/*******************************************************************************
* Copyright (c) 2014 Oracle and Accenture
* 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:
* Konstantin Komissarchik - initial implementation and ongoing maintenance
* Kamesh Sampath - initial implementation
*******************************************************************************/
package org.eclipse.sapphire.internal;
import org.eclipse.sapphire.Element;
import org.eclipse.sapphire.Event;
import org.eclipse.sapphire.InitialValueService;
import org.eclipse.sapphire.Listener;
import org.eclipse.sapphire.LoggingService;
import org.eclipse.sapphire.PropertyDef;
import org.eclipse.sapphire.Sapphire;
import org.eclipse.sapphire.modeling.annotations.InitialValue;
import org.eclipse.sapphire.modeling.el.FailSafeFunction;
import org.eclipse.sapphire.modeling.el.Function;
import org.eclipse.sapphire.modeling.el.FunctionResult;
import org.eclipse.sapphire.modeling.el.Literal;
import org.eclipse.sapphire.modeling.el.ModelElementFunctionContext;
import org.eclipse.sapphire.modeling.el.parser.ExpressionLanguageParser;
import org.eclipse.sapphire.services.ServiceCondition;
import org.eclipse.sapphire.services.ServiceContext;
/**
* Implementation of {@link InitialValueService} that draws the initial value from @{@link InitialValue} annotation.
*
* @author <a href="mailto:konstantin.komissarchik@oracle.com">Konstantin Komissarchik</a>
* @author <a href="mailto:kamesh.sampath@accenture.com">Kamesh Sampath</a>
*/
public final class StandardInitialValueService extends InitialValueService
{
private FunctionResult functionResult;
@Override
protected void initInitialValueService()
{
final InitialValue annotation = context( PropertyDef.class ).getAnnotation( InitialValue.class );
if( annotation != null )
{
final String expr = annotation.text();
if( expr.length() > 0 )
{
Function function = null;
try
{
function = ExpressionLanguageParser.parse( expr );
}
catch( Exception e )
{
Sapphire.service( LoggingService.class ).log( e );
function = null;
}
if( function != null )
{
function = FailSafeFunction.create( function, Literal.create( String.class ) );
final ModelElementFunctionContext context = new ModelElementFunctionContext( context( Element.class ) );
this.functionResult = function.evaluate( context );
final Listener listener = new Listener()
{
@Override
public void handle( final Event event )
{
refresh();
}
};
this.functionResult.attach( listener );
}
}
}
}
@Override
protected String compute()
{
if( this.functionResult == null )
{
return null;
}
else
{
return (String) this.functionResult.value();
}
}
@Override
public void dispose()
{
super.dispose();
if( this.functionResult != null )
{
try
{
this.functionResult.dispose();
}
catch( Exception e )
{
Sapphire.service( LoggingService.class ).log( e );
}
}
}
public static final class Condition extends ServiceCondition
{
@Override
public boolean applicable( final ServiceContext context )
{
final PropertyDef property = context.find( PropertyDef.class );
if( property != null )
{
return property.hasAnnotation( InitialValue.class );
}
return false;
}
}
}