ToggleNatureHandler.java

/**
 * 
 */
package se.sics.kompics.ide.builder;


import java.util.Iterator;

import org.eclipse.core.commands.AbstractHandler;
import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IProjectDescription;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.jface.viewers.ITreeSelection;
import org.eclipse.ui.handlers.HandlerUtil;

import se.sics.kompics.ide.Activator;

/**
 * The <code>ToggleNatureHandler</code> .
 *
 * @author Lars Kroll <lkr@lars-kroll.com>
 * @version $Id: $
 *
 */
public class ToggleNatureHandler extends AbstractHandler {

	/* (non-Javadoc)
	 * @see org.eclipse.core.commands.IHandler#execute(org.eclipse.core.commands.ExecutionEvent)
	 */
	@Override
	public Object execute(ExecutionEvent event) throws ExecutionException {
		ISelection iSel = HandlerUtil.getCurrentSelection(event);
		if (iSel instanceof IStructuredSelection) {
			IStructuredSelection selection = (ITreeSelection) iSel;
			for (Iterator it = ((IStructuredSelection) selection).iterator(); it
					.hasNext();) {
				Object element = it.next();
				IProject project = null;
				if (element instanceof IProject) {
					project = (IProject) element;
				} else if (element instanceof IAdaptable) {
					project = (IProject) ((IAdaptable) element)
							.getAdapter(IProject.class);
				}
				if (project != null) {
					toggleNature(project);
				}
			}
		} else {
			Activator.log("Unexpected selection type: " + iSel.getClass());
		}
		return null;
	}
	
	/**
	 * Toggles sample nature on a project
	 * 
	 * @param project
	 *            to have sample nature added or removed
	 */
	private void toggleNature(IProject project) {
		
		try {
			IProjectDescription description = project.getDescription();
			String[] natures = description.getNatureIds();
			Activator.log("Iterating over natures of Project: " + description.getName());
			for (int i = 0; i < natures.length; ++i) {
				Activator.log("Nature " + i + ": " + natures[i]);
				if (KompicsNature.NATURE_ID.equals(natures[i])) {
					// Remove the nature
					String[] newNatures = new String[natures.length - 1];
					System.arraycopy(natures, 0, newNatures, 0, i);
					System.arraycopy(natures, i + 1, newNatures, i,
							natures.length - i - 1);
					description.setNatureIds(newNatures);
					project.setDescription(description, null);
					Activator.log("toggling Kompics nature off");
					return;
				}
			}

			// Add the nature
			String[] newNatures = new String[natures.length + 1];
			System.arraycopy(natures, 0, newNatures, 0, natures.length);
			newNatures[natures.length] = KompicsNature.NATURE_ID;
			description.setNatureIds(newNatures);
			project.setDescription(description, null);
		} catch (CoreException e) {
			Activator.log(IStatus.ERROR, e.getMessage());
		}
		Activator.log("toggling Kompics nature on");
	}

}