package javax.swing;
+import java.awt.event.ItemEvent;
+import java.awt.event.ItemListener;
+
import javax.accessibility.Accessible;
import javax.accessibility.AccessibleContext;
+import javax.accessibility.AccessibleRole;
+import javax.accessibility.AccessibleState;
import javax.swing.plaf.ButtonUI;
+/**
+ * The <code>JToggleButton</code> component provides a stateful button,
+ * which can be either selected or unselected. This provides the basis
+ * for the implementations of radio buttons (<code>JRadioButton</code>)
+ * and check boxes (<code>JCheckBox</code>).
+ *
+ * @author Michael Koch <konqueror@gmx.de>
+ * @author Graydon Hoare <graydon@redhat.com>
+ * @author Andrew John Hughes <gnu_andrew@member.fsf.org>
+ * @see JRadioButton
+ * @see JCheckBox
+ * @since 1.2
+ */
public class JToggleButton extends AbstractButton implements Accessible
{
+
+ /**
+ * This class provides accessibility support for the toggle button.
+ */
+ protected class AccessibleJToggleButton
+ extends AccessibleAbstractButton
+ implements ItemListener
+ {
+
+ /**
+ * Constructor for the accessible toggle button.
+ */
+ public AccessibleJToggleButton()
+ {
+ super();
+ /* Register the accessible toggle button as a listener for item events */
+ addItemListener(this);
+ }
+
+ /**
+ * Returns the accessible role for the toggle button.
+ *
+ * @return An instance of <code>AccessibleRole</code>, describing
+ * the role of the toggle button.
+ */
+ public AccessibleRole getAccessibleRole()
+ {
+ return AccessibleRole.TOGGLE_BUTTON;
+ }
+
+ /**
+ * Monitors the toggle button for state changes and fires accessible
+ * property change events when they occur.
+ *
+ * @param event the event that occurred.
+ */
+ public void itemStateChanged(ItemEvent event)
+ {
+ /* Fire a state property change event as the button's state has changed */
+ if (event.getStateChange() == ItemEvent.SELECTED)
+ {
+ /* State has changed from unselected (null) to selected */
+ firePropertyChange(ACCESSIBLE_STATE_PROPERTY, null, AccessibleState.SELECTED);
+ }
+ else
+ {
+ /* State has changed from selected to unselected (null) */
+ firePropertyChange(ACCESSIBLE_STATE_PROPERTY, AccessibleState.ENABLED, null);
+ }
+ }
+
+ }
+ /**
+ * The model handles the storage and maintenance of the state of
+ * the toggle button. This follows the same paradigm (the MVC
+ * or Model-View-Controller design pattern) employed by
+ * other Swing components, where the data associated with a component
+ * is stored separately from the display aspects.
+ */
public static class ToggleButtonModel extends DefaultButtonModel
{
+ /**
+ * Compatible with Sun's JDK.
+ */
private static final long serialVersionUID = -1589950750899943974L;
+ /**
+ * Sets the pressed state of the button. The selected state
+ * of the button also changes follwing the button being pressed.
+ *
+ * @param b true if the button is pressed down.
+ */
public void setPressed(boolean b)
{
if (! isEnabled())
}
}
-
+ /**
+ * Compatible with Sun's JDK.
+ */
private static final long serialVersionUID = -3128248873429850443L;
+ /**
+ * Constructs an unselected toggle button with no text or icon.
+ */
public JToggleButton()
{
- this(null, null);
+ this(null, null, false);
}
+
+ /**
+ * Constructs a toggle button using the labelling, state
+ * and icon specified by the supplied action.
+ *
+ * @param a the action to use to define the properties of the button.
+ */
public JToggleButton(Action a)
{
this();
setAction(a);
}
+ /**
+ * Constructs an unselected toggle button with the supplied icon
+ * and no text.
+ *
+ * @param icon the icon to use.
+ */
public JToggleButton(Icon icon)
{
- this(null, icon);
+ this(null, icon, false);
}
- public JToggleButton (Icon icon, boolean selected)
+ /**
+ * Constructs a toggle button with the supplied icon and state.
+ *
+ * @param icon the icon to use.
+ * @param selected if true, the toggle button is initially in the
+ * selected state. Otherwise, the button is unselected.
+ */
+ public JToggleButton(Icon icon, boolean selected)
{
this(null, icon, selected);
}
+ /**
+ * Constructs an unselected toggle button using the supplied text
+ * and no icon.
+ *
+ * @param text the text to use.
+ */
public JToggleButton(String text)
{
- this(text, null);
+ this(text, null, false);
}
+ /**
+ * Constructs a toggle button with the supplied text and state.
+ *
+ * @param text the text to use.
+ * @param selected if true, the toggle button is initially in the
+ * selected state. Otherwise, the button is unselected.
+ */
public JToggleButton(String text, boolean selected)
{
this(text, null, selected);
}
+ /**
+ * Constructs an unselected toggle button with the supplied text
+ * and icon.
+ *
+ * @param text the text to use.
+ * @param icon the icon to use.
+ */
public JToggleButton(String text, Icon icon)
{
this(text, icon, false);
}
+ /**
+ * Constructs a toggle button with the supplied text, icon and state.
+ *
+ * @param text the text to use.
+ * @param icon the icon to use.
+ * @param selected if true, the toggle button is initially in the
+ * selected state. Otherwise, the button is unselected.
+ */
public JToggleButton (String text, Icon icon, boolean selected)
{
super(text, icon);
/**
* Gets the AccessibleContext associated with this <code>JToggleButton</code>.
+ * The context is created, if necessary.
*
* @return the associated context
*/
public AccessibleContext getAccessibleContext()
{
- return null;
+ /* Create the context if this is the first request */
+ if (accessibleContext == null)
+ {
+ /* Create the context */
+ accessibleContext = new AccessibleJToggleButton();
+ }
+ return accessibleContext;
}
/**
* Returns a string that specifies the name of the Look and Feel
* class that renders this component.
+ *
+ * @return The Look and Feel UI class in <code>String</code> form.
*/
public String getUIClassID()
{
return "ToggleButtonUI";
}
+ /**
+ * Returns a textual representation of this component for debugging.
+ * Users should not depend on anything as regards the content or formatting
+ * of this string, except for the fact that the returned string may never be
+ * null (only empty).
+ *
+ * @return the component in <code>String</code> form for debugging.
+ */
protected String paramString()
{
return "JToggleButton";
}
-
+ /**
+ * This method resets the toggle button's UI delegate to the default UI for
+ * the current look and feel.
+ */
public void updateUI()
{
- ButtonUI b = (ButtonUI)UIManager.getUI(this);
- setUI(b);
+ setUI((ButtonUI)UIManager.getUI(this));
}
+
}
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