/*
 * 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: CssDocumentProvider.java,v 1.1 2004-09-02 18:11:49 jsurfer Exp $
 */

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

import net.sourceforge.phpeclipse.css.core.internal.model.StyleSheet;
import net.sourceforge.phpeclipse.css.core.model.IStyleSheet;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IDocumentListener;
import org.eclipse.ui.editors.text.TextFileDocumentProvider;

/**
 * Document provider for CSS files.
 * 
 * TODO This class currently doubles as a model manager which will need to be 
 *      moved into core at some point, and would make this class pretty much
 *      useless
 */
public class CssDocumentProvider extends TextFileDocumentProvider {

	// Inner Classes -----------------------------------------------------------

	private class StyleSheetInfo extends FileInfo {
		private IStyleSheet styleSheet;
	}

	// TestFileDocumentProvider Implementation ---------------------------------

	/*
	 * @see TextFileDocumentProvider#createEmptyFileInfo()
	 */
	protected FileInfo createEmptyFileInfo() {
		return new StyleSheetInfo();
	}

	/*
	 * @see TextFileDocumentProvider#createFileInfo(Object)
	 */
	protected FileInfo createFileInfo(Object element) throws CoreException {
		FileInfo fileInfo = super.createFileInfo(element);
		if (!(fileInfo instanceof StyleSheetInfo)) {
			return null;
		}

		IDocument document = fileInfo.fTextFileBuffer.getDocument();
		IStyleSheet styleSheet = createStyleSheet(document);
		if (styleSheet instanceof IDocumentListener) {
			document.addDocumentListener((IDocumentListener) styleSheet);
		}
		StyleSheetInfo styleSheetInfo = (StyleSheetInfo) fileInfo;
		styleSheetInfo.styleSheet = styleSheet;

		return styleSheetInfo;
	}

	/*
	 * @see TextFileDocumentProvider#disposeFileInfo(Object, TextFileDocumentProvider.FileInfo)
	 */
	protected void disposeFileInfo(Object element, FileInfo info) {
		if (info instanceof StyleSheetInfo) {
			IDocument document = getDocument(element);
			// TODO Check whether this is really necessary, as the document is
			//      always null here
			if (document != null) {
				IStyleSheet styleSheet = ((StyleSheetInfo) info).styleSheet;
				if (styleSheet instanceof IDocumentListener) {
					document.removeDocumentListener((IDocumentListener)
							styleSheet);
				}
			}
		}
		super.disposeFileInfo(element, info);
	}

	// Public Methods ----------------------------------------------------------

	/**
	 * Creates the parsed style sheet object corresponding to the specified 
	 * document.
	 * 
	 * @param document the document to parse
	 * @return the parsed style sheet
	 */
	public IStyleSheet createStyleSheet(IDocument document) {
		return new StyleSheet(document);
	}

	/**
	 * Returns the style sheet associated with the specified element.
	 * 
	 * @param element the element
	 * @return the style sheet associated with the element
	 */
	public IStyleSheet getStyleSheet(Object element) {
		FileInfo info = getFileInfo(element);
		if (info instanceof StyleSheetInfo) {
			StyleSheetInfo styleSheetInfo = (StyleSheetInfo) info;
			return styleSheetInfo.styleSheet;
		}
		return null;
	}

}