plugins/org.eclipse.emf.parsley.common/src/org/eclipse/emf/parsley/ui/provider/FeatureCaptionProvider.java

/*******************************************************************************
 * Copyright (c) 2013 RCP Vision (http://www.rcp-vision.com) 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:
 * Lorenzo Bettini - initial API and implementation
 *******************************************************************************/
package org.eclipse.emf.parsley.ui.provider;

import org.eclipse.emf.parsley.runtime.util.PolymorphicDispatcher;

import java.lang.reflect.Method;
import java.util.Collections;

import org.eclipse.emf.ecore.EStructuralFeature;

import com.google.common.base.Predicate;

/**
 * Provides captions for EStructuralFeatures
 * 
 * @author Lorenzo Bettini - Initial Contribution and API
 * 
 */
public class FeatureCaptionProvider {

	private PolymorphicDispatcher.ErrorHandler<String> errorHandler = new PolymorphicDispatcher.NullErrorHandler<String>();

	public String getText(EStructuralFeature element) {
		String text = polymorphicGetText(element);
		if (text != null) {
			return text;
		}
		return defaultText(element);
	}

	protected String polymorphicGetText(EStructuralFeature element) {
		PolymorphicDispatcher<String> dispatcher = new PolymorphicDispatcher<String>(
				Collections.singletonList(this), getTextPredicate(element),
				errorHandler) {
			@Override
			protected String handleNoSuchMethod(Object... params) {
				if (PolymorphicDispatcher.NullErrorHandler.class
						.equals(errorHandler.getClass()))
					return null;
				return super.handleNoSuchMethod(params);
			}
		};

		return dispatcher.invoke(element);
	}

	protected Predicate<Method> getTextPredicate(EStructuralFeature feature) {
		String methodName = "text_" + feature.getEContainingClass().getName()
				+ "_" + feature.getName();
		return PolymorphicDispatcher.Predicates.forName(methodName, 1);
	}

	protected String defaultText(EStructuralFeature element) {
		return element.getName();
	}
}