http://blog.chinaunix.net/uid-7570422-id-3136430.html
由于希望改变TabbedPanel的tab的形状，查看了BasicTabbedPaneUI.java的一部分代码，
其中：
void paint ->paintContentBorder
paintTabArea (整个区域？) -> paintTab -> paintTabBackground
paintTabBorder(外框）
paintText（标题）
paintIcon(图片)
paintFocusIndicator
据我目前的理解应该是：要修改形状，主要是修改paintTabBackground和paintTabBorder？
Tab上Label的位置是由layoutLabel来决定。
下面是一个例子：
大部分函数是从BasicTabbedPaneUI.java 拷贝过来，但是修改了斜体字部分。
将Tab的形状修改为类似：
TabShapeTest.java
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.geom.Area;
import java.awt.geom.Path2D;
import java.awt.geom.Rectangle2D;
import javax.swing.Icon;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTabbedPane;
import javax.swing.SwingUtilities;
import javax.swing.text.View;
public class TabShapeTest extends JFrame{
/**
*
*/
private static final long serialVersionUID = 1L;
public static void main(String [] args) {
new TabShapeTest().setVisible(true);
}
public TabShapeTest() {
JTabbedPane tpShape = new JTabbedPane();
tpShape.setUI(new ShapeTabTabbedPaneUI());
add(tpShape);
setPreferredSize(new Dimension(280,300));
tpShape.addTab("first",new JPanel());
tpShape.addTab("second?????", new JPanel());
tpShape.addTab("third", new JPanel());
tpShape.setBackgroundAt(1, Color.yellow);
tpShape.setBackgroundAt(2, Color.BLUE);
pack();
}
ShapeTabTabbedPaneUI.java
public static class ShapeTabTabbedPaneUI extends javax.swing.plaf.basic.BasicTabbedPaneUI {
private Color selectedColor;
protected void installDefaults() {
super.installDefaults();
}
public ShapeTabTabbedPaneUI() {
}
protected void paintTabBackground(Graphics g, int tabPlacement,
int tabIndex, int x, int y, int w, int h, boolean isSelected) {
Graphics2D g2d = (Graphics2D) g;
g.setColor(!isSelected || selectedColor == null?
tabPane.getBackgroundAt(tabIndex) : selectedColor);
switch(tabPlacement) {
case LEFT:
g.fillRect(x+1, y+1, w-1, h-3);
break;
case RIGHT:
g.fillRect(x, y+1, w-2, h-3);
break;
case BOTTOM:
g.fillRect(x+1, y, w-3, h-1);
break;
case TOP:
default:
//g.fillRect(x+1, y+1, w-3, h-1);
g2d.fill(this.getTabArea(x+1, y+1, w-11, h-1));
}
}
private Shape getTabArea(int x, int y, int w, int h) {
Rectangle2D rec = new Rectangle2D.Double(x, y, w, h );
Area aRec = new Area(rec);
Path2D.Double triangle=new Path2D.Double();
triangle.moveTo(x+w, y);
triangle.lineTo(x+w+10, y+h/2);
triangle.lineTo(x+w, y+h);
triangle.closePath();
aRec.add(new Area(triangle));
triangle.reset();
return aRec;
}
protected void paintTabBorder(Graphics g, int tabPlacement, int tabIndex,
int x, int y, int w, int h, boolean isSelected) {
g.setColor(lightHighlight);
switch (tabPlacement) {
case LEFT:
g.drawLine(x+1, y+h-2, x+1, y+h-2); // bottom-left highlight
g.drawLine(x, y+2, x, y+h-3); // left highlight
g.drawLine(x+1, y+1, x+1, y+1); // top-left highlight
g.drawLine(x+2, y, x+w-1, y); // top highlight
g.setColor(shadow);
g.drawLine(x+2, y+h-2, x+w-1, y+h-2); // bottom shadow
g.setColor(darkShadow);
g.drawLine(x+2, y+h-1, x+w-1, y+h-1); // bottom dark shadow
break;
case RIGHT:
g.drawLine(x, y, x+w-3, y); // top highlight
g.setColor(shadow);
g.drawLine(x, y+h-2, x+w-3, y+h-2); // bottom shadow
g.drawLine(x+w-2, y+2, x+w-2, y+h-3); // right shadow
g.setColor(darkShadow);
g.drawLine(x+w-2, y+1, x+w-2, y+1); // top-right dark shadow
g.drawLine(x+w-2, y+h-2, x+w-2, y+h-2); // bottom-right dark shadow
g.drawLine(x+w-1, y+2, x+w-1, y+h-3); // right dark shadow
g.drawLine(x, y+h-1, x+w-3, y+h-1); // bottom dark shadow
break;
case BOTTOM:
g.drawLine(x, y, x, y+h-3); // left highlight
g.drawLine(x+1, y+h-2, x+1, y+h-2); // bottom-left highlight
g.setColor(shadow);
g.drawLine(x+2, y+h-2, x+w-3, y+h-2); // bottom shadow
g.drawLine(x+w-2, y, x+w-2, y+h-3); // right shadow
g.setColor(darkShadow);
g.drawLine(x+2, y+h-1, x+w-3, y+h-1); // bottom dark shadow
g.drawLine(x+w-2, y+h-2, x+w-2, y+h-2); // bottom-right dark shadow
g.drawLine(x+w-1, y, x+w-1, y+h-3); // right dark shadow
break;
case TOP:
default:
g.drawLine(x, y+2, x, y+h-1); // left highlight
g.drawLine(x+1, y+1, x+1, y+1); // top-left highlight
// g.drawLine(x+2, y, x+w-3, y); // top highlight
g.drawLine(x+2,y, x+w-10, y);
g.setColor(shadow);
// g.drawLine(x+w-2, y+2, x+w-2, y+h-1); // right shadow
g.drawLine(x+w-10,y, x+w-1, y+h/2-1);
g.drawLine(x+w-1,y+h/2+1,x+w-10,y+h);
g.setColor(darkShadow);
//g.drawLine(x+w-1, y+2, x+w-1, y+h-1); // right dark-shadow
//g.drawLine(x+w-2, y+1, x+w-2, y+1); // top-right shadow
g.drawLine(x+w-1,y+h/2+2,x+w-10,y+h+1);
}
}
protected void layoutLabel(int tabPlacement,
FontMetrics metrics, int tabIndex,
String title, Icon icon,
Rectangle tabRect, Rectangle iconRect,
Rectangle textRect, boolean isSelected ) {
textRect.x = textRect.y = iconRect.x = iconRect.y = 0;
View v = getTextViewForTab(tabIndex);
if (v != null) {
tabPane.putClientProperty("html", v);
}
SwingUtilities.layoutCompoundLabel(tabPane,
metrics, title, icon,
SwingUtilities.CENTER,
SwingUtilities.CENTER,
SwingUtilities.CENTER,
SwingUtilities.TRAILING,
tabRect,
iconRect,
textRect,
textIconGap);
tabPane.putClientProperty("html", null);
int xNudge = getTabLabelShiftX(tabPlacement, tabIndex, isSelected);
int yNudge = getTabLabelShiftY(tabPlacement, tabIndex, isSelected);
iconRect.x += xNudge;
iconRect.y += yNudge;
textRect.y += yNudge;
switch (tabPlacement) {
case LEFT:
textRect.x += xNudge;
break;
case RIGHT:
textRect.x += xNudge;
break;
case BOTTOM:
textRect.x += xNudge;
break;
case TOP:
default:
textRect.x += xNudge-4;
}
}
}
}
结果：
