标题位置可以分别设置为上下左右，4个位置。如下图所示:
/**
* Title PopupMenu
*
* @author zhangtao
*
* Msn & Mail: zht_dream@hotmail.com
*/
public class ZHTPopupMenu extends JPopupMenu {
public static final int POSITION_TOP = 1;
public static final int POSITION_BOTTOM = 2;
public static final int POSITION_LEFT = 3;
public static final int POSITION_RIGHT = 4;
private int titleSize = 30;
private Color titleColor = Color.BLACK;
private Color titleFillColor = Color.WHITE;
private boolean titleGradient = true;
private Color titleGradientColor = new Color(0, 50, 50);
private Font titleFont = new Font("Dialog", Font.BOLD, 12);
private int titlePosition = POSITION_LEFT;
private int titleGap = 5;
public ZHTPopupMenu() {
super();
}
public ZHTPopupMenu(String label) {
super(label);
}
@Override
public Insets getInsets() {
Insets insets = (Insets) super.getInsets().clone();
switch (titlePosition) {
case POSITION_TOP:
insets.top += titleSize;
break;
case POSITION_BOTTOM:
insets.bottom += titleSize;
break;
case POSITION_LEFT:
insets.left += titleSize;
break;
case POSITION_RIGHT:
insets.right += titleSize;
break;
}
return insets;
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D) g.create();
Dimension size = this.getSize();
GradientPaint paint;
g2d.setColor(titleFillColor);
String text = this.getLabel();
int len = 0;//text.length();
if (text != null && text.trim().length() > 0) {
len = text.length();
}
boolean hasEN = false;
for (int i = 0; i < len; i++) {
if (isEN(text.charAt(i))) {
hasEN = true;
break;
}
}
JLabel label = new JLabel(text);
label.setFont(titleFont);
label.setForeground(titleColor);
Dimension labelSize = label.getPreferredSize();
switch (titlePosition) {
case POSITION_TOP: {
if (titleGradient) {
paint = new GradientPaint(0, 0, titleFillColor, size.width, titleSize, titleGradientColor);
g2d.setPaint(paint);
}
g2d.fillRect(0, 0, size.width, titleSize);
if (len != 0) {
ZHTUtils.paintComponent(g2d, label, this, titleGap, titleGap, labelSize.width, labelSize.height);
}
}
break;
case POSITION_BOTTOM: {
if (titleGradient) {
paint = new GradientPaint(0, size.height - titleSize, titleFillColor, size.width, size.height, titleGradientColor);
g2d.setPaint(paint);
}
g2d.fillRect(0, size.height - titleSize, size.width, titleSize);
if (len != 0) {
ZHTUtils.paintComponent(g2d, label, this, titleGap, size.height - titleGap - labelSize.height, labelSize.width, labelSize.height);
}
}
break;
case POSITION_LEFT: {
if (titleGradient) {
paint = new GradientPaint(0, 0, titleFillColor, titleSize, size.height, titleGradientColor);
g2d.setPaint(paint);
}
g2d.fillRect(0, 0, titleSize, size.height);
if (len != 0) {
if (hasEN) {
g2d.rotate(90 * Math.PI / 180, titleGap, titleGap);
ZHTUtils.paintComponent(g2d, label, this, titleGap, titleGap - labelSize.height, labelSize.width, labelSize.height);
} else {
int sum = 0;
for (int i = 0; i < len; i++) {
label.setText(text.charAt(i) + "");
labelSize = label.getPreferredSize();
ZHTUtils.paintComponent(g2d, label, this, titleGap, sum, labelSize.width, labelSize.height);
sum += labelSize.height;
}
}
}
}
break;
case POSITION_RIGHT: {
if (titleGradient) {
paint = new GradientPaint(size.width - titleSize, 0, titleFillColor, size.width, size.height, titleGradientColor);
g2d.setPaint(paint);
}
g2d.fillRect(size.width - titleSize, 0, titleSize, size.height);
if (len != 0) {
if (hasEN) {
g2d.rotate(90 * Math.PI / 180, size.width - titleSize + titleGap, titleGap);
ZHTUtils.paintComponent(g2d, label, this, size.width - titleSize + titleGap, titleGap - labelSize.height, labelSize.width, labelSize.height);
} else {
int sum = 0;
for (int i = 0; i < len; i++) {
label.setText(text.charAt(i) + "");
labelSize = label.getPreferredSize();
ZHTUtils.paintComponent(g2d, label, this, size.width - titleGap - labelSize.width, sum, labelSize.width, labelSize.height);
sum += labelSize.height;
}
}
}
}
break;
}
}
public static boolean isEN(char cn) {
byte[] bytes = (String.valueOf(cn)).getBytes();
if (bytes == null || bytes.length > 2 || bytes.length <= 0) { // 错误
return false;
}
if (bytes.length == 1) { // 英文字符
return true;
}
if (bytes.length == 2) { // 中文字符
return false;
}
return false;
}
public int getTitleSize() {
return titleSize;
}
public void setTitleSize(int titleSize) {
this.titleSize = titleSize;
this.repaint();
}
public Color getTitleColor() {
return titleColor;
}
public void setTitleColor(Color titleColor) {
this.titleColor = titleColor;
this.repaint();
}
public Color getTitleFillColor() {
return titleFillColor;
}
public void setTitleFillColor(Color titleFillColor) {
this.titleFillColor = titleFillColor;
this.repaint();
}
public boolean isTitleGradient() {
return titleGradient;
}
public void setTitleGradient(boolean titleGradient) {
this.titleGradient = titleGradient;
this.repaint();
}
public Color getTitleGradientColor() {
return titleGradientColor;
}
public void setTitleGradientColor(Color titleGradientColor) {
this.titleGradientColor = titleGradientColor;
this.repaint();
}
public Font getTitleFont() {
return titleFont;
}
public void setTitleFont(Font titleFont) {
this.titleFont = titleFont;
this.repaint();
}
public int getTitlePosition() {
return titlePosition;
}
public void setTitlePosition(int titlePosition) {
this.titlePosition = titlePosition;
this.repaint();
}
public int getTitleGap() {
return titleGap;
}
public void setTitleGap(int titleGap) {
this.titleGap = titleGap;
this.repaint();
}
}