AccessibleHandleProvider.java

/*******************************************************************************
 * Copyright (c) 2000, 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;

import java.util.List;

/**
 * This class provides keyboard accessibility support for the {@link Handle Handles} of
 * the primary-selected {@link EditPart}. Handles are grabbable regions on the screen. 
 * Typically the user will grab a handle by pressing and holding the mouse button.  This
 * function must also be available via the keyboard for accessibility reasons.  Even mouse
 * Users will appreciate the fine-grained control offered by the keyboard for operations
 * like "nudging".
 * <P>The SelectionTool is the primary client for Handles. When it is active, the PERIOD
 * keystroke will cycle through the list of Accessibile locations (Points) supplied by the
 * current EditPart.  The "current EditPart" is defined as the EditPart with primary
 * selection.
 */

public interface AccessibleHandleProvider {

/**
 * Returns a list of Points in <B>absolute</B> coordinates where {@link Handle Handles}
 * are located.  {@link Tool Tools} that work with Handles should use these locations when
 * operating in accesible keyboard modes.
 * @return A list of absolute locations (Points relative to the Viewer's Control); cannot
 * be <code>null</code>
 */
List getAccessibleHandleLocations();

}