JSplitPane类测试实例
package swing;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import java.util.*;
/**
*JSplitPane 用于分隔两个（只能两个）Component。
*本程序是JSplitPane的一个测试例子
* @author oucq
*
*/
public class SplitPaneDemo extends JPanel
implements ListSelectionListener {
private JLabel picture;
private JList list;
private JSplitPane splitPane;
//图片名称信息
private String[] imageNames = { "Bird", "Cat", "Dog", "Rabbit", "Pig", "dukeWaveRed",
"kathyCosmo", "lainesTongue", "left", "middle", "right", "stickerface"};
public SplitPaneDemo() {
//创建一个图片列表，放到滚动面板中
list = new JList(imageNames);
list.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
list.setSelectedIndex(0);
list.addListSelectionListener(this);
//创建一个显示指定组件内容的 JScrollPane，只要组件的内容超过视图大小就会显示水平和垂直滚动条。
JScrollPane listScrollPane = new JScrollPane(list);
picture = new JLabel();
/*
* deriveFont:通过复制当前的 Font 对象，并应用新的样式，创建一个新 Font 对象。
* Font.ITALIC:新 Font 的样式
*/
picture.setFont(picture.getFont().deriveFont(Font.ITALIC));
//设置标签内容沿 X 轴的对齐方式。
picture.setHorizontalAlignment(JLabel.CENTER);
JScrollPane pictureScrollPane = new JScrollPane(picture);
//创建一个水平方向（沿 x 轴分割） 的JSplitPane对象，用于分割上面创建的两个滚动面板
splitPane = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT,
listScrollPane, pictureScrollPane);
//设置 oneTouchExpandable 属性的值，要使 JSplitPane 在分隔条上提供一个 UI 小部件来快速展开/折叠分隔条，此属性必须为 true
splitPane.setOneTouchExpandable(true);
//设置分隔条的位置
splitPane.setDividerLocation(150);
//Dimension 类封装单个对象中组件的宽度和高度（精确到整数）。该类与组件的某个属性关联。由 Component 类和 LayoutManager
//Provide minimum sizes for the two SplitPaneDemo in the split pane.
Dimension minimumSize = new Dimension(100, 50);
//将此组件的最低大小设置为一个常量值
listScrollPane.setMinimumSize(minimumSize);
pictureScrollPane.setMinimumSize(minimumSize);
//Provide a preferred size for the split pane.
splitPane.setPreferredSize(new Dimension(400, 200));
//显示选中图片
updateLabel(imageNames[list.getSelectedIndex()]);
}
//监听列表变化Listens to the list
public void valueChanged(ListSelectionEvent e) {
JList list = (JList)e.getSource();
updateLabel(imageNames[list.getSelectedIndex()]);
}
//在右边滚动面板的label中显示选择的图片Renders the selected image
protected void updateLabel (String name) {
ImageIcon icon = createImageIcon("images/" + name + ".gif");
picture.setIcon(icon);
if (icon != null) {
picture.setText(null);
} else {
picture.setText("Image not found");
}
}
//Used by SplitPaneDemo2
public JList getImageList() {
return list;
}
public JSplitPane getSplitPane() {
return splitPane;
}
/** Returns an ImageIcon, or null if the path was invalid. */
//在本类所在目录寻找指定路径的图片，找不到就返回null
protected static ImageIcon createImageIcon(String path) {
java.net.URL imgURL = SplitPaneDemo.class.getResource(path);
if (imgURL != null) {
return new ImageIcon(imgURL);
} else {
System.err.println("Couldn't find file: " + path);
return null;
}
}
/**
* Create the GUI and show it. For thread safety,
* this method should be invoked from the
* event-dispatching thread.
*/
private static void createAndShowGUI() {
//Create and set up the window.
JFrame frame = new JFrame("SplitPaneDemo");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
SplitPaneDemo splitPaneDemo = new SplitPaneDemo();
frame.getContentPane().add(splitPaneDemo.getSplitPane());
//Display the window.
frame.pack();
frame.setVisible(true);
}
public static void main(String[] args) {
//Schedule a job for the event-dispatching thread:
//creating and showing this application's GUI.
javax.swing.SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGUI();
}
});
}
}