nextapp.echo.app.Composite 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;
/**
* Composite component: a generic composite component abstract base class.
* This class is intended to be used as base class for composite components.
* Provides no rendering properties (other than those specified in Component).
* May contain at most one child component. May not contain a Pane component as
* a child.
*
* See the Panel component for a default implementation of a
* single-child container component.
*
* This class provides no benefit if you are providing a custom client-side
* synchronization/rendering peer. In such cases, Component itself should be
* derived instead of this class.
*/
public abstract class Composite extends Component {
/**
* Default constructor.
*/
public Composite() {
super();
}
/**
* Allow at most one child component.
*
* @see nextapp.echo.app.Component#isValidChild(nextapp.echo.app.Component)
*/
public boolean isValidChild(Component child) {
return getComponentCount() == 0 || indexOf(child) != -1;
}
}