| /******************************************************************************* |
| * Copyright (c) 2000, 2004 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 |
| * IBM Corporation - added support for requesting updates of a particular |
| * container for generic container operations. |
| * - canUpdateClasspathContainer(IPath, IJavaProject) |
| * - requestClasspathContainerUpdate(IPath, IJavaProject, IClasspathContainer) |
| * IBM Corporation - allow initializers to provide a readable description |
| * of a container reference, ahead of actual resolution. |
| * - getDescription(IPath, IJavaProject) |
| *******************************************************************************/ |
| package org.eclipse.jdt.core; |
| |
| import org.eclipse.core.runtime.CoreException; |
| import org.eclipse.core.runtime.IPath; |
| |
| /** |
| * Abstract base implementation of all classpath container initializer. |
| * Classpath variable containers are used in conjunction with the |
| * "org.eclipse.jdt.core.classpathContainerInitializer" extension point. |
| * <p> |
| * Clients should subclass this class to implement a specific classpath |
| * container initializer. The subclass must have a public 0-argument |
| * constructor and a concrete implementation of <code>initialize</code>. |
| * <p> |
| * Multiple classpath containers can be registered, each of them declares |
| * the container ID they can handle, so as to narrow the set of containers they |
| * can resolve, in other words, a container initializer is guaranteed to only be |
| * activated to resolve containers which match the ID they registered onto. |
| * <p> |
| * In case multiple container initializers collide on the same container ID, the first |
| * registered one will be invoked. |
| * |
| * @see IClasspathEntry |
| * @see IClasspathContainer |
| * @since 2.0 |
| */ |
| public abstract class ClasspathContainerInitializer { |
| |
| /** |
| * Creates a new classpath container initializer. |
| */ |
| public ClasspathContainerInitializer() { |
| // a classpath container initializer must have a public 0-argument constructor |
| } |
| |
| /** |
| * Binds a classpath container to a <code>IClasspathContainer</code> for a given project, |
| * or silently fails if unable to do so. |
| * <p> |
| * A container is identified by a container path, which must be formed of two segments. |
| * The first segment is used as a unique identifier (which this initializer did register onto), and |
| * the second segment can be used as an additional hint when performing the resolution. |
| * <p> |
| * The initializer is invoked if a container path needs to be resolved for a given project, and no |
| * value for it was recorded so far. The implementation of the initializer would typically set the |
| * corresponding container using <code>JavaCore#setClasspathContainer</code>. |
| * <p> |
| * A container initialization can be indirectly performed while attempting to resolve a project |
| * classpath using <code>IJavaProject#getResolvedClasspath(</code>; or directly when using |
| * <code>JavaCore#getClasspathContainer</code>. During the initialization process, any attempt |
| * to further obtain the same container will simply return <code>null</code> so as to avoid an |
| * infinite regression of initializations. |
| * <p> |
| * A container initialization may also occur indirectly when setting a project classpath, as the operation |
| * needs to resolve the classpath for validation purpose. While the operation is in progress, a referenced |
| * container initializer may be invoked. If the initializer further tries to access the referring project classpath, |
| * it will not see the new assigned classpath until the operation has completed. Note that once the Java |
| * change notification occurs (at the end of the operation), the model has been updated, and the project |
| * classpath can be queried normally. |
| * <p> |
| * This method is called by the Java model to give the party that defined |
| * this particular kind of classpath container the chance to install |
| * classpath container objects that will be used to convert classpath |
| * container entries into simpler classpath entries. The method is typically |
| * called exactly once for a given Java project and classpath container |
| * entry. This method must not be called by other clients. |
| * <p> |
| * There are a wide variety of conditions under which this method may be |
| * invoked. To ensure that the implementation does not interfere with |
| * correct functioning of the Java model, the implementation should use |
| * only the following Java model APIs: |
| * <ul> |
| * <li>{@link JavaCore#setClasspathContainer(IPath, IJavaProject[], IClasspathContainer[], org.eclipse.core.runtime.IProgressMonitor)}</li> |
| * <li>{@link JavaCore#getClasspathContainer(IPath, IJavaProject)}</li> |
| * <li>{@link JavaCore#create(org.eclipse.core.resources.IWorkspaceRoot)}</li> |
| * <li>{@link JavaCore#create(org.eclipse.core.resources.IProject)}</li> |
| * <li>{@link IJavaModel#getJavaProjects()}</li> |
| * <li>Java element operations marked as "handle-only"</li> |
| * </ul> |
| * The effects of using other Java model APIs are unspecified. |
| * </p> |
| * |
| * @param containerPath a two-segment path (ID/hint) identifying the container that needs |
| * to be resolved |
| * @param project the Java project in which context the container is to be resolved. |
| * This allows generic containers to be bound with project specific values. |
| * @throws CoreException if an exception occurs during the initialization |
| * |
| * @see JavaCore#getClasspathContainer(IPath, IJavaProject) |
| * @see JavaCore#setClasspathContainer(IPath, IJavaProject[], IClasspathContainer[], org.eclipse.core.runtime.IProgressMonitor) |
| * @see IClasspathContainer |
| */ |
| public abstract void initialize(IPath containerPath, IJavaProject project) throws CoreException; |
| |
| /** |
| * Returns <code>true</code> if this container initializer can be requested to perform updates |
| * on its own container values. If so, then an update request will be performed using |
| * <code>ClasspathContainerInitializer#requestClasspathContainerUpdate</code>/ |
| * <p> |
| * @param containerPath the path of the container which requires to be updated |
| * @param project the project for which the container is to be updated |
| * @return returns <code>true</code> if the container can be updated |
| * @since 2.1 |
| */ |
| public boolean canUpdateClasspathContainer(IPath containerPath, IJavaProject project) { |
| |
| // By default, classpath container initializers do not accept updating containers |
| return false; |
| } |
| |
| /** |
| * Request a registered container definition to be updated according to a container suggestion. The container suggestion |
| * only acts as a place-holder to pass along the information to update the matching container definition(s) held by the |
| * container initializer. In particular, it is not expected to store the container suggestion as is, but rather adjust |
| * the actual container definition based on suggested changes. |
| * <p> |
| * IMPORTANT: In reaction to receiving an update request, a container initializer will update the corresponding |
| * container definition (after reconciling changes) at its earliest convenience, using |
| * <code>JavaCore#setClasspathContainer(IPath, IJavaProject[], IClasspathContainer[], IProgressMonitor)</code>. |
| * Until it does so, the update will not be reflected in the Java Model. |
| * <p> |
| * In order to anticipate whether the container initializer allows to update its containers, the predicate |
| * <code>JavaCore#canUpdateClasspathContainer</code> should be used. |
| * <p> |
| * @param containerPath the path of the container which requires to be updated |
| * @param project the project for which the container is to be updated |
| * @param containerSuggestion a suggestion to update the corresponding container definition |
| * @throws CoreException when <code>JavaCore#setClasspathContainer</code> would throw any. |
| * @see JavaCore#setClasspathContainer(IPath, IJavaProject[], IClasspathContainer[], org.eclipse.core.runtime.IProgressMonitor) |
| * @see ClasspathContainerInitializer#canUpdateClasspathContainer(IPath, IJavaProject) |
| * @since 2.1 |
| */ |
| public void requestClasspathContainerUpdate(IPath containerPath, IJavaProject project, IClasspathContainer containerSuggestion) throws CoreException { |
| |
| // By default, classpath container initializers do not accept updating containers |
| } |
| |
| /** |
| * Returns a readable description for a container path. A readable description for a container path can be |
| * used for improving the display of references to container, without actually needing to resolve them. |
| * A good implementation should answer a description consistent with the description of the associated |
| * target container (see <code>IClasspathContainer.getDescription()</code>). |
| * |
| * @param containerPath the path of the container which requires a readable description |
| * @param project the project from which the container is referenced |
| * @return a string description of the container |
| * @since 2.1 |
| */ |
| public String getDescription(IPath containerPath, IJavaProject project) { |
| |
| // By default, a container path is the only available description |
| return containerPath.makeRelative().toString(); |
| } |
| |
| /** |
| * Returns an object which identifies a container for comparison purpose. This allows |
| * to eliminate redundant containers when accumulating classpath entries (e.g. |
| * runtime classpath computation). When requesting a container comparison ID, one |
| * should ensure using its corresponding container initializer. Indeed, a random container |
| * initializer cannot be held responsible for determining comparison IDs for arbitrary |
| * containers. |
| * <p> |
| * @param containerPath the path of the container which is being checked |
| * @param project the project for which the container is to being checked |
| * @return returns an Object identifying the container for comparison |
| * @since 3.0 |
| */ |
| public Object getComparisonID(IPath containerPath, IJavaProject project) { |
| |
| // By default, containers are identical if they have the same containerPath first segment, |
| // but this may be refined by other container initializer implementations. |
| if (containerPath == null) { |
| return null; |
| } else { |
| return containerPath.segment(0); |
| } |
| } |
| } |
| |
