Interface IAdapterManager
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public interface IAdapterManager
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 theIAdaptable
interface) funnelIAdaptable.getAdapter
invocations to their adapter manager'sIAdapterManger.getAdapter
method. The adapter manager then forwards this request unmodified to theIAdapterFactory.getAdapter
method on one of the registered adapter factories.Adapter factories can be registered programmatically using the
registerAdapters
method. Alternatively, they can be registered declaratively using theorg.eclipse.core.runtime.adapters
extension point. Factories registered with this extension point will not be able to provide adapters until their corresponding plugin has been activated.The following code snippet shows how one might register an adapter of type
com.example.acme.Sticky
on resources in the workspace.IAdapterFactory pr = new IAdapterFactory() { @Override public Class[] getAdapterList() { return new Class[] { com.example.acme.Sticky.class }; } @Override public <T> T getAdapter(Object adaptableObject, Class<T> 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);
This interface can be used without OSGi running.
This interface is not intended to be implemented by clients.
- See Also:
IAdaptable
,IAdapterFactory
- Restriction:
- This interface is not intended to be implemented by clients.
- Restriction:
- This interface is not intended to be extended by clients.
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Field Summary
Fields Modifier and Type Field Description static int
LOADED
This value can be returned to indicate that an adapter factory is loaded.static int
NONE
This value can be returned to indicate that no applicable adapter factory was found.static int
NOT_LOADED
This value can be returned to indicate that an adapter factory was found, but has not been loaded.
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Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description String[]
computeAdapterTypes(Class<?> adaptableClass)
Returns the types that can be obtained by convertingadaptableClass
via this manager.<T> Class<? super T>[]
computeClassOrder(Class<T> clazz)
Returns the class search order for a given class.<T> T
getAdapter(Object adaptable, Class<T> adapterType)
Returns an object which is an instance of the given class associated with the given object.Object
getAdapter(Object adaptable, String adapterTypeName)
Returns an object which is an instance of the given class name associated with the given object.boolean
hasAdapter(Object adaptable, String adapterTypeName)
Returns whether there is an adapter factory registered that may be able to convertadaptable
to an object of typeadapterTypeName
.Object
loadAdapter(Object adaptable, String adapterTypeName)
Returns an object that is an instance of the given class name associated with the given object.int
queryAdapter(Object adaptable, String adapterTypeName)
Returns a status of an adapter factory registered that may be able to convertadaptable
to an object of typeadapterTypeName
.void
registerAdapters(IAdapterFactory factory, Class<?> adaptable)
Registers the given adapter factory as extending objects of the given type.void
unregisterAdapters(IAdapterFactory factory)
Removes the given adapter factory completely from the list of registered factories.void
unregisterAdapters(IAdapterFactory factory, Class<?> adaptable)
Removes the given adapter factory from the list of factories registered as extending the given class.
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Field Detail
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NONE
static final int NONE
This value can be returned to indicate that no applicable adapter factory was found.- Since:
- org.eclipse.equinox.common 3.3
- See Also:
- Constant Field Values
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NOT_LOADED
static final int NOT_LOADED
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
- See Also:
- Constant Field Values
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LOADED
static final int LOADED
This value can be returned to indicate that an adapter factory is loaded.- Since:
- org.eclipse.equinox.common 3.3
- See Also:
- Constant Field Values
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Method Detail
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computeAdapterTypes
String[] computeAdapterTypes(Class<?> adaptableClass)
Returns the types that can be obtained by convertingadaptableClass
via this manager. Converting means that subsequent calls togetAdapter()
orloadAdapter()
could result in an adapted object.Note that the returned types do not guarantee that a subsequent call to
getAdapter
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 returnsnull
, thengetAdapter
will still returnnull
.- Parameters:
adaptableClass
- the adaptable class being queried- Returns:
- an array of type names that can be obtained by converting
adaptableClass
via this manager. An empty array is returned if there are none. - Since:
- 3.1
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computeClassOrder
<T> Class<? super T>[] computeClassOrder(Class<T> clazz)
Returns the class search order for a given class. The search order from a class with the definition
class X extends Y implements A, B
is as follows:- the target's class: X
- X's superclasses in order to
Object
- a breadth-first traversal of each class's interfaces in the
order returned by
getInterfaces
(in the example, X's superinterfaces then Y's superinterfaces)
- Parameters:
clazz
- the class for which to return the class order.- Returns:
- the class search order for the given class. The returned search order will minimally contain the target class.
- Since:
- 3.1
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getAdapter
<T> T getAdapter(Object adaptable, Class<T> adapterType)
Returns an object which is an instance of the given class associated with the given object. Returnsnull
if no such object can be found.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
null
.In most cases, it is preferable for client code to use
Adapters.adapt(Object, Class, boolean)
rather than calling this method directly since doing so will also detect interfaces supplied by theIAdaptable
interface- Parameters:
adaptable
- the adaptable object being queried (usually an instance ofIAdaptable
)adapterType
- the type of adapter to look up- Returns:
- an object of the given adapter type, or
null
if the given adaptable object does not have an available adapter of the given type
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getAdapter
Object getAdapter(Object adaptable, String adapterTypeName)
Returns an object which is an instance of the given class name associated with the given object. Returnsnull
if no such object can be found.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
null
. If activation of the plug-in providing the factory is required, use theloadAdapter
method instead.In most cases, it is preferable for client code to use
Adapters.adapt(Object, Class, boolean)
rather than calling this method directly since doing so will also detect interfaces supplied by theIAdaptable
interface- Parameters:
adaptable
- the adaptable object being queried (usually an instance ofIAdaptable
)adapterTypeName
- the fully qualified name of the type of adapter to look up- Returns:
- an object castable to the given adapter type, or
null
if the given adaptable object does not have an available adapter of the given type - Since:
- 3.0
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hasAdapter
boolean hasAdapter(Object adaptable, String adapterTypeName)
Returns whether there is an adapter factory registered that may be able to convertadaptable
to an object of typeadapterTypeName
.Note that a return value of
true
does not guarantee that a subsequent call togetAdapter
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 returnsnull
, thengetAdapter
will still returnnull
.- Parameters:
adaptable
- the adaptable object being queried (usually an instance ofIAdaptable
)adapterTypeName
- the fully qualified class name of an adapter to look up- Returns:
true
if there is an adapter factory that claims it can convertadaptable
to an object of typeadapterType
, andfalse
otherwise.- Since:
- 3.0
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queryAdapter
int queryAdapter(Object adaptable, String adapterTypeName)
Returns a status of an adapter factory registered that may be able to convertadaptable
to an object of typeadapterTypeName
.One of the following values can be returned:
NONE
if no applicable adapter factory was found;NOT_LOADED
if an adapter factory was found, but has not been loaded;LOADED
if an adapter factory was found, and it is loaded.
- Parameters:
adaptable
- the adaptable object being queried (usually an instance ofIAdaptable
)adapterTypeName
- the fully qualified class name of an adapter to look up- Returns:
- a status of the adapter
- Since:
- org.eclipse.equinox.common 3.3
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loadAdapter
Object loadAdapter(Object adaptable, String adapterTypeName)
Returns an object that is an instance of the given class name associated with the given object. Returnsnull
if no such object can be found.Note that unlike the
getAdapter
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 usinggetAdapter
instead.In most cases, it is preferable for client code to use
Adapters.adapt(Object, Class, boolean)
rather than calling this method directly since doing so will also detect interfaces supplied by theIAdaptable
interface.- Parameters:
adaptable
- the adaptable object being queried (usually an instance ofIAdaptable
)adapterTypeName
- the fully qualified name of the type of adapter to look up- Returns:
- an object castable to the given adapter type, or
null
if the given adaptable object does not have an available adapter of the given type - Since:
- 3.0
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registerAdapters
void registerAdapters(IAdapterFactory factory, Class<?> adaptable)
Registers the given adapter factory as extending objects of the given type.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.
- Parameters:
factory
- the adapter factoryadaptable
- the type being extended- See Also:
unregisterAdapters(IAdapterFactory)
,unregisterAdapters(IAdapterFactory, Class)
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unregisterAdapters
void unregisterAdapters(IAdapterFactory factory)
Removes the given adapter factory completely from the list of registered factories. Equivalent to callingunregisterAdapters(IAdapterFactory,Class)
on all classes against which it had been explicitly registered. Does nothing if the given factory is not currently registered.- Parameters:
factory
- the adapter factory to remove- See Also:
registerAdapters(IAdapterFactory, Class)
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unregisterAdapters
void unregisterAdapters(IAdapterFactory factory, Class<?> adaptable)
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.- Parameters:
factory
- the adapter factory to removeadaptable
- one of the types against which the given factory is registered- See Also:
registerAdapters(IAdapterFactory, Class)
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