org.eclipse.vex.core/src/org/eclipse/vex/core/internal/css/TextDecorationProperty.java

/*******************************************************************************
 * Copyright (c) 2004, 2008 John Krasnay and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     John Krasnay - initial API and implementation
 *******************************************************************************/
package org.eclipse.vex.core.internal.css;

import org.eclipse.vex.core.provisional.dom.INode;
import org.w3c.css.sac.LexicalUnit;

/**
 * The CSS text-decoration property.
 */
public class TextDecorationProperty extends AbstractProperty {

	/**
	 * Class constructor.
	 */
	public TextDecorationProperty() {
		super(CSS.TEXT_DECORATION);
	}

	@Override
	public Object calculate(final LexicalUnit lu, final Styles parentStyles, final Styles styles, final INode node) {
		if (isTextDecoration(lu)) {
			return lu.getStringValue();
		} else {
			// not specified, "inherit", or some other value
			if (parentStyles != null) {
				return parentStyles.getTextDecoration();
			} else {
				return CSS.NONE;
			}
		}
	}

	// =================================================== PRIVATE

	/**
	 * Returns true if the given lexical unit represents a text decoration.
	 *
	 * @param lu
	 *            LexicalUnit to check.
	 */
	private static boolean isTextDecoration(final LexicalUnit lu) {
		if (lu == null) {
			return false;
		} else if (lu.getLexicalUnitType() == LexicalUnit.SAC_IDENT) {
			final String s = lu.getStringValue();
			return s.equals(CSS.NONE) || s.equals(CSS.UNDERLINE) || s.equals(CSS.OVERLINE) || s.equals(CSS.LINE_THROUGH) || s.equals(CSS.BLINK);
		} else {
			return false;
		}
	}

}