/**
 * Copyright (c) 2009 Anyware Technologies 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:
 *     Anyware Technologies - initial API and implementation
 *
 * $Id: AbstractSourcePage.java,v 1.1 2009/08/19 14:54:21 bcabe Exp $
 */
package org.eclipse.pde.emfforms.internal.editor;

import java.io.IOException;
import java.io.StringWriter;
import java.util.Collections;
import java.util.EventObject;
import org.eclipse.core.databinding.DataBindingContext;
import org.eclipse.core.databinding.observable.value.IObservableValue;
import org.eclipse.emf.common.command.CommandStackListener;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.xmi.XMLResource;
import org.eclipse.emf.edit.domain.EditingDomain;
import org.eclipse.jface.layout.GridDataFactory;
import org.eclipse.jface.text.source.SourceViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.pde.emfforms.editor.AbstractEmfFormPage;
import org.eclipse.pde.emfforms.editor.EmfFormEditor;
import org.eclipse.pde.emfforms.internal.Activator;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Composite;

public abstract class AbstractSourcePage extends AbstractEmfFormPage {
	private SourceViewer _sourceViewer;

	public static final String ID = "emfforms.source"; //$NON-NLS-1$

	protected static final int VERTICAL_RULER_WIDTH = 12;

	private EditingDomain _editingDomain;
	private CommandStackListener _commandStackListener;

	/**
	 * @param editor
	 */
	public AbstractSourcePage(EmfFormEditor<?> editor) {
		super(editor);
	}

	public void bind(DataBindingContext bindingContext) {
		_editingDomain = ((EmfFormEditor<?>) getEditor()).getEditingDomain();

		_commandStackListener = new CommandStackListener() {
			public void commandStackChanged(EventObject event) {
				refreshSourceContent();
			}
		};
		_editingDomain.getCommandStack().addCommandStackListener(_commandStackListener);

		// initialize content
		refreshSourceContent();
	}

	private void refreshSourceContent() {
		EObject obj = (EObject) getObservedValue().getValue();

		// Copies the root to avoid modifying it
		final StringWriter writer = new StringWriter();
		try {
			((XMLResource) obj.eResource()).save(writer, Collections.EMPTY_MAP);
		} catch (IOException e) {
			Activator.log(e);
		}
		final String result = writer.toString();
		writer.flush();
		if (_sourceViewer != null)
			_sourceViewer.getDocument().set(result);
	}

	public void createContents(Composite parent) {
		GridLayout gl = new GridLayout(getNumColumns(), true);
		gl.verticalSpacing = 0;
		parent.setLayout(gl);

		_sourceViewer = createSourceViewer(parent);

		GridDataFactory.fillDefaults().grab(true, true).applyTo(_sourceViewer.getControl());
	}

	public abstract SourceViewer createSourceViewer(Composite parent);

	@Override
	public String getId() {
		return ID;
	}

	@Override
	public String getPartName() {
		return "Source"; //$NON-NLS-1$
	}

	@Override
	public Viewer getViewer() {
		return null;
	}

	private IObservableValue getObservedValue() {
		return ((EmfFormEditor<?>) getEditor()).getInputObservable();
	}

	@Override
	public void dispose() {
		if (_editingDomain != null)
			_editingDomain.getCommandStack().removeCommandStackListener(_commandStackListener);

		super.dispose();
	}
}