/*******************************************************************************
 * Copyright (c) 2008 IBM Corporation and others.
 * 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:
 *     IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.debug.examples.ui.midi.adapters;

import javax.sound.midi.MidiEvent;
import javax.sound.midi.Track;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.debug.internal.ui.model.elements.ElementContentProvider;
import org.eclipse.debug.internal.ui.viewers.model.provisional.IPresentationContext;
import org.eclipse.debug.internal.ui.viewers.model.provisional.IViewerUpdate;
import org.eclipse.debug.ui.IDebugUIConstants;

/**
 * Content provider for track in the variables view. Returns MIDI events
 * in the track.
 * 
 * @since 1.0
 */
public class TrackContentProvider extends ElementContentProvider {

	/* (non-Javadoc)
	 * @see org.eclipse.debug.internal.ui.model.elements.ElementContentProvider#getChildCount(java.lang.Object, org.eclipse.debug.internal.ui.viewers.model.provisional.IPresentationContext, org.eclipse.debug.internal.ui.viewers.model.provisional.IViewerUpdate)
	 */
	protected int getChildCount(Object element, IPresentationContext context, IViewerUpdate monitor) throws CoreException {
		Track track = (Track) element;
		if (IDebugUIConstants.ID_VARIABLE_VIEW.equals(context.getId())) {
			return track.size();
		}
		return 0;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.debug.internal.ui.model.elements.ElementContentProvider#getChildren(java.lang.Object, int, int, org.eclipse.debug.internal.ui.viewers.model.provisional.IPresentationContext, org.eclipse.debug.internal.ui.viewers.model.provisional.IViewerUpdate)
	 */
	protected Object[] getChildren(Object parent, int index, int length, IPresentationContext context, IViewerUpdate monitor) throws CoreException {
		if (IDebugUIConstants.ID_VARIABLE_VIEW.equals(context.getId())) {
			Track track = (Track) parent;
			MidiEvent[] events= new MidiEvent[length];
			for (int i = 0; i < length; i++) {
				events[i] = track.get(i+index); 
			}
			return events;
		}
		return EMPTY;
	}

	/* (non-Javadoc)
	 * @see org.eclipse.debug.internal.ui.model.elements.ElementContentProvider#supportsContextId(java.lang.String)
	 */
	protected boolean supportsContextId(String id) {
		return IDebugUIConstants.ID_VARIABLE_VIEW.equals(id);
	}

}