JTabbedPane标签美化式样自定义

通过继承BasicTabbedPaneUI类重写JTabbedPane标签式样，实现渐变的标签效果。

效果图：


相关代码：

public class TabbedPaneUI extends BasicTabbedPaneUI {    private Color selectColor;    private Color deSelectColor;    private int inclTab = 3;    private int anchoFocoV = inclTab;    private int anchoFocoH = 1;    private int anchoCarpetas = 18;    private Polygon shape;    private Color bgColor;    private Color frontColor;    private ColorSet selectedColorSet;    private ColorSet defaultColorSet;    private ColorSet hoverColorSet;    public TabbedPaneUI(String bgColorHex, String frontColorHex){        setColor(bgColorHex,frontColorHex);        selectedColorSet = new ColorSet();        selectedColorSet.topGradColor1 = Color.decode("#E0EEEE");//选中的最上层        selectedColorSet.topGradColor2 = Color.decode("#FFFFFF");//选中的第二层        selectedColorSet.bottomGradColor1 = Color.decode("#FFFFFF");//选中的第三层        selectedColorSet.bottomGradColor2 = Color.decode("#FFFFFF");//选中的最下层        defaultColorSet = new ColorSet();        defaultColorSet.topGradColor1 = Color.decode("#FFFFFF");//未选的最上层        defaultColorSet.topGradColor2 = Color.decode("#DEEBFE");        defaultColorSet.bottomGradColor1 = Color.decode("#D6E5F5");        defaultColorSet.bottomGradColor2 = Color.decode("#D6E5F5");        hoverColorSet = new ColorSet();        hoverColorSet.topGradColor1 = Color.decode("#FFFFFF");//鼠标悬停最上层        hoverColorSet.topGradColor2 = Color.decode("#FFFFFF");        hoverColorSet.bottomGradColor1 = Color.decode("#FFFFFF");        hoverColorSet.bottomGradColor2 = Color.decode("#FFFFFF");    }//  //  public static ComponentUI createUI(JComponent c) {//      return new TabbedPaneUI();//  }    @Override    protected void installDefaults() {        super.installDefaults();        RollOverListener l = new RollOverListener();        tabPane.addMouseListener(l);        tabPane.addMouseMotionListener(l);        selectColor = new Color(250, 192, 192);        deSelectColor = new Color(197, 193, 168);        tabAreaInsets.right = anchoCarpetas;    }    public void setColor(String bgColorHex, String frontColorHex){        bgColor = Color.decode(bgColorHex);        frontColor = Color.decode(frontColorHex);    }    @Override    protected void paintContentBorderTopEdge(Graphics g, int tabPlacement,            int selectedIndex, int x, int y, int w, int h) {        super.paintContentBorderTopEdge(g, tabPlacement, -1, x, y, w, h);    }    @Override    protected void paintTabArea(Graphics g, int tabPlacement, int selectedIndex) {        if (runCount > 1) {            int lines[] = new int[runCount];            for (int i = 0; i < runCount; i++) {                lines[i] = rects[tabRuns[i]].y                        + (tabPlacement == TOP ? maxTabHeight : 0);            }            Arrays.sort(lines);            if (tabPlacement == TOP) {                int fila = runCount;                for (int i = 0; i < lines.length - 1; i++, fila--) {                    Polygon carp = new Polygon();                    carp.addPoint(0, lines[i]);                    carp.addPoint(tabPane.getWidth() - 2 * fila - 2, lines[i]);                    carp.addPoint(tabPane.getWidth() - 2 * fila, lines[i] + 3);                    if (i < lines.length - 2) {                        carp.addPoint(tabPane.getWidth() - 2 * fila,                                lines[i + 1]);                        carp.addPoint(0, lines[i + 1]);                    } else {                        carp.addPoint(tabPane.getWidth() - 2 * fila, lines[i]                                + rects[selectedIndex].height);                        carp.addPoint(0, lines[i] + rects[selectedIndex].height);                    }                    carp.addPoint(0, lines[i]);                    g.setColor(hazAlfa(fila));                    g.fillPolygon(carp);                    g.setColor(darkShadow.darker());                    g.drawPolygon(carp);                }            } else {                int fila = 0;                for (int i = 0; i < lines.length - 1; i++, fila++) {                    Polygon carp = new Polygon();                    carp.addPoint(0, lines[i]);                    carp.addPoint(tabPane.getWidth() - 2 * fila - 1, lines[i]);                    carp.addPoint(tabPane.getWidth() - 2 * fila - 1,                            lines[i + 1] - 3);                    carp.addPoint(tabPane.getWidth() - 2 * fila - 3,                            lines[i + 1]);                    carp.addPoint(0, lines[i + 1]);                    carp.addPoint(0, lines[i]);                    g.setColor(hazAlfa(fila + 2));                    g.fillPolygon(carp);                    g.setColor(darkShadow.darker());                    g.drawPolygon(carp);                }            }        }        super.paintTabArea(g, tabPlacement, selectedIndex);    }    @Override    protected void paintTabBackground(Graphics g, int tabPlacement,            int tabIndex, int x, int y, int w, int h, boolean isSelected) {        Graphics2D g2D = (Graphics2D) g;        ColorSet colorSet;        Rectangle rect = rects[tabIndex];        if (isSelected) {            colorSet = selectedColorSet;        } else if (getRolloverTab() == tabIndex) {            colorSet = hoverColorSet;        } else {            colorSet = defaultColorSet;        }        g2D.setRenderingHint(RenderingHints.KEY_ANTIALIASING,                RenderingHints.VALUE_ANTIALIAS_ON);        int width = rect.width;        int xpos = rect.x;        int yPos = rect.y;        if (tabIndex > -1) {            width--;            xpos++;            yPos += 2;        }        g2D.setPaint(new GradientPaint(xpos, 0, colorSet.topGradColor1, xpos,                h / 2, colorSet.topGradColor2));        g2D.fill(this.getUpArea(xpos, yPos, width, h - 2));        g2D.setPaint(new GradientPaint(0, h / 2, colorSet.bottomGradColor1, 0,                h, colorSet.bottomGradColor2));        g2D.fill(this.getDownArea(xpos, yPos, width, h - 2));    }    private Shape getArea(int x, int y, int w, int h) {        RoundRectangle2D rect = new RoundRectangle2D.Float(x, y, w, h, 15, 15);        Area a = new Area(rect);        Rectangle2D rec = new Rectangle2D.Float(x, y + h / 2, w, h / 2);        Area b = new Area(rec);        a.add(b);        return a;    }    private Shape getUpArea(int x, int y, int w, int h) {        Rectangle2D rec = new Rectangle2D.Float(x, y, w, h / 3 );        Area a = new Area(rec);        RoundRectangle2D rect = new RoundRectangle2D.Float(x, y, w, h, 15, 15);        Area b = new Area(rect);        a.intersect(b);        return a;    }    private Shape getDownArea(int x, int y, int w, int h) {        Rectangle2D rec = new Rectangle2D.Float(x, y + h / 3, w, h*2 / 3 +1);        Area a = new Area(rec);        RoundRectangle2D rect = new RoundRectangle2D.Float(x, y, w, h, 15, 15);        // Area b = new Area(rect);        // a.intersect(b);        return a;    }    private class ColorSet {        Color topGradColor1;        Color topGradColor2;        Color bottomGradColor1;        Color bottomGradColor2;    }    @Override    protected void paintText(Graphics g, int tabPlacement, Font font,            FontMetrics metrics, int tabIndex, String title,            Rectangle textRect, boolean isSelected) {        super.paintText(g, tabPlacement, font, metrics, tabIndex, title,                textRect, isSelected);        g.setFont(font);        View v = getTextViewForTab(tabIndex);        if (v != null) {            // html            v.paint(g, textRect);        } else {            // plain text            int mnemIndex = tabPane.getDisplayedMnemonicIndexAt(tabIndex);            if (tabPane.isEnabled() && tabPane.isEnabledAt(tabIndex)) {                g.setColor(tabPane.getForegroundAt(tabIndex));                BasicGraphicsUtils                        .drawStringUnderlineCharAt(g, title, mnemIndex,                                textRect.x, textRect.y + metrics.getAscent());            } else { // tab disabled                g.setColor(Color.BLACK);                BasicGraphicsUtils                        .drawStringUnderlineCharAt(g, title, mnemIndex,                                textRect.x, textRect.y + metrics.getAscent());                g.setColor(tabPane.getBackgroundAt(tabIndex).darker());                BasicGraphicsUtils.drawStringUnderlineCharAt(g, title,                        mnemIndex, textRect.x - 1,                        textRect.y + metrics.getAscent() - 1);            }        }    }    //固定tab标签宽度    @Override    protected int calculateTabWidth(int tabPlacement, int tabIndex,            FontMetrics metrics) {        return 120;//      return 10 + anchoFocoV//              + super.calculateTabWidth(tabPlacement, tabIndex, metrics);    }    @Override    protected int calculateTabHeight(int tabPlacement, int tabIndex,            int fontHeight) {        if (tabPlacement == LEFT || tabPlacement == RIGHT) {            return super.calculateTabHeight(tabPlacement, tabIndex, fontHeight);        } else {            return anchoFocoH                    + super.calculateTabHeight(tabPlacement, tabIndex,                            fontHeight);        }    }    protected int calculateMaxTabHeight(int tabPlacement) {        return 25;    }    //set tab title hight    @Override    protected void paintTabBorder(Graphics g, int tabPlacement, int tabIndex,            int x, int y, int w, int h, boolean isSelected) {//      if (isSelected) {            g.setColor(Color.decode("#afafaf"));            int[] xp = new int[] { x, x, x + 3, x + w - inclTab - 6,                    x + w - inclTab - 3, x + w - inclTab, x + w - inclTab, x };            int[] yp = new int[] { y + h, y + 3, y, y, y, y + 3, y + h, y + h };            shape = new Polygon(xp, yp, xp.length);            Graphics2D g2D = (Graphics2D) g;            g2D.drawPolygon(shape);            g.setColor(Color.white);            g.drawLine(x, y + h, x + w - inclTab, y + h);//      }    }    protected int getTabLabelShiftY(int tabPlacement, int tabIndex,            boolean isSelected) {        return 0;    }    protected int getTabLabelShiftX(int tabPlacement, int tabIndex,            boolean isSelected) {        return 0;    }    @Override    protected void paintFocusIndicator(Graphics g, int tabPlacement,            Rectangle[] rects, int tabIndex, Rectangle iconRect,            Rectangle textRect, boolean isSelected) {        if (tabPane.hasFocus() || isSelected) {            // g.setColor(UIManager.getColor("ScrollBar.thumbShadow"));            // g.drawPolygon(shape);        }    }    protected Color hazAlfa(int fila) {        int alfa = 0;        if (fila >= 0) {            alfa = 50 + (fila > 7 ? 70 : 10 * fila);        }        return new Color(0, 0, 0, alfa);    }    private int lastRollOverTab = -1;    private class RollOverListener implements MouseMotionListener,            MouseListener {        public void mouseMoved(MouseEvent e) {            checkRollOver();        }        public void mouseEntered(MouseEvent e) {            checkRollOver();        }        public void mouseExited(MouseEvent e) {            tabPane.repaint();        }        private void checkRollOver() {            int currentRollOver = getRolloverTab();            if (currentRollOver != lastRollOverTab) {                lastRollOverTab = currentRollOver;                Rectangle tabsRect = new Rectangle(0, 0, tabPane.getWidth(),                         tabPane.getHeight()+1);                tabPane.repaint(tabsRect);            }        }    }}

关键点：
1. 继承BasicTabbedPaneUI类，这其中有我们必须要重写的一个方法：
public static ComponentUI createUI(JComponent c) {
return new XXXTabbedPaneUI();
}
其中XXXTabbedPaneUI就是自己实现的BasicTabbedPaneUI的子类的名字。

2．下面类出几个改变外观的重要的方法：
a. protectedvoid installDefaults() //可以改变一些BasicTabbedPaneUI中默认的属性。
b.protectedvoid paintTabArea(Graphics g, int tabPlacement, int selectedIndex) //绘制整个选项卡区域
c. protectedvoid paintTabBackground(Graphics g, int tabPlacement,
int tabIndex, int x, int y, int w, int h, boolean isSelected)
//绘制某个选项卡的背景色
d. protectedvoid paintContentBorder(Graphics g, int tabPlacement,
int selectedIndex) //绘制TabbedPane容器的四周边框样式。
e. protectedvoid paintFocusIndicator(Graphics g, int tabPlacement,
Rectangle[] rects, int tabIndex, Rectangle iconRect,
Rectangle textRect, boolean isSelected)
//绘制选中某个Tab后，获得焦点的样式。

3、具体paint（）渲染可参考前篇： JButton自定义式样