/*******************************************************************************
* Copyright (c) 2008, 2014 Stuart McCulloch
* 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:
* Stuart McCulloch - initial API and implementation
*******************************************************************************/
package org.eclipse.sisu.peaberry.eclipse;
import static com.google.inject.Guice.createInjector;
import static org.eclipse.core.runtime.ContributorFactoryOSGi.resolve;
import static org.eclipse.core.runtime.RegistryFactory.getRegistry;
import static org.eclipse.sisu.peaberry.eclipse.EclipseRegistry.eclipseRegistry;
import static org.eclipse.sisu.peaberry.Peaberry.osgiModule;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.logging.Logger;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IContributor;
import org.eclipse.core.runtime.IExecutableExtension;
import org.eclipse.core.runtime.IExecutableExtensionFactory;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.InvalidRegistryObjectException;
import org.eclipse.core.runtime.Status;
import com.google.inject.Injector;
import com.google.inject.Module;
/**
* {@link IExecutableExtensionFactory} that creates an injected extension based
* on the class named in the adapter data section. If the data section is empty
* the class is assumed to be in the {@code id} attribute. The factory searches
* the {@code org.eclipse.sisu.peaberry.eclipse.modules} extension for {@link Module}s
* belonging to the same plug-in and uses them to create a new {@link Injector}.
* This injector creates the injected extension and is then cached so it can be
* re-used for other extensions in the same plug-in.
* <p>
* To use the factory put it in front of your class name in the extension XML.
* Or replace your class with the factory and put your class in the {@code id}
* attribute instead. Because the implementation will be injected based on the
* bindings you could even replace your class name with one of its interfaces,
* and that interface will then be used to lookup the correct implementation.
* <p>
* Here's a more detailed walkthrough, based on the example RCP Mail Template:
*
* <pre> {@literal <}extension point="org.eclipse.ui.views"{@literal >}
* {@literal <}view name="Message"
* allowMultiple="true"
* icon="icons/sample2.gif"
* class="example.ViewImpl"
* id="example.view" /{@literal >}
* {@literal <}/extension{@literal >}</pre>
* becomes:
*
* <pre> {@literal <}extension point="org.eclipse.ui.views"{@literal >}
* {@literal <}view name="Message"
* allowMultiple="true"
* icon="icons/sample2.gif"
* class="org.eclipse.sisu.peaberry.eclipse.GuiceExtensionFactory:example.ViewImpl"
* id="example.view" /{@literal >}
* {@literal <}/extension{@literal >}
* {@literal <}extension point="org.eclipse.sisu.peaberry.eclipse.modules"{@literal >}
* {@literal <}module class="example.ViewModule" /{@literal >}
* {@literal <}/extension{@literal >}</pre>
* Here's the same example with the class in the {@code id} attribute:
*
* <pre> {@literal <}extension point="org.eclipse.ui.views"{@literal >}
* {@literal <}view name="Message"
* allowMultiple="true"
* icon="icons/sample2.gif"
* class="org.eclipse.sisu.peaberry.eclipse.GuiceExtensionFactory"
* id="example.ViewImpl" /{@literal >}
* {@literal <}/extension{@literal >}
* {@literal <}extension point="org.eclipse.sisu.peaberry.eclipse.modules"{@literal >}
* {@literal <}module class="example.ViewModule" /{@literal >}
* {@literal <}/extension{@literal >}</pre>
* and again, this time using an interface instead of the implementation:
*
* <pre> {@literal <}extension point="org.eclipse.ui.views"{@literal >}
* {@literal <}view name="Message"
* allowMultiple="true"
* icon="icons/sample2.gif"
* class="org.eclipse.sisu.peaberry.eclipse.GuiceExtensionFactory:org.eclipse.ui.IViewPart"
* id="example.view" /{@literal >}
* {@literal <}/extension{@literal >}
* {@literal <}extension point="org.eclipse.sisu.peaberry.eclipse.modules"{@literal >}
* {@literal <}module class="example.ViewModule" /{@literal >}
* {@literal <}/extension{@literal >}</pre>
*
* @author mcculls@gmail.com (Stuart McCulloch)
*/
public final class GuiceExtensionFactory
implements IExecutableExtension, IExecutableExtensionFactory {
public static final String POINT_ID = "org.eclipse.sisu.peaberry.eclipse.modules";
private static final Logger LOGGER = Logger.getLogger(GuiceExtensionFactory.class.getName());
// re-use injectors for extensions with the same contributor
private static final Map<IContributor, Injector> INJECTORS =
new HashMap<IContributor, Injector>();
private IConfigurationElement configuration;
private IContributor contributor;
private String clazzName;
public void setInitializationData(final IConfigurationElement config, final String name,
final Object data) {
configuration = config;
// find contributor while still valid
contributor = config.getContributor();
// if there's no (string-based) adapter data then class must be under "id"
clazzName = data instanceof String ? (String) data : config.getAttribute("id");
}
public Object create()
throws CoreException {
if (null == clazzName) {
throw newCoreException("Configuration is missing class information");
}
final Class<?> clazz;
try {
clazz = resolve(contributor).loadClass(clazzName);
} catch (final InvalidRegistryObjectException e) {
throw newCoreException(e);
} catch (final ClassNotFoundException e) {
throw newCoreException(e);
}
final Object o = getInjector().getInstance(clazz);
if (o instanceof IExecutableExtension) {
((IExecutableExtension) o).setInitializationData(configuration, null, null);
}
return o;
}
/**
* Remove any {@link Injector}s belonging to uninstalled bundles.
*/
public static void cleanup() {
synchronized (INJECTORS) { // LOCK
for (final IContributor c : INJECTORS.keySet()) {
if (null == resolve(c)) {
INJECTORS.remove(c);
}
}
} // UNLOCK
}
private Injector getInjector()
throws CoreException {
synchronized (INJECTORS) { // LOCK
Injector injector = INJECTORS.get(contributor);
if (null == injector) {
final List<Module> modules = new ArrayList<Module>();
// first add the OSGi service registry and Eclipse extension bindings
modules.add(osgiModule(resolve(contributor).getBundleContext(), eclipseRegistry()));
// now add any module extensions contributed by the current plug-in
for (final IConfigurationElement e : getRegistry().getConfigurationElementsFor(POINT_ID)) {
if (contributor.equals(e.getContributor())) {
modules.add((Module) e.createExecutableExtension("class"));
}
}
injector = createInjector(modules);
INJECTORS.put(contributor, injector);
}
return injector;
} // UNLOCK
}
private CoreException newCoreException(final Throwable e) {
LOGGER.warning(e.getMessage());
return new CoreException(new Status(IStatus.ERROR, contributor.getName(), e.getMessage(), e));
}
private CoreException newCoreException(final String message) {
LOGGER.warning(message);
return new CoreException(new Status(IStatus.ERROR, contributor.getName(), message));
}
}