/*******************************************************************************
 * Copyright (c) 2004, 2005 IBM Corporation 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/

package org.eclipse.gef.examples.text.model.commands;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.jface.util.Assert;

import org.eclipse.gef.examples.text.AppendableCommand;
import org.eclipse.gef.examples.text.GraphicalTextViewer;
import org.eclipse.gef.examples.text.SelectionRange;
import org.eclipse.gef.examples.text.edit.TextEditPart;
import org.eclipse.gef.examples.text.model.ModelLocation;

/**
 * @since 3.1
 */
public class CompoundEditCommand
	extends ExampleTextCommand
	implements AppendableCommand
{

private ModelLocation beginLocation;

List edits = new ArrayList();

private ModelLocation endLocation;

ArrayList pending;

/**
 * @since 3.1
 * @param label
 */
public CompoundEditCommand(String label) {
	super(label);
}

/**
 * @see org.eclipse.gef.commands.Command#execute()
 */
public void execute() {
	executePending();
}

public boolean canExecute() {
	return canExecutePending();
}

public boolean canExecutePending() {
	if (pending == null || pending.size() == 0)
		return false;
	for (int i = 0; i < pending.size(); i++) {
		MiniEdit edit = (MiniEdit)pending.get(i);
		if (edit == null || !edit.canApply())
			return false;
	}
	return true;
}

public void executePending() {
	Assert.isNotNull(pending);
	for (int i = 0; i < pending.size(); i++) {
		MiniEdit edit = (MiniEdit)pending.get(i);
		edit.apply();
	}
	edits.addAll(pending);
	pending = null;
}

public void flushPending() {
	pending = null;
}

public SelectionRange getExecuteSelectionRange(GraphicalTextViewer viewer) {
	ModelLocation loc = ((MiniEdit)edits.get(edits.size() - 1)).getResultingLocation();
	if (loc == null)
		return getUndoSelectionRange(viewer);
	return new SelectionRange(lookupModel(viewer, loc.model), loc.offset);
}

public SelectionRange getRedoSelectionRange(GraphicalTextViewer viewer) {
	return getExecuteSelectionRange(viewer);
}

public SelectionRange getUndoSelectionRange(GraphicalTextViewer viewer) {
	TextEditPart begin = lookupModel(viewer, beginLocation.model);
	if (endLocation == null)
		return new SelectionRange(begin, beginLocation.offset);
	TextEditPart end = lookupModel(viewer, endLocation.model);
	return new SelectionRange(begin, beginLocation.offset, end, endLocation.offset);
}

public void pendEdit(MiniEdit edit) {
	if (pending == null)
		pending = new ArrayList(2);
	pending.add(edit);
}

/**
 * @see org.eclipse.gef.commands.Command#redo()
 */
public void redo() {
	for (int i = 0; i < edits.size(); i++) {
		MiniEdit edit = (MiniEdit)edits.get(i);
		edit.reapply();
	}
}

public void setEndLocation(ModelLocation endLocation) {
	this.endLocation = endLocation;
}

public void setBeginLocation(ModelLocation startLocation) {
	this.beginLocation = startLocation;
}

/**
 * @see org.eclipse.gef.commands.Command#undo()
 */
public void undo() {
	for (int i = edits.size() - 1; i >= 0; i--) {
		MiniEdit edit = (MiniEdit)edits.get(i);
		edit.rollback();
	}
}

}