| /******************************************************************************* |
| * Copyright (c) 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.help.internal.base; |
| |
| import org.eclipse.core.expressions.EvaluationContext; |
| import org.eclipse.core.runtime.Platform; |
| |
| /* |
| * Supplies en evaluation context for filtering help documents. This is used for |
| * resolving variables in enablement expressions. |
| */ |
| public final class HelpEvaluationContext { |
| |
| private static final String VARIABLE_PLATFORM = "platform"; //$NON-NLS-1$ |
| |
| private static EvaluationContext context; |
| |
| /* |
| * Returns the evaluation context to use in help documents. |
| */ |
| public static EvaluationContext getContext() { |
| if (context == null) { |
| context = new EvaluationContext(null, Platform.class) { |
| public Object getVariable(String name) { |
| if (VARIABLE_PLATFORM.equals(name)) { |
| return Platform.class; |
| } |
| return null; |
| } |
| }; |
| } |
| return context; |
| } |
| |
| /* |
| * Sets the evaluation context to use in help documents. If help is running in |
| * workbench mode, the UI plug-in will contribute a context that also handles |
| * UI-related variables. |
| */ |
| public static void setContext(EvaluationContext context) { |
| HelpEvaluationContext.context = context; |
| } |
| |
| /* |
| * Not meant to be instantiated. |
| */ |
| private HelpEvaluationContext() { |
| } |
| } |