bundles/org.eclipse.wst.jsdt.web.core/src/org/eclipse/wst/jsdt/web/core/internal/project/JsNatureUninstaller.java

package org.eclipse.wst.jsdt.web.core.internal.project;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IProjectNature;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.NullProgressMonitor;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.SubProgressMonitor;
import org.eclipse.wst.common.project.facet.core.IDelegate;
import org.eclipse.wst.common.project.facet.core.IProjectFacetVersion;
import org.eclipse.wst.jsdt.internal.core.JavaProject;
import org.eclipse.wst.jsdt.web.core.internal.JSPCorePlugin;

public class JsNatureUninstaller implements IDelegate{
	public void execute(IProject project, IProjectFacetVersion fv, Object config, IProgressMonitor monitor) throws CoreException {
		
		if (monitor == null) {
			monitor = new NullProgressMonitor();
		}
		
		monitor.beginTask("Uninstalling Facet for JavaScript Development Tools" + ".", 100); //$NON-NLS-1$

		try {
			uninstallNature(project,monitor);
		} finally {
			monitor.done();
		}

	}
	
	public void uninstallNature( IProject project, IProgressMonitor monitor ) throws CoreException{

		monitor.beginTask("Uninstalling JavaScript Development Tools...", 100 );
		
		//by using natures we can leverage the precondition support
		monitor.subTask( "Removing nature..." );
		SubProgressMonitor sub = new SubProgressMonitor( monitor, 25 );
		
		if(!JavaProject.hasJavaNature(project)) return;
		
		try{
			
			IProjectNature jsNature = new JavaProject();
			monitor.worked(20);
			jsNature.setProject(project);
			monitor.worked(50);
			jsNature.deconfigure();
			monitor.worked(20);
			
		}catch(CoreException e){
			throw new CoreException( new Status(
				IStatus.ERROR,
				JSPCorePlugin.PLUGIN_ID,
				IStatus.OK,
				"Error installing runtime! JavaScript Development Tools could not be removed, or is not present in target project..", e) );
		}
	}
}