e755. customizing the icons in a jcheckbox component.txt

这里面包含了一百多个JAVA源文件

The icons used to depict the selected state of a checkbox component can be customized. The simplest customization requires two icons, one to depict the selected state and one to depict the unselected state. 
    // Set the unselected state icon
    Icon unselIcon = new ImageIcon("nosel-icon.gif");
    checkbox.setIcon(unselIcon);
    
    // Set the selected state icon
    Icon selIcon = new ImageIcon("sel-icon.gif");
    checkbox.setSelectedIcon(selIcon);

If the checkbox is disabled, grayed out icons are automatically generated for the customized icons. Here's how to customize these disabled icons: 
    // Set the unselected state icon
    Icon unselDisIcon = new ImageIcon("nosel-dis-icon.gif");
    checkbox.setDisabledIcon(unselDisIcon);
    
    // Set the selected state icon
    Icon selDisIcon = new ImageIcon("sel-dis-icon.gif");
    checkbox.setDisabledSelectedIcon(selDisIcon);

By default, when the user clicks on a checkbox, the pressed icon (if set) is displayed. Here's how to set it: 
    Icon pressedIcon = new ImageIcon("pres-icon.gif");
    checkbox.setPressedIcon(pressedIcon);

Finally, it is possible to display an icon when the cursor is moved over the checkbox. This is called the rollover icon. 
    Icon rollIcon = new ImageIcon("roll-icon.gif");
    checkbox.setRolloverIcon(rollIcon);