声明:本文章中介绍的内容可以在GPF项目中找到相应的实现。
GPF计划使用MDI的处理模式,Java的JDesktopPane和JInternalFrame已经为我们实现了这样的功能。但是,在将JInternalFrame最大化的时候,JDesktopPane和我们熟知的其他软件,如Word等,具有不同的处理方式。此时可以通过这里介绍的内容弥补这一缺点,使Swing的程序更类似于本地实现。
首先先看一下怎么使用JDesktopPane和JInternalFrame实现MDI。其实实现的方式很简单,就是在一个窗口中添加JDesktopPane,然后使用JDesktopPane的add方法,添加JInternalFrame的实例即可。具体的代码片段如下所示:
//...
final JDesktopPane desktopPane = new JDesktopPane();
//...
Container content = getContentPane();
content.add(desktopPane, BorderLayout.CENTER);
//...
InnerFrame iFrame = new InnerFrame();
iFrame.setVisible( true);
desktopPane.add(iFrame);
//...
final JDesktopPane desktopPane = new JDesktopPane();
//...
Container content = getContentPane();
content.add(desktopPane, BorderLayout.CENTER);
//...
InnerFrame iFrame = new InnerFrame();
iFrame.setVisible( true);
desktopPane.add(iFrame);
//...
由此即可按照Java提供的方式添加MDI的实现。我们可以看到它的运行截图如下所示:
可以看到,当JInternalFrame最大化的时候,仅仅是充满了整个JDesktopPane,并不会像一般的MDI程序一样,将最大化最小化的按钮显示在菜单栏。这是因为JInternalFrame是一个轻量级组件,必须依附在容器之中,因此它的大小不可能超出JDesktopPane。为了获得我们想要的效果,我们对JInternalFrame的UI进行改写:
class InnerFrame
extends JInternalFrame {
/** The is hidden. */
boolean isHidden = false;
/** The old ui. */
BasicInternalFrameUI oldUi = null;
/**
* Instantiates a new inner frame.
*/
public InnerFrame() {
oldUi = (BasicInternalFrameUI)getUI();
setSize(200, 200);
maximizable = true;
closable = true;
addComponentListener( new ComponentAdapter() {
public void componentResized(ComponentEvent e) {
InnerFrame selectedFrame = (InnerFrame)e.getSource();
if(selectedFrame.isMaximum()){
selectedFrame.hideNorthPanel();
opPane.setVisible( true);
try {
selectedFrame.setMaximum( true);
} catch (PropertyVetoException ex) {
ex.printStackTrace();
}
}
}
});
}
/**
* Hide north panel.
*/
public void hideNorthPanel(){
((BasicInternalFrameUI) this.getUI()).setNorthPane( null);
this.putClientProperty( "JInternalFrame.isPalette", Boolean.TRUE);
isHidden = true;
}
/**
* Show north panel.
*/
public void showNorthPanel() {
this.setUI(oldUi);
this.putClientProperty( "JInternalFrame.isPalette", Boolean.FALSE);
isHidden = false;
}
/* (non-Javadoc)
* @see javax.swing.JInternalFrame#updateUI()
*/
public void updateUI() {
super.updateUI();
if (isHidden) {
hideNorthPanel();
}
}
/** The is hidden. */
boolean isHidden = false;
/** The old ui. */
BasicInternalFrameUI oldUi = null;
/**
* Instantiates a new inner frame.
*/
public InnerFrame() {
oldUi = (BasicInternalFrameUI)getUI();
setSize(200, 200);
maximizable = true;
closable = true;
addComponentListener( new ComponentAdapter() {
public void componentResized(ComponentEvent e) {
InnerFrame selectedFrame = (InnerFrame)e.getSource();
if(selectedFrame.isMaximum()){
selectedFrame.hideNorthPanel();
opPane.setVisible( true);
try {
selectedFrame.setMaximum( true);
} catch (PropertyVetoException ex) {
ex.printStackTrace();
}
}
}
});
}
/**
* Hide north panel.
*/
public void hideNorthPanel(){
((BasicInternalFrameUI) this.getUI()).setNorthPane( null);
this.putClientProperty( "JInternalFrame.isPalette", Boolean.TRUE);
isHidden = true;
}
/**
* Show north panel.
*/
public void showNorthPanel() {
this.setUI(oldUi);
this.putClientProperty( "JInternalFrame.isPalette", Boolean.FALSE);
isHidden = false;
}
/* (non-Javadoc)
* @see javax.swing.JInternalFrame#updateUI()
*/
public void updateUI() {
super.updateUI();
if (isHidden) {
hideNorthPanel();
}
}
}
InnerFrame类继承自JInternalFrame,由于JInternalFrame没有对于窗口最大化事件的监听。所以,我们把它添加了一个ComponentListener。当组件大小改变时,调用componentResized方法,然后在这里判断如果组件大小是isMaximum()的,则将NorthPane隐藏掉。这里的JInternalFrame的NorthPane就是绘有关闭按钮的那一条面板。由于定义了hideNorthPane()和showNorthPane()这两个方法,是得我们对于InnerFrame的控制加强了。
修改后的完整代码如下所示:
import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.beans.PropertyVetoException;
import javax.swing.JButton;
import javax.swing.JDesktopPane;
import javax.swing.JFrame;
import javax.swing.JInternalFrame;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.plaf.basic.BasicInternalFrameUI;
/**
* MDIFrame is a frame using JInternalFrame to implements MDI as Word on Windows.
*
* @author Cheng
* @version 1.0.0 for GPF MDI test
*/
@SuppressWarnings( "serial")
public class MDIFrame extends JFrame {
/** The desktop pane. */
final JDesktopPane desktopPane = new JDesktopPane();
/** The operation pane with restore and close buttons. */
final JPanel opPane = new JPanel();
/**
* Instantiates a new mDI frame.
*/
public MDIFrame(){
setTitle( "MDI Frame");
setSize(600, 550);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final JMenuBar bar = new JMenuBar();
JMenuItem exit = new JMenuItem( "Exit");
exit.addActionListener( new ActionListener(){
@Override
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
});
bar.add(exit);
// operation pane with two button, set invisible at first
opPane.setLayout( new FlowLayout(FlowLayout.TRAILING));
JButton restore = new JButton( "#");
restore.setMargin( new Insets(0, 0, 0, 0));
restore.setPreferredSize( new Dimension(15, 15));
restore.addActionListener( new ActionListener(){
@Override
public void actionPerformed(ActionEvent e) {
InnerFrame i = (InnerFrame)desktopPane.getSelectedFrame();
try {
// notice this method, when JInternalFrame set maximun false
// this internal frame will be set as old size
i.setMaximum( false);
} catch (PropertyVetoException ex) {
ex.printStackTrace();
}
i.showNorthPanel();
opPane.setVisible( false);
}
});
opPane.add(restore);
JButton close = new JButton( "X");
close.setMargin( new Insets(0, 0, 0, 0));
close.setPreferredSize( new Dimension(15, 15));
close.addActionListener( new ActionListener(){
@Override
public void actionPerformed(ActionEvent e) {
JInternalFrame i = desktopPane.getSelectedFrame();
i.dispose();
opPane.setVisible( false);
}
});
opPane.add(close);
bar.add(opPane);
opPane.setVisible( false);
setJMenuBar(bar);
Container content = getContentPane();
content.add(desktopPane, BorderLayout.CENTER);
final JPanel ctrlPane = new JPanel();
JButton add = new JButton( "add");
add.addActionListener( new ActionListener(){
@Override
public void actionPerformed(ActionEvent e) {
InnerFrame iFrame = new InnerFrame();
iFrame.setVisible( true);
desktopPane.add(iFrame);
}
});
ctrlPane.add(add);
content.add(ctrlPane, BorderLayout.SOUTH);
setVisible( true);
}
/**
* The Class InnerFrame.
*/
class InnerFrame extends JInternalFrame {
/** The is hidden. */
boolean isHidden = false;
/** The old ui. */
BasicInternalFrameUI oldUi = null;
/**
* Instantiates a new inner frame.
*/
public InnerFrame() {
oldUi = (BasicInternalFrameUI)getUI();
setSize(200, 200);
maximizable = true;
closable = true;
addComponentListener( new ComponentAdapter() {
public void componentResized(ComponentEvent e) {
InnerFrame selectedFrame = (InnerFrame)e.getSource();
if(selectedFrame.isMaximum()){
selectedFrame.hideNorthPanel();
opPane.setVisible( true);
try {
selectedFrame.setMaximum( true);
} catch (PropertyVetoException ex) {
ex.printStackTrace();
}
}
}
});
}
/**
* Hide north panel.
*/
public void hideNorthPanel(){
((BasicInternalFrameUI) this.getUI()).setNorthPane( null);
this.putClientProperty( "JInternalFrame.isPalette", Boolean.TRUE);
isHidden = true;
}
/**
* Show north panel.
*/
public void showNorthPanel() {
this.setUI(oldUi);
this.putClientProperty( "JInternalFrame.isPalette", Boolean.FALSE);
isHidden = false;
}
/* (non-Javadoc)
* @see javax.swing.JInternalFrame#updateUI()
*/
public void updateUI() {
super.updateUI();
if (isHidden) {
hideNorthPanel();
}
}
}
/**
* The main method.
*
* @param args the arguments
*/
public static void main(String[] args) {
SwingUtilities.invokeLater( new Runnable(){
@Override
public void run() {
new MDIFrame();
}
});
}
}
import java.awt.Container;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;
import java.beans.PropertyVetoException;
import javax.swing.JButton;
import javax.swing.JDesktopPane;
import javax.swing.JFrame;
import javax.swing.JInternalFrame;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.SwingUtilities;
import javax.swing.plaf.basic.BasicInternalFrameUI;
/**
* MDIFrame is a frame using JInternalFrame to implements MDI as Word on Windows.
*
* @author Cheng
* @version 1.0.0 for GPF MDI test
*/
@SuppressWarnings( "serial")
public class MDIFrame extends JFrame {
/** The desktop pane. */
final JDesktopPane desktopPane = new JDesktopPane();
/** The operation pane with restore and close buttons. */
final JPanel opPane = new JPanel();
/**
* Instantiates a new mDI frame.
*/
public MDIFrame(){
setTitle( "MDI Frame");
setSize(600, 550);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final JMenuBar bar = new JMenuBar();
JMenuItem exit = new JMenuItem( "Exit");
exit.addActionListener( new ActionListener(){
@Override
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
});
bar.add(exit);
// operation pane with two button, set invisible at first
opPane.setLayout( new FlowLayout(FlowLayout.TRAILING));
JButton restore = new JButton( "#");
restore.setMargin( new Insets(0, 0, 0, 0));
restore.setPreferredSize( new Dimension(15, 15));
restore.addActionListener( new ActionListener(){
@Override
public void actionPerformed(ActionEvent e) {
InnerFrame i = (InnerFrame)desktopPane.getSelectedFrame();
try {
// notice this method, when JInternalFrame set maximun false
// this internal frame will be set as old size
i.setMaximum( false);
} catch (PropertyVetoException ex) {
ex.printStackTrace();
}
i.showNorthPanel();
opPane.setVisible( false);
}
});
opPane.add(restore);
JButton close = new JButton( "X");
close.setMargin( new Insets(0, 0, 0, 0));
close.setPreferredSize( new Dimension(15, 15));
close.addActionListener( new ActionListener(){
@Override
public void actionPerformed(ActionEvent e) {
JInternalFrame i = desktopPane.getSelectedFrame();
i.dispose();
opPane.setVisible( false);
}
});
opPane.add(close);
bar.add(opPane);
opPane.setVisible( false);
setJMenuBar(bar);
Container content = getContentPane();
content.add(desktopPane, BorderLayout.CENTER);
final JPanel ctrlPane = new JPanel();
JButton add = new JButton( "add");
add.addActionListener( new ActionListener(){
@Override
public void actionPerformed(ActionEvent e) {
InnerFrame iFrame = new InnerFrame();
iFrame.setVisible( true);
desktopPane.add(iFrame);
}
});
ctrlPane.add(add);
content.add(ctrlPane, BorderLayout.SOUTH);
setVisible( true);
}
/**
* The Class InnerFrame.
*/
class InnerFrame extends JInternalFrame {
/** The is hidden. */
boolean isHidden = false;
/** The old ui. */
BasicInternalFrameUI oldUi = null;
/**
* Instantiates a new inner frame.
*/
public InnerFrame() {
oldUi = (BasicInternalFrameUI)getUI();
setSize(200, 200);
maximizable = true;
closable = true;
addComponentListener( new ComponentAdapter() {
public void componentResized(ComponentEvent e) {
InnerFrame selectedFrame = (InnerFrame)e.getSource();
if(selectedFrame.isMaximum()){
selectedFrame.hideNorthPanel();
opPane.setVisible( true);
try {
selectedFrame.setMaximum( true);
} catch (PropertyVetoException ex) {
ex.printStackTrace();
}
}
}
});
}
/**
* Hide north panel.
*/
public void hideNorthPanel(){
((BasicInternalFrameUI) this.getUI()).setNorthPane( null);
this.putClientProperty( "JInternalFrame.isPalette", Boolean.TRUE);
isHidden = true;
}
/**
* Show north panel.
*/
public void showNorthPanel() {
this.setUI(oldUi);
this.putClientProperty( "JInternalFrame.isPalette", Boolean.FALSE);
isHidden = false;
}
/* (non-Javadoc)
* @see javax.swing.JInternalFrame#updateUI()
*/
public void updateUI() {
super.updateUI();
if (isHidden) {
hideNorthPanel();
}
}
}
/**
* The main method.
*
* @param args the arguments
*/
public static void main(String[] args) {
SwingUtilities.invokeLater( new Runnable(){
@Override
public void run() {
new MDIFrame();
}
});
}
}
修改之后的最大化可以是如图样子:
当然,按钮之类的很难看,不过修改那个的话就是很容易的了,在这里不再赘述。
本程序代码在Java 6 下编译通过。由于Java文件不允许上传,所以将后缀名改为txt,编译时请将文件名改为MDIFrame.java即可。