/*******************************************************************************
 * Copyright (c) 2000, 2004 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.ui.texteditor;



/**
 * Extension interface for actions. Actions implementing this interface not
 * only manage an enable/disable state but also manage a "hypothetical"
 * enable state, depending on whether the target they work on is writable
 * or read-only.
 * @since 2.0
 */
public interface IReadOnlyDependent {

	/**
	 * Returns whether the actions would be enabled if its target
	 * would be enabled given the writable state described by <code>isWritable</code>.
	 * <code>isEnabled()</code> and <code>isEnabled(boolean)</code> holds the following
	 * invariants:
	 * 	isEnabled() == false, if isEnabled(true) == false || isEnabled(false) == false
	 * 	isEnabled() == true, if isEnabled(true) == true || isEnabled(false) == true
	 * 
	 * @param isWritable
	 * @return the hypothetical enable state of the action
	 */
	boolean isEnabled(boolean isWritable);
}
