/*
 * Copyright (c) 2003-2004 Christopher Lenz and others.
 * All rights reserved. This program and the accompanying materials 
 * are made available under the terms of the Common Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/cpl-v10.html
 * 
 * Contributors:
 *     Christopher Lenz - initial API and implementation
 * 
 * $Id: CssOutlineLabelProvider.java,v 1.1 2004-09-02 18:11:49 jsurfer Exp $
 */

package net.sourceforge.phpeclipse.css.ui.internal.outline;

import net.sourceforge.phpeclipse.core.model.ISourceReference;
import net.sourceforge.phpeclipse.css.core.model.IAtRule;
import net.sourceforge.phpeclipse.css.core.model.IStyleRule;
import net.sourceforge.phpeclipse.css.ui.CssUI;

import org.eclipse.jface.viewers.LabelProvider;
import org.eclipse.swt.graphics.Image;

/**
 * Label provider for the CSS outline page.
 */
public class CssOutlineLabelProvider extends LabelProvider {

	// LabelProvider Implementation --------------------------------------------

	/**
	 * @see org.eclipse.jface.viewers.ILabelProvider#getImage(java.lang.Object)
	 */
	public Image getImage(Object element) {
		if (element instanceof IStyleRule) {
			return CssUI.getDefault().getImageRegistry().get(
				CssUI.ICON_STYLE_RULE);
		} else if (element instanceof IAtRule) {
			return CssUI.getDefault().getImageRegistry().get(
				CssUI.ICON_AT_RULE);
		}
		return null;
	}

	/**
	 * @see org.eclipse.jface.viewers.ILabelProvider#getText(java.lang.Object)
	 */
	public String getText(Object element) {
		StringBuffer text = new StringBuffer();
		if (element instanceof IStyleRule) {
			IStyleRule rule = (IStyleRule) element;
			ISourceReference selector = rule.getSelector();
			if (selector != null) {
				text.append(selector.getSource());
			}
		} else if (element instanceof IAtRule) {
			IAtRule rule = (IAtRule) element;
			ISourceReference name = rule.getName();
			ISourceReference value = rule.getValue();
			if (name != null) {
				text.append(name.getSource());
				if (value != null) {
					text.append(' ');
				}
			}
			if (value != null) {
				text.append(value.getSource());
			}
		}
		return normalizeWhitespace(text.toString());
	}

	// Private Methods ---------------------------------------------------------

	/**
	 * Replaces all whitespace characters by regular spaces, and trims excessive
	 * whitespace down to at most one whitespace between non-whitespace
	 * characters.
	 * 
	 * @param text The text to normalize
	 * @return The normalized text
	 */
	public String normalizeWhitespace(String text) {
		StringBuffer buf = new StringBuffer();
		boolean previousWasWhitespace = false;
		for (int i = 0; i < text.length(); i++) {
			char c = text.charAt(i);
			if ((c == 9) || (c == 10) || (c == 13)) { // Tab
				c = ' ';
			}
			if ((c != ' ') || !previousWasWhitespace) {
				buf.append(c);
			}
			previousWasWhitespace = (c == ' ');
		}
		return buf.toString();
	}

}