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/* Copyright (C) 2000 Free Software Foundation
This file is part of libgcj.
This software is copyrighted work licensed under the terms of the
Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
details. */
package java.awt;
import java.awt.event.*;
import java.awt.peer.CheckboxPeer;
/** This class implements a component which has an on/off state. Two
* or more Checkboxes can be grouped by a CheckboxGroup.
* @author Tom Tromey <tromey@redhat.com>
* @date December 25, 2000
*/
public class Checkbox extends Component implements ItemSelectable
{
/** Create a new checkbox.
* @param label The checkbox label. A null value is the same as "";
* this is the default.
* @param state The initial check state; defaults to false.
* @param group The CheckboxGroup. Defaults to null.
*/
public Checkbox ()
{
this (null, null, false);
}
public Checkbox (String label)
{
this (label, null, false);
}
public Checkbox (String label, boolean state)
{
this (label, null, state);
}
public Checkbox (String label, boolean state, CheckboxGroup group)
{
this (label, group, state);
}
public Checkbox (String label, CheckboxGroup group, boolean state)
{
this.label = label;
this.group = group;
this.state = state;
}
/** Add a listener for item events.
* @param listener The listener to add.
*/
public synchronized void addItemListener (ItemListener listener)
{
listeners = AWTEventMulticaster.add (listeners, listener);
}
/** This creates the component's peer. */
public void addNotify ()
{
if (peer == null)
peer = getToolkit ().createCheckbox (this);
}
/** Returns the current CheckboxGroup associated with this
* Checkbox. */
public CheckboxGroup getCheckboxGroup ()
{
return group;
}
/** Returns the current label; might be null. */
public String getLabel ()
{
return label;
}
/** Returns this checkbox's label if this checkbox is selected. */
public Object[] getSelectedObjects ()
{
Object[] r;
if (state)
{
r = new Object[1];
r[0] = label;
}
else
r = new Object[0];
return r;
}
/** Returns the current state of this checkbox. */
public boolean getState ()
{
return state;
}
/** Generates a String representation of this Checkbox's state. */
protected String paramString ()
{
return ("Checkbox["
+ "state=" + state + ","
+ "label=" + label + ","
+ "group=" + group + "]");
}
/** Process an event for this Checkbox.
* @param event The event the process.
*/
protected void processEvent (AWTEvent event)
{
if (event instanceof ItemEvent)
processItemEvent ((ItemEvent) event);
else
super.processEvent (event);
}
/** Process an item event for this Checkbox.
* @param event The ItemEvent to process
*/
protected void processItemEvent (ItemEvent event)
{
if (listeners != null)
listeners.itemStateChanged (event);
}
/** Remove an item listener.
* @param listener Item listener to remove.
*/
public synchronized void removeItemListener (ItemListener listener)
{
listeners = AWTEventMulticaster.remove (listeners, listener);
}
/** Set this checkbox's group.
* @param group The new group. null means remove the Checkbox from
* its group.
*/
public void setCheckboxGroup (CheckboxGroup group)
{
this.group = group;
if (peer != null)
{
CheckboxPeer cp = (CheckboxPeer) peer;
cp.setCheckboxGroup (group);
}
}
/** Set the checkbox's label.
* @param label The new label
*/
public synchronized void setLabel (String label)
{
this.label = label;
if (peer != null)
{
CheckboxPeer cp = (CheckboxPeer) peer;
// FIXME: unclear what to do here; we err on the side of
// caution.
cp.setLabel (label == null ? "" : label);
}
}
/** Set the checkbox's state.
* @param state The new state.
*/
public void setState (boolean state)
{
this.state = state;
if (peer != null)
{
CheckboxPeer cp = (CheckboxPeer) peer;
cp.setState (state);
}
}
private ItemListener listeners;
String label;
CheckboxGroup group;
boolean state;
}
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