如何防止将JLabel拖到JDesktopPane边界外？
我已经完成了一个应用程序，其中有一个JLabel放在JDesktopPane中，JLabel可以拖到任何地方，但拖动问题的同时可以将JLabel拖到JDesktopPane的边界之外？任何人都可以告诉我如何防止这种情况？
以及
应用程序中的任何人都可以告诉我如何通过双击来编辑JLabel文本值。目前我通过 JOptionPane.showInputDialog（）完成了这项工作，我们是否可以通过双击它来编辑JLabel的文本，并以任何其他方式编辑它而不是使用 JOptionPane。 showInputDialog
我的代码就是这个
import java.awt.Point;
import javax.swing.*;
public class Testing extends javax.swing.JFrame {
private int clicX = 0,clicX1 = 0;
private int clicY = 0,clicY1 = 0;
private boolean drag = false,drag1 = false;
public Testing() {
initComponents();
headlabel.setVisible(false);
footlabel.setVisible(false);
}
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
//自动生成的代码
private void initComponents() {
head = new javax.swing.JCheckBox();
jDesktopPane1 = new javax.swing.JDesktopPane();
headlabel = new javax.swing.JLabel();
footlabel = new javax.swing.JLabel();
foot = new javax.swing.JCheckBox();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
head.setText("Head");
head.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
headActionPerformed(evt);
}
}); jDesktopPane1.setBackground(javax.swing.UIManager.getDefaults().getColor("Button.background"));
headlabel.setBackground(new java.awt.Color(255, 255, 255));
headlabel.setFont(new java.awt.Font("Tahoma", 1, 14)); // NOI18N
headlabel.setForeground(new java.awt.Color(255, 255, 255));
headlabel.setText("Heading");
headlabel.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
headlabelMouseClicked(evt);
}
public void mousePressed(java.awt.event.MouseEvent evt) {
headlabelMousePressed(evt);
}
public void mouseReleased(java.awt.event.MouseEvent evt) {
headlabelMouseReleased(evt);
}
});
headlabel.addMouseMotionListener(new java.awt.event.MouseMotionAdapter() {
public void mouseDragged(java.awt.event.MouseEvent evt) {
headlabelMouseDragged(evt);
}
});
headlabel.setBounds(80, 20, 100, 20);
jDesktopPane1.add(headlabel, javax.swing.JLayeredPane.DEFAULT_LAYER);
footlabel.setBackground(new java.awt.Color(255, 255, 255));
footlabel.setFont(new java.awt.Font("Tahoma", 1, 14)); // NOI18N
footlabel.setForeground(new java.awt.Color(255, 255, 255));
footlabel.setText("Foot");
footlabel.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
footlabelMouseClicked(evt);
}
public void mousePressed(java.awt.event.MouseEvent evt) {
footlabelMousePressed(evt);
}
public void mouseReleased(java.awt.event.MouseEvent evt) {
footlabelMouseReleased(evt);
}
});
footlabel.addMouseMotionListener(new java.awt.event.MouseMotionAdapter() {
public void mouseDragged(java.awt.event.MouseEvent evt) {
footlabelMouseDragged(evt);
}
});
footlabel.setBounds(100, 280, 100, 20);
jDesktopPane1.add(footlabel, javax.swing.JLayeredPane.DEFAULT_LAYER);
foot.setText("Foot");
foot.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
footActionPerformed(evt);
}
});
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(head, javax.swing.GroupLayout.PREFERRED_SIZE, 81, javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(foot, javax.swing.GroupLayout.PREFERRED_SIZE, 81, javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 52, Short.MAX_VALUE)
.addComponent(jDesktopPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 264, javax.swing.GroupLayout.PREFERRED_SIZE)
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup()
.addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addComponent(jDesktopPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 305, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addGap(52, 52, 52)
.addComponent(head)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(foot)
.addGap(0, 0, Short.MAX_VALUE)))
.addContainerGap())
);
pack();
}// </editor-fold>
//功能定义
private void headlabelMouseClicked(java.awt.event.MouseEvent evt) {
if (evt.getClickCount() == 2) {
String str = JOptionPane.showInputDialog(null, "Enter text : ", "Enter text", 1);
Point location = headlabel.getLocation();
headlabel.setLocation(location);
headlabel.setText(str);
}
}
private void headlabelMouseReleased(java.awt.event.MouseEvent evt) {
// drag = false;
}
private void headlabelMousePressed(java.awt.event.MouseEvent evt) {
drag = true;
if (evt.getSource() == headlabel) {
}
if (evt.getSource() == headlabel) {
clicX = evt.getX();
clicY = evt.getY();
}
}
private void headlabelMouseDragged(java.awt.event.MouseEvent evt) {
if (evt.getSource() == headlabel) {
javax.swing.JComponent jc = (javax.swing.JComponent)evt.getSource();
jc.setLocation(jc.getX()+evt.getX()-clicX, jc.getY()+evt.getY()-clicY);
}
}
private void headActionPerformed(java.awt.event.ActionEvent evt) {
if (head.isSelected()) {
headlabel.setVisible(true);
} else {
headlabel.setVisible(false);
}
}
private void footlabelMouseClicked(java.awt.event.MouseEvent evt) {
if (evt.getClickCount() == 2) {
String str = JOptionPane.showInputDialog(null, "Enter text : ", "Enter text", 1);
Point location = footlabel.getLocation();
footlabel.setLocation(location);
footlabel.setText(str);
}
}
private void footlabelMousePressed(java.awt.event.MouseEvent evt) {
drag1 = true;
if (evt.getSource() == footlabel) {
}
if (evt.getSource() == footlabel) {
clicX1 = evt.getX();
clicY1 = evt.getY();
}
}
private void footlabelMouseReleased(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
}
private void footlabelMouseDragged(java.awt.event.MouseEvent evt) {
if (evt.getSource() == footlabel) {
javax.swing.JComponent jc = (javax.swing.JComponent)evt.getSource();
jc.setLocation(jc.getX()+evt.getX()-clicX1, jc.getY()+evt.getY()-clicY1);
}
}
private void footActionPerformed(java.awt.event.ActionEvent evt) {
if (foot.isSelected()) {
footlabel.setVisible(true);
} else {
footlabel.setVisible(false);
}
}
public static void main(String args[])
{
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(Testing.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(Testing.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(Testing.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Testing.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Testing().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JCheckBox foot;
private javax.swing.JLabel footlabel;
private javax.swing.JCheckBox head;
private javax.swing.JLabel headlabel;
private javax.swing.JDesktopPane jDesktopPane1;
// End of variables declaration
}
答案 0 :(得分：2)
基本思想是防止组件走出其父边界。因此，在更改标签位置时，在鼠标侦听器/拖动器中，应验证标签的边界是否保留在标签父级的边界内。如果没有，那么你应该“修复”边界，以便标签保持在其父组件的边界内。
这是一个例子（它不使用JDesktopPane，但解决方案应该类似）。它缺少一些小的调整，但它基本上运作良好：
import java.awt.Component;
import java.awt.Point;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingUtilities;
public class TestLimitedDrag {
public static class MouseDragger extends MouseAdapter {
private Point startPoint;
private Component draggedObject;
@Override
public void mousePressed(MouseEvent e) {
draggedObject = (Component) e.getSource();
startPoint = SwingUtilities.convertPoint(draggedObject, e.getPoint(), draggedObject.getParent());
}
@Override
public void mouseDragged(MouseEvent e) {
Point location = SwingUtilities.convertPoint(draggedObject, e.getPoint(), draggedObject.getParent());
if (draggedObject.getParent().getBounds().contains(location)) {
Point newLocation = draggedObject.getLocation();
newLocation.translate(location.x - startPoint.x, location.y - startPoint.y);
newLocation.x = Math.max(newLocation.x, 0);
newLocation.x = Math.min(newLocation.x, draggedObject.getParent().getWidth() - draggedObject.getWidth());
newLocation.y = Math.max(newLocation.y, 0);
newLocation.y = Math.min(newLocation.y, draggedObject.getParent().getHeight() - draggedObject.getHeight());
draggedObject.setLocation(newLocation);
startPoint = location;
}
}
@Override
public void mouseReleased(MouseEvent e) {
startPoint = null;
draggedObject = null;
}
public void makeDraggable(Component component) {
component.addMouseListener(this);
component.addMouseMotionListener(this);
}
}
private void initUI() {
JFrame frame = new JFrame(TestLimitedDrag.class.getSimpleName());
frame.setLayout(null);
MouseDragger dragger = new MouseDragger();
JLabel labelToDrag = new JLabel("Drag me");
dragger.makeDraggable(labelToDrag);
frame.add(labelToDrag);
labelToDrag.setSize(labelToDrag.getPreferredSize());
labelToDrag.setLocation(50, 50);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setSize(300, 300);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
new TestLimitedDrag().initUI();
}
});
}
}