IAdaptable¶

Learning how IAdaptable works is one of the big ideas you want to be comfortable with when starting Eclipse RCP development.

Reference:

Example Use¶

You can use the getAdapter method anywhere you would normally do an instanceof check.

BEFORE:

if( object instanceof IMap ){
   // work on a IMap
}

AFTER:

IMap map = (map)adaptable.getAdapter(IMap.class);
if( map != null ){
    // work on the map
}

Implementation¶

At a minimum every implementation of IAdaptable should implement the following:

class Foo implements IAdaptable {
  public String text;
  public Object getAdapter(Class adapter) {
     return Platform.getAdapterManager().getAdapter(this, adapter);
  }
}

Alternative: If you want you could also extend the “PlatformObject” for the same effect:

class Foo extends PlatformObject {
  public String text;
}

Example of Direct Implementation¶

You have a choice of two ways to make new “adapters” available:

Directly code in your class:

class Foo implements IAdaptable {
  public String text;
  public Object getAdapter(Class adapter) {
     if( adapter.isAssignableFrom( String.class ) ){
        return text;
     }
     return Platform.getAdapterManager().getAdapter(this, adapter);
  }
}

Example Using AdapterFactory¶

You can also implement an AdapterFactory to do the work:

public class FooStringFactory implements IAdapterFactory {
  private static final Class[] TARGETS = {
    String.class,
  };
  public Class[] getAdapterList() {
    return TARGETS;
  }
  public Object getAdapter(Object adaptableObject, Class adapterType) {
    if (adapterType.isAssignableFrom( String.class )) {
      return ((Foo)adaptableObject).text;
    }return null;
  }
}

And contribute it to the Platform.getAdapterManager using the following plugin.xml fragment:

<extension point="org.eclipse.core.runtime.adapters">
  <factory class="FooStringFactory" adaptableType="Foo">
    <adapter type="java.lang.String"/>
   </factory>
</extension>

Alternative: Registering AdapterFactory by Hand

Platform.getAdapterManager().registerAdapters(new FooStringFactory(), Foo.class);

uDig

IAdaptable¶

Example Use¶

Implementation¶

Example of Direct Implementation¶

Example Using AdapterFactory¶