| /******************************************************************************* |
| * Copyright (c) 2005, 2006 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.handlers; |
| |
| import org.eclipse.core.commands.IHandler; |
| import org.eclipse.core.expressions.IEvaluationContext; |
| import org.eclipse.ui.internal.services.IEvaluationResultCache; |
| |
| /** |
| * <p> |
| * A token representing the activation of a handler. This token can later be |
| * used to cancel that activation. Without this token, then handler will only |
| * become inactive if the component in which the handler was activated is |
| * destroyed. |
| * </p> |
| * <p> |
| * This interface is not intended to be implemented or extended by clients. |
| * </p> |
| * |
| * @since 3.1 |
| * @see org.eclipse.ui.ISources |
| * @see org.eclipse.ui.ISourceProvider |
| */ |
| public interface IHandlerActivation extends IEvaluationResultCache, Comparable { |
| |
| /** |
| * The depth at which the root exists. |
| * |
| * @since 3.2 |
| */ |
| public static final int ROOT_DEPTH = 1; |
| |
| /** |
| * Clears the cached computation of the <code>isActive</code> method, if |
| * any. This method is only intended for internal use. It provides a |
| * mechanism by which <code>ISourceProvider</code> events can invalidate |
| * state on a <code>IHandlerActivation</code> instance. |
| * |
| * @deprecated Use {@link IEvaluationResultCache#clearResult()} instead. |
| */ |
| public void clearActive(); |
| |
| /** |
| * Returns the identifier of the command whose handler is being activated. |
| * |
| * @return The command identifier; never <code>null</code>. |
| */ |
| public String getCommandId(); |
| |
| /** |
| * Returns the depth at which this activation was created within the |
| * services hierarchy. The root of the hierarchy is at a depth of |
| * <code>1</code>. This is used as the final tie-breaker in the event |
| * that no other method can be used to determine a winner. |
| * |
| * @return The depth at which the handler was inserted into the services |
| * hierarchy; should be a positive integer. |
| * @since 3.2 |
| */ |
| public int getDepth(); |
| |
| /** |
| * Returns the handler that should be activated. |
| * |
| * @return The handler; may be <code>null</code>. |
| */ |
| public IHandler getHandler(); |
| |
| /** |
| * Returns the handler service from which this activation was requested. |
| * This is used to ensure that an activation can only be retracted from the |
| * same service which issued it. |
| * |
| * @return The handler service; never <code>null</code>. |
| */ |
| public IHandlerService getHandlerService(); |
| |
| /** |
| * Returns whether this handler activation is currently active -- given the |
| * current state of the workbench. This method should cache its computation. |
| * The cache will be cleared by a call to <code>clearActive</code>. |
| * |
| * @param context |
| * The context in which this state should be evaluated; must not |
| * be <code>null</code>. |
| * @return <code>true</code> if the activation is currently active; |
| * <code>false</code> otherwise. |
| * @deprecated Use |
| * {@link IEvaluationResultCache#evaluate(IEvaluationContext)} |
| * instead. |
| */ |
| public boolean isActive(IEvaluationContext context); |
| } |