org.eclipse.jdt.internal.core.DiscardWorkingCopyOperation.java Source code

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Here is the source code for org.eclipse.jdt.internal.core.DiscardWorkingCopyOperation.java

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/*******************************************************************************
 * Copyright (c) 2000, 2015 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Stephan Herrmann - Contribution for
 *                        Bug 458577 - IClassFile.getWorkingCopy() may lead to NPE in BecomeWorkingCopyOperation
 *******************************************************************************/
package org.eclipse.jdt.internal.core;

import org.eclipse.core.resources.IResource;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IJavaElementDelta;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.JavaModelException;

/**
 * Discards a working copy (decrement its use count and remove its working copy info if the use count is 0)
 * and signal its removal through a delta.
 */
public class DiscardWorkingCopyOperation extends JavaModelOperation {

    public DiscardWorkingCopyOperation(IJavaElement workingCopy) {
        super(new IJavaElement[] { workingCopy });
    }

    @Override
    protected void executeOperation() throws JavaModelException {
        CompilationUnit workingCopy = getWorkingCopy();

        JavaModelManager manager = JavaModelManager.getJavaModelManager();
        int useCount = manager.discardPerWorkingCopyInfo(workingCopy);
        if (useCount == 0) {
            IJavaProject javaProject = workingCopy.getJavaProject();
            if (ExternalJavaProject.EXTERNAL_PROJECT_NAME.equals(javaProject.getElementName())) {
                manager.removePerProjectInfo((JavaProject) javaProject,
                        true /* remove external jar files indexes and timestamps*/);
                manager.containerRemove(javaProject);
            }
            if (!workingCopy.isPrimary()) {
                // report removed java delta for a non-primary working copy
                JavaElementDelta delta = new JavaElementDelta(getJavaModel());
                delta.removed(workingCopy);
                addDelta(delta);
                removeReconcileDelta(workingCopy);
            } else {
                IResource resource = workingCopy.getResource();
                if (resource != null) {
                    if (resource.isAccessible()) {
                        // report a F_PRIMARY_WORKING_COPY change delta for a primary working copy
                        JavaElementDelta delta = new JavaElementDelta(getJavaModel());
                        delta.changed(workingCopy, IJavaElementDelta.F_PRIMARY_WORKING_COPY);
                        addDelta(delta);
                    } else {
                        // report a REMOVED delta
                        JavaElementDelta delta = new JavaElementDelta(getJavaModel());
                        delta.removed(workingCopy, IJavaElementDelta.F_PRIMARY_WORKING_COPY);
                        addDelta(delta);
                    }
                }
            }
        }
    }

    /**
     * Returns the working copy this operation is working on.
     */
    protected CompilationUnit getWorkingCopy() {
        return (CompilationUnit) getElementToProcess();
    }

    /**
     * @see JavaModelOperation#isReadOnly
     */
    @Override
    public boolean isReadOnly() {
        return true;
    }
}