/** may return a single object, or a collection */
public static Object getNavigationSelectionObject() {
if (!PlatformUI.getWorkbench().hasService(IHandlerService.class)) return null;
IHandlerService hs =
(IHandlerService) PlatformUI.getWorkbench().getService(IHandlerService.class);
IEvaluationContext ctx = hs.getCurrentState();
if (ctx == null) return null;
return ctx.getDefaultVariable();
}
/* (non-Javadoc)
* @see Expression#evaluate(IVariablePool)
*/
public EvaluationResult evaluate(IEvaluationContext context) throws CoreException {
if (fTypeName == null) return EvaluationResult.FALSE;
Object var = context.getDefaultVariable();
Object adapted = null;
IAdapterManager manager = Platform.getAdapterManager();
if (Expressions.isInstanceOf(var, fTypeName)) {
adapted = var;
} else {
if (manager.hasAdapter(var, fTypeName)) {
adapted = manager.getAdapter(var, fTypeName);
} else {
// if the adapter manager doesn't have an adapter contributed,
// try to see if the variable itself implements IAdaptable
if (var instanceof IAdaptable) {
try {
Class typeClazz = Class.forName(fTypeName, false, var.getClass().getClassLoader());
adapted = ((IAdaptable) var).getAdapter(typeClazz);
} catch (ClassNotFoundException e) {
}
}
if (adapted == null) {
// all attempts failed, return false
return EvaluationResult.FALSE;
}
}
}
// the adapted result is null but hasAdapter returned true check
// if the adapter is loaded.
if (adapted == null) {
if (manager.queryAdapter(var, fTypeName) == IAdapterManager.NOT_LOADED) {
return EvaluationResult.NOT_LOADED;
} else {
return EvaluationResult.FALSE;
}
}
return evaluateAnd(new DefaultVariable(context, adapted));
}
