/* 
 * This file is part of the Echo Web Application Framework (hereinafter "Echo").
 * Copyright (C) 2002-2005 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.echo2.webcontainer.propertyrender;

import nextapp.echo2.app.Extent;
import nextapp.echo2.app.Insets;
import nextapp.echo2.webrender.output.CssStyle;

/**
 * Utility class for rendering <code>nextapp.echo2.app.Insets</code>
 * properties to CSS.
 */
public class InsetsRender {

    /**
     * Renders an <code>Insets</code> property to the given CSS style.
     * Null property values are ignored.
     * 
     * @param cssStyle the target <code>CssStyle</code>
     * @param cssAttribute the CSS attribute name, e.g., "margin" or "padding".
     * @param insets the property value
     */
    public static void renderToStyle(CssStyle cssStyle, String cssAttribute, Insets insets) {
        if (insets == null) {
            return;
        }
        cssStyle.setAttribute(cssAttribute, renderCssAttributeValue(insets));
    }

    /**
     * Renders a CSS attribute value representation of an <code>Insets</code>.
     * 
     * @param insets the <code>Insets</code> to render
     * @return a CSS attribute value representation
     */
    public static String renderCssAttributeValue(Insets insets) {
        Extent top = insets.getTop();
        if (top != null && top.equals(insets.getLeft()) && top.equals(insets.getRight())
                    && top.equals(insets.getBottom())) {
            return ExtentRender.renderCssAttributeValue(top);
        } else {
            StringBuffer out = new StringBuffer();
            if (top == null) {
                out.append("0px");
            } else {
                out.append(ExtentRender.renderCssAttributeValue(top));
            }
            out.append(" ");
            if (insets.getRight() == null) {
                out.append("0px");
            } else {
                out.append(ExtentRender.renderCssAttributeValue(insets.getRight()));
            }
            out.append(" ");
            if (insets.getBottom() == null) {
                out.append("0px");
            } else {
                out.append(ExtentRender.renderCssAttributeValue(insets.getBottom()));
            }
            out.append(" ");
            if (insets.getLeft() == null) {
                out.append("0px");
            } else {
                out.append(ExtentRender.renderCssAttributeValue(insets.getLeft()));
            }
            return out.toString();
        }
    }
    
    /** Non-instantiable class. */
    private InsetsRender() { }
}
