jelly-tags/swing/src/java/org/apache/commons/jelly/tags/swing/BorderAlignTag.java

/*
 * $Header: /home/cvs/jakarta-commons-sandbox/jelly/src/java/org/apache/commons/jelly/tags/define/DynamicTag.java,v 1.7 2002/05/17 15:18:12 jstrachan Exp $
 * $Revision: 1.7 $
 * $Date: 2002/05/17 15:18:12 $
 *
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2002 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Commons", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 * 
 * $Id: DynamicTag.java,v 1.7 2002/05/17 15:18:12 jstrachan Exp $
 */
package org.apache.commons.jelly.tags.swing;

import java.awt.BorderLayout;
import java.awt.Component;

import org.apache.commons.jelly.JellyException;
import org.apache.commons.jelly.TagSupport;
import org.apache.commons.jelly.XMLOutput;

/** 
 * Represents a layout of a child component within its parent &lt;borderLayout&gt; layout.
 *
 * @author <a href="mailto:jstrachan@apache.org">James Strachan</a>
 * @version $Revision: 1.7 $
 */
public class BorderAlignTag extends TagSupport implements ContainerTag {

    private String align;
    
    // ContainerTag interface
    //-------------------------------------------------------------------------                    
    
    /**
     * Adds a child component to this parent
     */
    public void addChild(Component component, Object constraints) throws Exception {
        BorderLayoutTag tag = (BorderLayoutTag) findAncestorWithClass( BorderLayoutTag.class );
        if (tag == null) {
            throw new JellyException( "this tag must be nested within a <tr> tag" );
        }
        tag.addLayoutComponent(component, getConstraints());
    }
    
    // Tag interface
    //-------------------------------------------------------------------------                    
    public void doTag(final XMLOutput output) throws Exception {
        invokeBody(output);
    }
    
    // Properties
    //-------------------------------------------------------------------------                    
    
    /**
     * Returns the align.
     * @return String
     */
    public String getAlign() {
        return align;
    }

    /**
     * Sets the alignment of the child component which is a case insensitive value 
     * of {NORTH, SOUTH, EAST, WEST, CENTER} which defaults to CENTER
     */
    public void setAlign(String align) {
        this.align = align;
    }

    // Implementation methods
    //-------------------------------------------------------------------------                    

    protected Object getConstraints() {
        if ("north".equalsIgnoreCase(align)) {
            return BorderLayout.NORTH;
        }
        else if ("south".equalsIgnoreCase(align)) {
            return BorderLayout.SOUTH;
        }
        else if ("east".equalsIgnoreCase(align)) {
            return BorderLayout.EAST;
        }
        else if ("west".equalsIgnoreCase(align)) {
            return BorderLayout.WEST;
        }
        else {
            // default to CENTER
            return BorderLayout.CENTER;
        }
    }
}