
9. import java.awt.Insets;
10. import java.awt.RenderingHints;
11. import java.awt.Toolkit;
12. import java.awt.event.AWTEventListener;
13. import java.awt.event.KeyEvent;
14. import java.awt.event.MouseAdapter;
15. import java.awt.event.MouseEvent;
16. import java.awt.event.WindowAdapter;
17. import java.awt.event.WindowEvent;
18. import java.awt.geom.Rectangle2D;
19. import java.awt.image.BufferedImage;
20. import java.io.File;
21. import java.io.FileNotFoundException;
22. import java.util.ArrayList;
23. import java.util.List;
24. import java.util.Scanner;
25. import javax.swing.JComponent;
26. import javax.swing.JDialog;
27. import javax.swing.JPanel;
28. import javax.swing.JSlider;
29. import javax.swing.event.ChangeEvent;
30. import javax.swing.event.ChangeListener;
31. /**
32. * 创建一个模态的颜色选择对话框，可以加载用户预先定义存储好的颜色.
33. *
34. * @author Biao
35. *
36. */
37. @SuppressWarnings("serial")
38. public class ColorChooser extends JDialog {
39. private static ColorChooser instance = new ColorChooser();
40. private ColorPanel colorPanel = new ColorPanel();
41. private Color color;
42. public static Color chooseColor(JComponent ower, Color defaultColor) {
43. instance.color = defaultColor;
44. instance.colorPanel.startSelect(defaultColor);
45. instance.pack();
46. instance.setLocationRelativeTo(ower);
47. instance.setVisible(true);
48. return instance.color;
49. }
50. private ColorChooser() {
51. setTitle("Choose a color");
52. setModal(true);
53. setResizable(false);
54. setBackground(Color.DARK_GRAY);
55. getContentPane().add(colorPanel, BorderLayout.CENTER);
56. this.addWindowListener(new WindowAdapter() {
57. @Override
58. public void windowClosing(WindowEvent e) {
59. gotoHell(color);
60. }
61. });
62. colorPanel.addChangeListener(new ChangeListener() {
63. @Override
64. public void stateChanged(ChangeEvent e) {
65. Color c = colorPanel.getColor();
66. if (colorPanel.isDoubleClickSelection()) {
67. gotoHell(c);
68. }
69. int r = c.getRed();
70. int g = c.getGreen();
71. int b = c.getBlue();
72. int a = c.getAlpha();
73. String hex = ColorPanel.colorToHexString(new Color(r, g, b, a));
74. String title = String.format("RGBA(%d,%d,%d,%d) Hex(%s)", r, g, b, a, hex);
75. setTitle(title);
76. }
77. });
78. // 处理JDialog所有子组件的按键事件
79. // 按下回车使用选择的颜色，按下Esc返回默认传进来的颜色
80. Toolkit.getDefaultToolkit().addAWTEventListener(new AWTEventListener() {
81. @Override
82. public void eventDispatched(AWTEvent event) {
83. KeyEvent ke = (KeyEvent) event;
84. if (ke.getID() == KeyEvent.KEY_PRESSED) {
85. if (event.getSource() instanceof Component) {
86. Component com = (Component) event.getSource();
87. if (ke.getKeyCode() == KeyEvent.VK_ESCAPE && hasChild(com)) {
88. gotoHell(color); // 取消时返回默认的颜色
89. } else if (ke.getKeyCode() == KeyEvent.VK_ENTER && hasChild(com)) {
90. gotoHell(colorPanel.getColor());
91. }
92. }
93. }
94. }
95. }, AWTEvent.KEY_EVENT_MASK);
96. }
97. // 是否包含了组件
98. public boolean hasChild(Component c) {
99. for (Component parent = c; parent != null; parent = parent.getParent()) {
100. if (parent == this) { return true; }
101. }
102. return false;
103. }
104. // 隐藏颜色选择对话框
105. public void gotoHell(Color c) {
106. color = (c == null) ? color : c;
107. setVisible(false);
108. }
109. }
110. @SuppressWarnings("serial")
111. class ColorPanel extends JPanel {
112. final static private int columnSize = 21; // 每行最多显示21个颜色
113. final static private int sliderHeight = 20; // Slider的高度
114. final static private int previewHeight = 20; // 预览区的高度
115. final static private int colorRectWidth = 20; // 颜色小方块的宽度
116. final static private int colorRectHeight = 20;// 颜色小方块的高度
117. private int width = 520; // Color panel的尺寸
118. private int height = 340;
119. private Insets padding = new Insets(10, 10, 0, 10); // 边距
120. private int margin = padding.top;
121. private Color color = Color.WHITE;
122. private List<Color> storedColors = new ArrayList<Color>(); // 用户存储的颜色
123. private List<Color> defaultColors = new ArrayList<Color>(); // 使用算法生成的默认颜色
124. private Rectangle2D previewRect = new Rectangle2D.Float(); // 预览区域
125. private Rectangle2D colorsImageRect = new Rectangle2D.Double(); // 显示颜色的区域
126. private BufferedImage colorsImage; // 需要使用颜色信息来创建确定大小
127. // 调节rgba的slider
128. private JSlider redSlider = new JSlider(0, 255, 255);
129. private JSlider greenSlider = new JSlider(0, 255, 255);
130. private JSlider blueSlider = new JSlider(0, 255, 255);
131. private JSlider alphaSlider = new JSlider(0, 255, 255);
132. // 双击时如果选中颜色，则选择完成
133. private boolean doubleClickSelection = false;
134. private List<ChangeListener> changeListeners = new ArrayList<ChangeListener>();
135. public ColorPanel() {
136. // 创建颜色和显示颜色的小方块缓冲图像
137. prepareColors();
138. prepareColorsImage();
139. // 窗口的大小需要用color buffer image的大小来确定，所以必须在这里调用
140. prepareSize();
141. preparePreview();
142. prepareSliders();
143. this.addMouseListener(new MouseAdapter() {
144. @Override
145. public void mouseClicked(MouseEvent e) {
146. int x = e.getX();
147. int y = e.getY();
148. Color c = getColorAt(x, y);
149. if (e.getButton() == MouseEvent.BUTTON1 && e.getClickCount() == 1) {
150. // 单击时设置选中的颜色
151. if (c != null) {
152. setColor(c);
153. fireStateChanged();
154. }
155. } else if (e.getButton() == MouseEvent.BUTTON1 && e.getClickCount() == 2) {
156. // 双击时返回选中的颜色，隐藏颜色选取窗口
157. if (c != null || previewRect.contains(x, y)) {
158. setDoubleClickSelection(true);
159. fireStateChanged();
160. }
161. }
162. }
163. });
164. redSlider.addChangeListener(new ChangeListener() {
165. @Override
166. public void stateChanged(ChangeEvent e) {
167. setR(redSlider.getValue());
168. fireStateChanged();
169. }
170. });
171. greenSlider.addChangeListener(new ChangeListener() {
172. @Override
173. public void stateChanged(ChangeEvent e) {
174. setG(greenSlider.getValue());
175. fireStateChanged();
176. }
177. });
178. blueSlider.addChangeListener(new ChangeListener() {
179. @Override
180. public void stateChanged(ChangeEvent e) {
181. setB(blueSlider.getValue());
182. fireStateChanged();
183. }
184. });
185. alphaSlider.addChangeListener(new ChangeListener() {
186. @Override
187. public void stateChanged(ChangeEvent e) {
188. setA(alphaSlider.getValue());
189. fireStateChanged();
190. }
191. });
192. }
193. @Override
194. protected void paintComponent(Graphics g) {
195. super.paintComponent(g);
196. setBackground(Color.DARK_GRAY);
197. Graphics2D g2d = (Graphics2D) g;
198. g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
199. // 绘制颜色方块的缓冲图片
200. int x = (int) colorsImageRect.getX();
201. int y = (int) colorsImageRect.getY();
202. int w = (int) colorsImageRect.getWidth();
203. int h = (int) colorsImageRect.getHeight();
204. g2d.drawImage(colorsImage, x, y, w, h, null);
205. // 绘制颜色预览
206. TransparentPainter.paint(g2d, previewRect);
207. g2d.setPaint(color);
208. g2d.fill(previewRect);
209. }
210. public void startSelect(Color color) {
211. setColor(color);
212. setDoubleClickSelection(false);
213. }
214. public boolean isDoubleClickSelection() {
215. return doubleClickSelection;
216. }
217. protected void setDoubleClickSelection(boolean doubleClickSelection) {
218. this.doubleClickSelection = doubleClickSelection;
219. }
220. // 当属性改变事件发生时，调用监听器并且重绘
221. public void fireStateChanged() {
222. for (ChangeListener l : changeListeners) {
223. l.stateChanged(new ChangeEvent(this));
224. }
225. repaint();
226. }
227. public void addChangeListener(ChangeListener l) {
228. changeListeners.add(l);
229. }
230. public void removeChangeListener(ChangeListener l) {
231. changeListeners.remove(l);
232. }
233. // 选得鼠标选中的颜色
234. public Color getColorAt(int x, int y) {
235. // 如果不在显示颜色的图片中，则返回null
236. if (!colorsImageRect.contains(x, y)) { return null; }
237. // 以图片的左上角为原点
238. x -= colorsImageRect.getX();
239. y -= colorsImageRect.getY();
240. if (y <= getHeightOfColorsRect(storedColors)) {
241. int i = y / colorRectHeight * columnSize + x / colorRectWidth;
242. return i >= storedColors.size() ? null : storedColors.get(i);
243. } else {
244. y -= getHeightOfColorsRect(storedColors) + margin;
245. int i = y / colorRectHeight * columnSize + x / colorRectWidth;
246. return i >= defaultColors.size() ? null : defaultColors.get(i);
247. }
248. }
249. // 返回当前选中的颜色
250. public Color getColor() {
251. return color;
252. }
253. // 设置当前颜色
254. public void setColor(Color color) {
255. this.color = (color == null) ? Color.WHITE : color;
256. setSliderValues(color.getRed(), color.getGreen(), color.getBlue(), color.getAlpha());
257. }
258. public void setColor(int r, int g, int b) {
259. this.color = new Color(r, g, b, 255);
260. setSliderValues(r, g, b, 255);
261. }
262. public void setColor(int r, int g, int b, int a) {
263. r = clamp(r);
264. g = clamp(g);
265. b = clamp(b);
266. a = clamp(a);
267. this.color = new Color(r, g, b, a);
268. setSliderValues(r, g, b, a);
269. }
270. public void setR(int r) {
271. setColor(r, color.getGreen(), color.getBlue(), color.getAlpha());
272. }
273. public void setG(int g) {
274. setColor(color.getRed(), g, color.getBlue(), color.getAlpha());
275. }
276. public void setB(int b) {
277. setColor(color.getRed(), color.getGreen(), b, color.getAlpha());
278. }
279. public void setA(int a) {
280. setColor(color.getRed(), color.getGreen(), color.getBlue(), a);
281. }
282. public int clamp(int val) {
283. val = val < 0 ? 0 : val;
284. val = val > 255 ? 255 : val;
285. return val;
286. }
287. // 设置slier的值
288. private void setSliderValues(int r, int g, int b, int a) {
289. redSlider.setValue(r);
290. greenSlider.setValue(g);
291. blueSlider.setValue(b);
292. alphaSlider.setValue(a);
293. fireStateChanged();
294. }
295. /**
296. * 把16进制模式的字符串转化成颜色.
297. *
298. * @param hex
299. *        表示颜色的16进制字符串，格式为#rgb, #rrggbb, #aarrggbb
300. * @return 返回字符串的颜色，如果字符串格式不对，返回null
301. */
302. public static Color parseColorHex(String hex) {
303. // #rgb, #rrggbb, #aarrggbb
304. // 检查长度
305. if (hex == null || hex.length() != 4 && hex.length() != 7 && hex.length() != 9
306. && hex.charAt(0) != '#') { return null; }
307. // 检查字符是否有效
308. for (int i = 1; i < hex.length(); ++i) {
309. char aChar = hex.charAt(i);
310. if (!('0' <= aChar && aChar <= '9') && !('a' <= aChar && aChar <= 'f')
311. && !('A' <= aChar && aChar <= 'F')) { return null; }
312. }
313. if (hex.length() == 4) {
314. // #rgb
315. int r = Integer.valueOf(hex.charAt(1) + "" + hex.charAt(1), 16);
316. int g = Integer.valueOf(hex.charAt(2) + "" + hex.charAt(2), 16);
317. int b = Integer.valueOf(hex.charAt(3) + "" + hex.charAt(3), 16);
318. return new Color(r, g, b);
319. } else if (hex.length() == 7) {
320. // #rrggbb
321. int r = Integer.valueOf(hex.substring(1, 3), 16);
322. int g = Integer.valueOf(hex.substring(3, 5), 16);
323. int b = Integer.valueOf(hex.substring(5, 7), 16);
324. return new Color(r, g, b);
325. } else if (hex.length() == 9) {
326. // #aarrggbb
327. int a = Integer.valueOf(hex.substring(1, 3), 16);
328. int r = Integer.valueOf(hex.substring(3, 5), 16);
329. int g = Integer.valueOf(hex.substring(5, 7), 16);
330. int b = Integer.valueOf(hex.substring(7, 9), 16);
331. return new Color(r, g, b, a);
332. }
333. return null;
334. }
335. public static char[] hexDight = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B',
336. 'C', 'D', 'E', 'F' };
337. /**
338. * 把颜色的表示转换为16进制表示#rrggbbaa
339. *
340. * @param color
341. * @return 返回颜色的16进制字符串
342. */
343. public static String colorToHexString(Color color) {
344. if (color == null) { return "null"; }
345. int r = color.getRed();
346. int g = color.getGreen();
347. int b = color.getBlue();
348. int a = color.getAlpha();
349. StringBuilder sb = new StringBuilder("#");
350. sb.append(hexDight[a >> 4 & 0xF]);
351. sb.append(hexDight[a & 0xF]);
352. sb.append(hexDight[r >> 4 & 0xF]);
353. sb.append(hexDight[r & 0xF]);
354. sb.append(hexDight[g >> 4 & 0xF]);
355. sb.append(hexDight[g & 0xF]);
356. sb.append(hexDight[b >> 4 & 0xF]);
357. sb.append(hexDight[b & 0xF]);
358. return sb.toString();
359. }
360. private void prepareColors() {
361. // 从文件中读取颜色
362. try {
363. Scanner scanner = new Scanner(new File("resources/colors.txt"));
364. while (scanner.hasNextLine()) {
365. try {
366. Color c = parseColorHex(scanner.nextLine().trim());
367. if (c != null) {
368. storedColors.add(c);
369. }
370. } catch (Exception e) {
371. }
372. }
373. } catch (FileNotFoundException e) {
374. e.printStackTrace();
375. }
376. // 创建一些默认的颜色
377. final float delta = 0.2f;
378. for (float r = 0; r <= 1.0; r += delta) {
379. for (float g = 0; g <= 1.0; g += delta) {
380. for (float b = 0; b <= 1.0; b += delta) {
381. defaultColors.add(new Color(r, g, b));
382. }
383. }
384. }
385. }
386. private int getHeightOfColorsRect(List<Color> li) {
387. int row = (int) Math.ceil(li.size() / (float) columnSize);
388. return row * colorRectWidth;
389. }
390. private void prepareColorsImage() {
391. margin = padding.top;
392. int w = columnSize * colorRectWidth;
393. int h = getHeightOfColorsRect(storedColors) + getHeightOfColorsRect(defaultColors) + margin;
394. int x = 0;
395. int y = 0;
396. colorsImageRect.setRect(padding.top, padding.top, w, h);
397. colorsImage = new BufferedImage(w, h, BufferedImage.TYPE_INT_ARGB);
398. Graphics2D g2d = colorsImage.createGraphics();
399. // 绘制用户存储的颜色
400. for (int i = 0; i < storedColors.size(); ++i) {
401. g2d.setPaint(storedColors.get(i));
402. g2d.fillRect(x, y, colorRectWidth, colorRectHeight);
403. x += colorRectWidth;
404. if ((i + 1) % columnSize == 0) {
405. x = 0;
406. y += colorRectHeight;
407. }
408. }
409. x = 0;
410. y = getHeightOfColorsRect(storedColors) + margin;
411. // 绘制默认的颜色
412. for (int i = 0; i < defaultColors.size(); ++i) {
413. g2d.setPaint(defaultColors.get(i));
414. g2d.fillRect(x, y, colorRectWidth, colorRectHeight);
415. x += colorRectWidth;
416. if ((i + 1) % columnSize == 0) {
417. x = 0;
418. y += colorRectHeight;
419. }
420. }
421. }
422. private void prepareSize() {
423. width = padding.left + colorsImage.getWidth() + padding.right;
424. height = padding.top + colorsImage.getHeight() + padding.top + previewHeight + sliderHeight;
425. }
426. private void preparePreview() {
427. int x = padding.left;
428. int y = height - sliderHeight - previewHeight;
429. int w = width - padding.left - padding.right;
430. previewRect.setRect(x, y, w, previewHeight);
431. }
432. private void prepareSliders() {
433. setLayout(null);
434. int margin = 0; // slider之间的间隔，实际没必须
435. int h = sliderHeight;
436. int w = (width - padding.left - padding.right) / 4;
437. int x = padding.left;
438. int y = height - h + 2;
439. redSlider.setBounds(x, y, w, h);
440. x += w + margin;
441. greenSlider.setBounds(x, y, w, h);
442. x += w + margin;
443. blueSlider.setBounds(x, y, w, h);
444. x += w + margin;
445. alphaSlider.setBounds(x, y, w, h);
446. add(redSlider);
447. add(greenSlider);
448. add(blueSlider);
449. add(alphaSlider);
450. }
451. @Override
452. public Dimension getMinimumSize() {
453. return new Dimension(width, height);
454. }
455. @Override
456. public Dimension getMaximumSize() {
457. return new Dimension(width, height);
458. }
459. @Override
460. public Dimension getPreferredSize() {
461. return new Dimension(width, height);
462. }
463. }

1. package gradient;
2. import java.awt.Color;
3. import java.awt.Graphics2D;
4. import java.awt.geom.Rectangle2D;
5. /**
6. * 绘制Photoshop中透明色的效果.
7. *
8. * @author Biao
9. *
10. */
11. public class TransparentPainter {
12. public static void paint(Graphics2D g2d, Rectangle2D rect) {
13. g2d.setClip(rect);
14. int sx = (int) rect.getX();
15. int sy = (int) rect.getY();
16. int w = (int) rect.getWidth();
17. int h = (int) rect.getHeight();
18. Color color = Color.WHITE;
19. Color color1 = Color.WHITE;
20. Color color2 = Color.LIGHT_GRAY;
21. int delta = 10;
22. boolean odd = false;
23. for (int y = sy; y <= h + sy; y += delta) {
24. color = (odd) ? color1 : color2;
25. for (int x = sx; x <= w + sx; x += delta) {
26. g2d.setPaint(color);
27. g2d.fillRect(x, y, w, h);
28. color = (color == color1) ? color2 : color1;
29. }
30. odd = !odd;
31. }
32. g2d.setClip(null);
33. }
34. }

1. package gradient;
2. import java.awt.geom.Point2D;
3. public class GeometryUtil {
4. // 两点之间的距离
5. public static double distanceOfPoints(Point2D p1, Point2D p2) {
6. double disX = p2.getX() - p1.getX();
7. double disY = p2.getY() - p1.getY();
8. double dis = Math.sqrt(disX * disX + disY * disY);
9. return dis;
10. }
11. // 两点的中点
12. public static Point2D middlePoint(Point2D p1, Point2D p2) {
13. double x = (p1.getX() + p2.getX()) / 2;
14. double y = (p1.getY() + p2.getY()) / 2;
15. return new Point2D.Double(x, y);
16. }
17. // 在两点所在直线上，以从startPoint到endPoint为方向，离startPoint的距离disToStartPoint的点
18. public static Point2D extentPoint(Point2D startPoint, Point2D endPoint, double disToStartPoint) {
19. double disX = endPoint.getX() - startPoint.getX();
20. double disY = endPoint.getY() - startPoint.getY();
21. double dis = Math.sqrt(disX * disX + disY * disY);
22. double sin = (endPoint.getY() - startPoint.getY()) / dis;
23. double cos = (endPoint.getX() - startPoint.getX()) / dis;
24. double deltaX = disToStartPoint * cos;
25. double deltaY = disToStartPoint * sin;
26. return new Point2D.Double(startPoint.getX() + deltaX, startPoint.getY() + deltaY);
27. }
28. }