nextapp.echo.app.button.ButtonGroup Maven / Gradle / Ivy
/*
* This file is part of the Echo Web Application Framework (hereinafter "Echo").
* Copyright (C) 2002-2009 NextApp, Inc.
*
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*/
package nextapp.echo.app.button;
import java.io.Serializable;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
import nextapp.echo.app.ApplicationInstance;
import nextapp.echo.app.RadioButton;
import nextapp.echo.app.RenderIdSupport;
/**
* A collection of radio buttons which allows the selection of only one
* radio button at a time.
*/
public class ButtonGroup
implements RenderIdSupport, Serializable {
/** Serial Version UID. */
private static final long serialVersionUID = 20070101L;
private static final RadioButton[] EMPTY = new RadioButton[0];
private String id = ApplicationInstance.generateSystemId();
private Set buttons;
/**
* Adds a RadioButton to the group.
* Applications should use RadioButton.setGroup() to add
* buttons from a group rather than invoking this method.
*
* @param radioButton the RadioButton to add
* @see RadioButton#setGroup(ButtonGroup)
*/
public void addButton(RadioButton radioButton) {
if (buttons == null) {
buttons = new HashSet();
}
buttons.add(radioButton);
updateSelection(radioButton);
}
/**
* Returns all RadioButtons in the group.
*
* @return the RadioButton
*/
public RadioButton[] getButtons() {
if (buttons == null) {
return EMPTY;
} else {
return (RadioButton[]) buttons.toArray(new RadioButton[buttons.size()]);
}
}
/**
* @see nextapp.echo.app.RenderIdSupport#getRenderId()
*/
public String getRenderId() {
return id;
}
/**
* Removes a RadioButton from the group.
* Applications should use RadioButton.setGroup() to remove
* buttons from a group rather than invoking this method.
*
* @param radioButton the RadioButton to remove
* @see RadioButton#setGroup(ButtonGroup)
*/
public void removeButton(RadioButton radioButton) {
if (buttons != null) {
buttons.remove(radioButton);
}
}
/**
* Notifies the ButtonGroup that a RadioButton
* within its domain may have changed state.
*
* @param changedButton the changed RadioButton
*/
public void updateSelection(RadioButton changedButton) {
if (buttons == null || !changedButton.isSelected()) {
return;
}
Iterator buttonIt = buttons.iterator();
while (buttonIt.hasNext()) {
RadioButton button = (RadioButton) buttonIt.next();
if (!button.equals(changedButton)) {
button.setSelected(false);
}
}
}
}