/*******************************************************************************
* Copyright (c) 2000, 2008 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.ui.contexts;
/**
* An instance of this interface is an context as defined by the extension point
* <code>org.eclipse.ui.contexts</code>.
* <p>
* An instance of this interface can be obtained from an instance of
* <code>IContextManager</code> for any identifier, whether or not an context
* with that identifier is defined in the extension registry.
* </p>
* <p>
* The handle-based nature of this API allows it to work well with runtime
* plugin activation and deactivation. If a context is defined, that means that
* its corresponding plug-in is active. If the plug-in is then deactivated, the
* context will still exist but it will be undefined. An attempts to use an
* undefined context will result in a <code>NotDefinedException</code> being
* thrown.
* </p>
* <p>
* This interface is not intended to be extended or implemented by clients.
* </p>
*
* @since 1.1
* @see org.eclipse.ui.contexts.IContextManager
* @see org.eclipse.core.commands.contexts.Context
* @deprecated Please use the "org.eclipse.core.commands" plug-in instead.
* @noimplement This interface is not intended to be implemented by clients.
*/
public interface IContext extends Comparable {
/**
* Registers an instance of <code>IContextListener</code> to listen for
* changes to properties of this instance.
*
* @param contextListener
* the instance to register. Must not be <code>null</code>. If
* an attempt is made to register an instance which is already
* registered with this instance, no operation is performed.
*/
void addContextListener(IContextListener contextListener);
/**
* Returns the identifier of this instance.
*
* @return the identifier of this instance. Guaranteed not to be
* <code>null</code>.
*/
String getId();
/**
* Returns the name of this instance suitable for display to the user.
* <p>
* Notification is sent to all registered listeners if this property
* changes.
* </p>
*
* @return the name of this instance. Guaranteed not to be <code>null</code>.
* @throws NotDefinedException
* if this instance is not defined.
*/
String getName() throws NotDefinedException;
/**
* Returns the identifier of the parent of this instance.
* <p>
* Notification is sent to all registered listeners if this property
* changes.
* </p>
*
* @return the identifier of the parent of this instance. May be
* <code>null</code>.
* @throws NotDefinedException
* if this instance is not defined.
*/
String getParentId() throws NotDefinedException;
/**
* Returns whether or not this instance is defined.
* <p>
* Notification is sent to all registered listeners if this property
* changes.
* </p>
*
* @return true, iff this instance is defined.
*/
boolean isDefined();
/**
* Returns whether or not this instance is enabled.
* <p>
* Notification is sent to all registered listeners if this property
* changes.
* </p>
*
* @return true, iff this instance is enabled.
*/
boolean isEnabled();
/**
* Unregisters an instance of <code>IContextListener</code> listening for
* changes to properties of this instance.
*
* @param contextListener
* the instance to unregister. Must not be <code>null</code>.
* If an attempt is made to unregister an instance which is not
* already registered with this instance, no operation is
* performed.
*/
void removeContextListener(IContextListener contextListener);
}