/*******************************************************************************
* Copyright (c) 2000, 2009 IBM Corporation 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:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.core.runtime;
/**
* An adapter manager maintains a registry of adapter factories. Clients
* directly invoke methods on an adapter manager to register and unregister
* adapters. All adaptable objects (that is, objects that implement the <code>IAdaptable</code>
* interface) funnel <code>IAdaptable.getAdapter</code> invocations to their
* adapter manager's <code>IAdapterManger.getAdapter</code> method. The
* adapter manager then forwards this request unmodified to the <code>IAdapterFactory.getAdapter</code>
* method on one of the registered adapter factories.
* <p>
* Adapter factories can be registered programmatically using the <code>registerAdapters</code>
* method. Alternatively, they can be registered declaratively using the
* <code>org.eclipse.core.runtime.adapters</code> extension point. Factories registered
* with this extension point will not be able to provide adapters until their
* corresponding plugin has been activated.
* <p>
* The following code snippet shows how one might register an adapter of type
* <code>com.example.acme.Sticky</code> on resources in the workspace.
* <p>
*
* <pre>
* IAdapterFactory pr = new IAdapterFactory() {
* public Class[] getAdapterList() {
* return new Class[] { com.example.acme.Sticky.class };
* }
* public Object getAdapter(Object adaptableObject, Class adapterType) {
* IResource res = (IResource) adaptableObject;
* QualifiedName key = new QualifiedName("com.example.acme", "sticky-note");
* try {
* com.example.acme.Sticky v = (com.example.acme.Sticky) res.getSessionProperty(key);
* if (v == null) {
* v = new com.example.acme.Sticky();
* res.setSessionProperty(key, v);
* }
* } catch (CoreException e) {
* // unable to access session property - ignore
* }
* return v;
* }
* }
* Platform.getAdapterManager().registerAdapters(pr, IResource.class);
* </pre>
*
* </p><p>
* This interface can be used without OSGi running.
* </p><p>
* This interface is not intended to be implemented by clients.
* </p>
* @see IAdaptable
* @see IAdapterFactory
* @noextend This interface is not intended to be extended by clients.
* @noimplement This interface is not intended to be implemented by clients.
*/
public interface IAdapterManager {
/**
* This value can be returned to indicate that no applicable adapter factory
* was found.
* @since org.eclipse.equinox.common 3.3
*/
public static final int NONE = 0;
/**
* This value can be returned to indicate that an adapter factory was found,
* but has not been loaded.
* @since org.eclipse.equinox.common 3.3
*/
public static final int NOT_LOADED = 1;
/**
* This value can be returned to indicate that an adapter factory is loaded.
* @since org.eclipse.equinox.common 3.3
*/
public static final int LOADED = 2;
/**
* Returns the types that can be obtained by converting <code>adaptableClass</code>
* via this manager. Converting means that subsequent calls to <code>getAdapter()</code>
* or <code>loadAdapter()</code> could result in an adapted object.
* <p>
* Note that the returned types do not guarantee that
* a subsequent call to <code>getAdapter</code> with the same type as an argument
* will return a non-null result. If the factory's plug-in has not yet been
* loaded, or if the factory itself returns <code>null</code>, then
* <code>getAdapter</code> will still return <code>null</code>.
* </p>
* @param adaptableClass the adaptable class being queried
* @return an array of type names that can be obtained by converting
* <code>adaptableClass</code> via this manager. An empty array
* is returned if there are none.
* @since 3.1
*/
public String[] computeAdapterTypes(Class adaptableClass);
/**
* Returns the class search order for a given class. The search order from a
* class with the definition <br>
* <code>class X extends Y implements A, B</code><br>
* is as follows:
* <ul>
* <li>the target's class: X
* <li>X's superclasses in order to <code>Object</code>
* <li>a breadth-first traversal of each class's interfaces in the
* order returned by <code>getInterfaces</code> (in the example, X's
* superinterfaces then Y's superinterfaces) </li>
* </ul>
*
* @param clazz the class for which to return the class order.
* @return the class search order for the given class. The returned
* search order will minimally contain the target class.
* @since 3.1
*/
public Class[] computeClassOrder(Class clazz);
/**
* Returns an object which is an instance of the given class associated
* with the given object. Returns <code>null</code> if no such object can
* be found.
* <p>
* Note that this method will never cause plug-ins to be loaded. If the
* only suitable factory is not yet loaded, this method will return <code>null</code>.
*
* @param adaptable the adaptable object being queried (usually an instance
* of <code>IAdaptable</code>)
* @param adapterType the type of adapter to look up
* @return an object castable to the given adapter type, or <code>null</code>
* if the given adaptable object does not have an available adapter of the
* given type
*/
public Object getAdapter(Object adaptable, Class adapterType);
/**
* Returns an object which is an instance of the given class name associated
* with the given object. Returns <code>null</code> if no such object can
* be found.
* <p>
* Note that this method will never cause plug-ins to be loaded. If the
* only suitable factory is not yet loaded, this method will return <code>null</code>.
* If activation of the plug-in providing the factory is required, use the
* <code>loadAdapter</code> method instead.
*
* @param adaptable the adaptable object being queried (usually an instance
* of <code>IAdaptable</code>)
* @param adapterTypeName the fully qualified name of the type of adapter to look up
* @return an object castable to the given adapter type, or <code>null</code>
* if the given adaptable object does not have an available adapter of the
* given type
* @since 3.0
*/
public Object getAdapter(Object adaptable, String adapterTypeName);
/**
* Returns whether there is an adapter factory registered that may be able
* to convert <code>adaptable</code> to an object of type <code>adapterTypeName</code>.
* <p>
* Note that a return value of <code>true</code> does not guarantee that
* a subsequent call to <code>getAdapter</code> with the same arguments
* will return a non-null result. If the factory's plug-in has not yet been
* loaded, or if the factory itself returns <code>null</code>, then
* <code>getAdapter</code> will still return <code>null</code>.
*
* @param adaptable the adaptable object being queried (usually an instance
* of <code>IAdaptable</code>)
* @param adapterTypeName the fully qualified class name of an adapter to
* look up
* @return <code>true</code> if there is an adapter factory that claims
* it can convert <code>adaptable</code> to an object of type <code>adapterType</code>,
* and <code>false</code> otherwise.
* @since 3.0
*/
public boolean hasAdapter(Object adaptable, String adapterTypeName);
/**
* Returns a status of an adapter factory registered that may be able
* to convert <code>adaptable</code> to an object of type <code>adapterTypeName</code>.
* <p>
* One of the following values can be returned:<ul>
* <li>{@link org.eclipse.core.runtime.IAdapterManager#NONE} if no applicable adapter factory was found;</li>
* <li>{@link org.eclipse.core.runtime.IAdapterManager#NOT_LOADED} if an adapter factory was found, but has not been loaded;</li>
* <li>{@link org.eclipse.core.runtime.IAdapterManager#LOADED} if an adapter factory was found, and it is loaded.</li>
* </ul></p>
* @param adaptable the adaptable object being queried (usually an instance
* of <code>IAdaptable</code>)
* @param adapterTypeName the fully qualified class name of an adapter to
* look up
* @return a status of the adapter
* @since org.eclipse.equinox.common 3.3
*/
public int queryAdapter(Object adaptable, String adapterTypeName);
/**
* Returns an object that is an instance of the given class name associated
* with the given object. Returns <code>null</code> if no such object can
* be found.
* <p>
* Note that unlike the <code>getAdapter</code> methods, this method
* will cause the plug-in that contributes the adapter factory to be loaded
* if necessary. As such, this method should be used judiciously, in order
* to avoid unnecessary plug-in activations. Most clients should avoid
* activation by using <code>getAdapter</code> instead.
*
* @param adaptable the adaptable object being queried (usually an instance
* of <code>IAdaptable</code>)
* @param adapterTypeName the fully qualified name of the type of adapter to look up
* @return an object castable to the given adapter type, or <code>null</code>
* if the given adaptable object does not have an available adapter of the
* given type
* @since 3.0
*/
public Object loadAdapter(Object adaptable, String adapterTypeName);
/**
* Registers the given adapter factory as extending objects of the given
* type.
* <p>
* If the type being extended is a class, the given factory's adapters are
* available on instances of that class and any of its subclasses. If it is
* an interface, the adapters are available to all classes that directly or
* indirectly implement that interface.
* </p>
*
* @param factory the adapter factory
* @param adaptable the type being extended
* @see #unregisterAdapters(IAdapterFactory)
* @see #unregisterAdapters(IAdapterFactory, Class)
*/
public void registerAdapters(IAdapterFactory factory, Class adaptable);
/**
* Removes the given adapter factory completely from the list of registered
* factories. Equivalent to calling <code>unregisterAdapters(IAdapterFactory,Class)</code>
* on all classes against which it had been explicitly registered. Does
* nothing if the given factory is not currently registered.
*
* @param factory the adapter factory to remove
* @see #registerAdapters(IAdapterFactory, Class)
*/
public void unregisterAdapters(IAdapterFactory factory);
/**
* Removes the given adapter factory from the list of factories registered
* as extending the given class. Does nothing if the given factory and type
* combination is not registered.
*
* @param factory the adapter factory to remove
* @param adaptable one of the types against which the given factory is
* registered
* @see #registerAdapters(IAdapterFactory, Class)
*/
public void unregisterAdapters(IAdapterFactory factory, Class adaptable);
}