/*****************************************************************************
* Copyright (c) 2006-2008 g-Eclipse Consortium
* 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
*
* Initial development of the original code was made for the
* g-Eclipse project founded by European Union
* project number: FP6-IST-034327 http://www.geclipse.eu/
*
* Contributors:
* Mathias Stuempert - initial API and implementation
*****************************************************************************/
package eu.geclipse.core.internal.model;
import eu.geclipse.core.model.IDefaultGridElementManager;
import eu.geclipse.core.model.IGridElement;
import eu.geclipse.core.reporting.ProblemException;
/**
* Internal abstract implementation of an {@link IDefaultGridElementManager}.
*/
public abstract class AbstractDefaultGridElementManager
extends AbstractGridElementManager
implements IDefaultGridElementManager {
/**
* The current default element.
*/
private IGridElement defaultElement;
/* (non-Javadoc)
* @see eu.geclipse.core.model.IDefaultGridElementManager#getDefault()
*/
public IGridElement getDefault() {
return this.defaultElement;
}
/* (non-Javadoc)
* @see eu.geclipse.core.model.IDefaultGridElementManager#setDefault(eu.geclipse.core.model.IGridElement)
*/
public void setDefault( final IGridElement element ) throws ProblemException {
if ( ( element != null ) && ( element != this.defaultElement ) ) {
addElement( element );
this.defaultElement = element;
updateDefault();
}
}
/* (non-Javadoc)
* @see eu.geclipse.core.internal.model.AbstractGridElementManager#addElement(eu.geclipse.core.model.IGridElement)
*/
@Override
public boolean addElement( final IGridElement element ) throws ProblemException {
boolean result = super.addElement( element );
if ( result ) {
updateDefault();
}
return result;
}
/* (non-Javadoc)
* @see eu.geclipse.core.internal.model.AbstractGridElementManager#removeElement(eu.geclipse.core.model.IGridElement)
*/
@Override
public boolean removeElement( final IGridElement element ) {
boolean result = super.removeElement( element );
if ( result ) {
updateDefault();
}
return result;
}
/**
* Update the default element.
*
* @return True if the default element has changed during this
* operation.
*/
protected boolean updateDefault() {
boolean changed = false;
if ( ( this.defaultElement != null )
&& !contains( this.defaultElement ) ) {
this.defaultElement = null;
changed = true;
}
if ( ( this.defaultElement == null ) && hasChildren() ) {
this.defaultElement = getChildren( null )[0];
changed = true;
}
return changed;
}
}