为JComboBox提供水平滚动条的便携方式

Question

从Coderanch和Sun Forum我知道为JComboBox提供水平滚动条的技术。

然而，他们建议的解决方案是有界的，看起来特别的感觉。

正如您所看到的，如果用户在Linux机器上使用GTK +看起来感觉，或者具有Nimbus外观的Windows机器，下面的关键代码片段将不能很好地工作。

我怎么能有一个便携的方式，使JComboBox能够有一个水平滚动条？

完整的源代码是AutoCompleteJComboBox.java

的关键代码片段如下：

package org.yccheok.jstock.gui; 

public class AutoCompleteJComboBox extends JComboBox { 

    @Override 
    public void setUI(ComboBoxUI ui) 
    { 
     if (ui != null) 
     { 
      // Let's try our own customized UI. 
      Class c = ui.getClass(); 
      final String myClass = "org.yccheok.jstock.gui.AutoCompleteJComboBox$My" + c.getSimpleName(); 

      try { 
       ComboBoxUI myUI = (ComboBoxUI) Class.forName(myClass).newInstance(); 
       super.setUI(myUI); 
       return; 
      } catch (ClassNotFoundException ex) { 
       log.error(null, ex); 
      } catch (InstantiationException ex) { 
       log.error(null, ex); 
      } catch (IllegalAccessException ex) { 
       log.error(null, ex); 
      } 
     } 

     // Either null, or we fail to use our own customized UI. 
     // Fall back to default. 
     super.setUI(ui); 
    } 

    // This is a non-portable method to make combo box horizontal scroll bar. 
    // Whenever there is a new look-n-feel, we need to manually provide the ComboBoxUI. 
    // Any idea on how to make this portable? 
    // 
    protected static class MyWindowsComboBoxUI extends com.sun.java.swing.plaf.windows.WindowsComboBoxUI 
    { 
     @Override 
     protected ComboPopup createPopup() 
     { 
      return new MyComboPopup(comboBox); 
     } 
    } 

    protected static class MyMotifComboBoxUI extends com.sun.java.swing.plaf.motif.MotifComboBoxUI 
    { 
     @Override 
     protected ComboPopup createPopup() 
     { 
      return new MyComboPopup(comboBox); 
     } 
    } 

    protected static class MyMetalComboBoxUI extends javax.swing.plaf.metal.MetalComboBoxUI 
    { 
     @Override 
     protected ComboPopup createPopup() 
     { 
      return new MyComboPopup(comboBox); 
     } 
    } 

    private static class MyComboPopup extends BasicComboPopup 
    { 
     public MyComboPopup(JComboBox combo) 
     { 
      super(combo); 
     } 

     @Override 
     public JScrollPane createScroller() 
     { 
      return new JScrollPane(list,JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, 
        JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED); 
     } 
    } 
} 

Answer 1

我得到了通过下面的论坛解决我的问题 Oracle Java Swing Forum