Fix Findbugs warnings

[deliverable/tracecompass.git] / org.eclipse.linuxtools.lttng2.ui / src / org / eclipse / linuxtools / internal / lttng2 / ui / views / control / handlers / BaseCreateChannelHandler.java

/**********************************************************************
 * Copyright (c) 2012 Ericsson
 * 
 * All rights reserved. This program and the accompanying materials are
 * made available under the terms of the Eclipse Public License v1.0 which
 * accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors: 
 *   Bernd Hufmann - Initial API and implementation
 **********************************************************************/
package org.eclipse.linuxtools.internal.lttng2.ui.views.control.handlers;

import java.util.ArrayList;
import java.util.List;

import org.eclipse.core.commands.ExecutionEvent;
import org.eclipse.core.commands.ExecutionException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.jobs.Job;
import org.eclipse.jface.window.Window;
import org.eclipse.linuxtools.internal.lttng2.ui.Activator;
import org.eclipse.linuxtools.internal.lttng2.ui.views.control.Messages;
import org.eclipse.linuxtools.internal.lttng2.ui.views.control.dialogs.ICreateChannelDialog;
import org.eclipse.linuxtools.internal.lttng2.ui.views.control.dialogs.TraceControlDialogFactory;
import org.eclipse.linuxtools.internal.lttng2.ui.views.control.model.IChannelInfo;
import org.eclipse.linuxtools.internal.lttng2.ui.views.control.model.impl.TraceDomainComponent;

/**
 * <b><u>BaseCreateChannelHandler</u></b>
 * <p>
 * Base implementation of aCommand handler implementation to create a trace channel.  
 * </p>
 */
abstract class BaseCreateChannelHandler extends BaseControlViewHandler {

    // ------------------------------------------------------------------------
    // Attributes
    // ------------------------------------------------------------------------
    protected CommandParameter fParam;

    // ------------------------------------------------------------------------
    // Operations
    // ------------------------------------------------------------------------
    /**
     * Enables channels with given names which are part of this domain. If a given channel 
     * doesn't exists it creates a new channel with the given parameters (or default values 
     * if given parameter is null). 
     * @param - a parameter instance with data for the command execution
     * @param channelNames - a list of channel names to enable on this domain
     * @param info - channel information to set for the channel (use null for default)
     * @param isKernel -  a flag for indicating kernel or UST.
     * @param monitor - a progress monitor
     * @throws ExecutionException
     */
    abstract public void enableChannel(CommandParameter param, List<String> channelNames, IChannelInfo info, boolean isKernel, IProgressMonitor monitor) throws ExecutionException; 
    
    /**
     * @param - a parameter instance with data for the command execution
     * @return returns the relevant domain (null if domain is not known)
     */
    abstract public TraceDomainComponent getDomain(CommandParameter param);

    /*
     * (non-Javadoc)
     * @see org.eclipse.core.commands.AbstractHandler#execute(org.eclipse.core.commands.ExecutionEvent)
     */
    @Override
    public Object execute(ExecutionEvent event) throws ExecutionException {
        fLock.lock();
        try {
            final CommandParameter param = fParam.clone();

            final ICreateChannelDialog dialog =  TraceControlDialogFactory.getInstance().getCreateChannelDialog();
            dialog.setDomainComponent(getDomain(param));

            if (dialog.open() != Window.OK) {
                return null;
            }

            Job job = new Job(Messages.TraceControl_ChangeChannelStateJob) {
                @Override
                protected IStatus run(IProgressMonitor monitor) {
                    StringBuffer errorString = new StringBuffer();

                    List<String> channelNames = new ArrayList<String>();                    
                    channelNames.add(dialog.getChannelInfo().getName());

                    try {
                        enableChannel(param, channelNames, dialog.getChannelInfo(), dialog.isKernel(), monitor);
                    } catch (ExecutionException e) {
                        errorString.append(e.toString());
                        errorString.append("\n"); //$NON-NLS-1$
                    }

                    // get session configuration in all cases
                    try {
                        param.getSession().getConfigurationFromNode(monitor);
                    } catch (ExecutionException e) {
                        errorString.append(Messages.TraceControl_ListSessionFailure);
                        errorString.append(": "); //$NON-NLS-1$
                        errorString.append(e.toString());
                    } 

                    if (errorString.length() > 0) {
                        return new Status(Status.ERROR, Activator.PLUGIN_ID, errorString.toString());
                    }
                    return Status.OK_STATUS;
                }
            };
            job.setUser(true);
            job.schedule();
        } finally {
            fLock.unlock();
        }
        return null;
    }

}