org.eclipse.ziggurat.inject.BindingManager.java Source code

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Here is the source code for org.eclipse.ziggurat.inject.BindingManager.java

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/*******************************************************************************
 * Copyright (c) 2013 Atos.
 * 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:
 *     Atos - initial API and implementation
 ******************************************************************************/
package org.eclipse.ziggurat.inject;

import java.util.Collection;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Map;
import java.util.SortedSet;
import java.util.TreeSet;

import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.InvalidRegistryObjectException;
import org.eclipse.core.runtime.Platform;
import org.eclipse.e4.core.di.InjectorFactory;

import com.google.common.base.Supplier;
import com.google.common.collect.Multimaps;
import com.google.common.collect.SortedSetMultimap;

@SuppressWarnings({ "rawtypes", "restriction" })
public class BindingManager {

    private static String EXT_POINT = "binding";

    @SuppressWarnings("unchecked")
    public static void registerBindings() {
        Map<Class, Collection<PriorityClass>> map = new HashMap<Class, Collection<PriorityClass>>();
        Supplier<SortedSet<PriorityClass>> factory = new Supplier<SortedSet<PriorityClass>>() {

            @Override
            public SortedSet<PriorityClass> get() {
                SortedSet<PriorityClass> sorted = new TreeSet<PriorityClass>(new Comparator<PriorityClass>() {
                    @Override
                    public int compare(PriorityClass o1, PriorityClass o2) {
                        int result = new Integer(o1.priority).compareTo(o2.priority);
                        if (result == 0 && !o1.equals(o2)) {
                            result = -1;
                        }
                        return result;
                    }
                });
                return sorted;
            }
        };
        SortedSetMultimap<Class, PriorityClass> multi = Multimaps.newSortedSetMultimap(map, factory);
        IConfigurationElement[] elements = Platform.getExtensionRegistry()
                .getConfigurationElementsFor(ZigguratInject.PLUGIN_ID, EXT_POINT);
        for (IConfigurationElement e : elements) {
            String theInterface = e.getAttribute("interface");
            String theImpl = e.getAttribute("impl");
            String name = e.getAttribute("name");
            Class theInterfaceC = loadClass(e, theInterface);
            Class theImplC = loadClass(e, theImpl);
            int priority = 0;
            String prio = e.getAttribute("priority");
            if (prio != null && prio.length() > 0) {
                try {
                    priority = Integer.parseInt(prio);
                } catch (NumberFormatException ex) {
                }
            }
            if (theInterfaceC != null && theImplC != null && theInterfaceC.isAssignableFrom(theImplC)) {
                PriorityClass priorityClass = new PriorityClass();
                priorityClass.aClass = theImplC;
                priorityClass.priority = priority;
                priorityClass.name = name;
                multi.put(theInterfaceC, priorityClass);
            }
        }
        for (Class c : multi.keys()) {
            PriorityClass last = null;
            // for each priority class if name is present a binding is created with the given name
            for (PriorityClass pc : multi.get(c)) {
                if (pc.name != null && pc.name.length() > 0) {
                    InjectorFactory.getDefault().addBinding(c).implementedBy(pc.aClass).named(pc.name);
                }
                last = pc;
            }
            if (last != null) {
                // the binding by default is made by a class with no name
                InjectorFactory.getDefault().addBinding(c).implementedBy(last.aClass);
            }
        }

    }

    private static Class loadClass(IConfigurationElement e, String theClass) {
        try {
            return Platform.getBundle(e.getContributor().getName()).loadClass(theClass);
        } catch (InvalidRegistryObjectException e1) {
            e1.printStackTrace();
        } catch (ClassNotFoundException e1) {
            e1.printStackTrace();
        }
        return null;
    }

    private static class PriorityClass {

        public String name;

        public Class aClass;

        public int priority;
    }

}