我看这个问题之前问过：
JSplitPane setOneTouchExpandable(true) 未显示
我测试了我的代码，但是当 LookAndFeel 是 Motif 时，我无法拖动 JSplitPane。
public class JFr_SplitPaneMotif extends JFrame {
private JButton jbRight = new JButton();
private JLabel jlLeft = new JLabel();
private JPanel jpLeft = new JPanel();
private JPanel jpRight = new JPanel();
private JPanel jpMain = new JPanel();
private JSplitPane jspMain = new JSplitPane();
private JTextField jtfLeft = new JTextField();
private JTextField jtfRight = new JTextField();
public JFr_SplitPaneMotif() {
setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
jpMain.setBorder(BorderFactory.createEtchedBorder());
jpMain.setPreferredSize(new Dimension(692, 36));
jspMain.setDividerLocation(0.5);
jspMain.setOneTouchExpandable(true);
jspMain.setPreferredSize(new Dimension(338, 30));
jlLeft.setBorder(BorderFactory.createEtchedBorder());
jpLeft.setPreferredSize(new Dimension(320, 25));
jlLeft.setPreferredSize(new Dimension(24, 18));
jtfLeft.setPreferredSize(new Dimension(6, 25));
jpRight.setPreferredSize(new Dimension(320, 25));
jbRight.setPreferredSize(new Dimension(24, 18));
jbRight.setMinimumSize(new Dimension(24, 18)); /*Why is smaller?*/
jtfRight.setPreferredSize(new Dimension(6, 25));
GroupLayout jpLeftLayout = new GroupLayout(jpLeft);
jpLeft.setLayout(jpLeftLayout);
jpLeftLayout.setHorizontalGroup(
jpLeftLayout.createParallelGroup(Alignment.LEADING)
.addGroup(jpLeftLayout.createSequentialGroup()
.addGap(4, 4, 4)
.addComponent(jlLeft, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
.addGap(2, 2, 2)
.addComponent(jtfLeft, GroupLayout.DEFAULT_SIZE, GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addContainerGap())
);
jpLeftLayout.setVerticalGroup(
jpLeftLayout.createParallelGroup(Alignment.LEADING)
.addGroup(jpLeftLayout.createSequentialGroup()
.addGap(3, 3, 3)
.addComponent(jlLeft, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
.addContainerGap(GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE))
.addComponent(jtfLeft, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
);
jspMain.setLeftComponent(jpLeft);
GroupLayout jpRightLayout = new GroupLayout(jpRight);
jpRight.setLayout(jpRightLayout);
jpRightLayout.setHorizontalGroup(
jpRightLayout.createParallelGroup(Alignment.LEADING)
.addGroup(jpRightLayout.createSequentialGroup()
.addGap(4, 4, 4)
.addComponent(jbRight, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
.addGap(2, 2, 2)
.addComponent(jtfRight, GroupLayout.DEFAULT_SIZE, GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addContainerGap())
);
jpRightLayout.setVerticalGroup(
jpRightLayout.createParallelGroup(Alignment.LEADING)
.addGroup(jpRightLayout.createParallelGroup(Alignment.CENTER)
.addComponent(jbRight, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
.addComponent(jtfRight, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE))
);
jspMain.setRightComponent(jpRight);
GroupLayout jpMainLayout = new GroupLayout(jpMain);
jpMain.setLayout(jpMainLayout);
jpMainLayout.setHorizontalGroup(
jpMainLayout.createParallelGroup(Alignment.LEADING)
.addComponent(jspMain, Alignment.TRAILING, GroupLayout.DEFAULT_SIZE, GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);
jpMainLayout.setVerticalGroup(
jpMainLayout.createParallelGroup(Alignment.LEADING)
.addGroup(Alignment.TRAILING, jpMainLayout.createSequentialGroup()
.addGap(0, 0, 0)
.addComponent(jspMain, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE))
);
GroupLayout layout = new GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(Alignment.LEADING)
.addGap(0, 702, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(Alignment.LEADING)
.addGroup(Alignment.TRAILING, layout.createSequentialGroup()
.addGap(0, 0, 0)
.addComponent(jpMain, GroupLayout.DEFAULT_SIZE, GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addContainerGap()))
);
layout.setVerticalGroup(
layout.createParallelGroup(Alignment.LEADING)
.addGap(0, 54, Short.MAX_VALUE)
.addGroup(layout.createParallelGroup(Alignment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGap(0, 0, 0)
.addComponent(jpMain, GroupLayout.PREFERRED_SIZE, GroupLayout.DEFAULT_SIZE, GroupLayout.PREFERRED_SIZE)
.addContainerGap(GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)))
);
pack();
}
public static void main(String args[]) {
try {
UIManager.setLookAndFeel("com.sun.java.swing.plaf.motif.MotifLookAndFeel");
} catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
}
EventQueue.invokeLater(new Runnable() {
public void run() {
new JFr_SplitPaneMotif().setVisible(true);
}
});
}
}
我正在测试，我有我的图像：
Linux：
苹果电脑：
视窗：
问题：
如何减小 JSplitPane 的（左右）“三角形”的大小？
为什么JButton 不保留preferredSise？