* Either isSelected/setSelected or
* getState/setState can be used
* to determine/specify the menu item's selection state. The
* preferred methods are isSelected and
* setSelected, which work for all menus and buttons.
* The getState and setState methods exist for
* compatibility with other component sets.
*
* Menu items can be configured, and to some degree controlled, by
* Actions. Using an
* Action with a menu item has many benefits beyond directly
* configuring a menu item. Refer to
* Swing Components Supporting Action for more
* details, and you can find more information in How
* to Use Actions, a section in The Java Tutorial.
*
* For further information and examples of using check box menu items, * see How to Use Menus, * a section in The Java Tutorial. *
* Warning: Swing is not thread safe. For more * information see Swing's Threading * Policy. *
* Warning:
* Serialized objects of this class will not be compatible with
* future Swing releases. The current serialization support is
* appropriate for short term storage or RMI between applications running
* the same version of Swing. As of 1.4, support for long term storage
* of all JavaBeansTM
* has been added to the java.beans package.
* Please see {@link java.beans.XMLEncoder}.
*
* @beaninfo
* attribute: isContainer false
* description: A menu item which can be selected or deselected.
*
* @author Georges Saab
* @author David Karlton
*/
public class JCheckBoxMenuItem extends JMenuItem implements SwingConstants,
Accessible
{
/**
* @see #getUIClassID
* @see #readObject
*/
private static final String uiClassID = "CheckBoxMenuItemUI";
/**
* Creates an initially unselected check box menu item with no set text or icon.
*/
public JCheckBoxMenuItem() {
this(null, null, false);
}
/**
* Creates an initially unselected check box menu item with an icon.
*
* @param icon the icon of the CheckBoxMenuItem.
*/
public JCheckBoxMenuItem(Icon icon) {
this(null, icon, false);
}
/**
* Creates an initially unselected check box menu item with text.
*
* @param text the text of the CheckBoxMenuItem
*/
public JCheckBoxMenuItem(String text) {
this(text, null, false);
}
/**
* Creates a menu item whose properties are taken from the
* Action supplied.
*
* @since 1.3
*/
public JCheckBoxMenuItem(Action a) {
this();
setAction(a);
}
/**
* Creates an initially unselected check box menu item with the specified text and icon.
*
* @param text the text of the CheckBoxMenuItem
* @param icon the icon of the CheckBoxMenuItem
*/
public JCheckBoxMenuItem(String text, Icon icon) {
this(text, icon, false);
}
/**
* Creates a check box menu item with the specified text and selection state.
*
* @param text the text of the check box menu item.
* @param b the selected state of the check box menu item
*/
public JCheckBoxMenuItem(String text, boolean b) {
this(text, null, b);
}
/**
* Creates a check box menu item with the specified text, icon, and selection state.
*
* @param text the text of the check box menu item
* @param icon the icon of the check box menu item
* @param b the selected state of the check box menu item
*/
public JCheckBoxMenuItem(String text, Icon icon, boolean b) {
super(text, icon);
setModel(new JToggleButton.ToggleButtonModel());
setSelected(b);
setFocusable(false);
}
/**
* Returns the name of the L&F class
* that renders this component.
*
* @return "CheckBoxMenuItemUI"
* @see JComponent#getUIClassID
* @see UIDefaults#getUI
*/
public String getUIClassID() {
return uiClassID;
}
/**
* Returns the selected-state of the item. This method
* exists for AWT compatibility only. New code should
* use isSelected() instead.
*
* @return true if the item is selected
*/
public boolean getState() {
return isSelected();
}
/**
* Sets the selected-state of the item. This method
* exists for AWT compatibility only. New code should
* use setSelected() instead.
*
* @param b a boolean value indicating the item's
* selected-state, where true=selected
* @beaninfo
* description: The selection state of the check box menu item
* hidden: true
*/
public synchronized void setState(boolean b) {
setSelected(b);
}
/**
* Returns an array (length 1) containing the check box menu item
* label or null if the check box is not selected.
*
* @return an array containing one Object -- the text of the menu item
* -- if the item is selected; otherwise null
*/
public Object[] getSelectedObjects() {
if (isSelected() == false)
return null;
Object[] selectedObjects = new Object[1];
selectedObjects[0] = getText();
return selectedObjects;
}
/**
* See readObject() and writeObject() in JComponent for more
* information about serialization in Swing.
*/
private void writeObject(ObjectOutputStream s) throws IOException {
s.defaultWriteObject();
if (getUIClassID().equals(uiClassID)) {
byte count = JComponent.getWriteObjCounter(this);
JComponent.setWriteObjCounter(this, --count);
if (count == 0 && ui != null) {
ui.installUI(this);
}
}
}
/**
* Returns a string representation of this JCheckBoxMenuItem. This method
* is intended to be used only for debugging purposes, and the
* content and format of the returned string may vary between
* implementations. The returned string may be empty but may not
* be null.
*
* @return a string representation of this JCheckBoxMenuItem.
*/
protected String paramString() {
return super.paramString();
}
/**
* Overriden to return true, JCheckBoxMenuItem supports
* the selected state.
*/
boolean shouldUpdateSelectedStateFromAction() {
return true;
}
/////////////////
// Accessibility support
////////////////
/**
* Gets the AccessibleContext associated with this JCheckBoxMenuItem.
* For JCheckBoxMenuItems, the AccessibleContext takes the form of an
* AccessibleJCheckBoxMenuItem.
* A new AccessibleJCheckBoxMenuItem instance is created if necessary.
*
* @return an AccessibleJCheckBoxMenuItem that serves as the
* AccessibleContext of this AccessibleJCheckBoxMenuItem
*/
public AccessibleContext getAccessibleContext() {
if (accessibleContext == null) {
accessibleContext = new AccessibleJCheckBoxMenuItem();
}
return accessibleContext;
}
/**
* This class implements accessibility support for the
* JCheckBoxMenuItem class. It provides an implementation
* of the Java Accessibility API appropriate to checkbox menu item
* user-interface elements.
*
* Warning:
* Serialized objects of this class will not be compatible with
* future Swing releases. The current serialization support is
* appropriate for short term storage or RMI between applications running
* the same version of Swing. As of 1.4, support for long term storage
* of all JavaBeansTM
* has been added to the java.beans package.
* Please see {@link java.beans.XMLEncoder}.
*/
protected class AccessibleJCheckBoxMenuItem extends AccessibleJMenuItem {
/**
* Get the role of this object.
*
* @return an instance of AccessibleRole describing the role of the
* object
*/
public AccessibleRole getAccessibleRole() {
return AccessibleRole.CHECK_BOX;
}
} // inner class AccessibleJCheckBoxMenuItem
}