Java 如何扩展JComboBox,允许用户通过单击x按钮(如Internet浏览器选项卡)删除列表项?
我试图创建一个类似于JComboBox的对象,但我希望用户能够从列表中删除一项。假设每个列表元素的右侧都有一个x图标或按钮,就像您在internet浏览器的选项卡上看到的那样,单击x将删除相应的列表项 我一直在尝试用新的编辑器和渲染器扩展JComboBox,尝试在每个标签旁边添加一个按钮,但几乎没有成功。什么是一种体面的方式 我发现所有扩展JComboBox的教程和示例似乎只涉及JLabel功能,这似乎阻止了我需要的按钮功能 谢谢你的帮助 退房。也许会有帮助Java 如何扩展JComboBox,允许用户通过单击x按钮(如Internet浏览器选项卡)删除列表项?,java,swing,jbutton,jlabel,jcombobox,Java,Swing,Jbutton,Jlabel,Jcombobox,我试图创建一个类似于JComboBox的对象,但我希望用户能够从列表中删除一项。假设每个列表元素的右侧都有一个x图标或按钮,就像您在internet浏览器的选项卡上看到的那样,单击x将删除相应的列表项 我一直在尝试用新的编辑器和渲染器扩展JComboBox,尝试在每个标签旁边添加一个按钮,但几乎没有成功。什么是一种体面的方式 我发现所有扩展JComboBox的教程和示例似乎只涉及JLabel功能,这似乎阻止了我需要的按钮功能 谢谢你的帮助 退房。也许会有帮助 import java.awt.*;
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.accessibility.*;
import javax.swing.*;
import javax.swing.plaf.basic.*;
public final class RemoveButtonInComboItemTest {
public JComponent makeUI() {
final JComboBox<String> c = new RemoveButtonComboBox<>(
new DefaultComboBoxModel<>(new String[] {"aaaaa", "bbb", "cc", "d", "eeee"}));
c.setPrototypeDisplayValue("MMMMMMMMMMMMMMMMMM");
JPanel p = new JPanel();
p.add(c);
p.add(new JButton(new AbstractAction("add") {
@Override public void actionPerformed(ActionEvent e) {
MutableComboBoxModel<String> m = (MutableComboBoxModel<String>) c.getModel();
m.insertElementAt(new Date().toString(), m.getSize());
}
}));
p.setBorder(BorderFactory.createEmptyBorder(20, 0, 0, 0));
return p;
}
public static void main(String... args) {
EventQueue.invokeLater(new Runnable() {
@Override public void run() {
createAndShowGUI();
}
});
}
public static void createAndShowGUI() {
JFrame f = new JFrame();
f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
f.getContentPane().add(new RemoveButtonInComboItemTest().makeUI());
f.setSize(320, 240);
f.setLocationRelativeTo(null);
f.setVisible(true);
}
}
class RemoveButtonComboBox<E> extends JComboBox<E> {
private transient CellButtonsMouseListener cbml;
public RemoveButtonComboBox(ComboBoxModel<E> aModel) {
super(aModel);
}
@Override public void updateUI() {
if (Objects.nonNull(cbml)) {
JList<?> list = getList();
if (Objects.nonNull(list)) {
list.removeMouseListener(cbml);
list.removeMouseMotionListener(cbml);
}
}
super.updateUI();
setRenderer(new ButtonsRenderer<E>(this));
JList<?> list = getList();
if (Objects.nonNull(list)) {
cbml = new CellButtonsMouseListener();
list.addMouseListener(cbml);
list.addMouseMotionListener(cbml);
}
}
protected JList<?> getList() {
Accessible a = getAccessibleContext().getAccessibleChild(0);
if (a instanceof BasicComboPopup) {
return ((BasicComboPopup) a).getList();
} else {
return null;
}
}
}
class CellButtonsMouseListener extends MouseAdapter {
private int prevIndex = -1;
private JButton prevButton;
private static void listRepaint(JList list, Rectangle rect) {
if (Objects.nonNull(rect)) {
list.repaint(rect);
}
}
@Override public void mouseMoved(MouseEvent e) {
JList list = (JList) e.getComponent();
Point pt = e.getPoint();
int index = list.locationToIndex(pt);
if (!list.getCellBounds(index, index).contains(pt)) {
if (prevIndex >= 0) {
Rectangle r = list.getCellBounds(prevIndex, prevIndex);
listRepaint(list, r);
}
index = -1;
prevButton = null;
return;
}
if (index >= 0) {
JButton button = getButton(list, pt, index);
ButtonsRenderer renderer = (ButtonsRenderer) list.getCellRenderer();
if (Objects.nonNull(button)) {
renderer.rolloverIndex = index;
if (!button.equals(prevButton)) {
Rectangle r = list.getCellBounds(prevIndex, index);
listRepaint(list, r);
}
} else {
renderer.rolloverIndex = -1;
Rectangle r = null;
if (prevIndex == index) {
if (prevIndex >= 0 && Objects.nonNull(prevButton)) {
r = list.getCellBounds(prevIndex, prevIndex);
}
} else {
r = list.getCellBounds(index, index);
}
listRepaint(list, r);
prevIndex = -1;
}
prevButton = button;
}
prevIndex = index;
}
@Override public void mousePressed(MouseEvent e) {
JList list = (JList) e.getComponent();
Point pt = e.getPoint();
int index = list.locationToIndex(pt);
if (index >= 0) {
JButton button = getButton(list, pt, index);
if (Objects.nonNull(button)) {
listRepaint(list, list.getCellBounds(index, index));
}
}
}
@Override public void mouseReleased(MouseEvent e) {
JList list = (JList) e.getComponent();
Point pt = e.getPoint();
int index = list.locationToIndex(pt);
if (index >= 0) {
JButton button = getButton(list, pt, index);
if (Objects.nonNull(button)) {
ButtonsRenderer renderer = (ButtonsRenderer) list.getCellRenderer();
button.doClick();
Rectangle r = list.getCellBounds(index, index);
listRepaint(list, r);
}
}
}
@Override public void mouseExited(MouseEvent e) {
JList list = (JList) e.getComponent();
ButtonsRenderer renderer = (ButtonsRenderer) list.getCellRenderer();
renderer.rolloverIndex = -1;
}
@SuppressWarnings("unchecked")
private static JButton getButton(JList list, Point pt, int index) {
Container c = (Container) list.getCellRenderer().getListCellRendererComponent(
list, "", index, false, false);
Rectangle r = list.getCellBounds(index, index);
c.setBounds(r);
//c.doLayout();
pt.translate(-r.x, -r.y);
Component b = SwingUtilities.getDeepestComponentAt(c, pt.x, pt.y);
if (b instanceof JButton) {
return (JButton) b;
} else {
return null;
}
}
}
class ButtonsRenderer<E> extends JPanel implements ListCellRenderer<E> {
private static final Color EVEN_COLOR = new Color(230, 255, 230);
private final RemoveButtonComboBox<E> comboBox;
private JList list;
private int index;
public int rolloverIndex = -1;
private final JLabel label = new DefaultListCellRenderer();
private final JButton deleteButton = new JButton(new AbstractAction("x") {
@Override public void actionPerformed(ActionEvent e) {
MutableComboBoxModel m = (MutableComboBoxModel) list.getModel();
if (m.getSize() > 1) {
m.removeElementAt(index);
comboBox.showPopup();
}
}
}) {
@Override public Dimension getPreferredSize() {
return new Dimension(16, 16);
}
};
public ButtonsRenderer(RemoveButtonComboBox<E> comboBox) {
super(new BorderLayout(0, 0));
this.comboBox = comboBox;
label.setOpaque(false);
setOpaque(true);
add(label);
deleteButton.setBorder(BorderFactory.createEmptyBorder());
deleteButton.setContentAreaFilled(false);
add(deleteButton, BorderLayout.EAST);
}
@Override public Component getListCellRendererComponent(
JList<? extends E> list, E value, int index,
boolean isSelected, boolean cellHasFocus) {
label.setText(Objects.toString(value, ""));
this.list = list;
this.index = index;
if (isSelected) {
setBackground(list.getSelectionBackground());
label.setForeground(list.getSelectionForeground());
} else {
setBackground(index % 2 == 0 ? EVEN_COLOR : list.getBackground());
label.setForeground(list.getForeground());
}
MutableComboBoxModel m = (MutableComboBoxModel) list.getModel();
if (index < 0 || m.getSize() - 1 <= 0) {
setOpaque(false);
deleteButton.setVisible(false);
label.setForeground(list.getForeground());
} else {
setOpaque(true);
boolean f = index == rolloverIndex;
deleteButton.setVisible(true);
deleteButton.getModel().setRollover(f);
deleteButton.setForeground(f ? Color.WHITE : list.getForeground());
}
return this;
}
}
import java.awt.*;
导入java.awt.event.*;
导入java.util.*;
导入javax.accessibility.*;
导入javax.swing.*;
导入javax.swing.plaf.basic.*;
公共最终类RemoveButtonInComboItemTest{
公共JComponent makeUI(){
最终jComboxC=新移除的按钮ComboxC(
新的DefaultComboxModel(新字符串[]{“AAAA”、“bbb”、“cc”、“d”、“eeee”});
c、 setPrototypeDisplayValue(“mmmmmmmmmmmm”);
JPanel p=新的JPanel();
p、 添加(c);
p、 添加(新JButton)(新抽象操作(“添加”){
@覆盖已执行的公共无效操作(ActionEvent e){
mutableComboxModel m=(mutableComboxModel)c.getModel();
m、 insertElementAt(newdate().toString(),m.getSize());
}
}));
p、 setBorder(BorderFactory.createEmptyByOrder(20,0,0,0));
返回p;
}
公共静态void main(字符串…参数){
invokeLater(新的Runnable(){
@重写公共无效运行(){
createAndShowGUI();
}
});
}
公共静态void createAndShowGUI(){
JFrame f=新的JFrame();
f、 setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
f、 getContentPane().add(新建RemoveButtonInComboItemTest().makeUI());
f、 设置大小(320240);
f、 setLocationRelativeTo(空);
f、 setVisible(真);
}
}
类RemoveButtonComboBox扩展了JComboBox{
私人临时手机按键鼠标听筒cbml;
public RemoveButtonComboBox(ComboBoxModel aModel){
超级(阿莫代尔);
}
@重写公共void updateUI(){
if(Objects.nonNull(cbml)){
JList=getList();
if(Objects.nonNull(列表)){
列表。移除鼠标侦听器(cbml);
list.removeMouseMotionListener(cbml);
}
}
super.updateUI();
设置渲染器(新按钮渲染器(此));
JList=getList();
if(Objects.nonNull(列表)){
cbml=新的CellButtonsMouseListener();
列表。添加MouseListener(cbml);
list.addMouseMotionListener(cbml);
}
}
受保护的JList getList(){
可访问a=getAccessibleContext().getAccessibleChild(0);
if(基本组件弹出窗口的实例){
return((basicmbopopup)a.getList();
}否则{
返回null;
}
}
}
类CellButtonMouseListener扩展了MouseAdapter{
私有索引=-1;
私有JButton-prevButton;
私有静态void listRepaint(JList列表,矩形rect){
if(Objects.nonNull(rect)){
列表。重新绘制(rect);
}
}
@覆盖公共void mouseMoved(MouseEvent e){
JList=(JList)e.getComponent();
点pt=e.getPoint();
int index=list.locationToIndex(pt);
如果(!list.getCellBounds(index,index).contains(pt)){
如果(prevIndex>=0){
矩形r=list.getCellBounds(prevIndex,prevIndex);
列表重新绘制(列表,r);
}
指数=-1;
prevButton=null;
返回;
}
如果(索引>=0){
JButton button=getButton(列表、pt、索引);
ButtonsRenderer呈现程序=(ButtonsRenderer)list.getCellRenderer();
if(Objects.nonNull(按钮)){
renderer.rolloverIndex=索引;
如果(!button.equals(prevButton)){
矩形r=list.getCellBounds(prevIndex,index);
列表重新绘制(列表,r);
}
}否则{
renderer.rolloverIndex=-1;
矩形r=null;
如果(prevIndex==索引){
if(prevIndex>=0&&Objects.nonNull(prevButton)){
r=list.getCellBounds(prevIndex,prevIndex);
}
}否则{
r=list.getCellBounds(index,index);
}
列表重新绘制(列表,r);
prevIndex=-1;
}
prevButton=按钮;
}
指数=指数;
}
@覆盖公共无效鼠标按下(MouseEvent e){
JList=(JList)e.getComponent();
点pt=e.getPoint();
int index=list.locationToIndex(pt);
如果(索引>=0){
JButton button=getButton(列表、pt、索引);
if(Objects.nonNull(按钮)){
listRepaint(list,list.getCellBounds(index,index));
}
}
}
@覆盖公共无效MouseEvent(MouseEvent e){
JList=(JList)e.getComponent();
点pt=e.getPoint();
int index=list.locationToIndex(pt);
如果(索引>=0){
JButton button=getButton(列表、pt、索引);
if(Objects.nonNull(按钮)){
ButtonsRenderer呈现程序=(ButtonsRenderer)list.getCellRenderer();
button.doClick();
矩形r=list.getCellBounds(index,index);
列表重新绘制(列表,r);
}
}
}
@覆盖公共void mouseExited(MouseEvent e){
JList=(JList)e.getComponent();
ButtonsRenderer呈现程序=(ButtonsRenderer)list.getCellRenderer();
renderer.rolloverIndex=-1;
}
@抑制警告(“未选中”)
私有静态JButton getButton(JList列表、点pt、int索引){
容器c=(容器)列表.getCellRenderer().GetListCellRenderComponent(
列表“”,索引,假,假);
矩形r=list.getCellBounds(index,index);
c、 立根(r);
//c、 doLayout();
pt.translate(-r.x,-r.y);
组件b=SwingUtilities.GetDeepTestComponentAt(c,pt.x,pt.y);
如果