/*******************************************************************************
 * Copyright (c) 2000, 2003 IBM Corporation 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.jface.viewers;


import org.eclipse.jface.util.Assert;
import org.eclipse.swt.SWT;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;

/**
 * A cell editor that manages a checkbox.
 * The cell editor's value is a boolean.
 * <p>
 * This class may be instantiated; it is not intended to be subclassed.
 * </p>
 * <p>
 * Note that this implementation simply fakes it and does does not create
 * any new controls. The mere activation of this editor means that the value
 * of the check box is being toggled by the end users; the listener method
 * <code>applyEditorValue</code> is immediately called to signal the change.
 * </p>
 */
public class CheckboxCellEditor extends CellEditor {

	/**
	 * The checkbox value.
	 */
	/* package */
	boolean value = false;

	/**
	 * Default CheckboxCellEditor style
	 */
	private static final int defaultStyle = SWT.NONE;

	/**
	 * Creates a new checkbox cell editor with no control
	 * @since 2.1
	 */
	public CheckboxCellEditor() {
		setStyle(defaultStyle);
	}
	/**
	 * Creates a new checkbox cell editor parented under the given control.
	 * The cell editor value is a boolean value, which is initially <code>false</code>. 
	 * Initially, the cell editor has no cell validator.
	 *
	 * @param parent the parent control
	 */
	public CheckboxCellEditor(Composite parent) {
		this(parent, defaultStyle);
	}
	/**
	 * Creates a new checkbox cell editor parented under the given control.
	 * The cell editor value is a boolean value, which is initially <code>false</code>. 
	 * Initially, the cell editor has no cell validator.
	 *
	 * @param parent the parent control
	 * @param style the style bits
	 * @since 2.1
	 */
	public CheckboxCellEditor(Composite parent, int style) {
		super(parent, style);
	}
	/**
	 * The <code>CheckboxCellEditor</code> implementation of
	 * this <code>CellEditor</code> framework method simulates
	 * the toggling of the checkbox control and notifies
	 * listeners with <code>ICellEditorListener.applyEditorValue</code>.
	 */
	public void activate() {
		value = !value;
		fireApplyEditorValue();
	}
	/**
	 * The <code>CheckboxCellEditor</code> implementation of
	 * this <code>CellEditor</code> framework method does
	 * nothing and returns <code>null</code>.
	 */
	protected Control createControl(Composite parent) {
		return null;
	}
	/**
	 * The <code>CheckboxCellEditor</code> implementation of
	 * this <code>CellEditor</code> framework method returns
	 * the checkbox setting wrapped as a <code>Boolean</code>.
	 *
	 * @return the Boolean checkbox value
	 */
	protected Object doGetValue() {
		return new Boolean(value);
	}
	/* (non-Javadoc)
	 * Method declared on CellEditor.
	 */
	protected void doSetFocus() {
		// Ignore
	}
	/**
	 * The <code>CheckboxCellEditor</code> implementation of
	 * this <code>CellEditor</code> framework method accepts
	 * a value wrapped as a <code>Boolean</code>.
	 *
	 * @param value a Boolean value
	 */
	protected void doSetValue(Object value) {
		Assert.isTrue(value instanceof Boolean);
		this.value = ((Boolean) value).booleanValue();
	}
}