* Buttons can be configured, and to some degree controlled, by
* Actions. Using an
* Action with a button has many benefits beyond directly
* configuring a button. 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.
*
* 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 JavaBeans™
* has been added to the java.beans package.
* Please see {@link java.beans.XMLEncoder}.
*
* @see JRadioButton
*
* @beaninfo
* attribute: isContainer false
* description: A component which can be selected or deselected.
*
* @author Jeff Dinkins
*/
public class JCheckBox extends JToggleButton implements Accessible {
/** Identifies a change to the flat property. */
public static final String BORDER_PAINTED_FLAT_CHANGED_PROPERTY = "borderPaintedFlat";
private boolean flat = false;
/**
* @see #getUIClassID
* @see #readObject
*/
private static final String uiClassID = "CheckBoxUI";
/**
* Creates an initially unselected check box button with no text, no icon.
*/
public JCheckBox () {
this(null, null, false);
}
/**
* Creates an initially unselected check box with an icon.
*
* @param icon the Icon image to display
*/
public JCheckBox(Icon icon) {
this(null, icon, false);
}
/**
* Creates a check box with an icon and specifies whether
* or not it is initially selected.
*
* @param icon the Icon image to display
* @param selected a boolean value indicating the initial selection
* state. If true the check box is selected
*/
public JCheckBox(Icon icon, boolean selected) {
this(null, icon, selected);
}
/**
* Creates an initially unselected check box with text.
*
* @param text the text of the check box.
*/
public JCheckBox (String text) {
this(text, null, false);
}
/**
* Creates a check box where properties are taken from the
* Action supplied.
*
* @since 1.3
*/
public JCheckBox(Action a) {
this();
setAction(a);
}
/**
* Creates a check box with text and specifies whether
* or not it is initially selected.
*
* @param text the text of the check box.
* @param selected a boolean value indicating the initial selection
* state. If true the check box is selected
*/
public JCheckBox (String text, boolean selected) {
this(text, null, selected);
}
/**
* Creates an initially unselected check box with
* the specified text and icon.
*
* @param text the text of the check box.
* @param icon the Icon image to display
*/
public JCheckBox(String text, Icon icon) {
this(text, icon, false);
}
/**
* Creates a check box with text and icon,
* and specifies whether or not it is initially selected.
*
* @param text the text of the check box.
* @param icon the Icon image to display
* @param selected a boolean value indicating the initial selection
* state. If true the check box is selected
*/
public JCheckBox (String text, Icon icon, boolean selected) {
super(text, icon, selected);
setUIProperty("borderPainted", Boolean.FALSE);
setHorizontalAlignment(LEADING);
}
/**
* Sets the borderPaintedFlat property,
* which gives a hint to the look and feel as to the
* appearance of the check box border.
* This is usually set to true when a
* JCheckBox instance is used as a
* renderer in a component such as a JTable or
* JTree. The default value for the
* borderPaintedFlat property is false.
* This method fires a property changed event.
* Some look and feels might not implement flat borders;
* they will ignore this property.
*
* @param b true requests that the border be painted flat;
* false requests normal borders
* @see #isBorderPaintedFlat
* @beaninfo
* bound: true
* attribute: visualUpdate true
* description: Whether the border is painted flat.
* @since 1.3
*/
public void setBorderPaintedFlat(boolean b) {
boolean oldValue = flat;
flat = b;
firePropertyChange(BORDER_PAINTED_FLAT_CHANGED_PROPERTY, oldValue, flat);
if (b != oldValue) {
revalidate();
repaint();
}
}
/**
* Gets the value of the borderPaintedFlat property.
*
* @return the value of the borderPaintedFlat property
* @see #setBorderPaintedFlat
* @since 1.3
*/
public boolean isBorderPaintedFlat() {
return flat;
}
/**
* Resets the UI property to a value from the current look and feel.
*
* @see JComponent#updateUI
*/
public void updateUI() {
setUI((ButtonUI)UIManager.getUI(this));
}
/**
* Returns a string that specifies the name of the L&F class
* that renders this component.
*
* @return the string "CheckBoxUI"
* @see JComponent#getUIClassID
* @see UIDefaults#getUI
* @beaninfo
* expert: true
* description: A string that specifies the name of the L&F class
*/
public String getUIClassID() {
return uiClassID;
}
/**
* The icon for checkboxs comes from the look and feel,
* not the Action; this is overriden to do nothing.
*/
void setIconFromAction(Action a) {
}
/*
* 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);
}
}
}
/**
* See JComponent.readObject() for information about serialization
* in Swing.
*/
private void readObject(ObjectInputStream s)
throws IOException, ClassNotFoundException
{
s.defaultReadObject();
if (getUIClassID().equals(uiClassID)) {
updateUI();
}
}
/**
* Returns a string representation of this JCheckBox. 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.
* specific new aspects of the JFC components.
*
* @return a string representation of this JCheckBox.
*/
protected String paramString() {
return super.paramString();
}
/////////////////
// Accessibility support
////////////////
/**
* Gets the AccessibleContext associated with this JCheckBox.
* For JCheckBoxes, the AccessibleContext takes the form of an
* AccessibleJCheckBox.
* A new AccessibleJCheckBox instance is created if necessary.
*
* @return an AccessibleJCheckBox that serves as the
* AccessibleContext of this JCheckBox
* @beaninfo
* expert: true
* description: The AccessibleContext associated with this CheckBox.
*/
public AccessibleContext getAccessibleContext() {
if (accessibleContext == null) {
accessibleContext = new AccessibleJCheckBox();
}
return accessibleContext;
}
/**
* This class implements accessibility support for the
* JCheckBox class. It provides an implementation of the
* Java Accessibility API appropriate to check box 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 JavaBeans™
* has been added to the java.beans package.
* Please see {@link java.beans.XMLEncoder}.
*/
protected class AccessibleJCheckBox extends AccessibleJToggleButton {
/**
* Get the role of this object.
*
* @return an instance of AccessibleRole describing the role of the object
* @see AccessibleRole
*/
public AccessibleRole getAccessibleRole() {
return AccessibleRole.CHECK_BOX;
}
} // inner class AccessibleJCheckBox
}