AbstractCSpecAction.java

/*****************************************************************************
 * Copyright (c) 2006-2013, Cloudsmith Inc.
 * The code, documentation and other materials contained herein have been
 * licensed under the Eclipse Public License - v 1.0 by the copyright holder
 * listed above, as the Initial Contributor under such license. The text of
 * such license is available at www.eclipse.org.
 *****************************************************************************/
package org.eclipse.buckminster.ui;

import org.eclipse.buckminster.core.CorePlugin;
import org.eclipse.buckminster.core.cspec.model.CSpec;
import org.eclipse.buckminster.core.metadata.MetadataSynchronizer;
import org.eclipse.buckminster.core.metadata.WorkspaceInfo;
import org.eclipse.buckminster.runtime.AttachableProgressMonitor;
import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.QualifiedName;
import org.eclipse.core.runtime.jobs.IJobChangeEvent;
import org.eclipse.core.runtime.jobs.IJobChangeListener;
import org.eclipse.core.runtime.jobs.IJobManager;
import org.eclipse.core.runtime.jobs.Job;
import org.eclipse.core.runtime.jobs.JobChangeAdapter;
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.dialogs.MessageDialog;
import org.eclipse.jface.viewers.ISelection;
import org.eclipse.jface.viewers.IStructuredSelection;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.ui.IObjectActionDelegate;
import org.eclipse.ui.IWorkbenchPart;
import org.eclipse.ui.IWorkbenchPartSite;

/**
 * Operate on the selected object adapted to CSpec.class.
 *
 * @author Thomas Hallgren
 * @author Henrik Lindberg
 */
public abstract class AbstractCSpecAction implements IObjectActionDelegate {
	protected IWorkbenchPart activePart;

	private CSpec selectedComponent;

	private IAdaptable selection;

	/**
	 * tries to obtain a CSpec from the current selection. This operation is
	 * potentially long running if {@link WorkspaceInfo} has not been
	 * initialized yet.
	 *
	 * @param progressMonitor
	 * @return the cspec for the given component or <code>null</code> if not
	 *         available
	 * @see WorkspaceInfo#isFullyInitialized()
	 */
	public CSpec fetchCSpec(final IProgressMonitor progressMonitor) {
		if (selectedComponent != null) {
			return selectedComponent;
		} else if (selection != null) {
			if (WorkspaceInfo.isFullyInitialized() || Job.getJobManager().isSuspended()) {
				// Query the cspec directly if the WorkspaceInfo is already
				// initialized or fall back to
				// blocking mode if the job manager is currently suspended.
				selectedComponent = selection.getAdapter(CSpec.class);
				progressMonitor.done();
			} else {
				// if WorkspaceInfo has not been initialized and the JobManager
				// is not suspended we try to attach the
				// given progress monitor to the CatchUpWorkspaceJob
				IJobChangeListener listener = new JobListener(progressMonitor);
				Job.getJobManager().addJobChangeListener(listener);
				selectedComponent = selection.getAdapter(CSpec.class);
				Job.getJobManager().removeJobChangeListener(listener);
			}

		}
		return selectedComponent;
	}

	protected abstract void run(CSpec cspec, Shell shell);

	@Override
	public void run(IAction action) {
		if (activePart == null)
			return;

		IWorkbenchPartSite site = activePart.getSite();
		final Shell shell = site.getShell();
		if (selectedComponent == null) {
			run(shell);
		} else {
			run(selectedComponent, shell);
		}

	}

	protected void run(Shell shell) {
		MessageDialog.openInformation(shell, null, Messages.no_component_is_selected);

	}

	@Override
	public void selectionChanged(IAction action, ISelection _selection) {
		selectedComponent = null;
		if (!(_selection instanceof IStructuredSelection))
			return;

		IStructuredSelection s = (IStructuredSelection) _selection;
		if (s.size() != 1)
			return;

		Object first = s.getFirstElement();
		// If the selected object is a CSpec, or adaptable to CSpec, use it.
		if (first instanceof IAdaptable) {
			// if the WorkspaceInfo is already initialized, it's safe to query
			// directly for the adapter
			if (WorkspaceInfo.isFullyInitialized()) {
				selectedComponent = ((IAdaptable) first).getAdapter(CSpec.class);
				action.setEnabled(selectedComponent != null);
			} else {
				action.setEnabled(true);
			}

			selection = (IAdaptable) first;
		}

	}

	@Override
	public void setActivePart(IAction action, IWorkbenchPart targetPart) {
		activePart = targetPart;
	}

	protected void setSelectedComponent(CSpec cspec) {
		selectedComponent = cspec;
	}
}

/**
 * Monitors the jobs that are changed to running and scheduled state until it
 * finds the WorkspaceCatchUpJob. Once this job is found, it is asked for an
 * {@link AttachableProgressMonitor}. The given {@link IProgressMonitor} will be
 * attached to the # {@link AttachableProgressMonitor} and the listener removes
 * itself from the {@link IJobManager}
 *
 *
 * @see AttachableProgressMonitor
 * @see IJobManager#removeJobChangeListener(IJobChangeListener)
 * @author Johannes Utzig
 *
 */
class JobListener extends JobChangeAdapter {

	private static final QualifiedName QN_ATTACHABLE_PROGRESS_MONITOR = new QualifiedName(CorePlugin.getID(), "attachableProgressMonitor"); //$NON-NLS-1$

	private IProgressMonitor monitorToAttach;

	public JobListener(IProgressMonitor monitorToAttach) {
		super();
		this.monitorToAttach = monitorToAttach;
	}

	private void handleEvent(IJobChangeEvent event) {
		if (event.getJob().belongsTo(MetadataSynchronizer.class)) {
			Job job = event.getJob();

			Object o = job.getProperty(QN_ATTACHABLE_PROGRESS_MONITOR);
			if (o instanceof AttachableProgressMonitor) {
				// that we got here means that we found the CatchUpWorkspaceJob
				// so the listener can deregister itself
				// now
				AttachableProgressMonitor monitor = (AttachableProgressMonitor) o;
				Job.getJobManager().removeJobChangeListener(this);
				monitor.attachProgressMonitor(monitorToAttach);

			}
		}
	}

	@Override
	public void running(IJobChangeEvent event) {
		handleEvent(event);
	}

	@Override
	public void scheduled(IJobChangeEvent event) {
		handleEvent(event);
	}

}