bundles/org.eclipse.wst.jsdt.core/src/org/eclipse/wst/jsdt/core/WorkingCopyOwner.java

/*******************************************************************************
 * Copyright (c) 2000, 2009 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.wst.jsdt.core;

import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.Path;
import org.eclipse.wst.jsdt.internal.core.BufferManager;
import org.eclipse.wst.jsdt.internal.core.CompilationUnit;
import org.eclipse.wst.jsdt.internal.core.DefaultWorkingCopyOwner;
import org.eclipse.wst.jsdt.internal.core.ExternalJavaProject;
import org.eclipse.wst.jsdt.internal.core.PackageFragment;

/**
 * The owner of an {@link IJavaScriptUnit} handle in working copy mode.
 * An owner is used to identify a working copy and to create its buffer.
 * <p>
 * Clients should subclass this class to instantiate a working copy owner that is specific to their need and that
 * they can pass in to various APIs (e.g. {@link IType#resolveType(String, WorkingCopyOwner)}.
 * Clients can also override the default implementation of {@link #createBuffer(IJavaScriptUnit)}.
 * </p><p>
 * Note: even though this class has no abstract method, which means that it provides functional default behavior,
 * it is still an abstract class, as clients are intended to own their owner implementation.
 * </p>
 * @see IJavaScriptUnit#becomeWorkingCopy(org.eclipse.core.runtime.IProgressMonitor)
 * @see IJavaScriptUnit#discardWorkingCopy()
 * @see IJavaScriptUnit#getWorkingCopy(org.eclipse.core.runtime.IProgressMonitor)
 *  
 * Provisional API: This class/interface is part of an interim API that is still under development and expected to 
 * change significantly before reaching stability. It is being made available at this early stage to solicit feedback 
 * from pioneering adopters on the understanding that any code that uses this API will almost certainly be broken 
 * (repeatedly) as the API evolves.
 */
public abstract class WorkingCopyOwner {

	/**
	 * Sets the buffer provider of the primary working copy owner. Note that even if the
	 * buffer provider is a working copy owner, only its <code>createBuffer(IJavaScriptUnit)</code>
	 * method is used by the primary working copy owner. It doesn't replace the internal primary
	 * working owner.
 	 * <p>
	 * This method is for internal use by the jsdt-related plug-ins.
	 * Clients outside of the jsdt should not reference this method.
	 * </p>
	 *
	 * @param primaryBufferProvider the primary buffer provider
	 */
	public static void setPrimaryBufferProvider(WorkingCopyOwner primaryBufferProvider) {
		DefaultWorkingCopyOwner.PRIMARY.primaryBufferProvider = primaryBufferProvider;
	}

	/**
	 * Creates a buffer for the given working copy.
	 * The new buffer will be initialized with the contents of the underlying file
	 * if and only if it was not already initialized by the compilation owner (a buffer is
	 * uninitialized if its content is <code>null</code>).
	 * <p>
	 * Note: This buffer will be associated to the working copy for its entire life-cycle. Another
	 * working copy on same unit but owned by a different owner would not share the same buffer
	 * unless its owner decided to implement such a sharing behaviour.
	 * </p>
	 *
	 * @param workingCopy the working copy of the buffer
	 * @return IBuffer the created buffer for the given working copy
	 * @see IBuffer
	 */
	public IBuffer createBuffer(IJavaScriptUnit workingCopy) {

		return BufferManager.createBuffer(workingCopy);
	}

	/**
	 * Returns the problem requestor used by a working copy of this working copy owner.
	 * <p>
	 * By default, no problem requestor is configured. Clients can override this
	 * method to provide a requestor.
	 * </p>
	 *
	 * @param workingCopy The problem requestor used for the given working copy.
	 * @return the problem requestor to be used by working copies of this working
	 * copy owner or <code>null</code> if no problem requestor is configured.
	 *
	 */
	public IProblemRequestor getProblemRequestor(IJavaScriptUnit workingCopy) {
		return null;
	}

	/**
	 * Returns a new working copy with the given name using this working copy owner to
	 * create its buffer.
	 * <p>
	 * This working copy always belongs to the default package in a package
	 * fragment root that corresponds to its JavaScript project, and this JavaScript project never exists.
	 * However this JavaScript project has the given includepath that is used when resolving names
	 * in this working copy.
	 * </p><p>
	 * If a DOM AST is created using this working copy, then given includepath will be used
	 *  if bindings need to be resolved. Problems will be reported to the problem requestor
	 * of the current working copy owner problem if it is not <code>null</code>.
	 * <p></p>
	 * Options used to create the DOM AST are got from {@link JavaScriptCore#getOptions()}
	 * as it is not possible to set the options on a non-existing JavaScript project.
	 * </p><p>
	 * When the working copy instance is created, an {@link IJavaScriptElementDelta#ADDED added delta} is
	 * reported on this working copy.
	 * </p><p>
	 * Once done with the working copy, users of this method must discard it using
	 * {@link IJavaScriptUnit#discardWorkingCopy()}.
	 * </p><p>
	 * Note that when such working copy is committed, only its buffer is saved (see
	 * {@link IBuffer#save(IProgressMonitor, boolean)}) but no resource is created.
	 * </p><p>
	 * This method is not intended to be overriden by clients.
	 * </p>
	 *
	 * @param name the name of the working copy (e.g. "X.js")
	 * @param classpath the includepath used to resolve names in this working copy
	 * @param monitor a progress monitor used to report progress while opening the working copy
	 * 	or <code>null</code> if no progress should be reported
	 * @throws JavaScriptModelException if the contents of this working copy can
	 *   not be determined.
	 * @return a new working copy
	 * @see IJavaScriptUnit#becomeWorkingCopy(IProgressMonitor)
	 *
	 */
	public final IJavaScriptUnit newWorkingCopy(String name, IIncludePathEntry[] classpath, IProgressMonitor monitor) throws JavaScriptModelException {
		ExternalJavaProject project = new ExternalJavaProject(classpath);
		IPackageFragment parent = project.getPackageFragmentRoot(Path.EMPTY).getPackageFragment(IPackageFragment.DEFAULT_PACKAGE_NAME);
		CompilationUnit result = new CompilationUnit((PackageFragment) parent, name, this);
		result.becomeWorkingCopy(getProblemRequestor(result), monitor);
		return result;
	}

}