bundles/org.eclipse.emf.ecp.edit.swt/src/org/eclipse/emf/ecp/edit/internal/swt/controls/ReferenceMultiControlTester.java

/*******************************************************************************
 * Copyright (c) 2011-2013 EclipseSource Muenchen GmbH 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:
 * Eugen Neufeld - initial API and implementation
 * 
 *******************************************************************************/
package org.eclipse.emf.ecp.edit.internal.swt.controls;

import org.eclipse.emf.ecore.EAttribute;
import org.eclipse.emf.ecore.EObject;
import org.eclipse.emf.ecore.EReference;
import org.eclipse.emf.ecore.EStructuralFeature;
import org.eclipse.emf.ecp.edit.ECPControlDescription;
import org.eclipse.emf.ecp.edit.ECPControlFactory;
import org.eclipse.emf.ecp.edit.internal.swt.Activator;
import org.eclipse.emf.ecp.edit.util.ECPApplicableTester;
import org.eclipse.emf.ecp.edit.util.ECPStaticApplicableTester;
import org.eclipse.emf.edit.provider.IItemPropertyDescriptor;

/**
 * This is a dynamic tester for an reference multi control. It tests whether there is a control with a static tester
 * which would fit.
 * 
 * @author Eugen Neufeld
 * 
 */
public class ReferenceMultiControlTester implements ECPApplicableTester {

	/** {@inheritDoc} **/
	public int isApplicable(IItemPropertyDescriptor itemPropertyDescriptor, EObject eObject) {
		int bestPriority = NOT_APPLICABLE;
		ECPControlFactory controlFactory = Activator.getDefault().getECPControlFactory();
		if (controlFactory == null) {
			Activator.getDefault().ungetECPControlFactory();
			return bestPriority;
		}
		for (ECPControlDescription description : controlFactory.getControlDescriptors()) {
			for (ECPApplicableTester tester : description.getTester()) {
				if (ECPStaticApplicableTester.class.isInstance(tester)) {
					ECPStaticApplicableTester test = (ECPStaticApplicableTester) tester;
					int priority = getTesterPriority(test, itemPropertyDescriptor, eObject);
					if (bestPriority < priority) {
						bestPriority = priority;
					}
				} else {
					continue;
				}
			}
		}
		Activator.getDefault().ungetECPControlFactory();
		return bestPriority;
	}

	/**
	 * Calculates the priority of the attribute tester.
	 * 
	 * @param tester the tester to get the priority for
	 * @param itemPropertyDescriptor the {@link IItemPropertyDescriptor}
	 * @param eObject the {@link EObject}
	 * @return the priority
	 */
	public static int getTesterPriority(ECPStaticApplicableTester tester,
		IItemPropertyDescriptor itemPropertyDescriptor, EObject eObject) {

		if (!itemPropertyDescriptor.isMany(eObject)) {
			return NOT_APPLICABLE;
		}
		EStructuralFeature feature = (EStructuralFeature) itemPropertyDescriptor.getFeature(eObject);
		if (EAttribute.class.isInstance(feature)) {
			return NOT_APPLICABLE;
		} else if (EReference.class.isInstance(feature)) {
			if (((EReference) feature).isContainment()) {
				return NOT_APPLICABLE;
			}
			Class<?> instanceClass = feature.getEType().getInstanceClass();
			if (!tester.getSupportedClassType().isAssignableFrom(instanceClass)) {
				return NOT_APPLICABLE;
			}
		}
		if (!tester.isSingleValue()) {
			return NOT_APPLICABLE;
		}
		if (tester.getSupportedEObject().isInstance(eObject)
			&& (tester.getSupportedFeature() == null || feature.equals(eObject.eClass().getEStructuralFeature(
				tester.getSupportedFeature())))) {
			return tester.getPriority() + 1;
		}
		return NOT_APPLICABLE;
	}

}