Conditional menu contribution relying on java code

Context

Last few days I need to build a contextual menu on a TreeViewer provides by antother plugin. This TreeView containing EClass instance (comming from ecore and genmodel).

What I want to do is implement functions allowing  :

• the create a new Resource containing a particular selected object
• to absord the contend of a ressource containing a particular selected object

To build those functions, I rely on a provide popup menu (comming from EMF Client Plateform : ECP)

and found usefull links : Advanced features in Eclipse popup menus – Take 2: The new API

Developments

So I add :

• command (extension org.eclipse.ui.commands)
• menu entries using contributionItems (extension org.eclipse.ui.menus)
• contribution item refers a command 
• handler (extension org.eclipse.ui.handlers)
• refers a command
• describs "visiblewhen" using 
• iterate
• and
• instanceof
• test refers a propertyTester
• count
• propertyTester (extension org.eclipse.core.expressions.propertyTesters)

Plugin.xml fragment

here I just show how to detect that the selected "MyObject" is not already in a particular resource.

Command

<extension
         point="org.eclipse.ui.commands">
      <command
            id="franckys.gui.command.makeFragment"
            name="Make fragment">
      </command>
   </extension>

Contribution item

   <extension
         point="org.eclipse.ui.menus">
       <menuContribution
            allPopups="false"
            locationURI="popup:org.eclipse.emf.ecp.navigator.viewer?after=additions">
         <command
               commandId="franckys.gui.command.makeFragment"
               style="push">
         </command>
      </menuContribution>
   </extension>

handler

Here the expected behavior is obtain using "test" in java and "instanceof" checking.

   <extension point="org.eclipse.ui.handlers">
  <handler
   class="franckys.gui.handlers.MakeFragment"
   commandId="franckys.gui.command.makeFragment">
   <enabledWhen>
    <with variable="selection">
     <iterate>
      <and>
       <instanceof
       value="franckys.model.MyObject">
       </instanceof>
       <test
       property="franckys.isFragment"
       value="false">
       </test>
      </and>
     </iterate>
     <count
      value="1">
     </count>
    </with>
   </enabledWhen>
  </handler>
 </extension>

propertyTester

   <extension
         point="org.eclipse.core.expressions.propertyTesters">
      <propertyTester
            class="franckys.propertytester.IsFragmentTester"
            id="franckys.propertytester.isfragment"
            namespace="franckys"
            properties="isFragment"
            type="org.eclipse.emf.ecore.EObject">
      </propertyTester>
   </extension>

source code

propertyTester

import org.eclipse.core.expressions.PropertyTester;

import franckys.model.MyObject;

public class IsFragmentTester extends PropertyTester {

 public IsFragmentTester() {
 }

 @Override
 public boolean test(Object receiver, String property, Object[] args,
  Object expectedValue) {
 if (receiver instanceof MyObject) {
  MyObject myo = (MyObject) receiver;
  if("isFragment".equals(property)) {
   Boolean value = (Boolean)expectedValue;
   boolean bool = myo.eResource() == myo.eContainer().eResource();
   if(value.booleanValue()==false) {
    return bool;
   } else {
    return !bool;
   }
  }
 }
 return false;
 }
}

Handler

public class MakeFragment extends AbstractHandler {
 @Override
 public Object execute(ExecutionEvent event) throws ExecutionException {
 //Do the job in emf transaction
 }
}