| /******************************************************************************* |
| * Copyright (c) 2005, 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.core.databinding.observable; |
| |
| /** |
| * An object with state that allows to listen for state changes. |
| * |
| * <p> |
| * Implementations must not manage listeners themselves, listener management |
| * must be delegated to a private instance of type {@link ChangeSupport} if it |
| * is not inherited from {@link AbstractObservable}. |
| * </p> |
| * |
| * @noextend This interface is not intended to be extended by clients. |
| * @noimplement This interface is not intended to be implemented by clients. |
| * Clients should instead subclass one of the classes in the |
| * framework that implement this interface. Note that direct |
| * implementers of this interface outside of the framework will be |
| * broken in future releases when methods are added to this |
| * interface. |
| * |
| * @since 1.0 |
| * |
| */ |
| public interface IObservable { |
| |
| /** |
| * Returns the realm for this observable. Unless otherwise specified, |
| * getters and setters must be accessed from within this realm. Listeners |
| * will be within this realm when they receive events from this observable. |
| * <p> |
| * Because observables can only be accessed from within one realm, and they |
| * always fire events on that realm, their state can be observed in an |
| * incremental way. It is always safe to call getters of an observable from |
| * within a change listener attached to that observable. |
| * </p> |
| * |
| * @return the realm |
| */ |
| public Realm getRealm(); |
| |
| /** |
| * Adds the given change listener to the list of change listeners. Change |
| * listeners are notified about changes of the state of this observable in a |
| * generic way, without specifying the change that happened. To get the |
| * changed state, a change listener needs to query for the current state of |
| * this observable. |
| * |
| * @param listener |
| */ |
| public void addChangeListener(IChangeListener listener); |
| |
| /** |
| * Removes the given change listener from the list of change listeners. Has |
| * no effect if the given listener is not registered as a change listener. |
| * |
| * @param listener |
| */ |
| public void removeChangeListener(IChangeListener listener); |
| |
| /** |
| * Adds the given stale listener to the list of stale listeners. Stale |
| * listeners are notified when an observable object becomes stale, not when |
| * is becomes non-stale. |
| * |
| * @param listener |
| * |
| * @see #isStale() |
| */ |
| public void addStaleListener(IStaleListener listener); |
| |
| /** |
| * Removes the given stale listener from the list of stale listeners. Has no |
| * effect if the given listener is not registered as a stale listener. |
| * |
| * @param listener |
| */ |
| public void removeStaleListener(IStaleListener listener); |
| |
| /** |
| * Returns whether the state of this observable is stale and is expected to |
| * change soon. A non-stale observable that becomes stale will notify its |
| * stale listeners. A stale object that becomes non-stale does so by |
| * changing its state and notifying its change listeners, it does <b>not</b> |
| * notify its stale listeners about becoming non-stale. Clients that do not |
| * expect asynchronous changes may ignore staleness of observable objects. |
| * |
| * @return true if this observable's state is stale and will change soon. |
| * |
| * @TrackedGetter - implementers must call |
| * {@link ObservableTracker#getterCalled(IObservable)}. |
| */ |
| public boolean isStale(); |
| |
| /** |
| * Disposes of this observable object, removing all listeners registered |
| * with this object, and all listeners this object might have registered on |
| * other objects. |
| */ |
| public void dispose(); |
| } |