Create a Customized GMF DnD Framework

Create a Customized GMF DnD Framework

• 1.
  Customizing GMF DnDFramework Step 1 : Contributing custom edit policy provider to GMF editor In our DnD handler plugin, we contribute com.tibco.xpd.cm.boma.dnd.core.BOMADnDEditPolicyProvider to the org.eclipse.gmf.runtime.diagram.ui.editpolicyProviders. This Presentation Edit Policy Provider extension point is used to define editpolicy providers for the editpolicy service. The editpolicy service allows plug-ins to modify or enhance the behavior of an editpart via an editpolicy without modifying the editpart code. Step 2 : Attach a custom edit policy and a drop target listener to the edit part public void createEditPolicies(EditPart editPart) { if (isEditPartValid(editPart)) { /** if the edit part is valid, install the dnd edit policy editPart.installEditPolicy(EditPolicyRoles.DRAG_DROP_ROLE, dndPolicy); editPart.getViewer().addDropTargetListener(dndListner); **/ } } public boolean provides(IOperation operation) { if(operation instanceof CreateEditPoliciesOperation){ EditPart editPart = ((CreateEditPoliciesOperation) operation).getEditPart(); return isEditPartValid(editPart); } return false; // Custom Edit Policy public class BOMADragDropEditPolicy extends DragDropEditPolicy { //------ } Step 3 : Prepare the list of objects to be dropped and set it on the Drop Request @Override protected List<Object> getObjectsBeingDropped() { ISelection selection =
• 2.
  LocalSelectionTransfer.getInstance().getSelection(); if (selection instanceof IStructuredSelection) { sourceObjectList = ((IStructuredSelection) selection).toList(); } return sourceObjectList; } @Override protected Request createTargetRequest() { DropObjectsRequest req = new DropObjectsRequest(); req.setObjects(getObjectsBeingDropped()); return req; } Step 4: Return an edit part that can produce an executable command for the target request private EditPart calculateTargetEditPart() { updateTargetRequest(); EditPart ep = getViewer() .findObjectAtExcluding( getDropLocation(), getExclusionSet(), new EditPartViewer.Conditional() { public boolean evaluate(EditPart editpart) { Command command = editpart.getCommand(getTargetRequest()); return command != null; } }); /*if (ep != null) { Command command = ep.getCommand(getTargetRequest()); return (command != null && command.canExecute())? ep : null; }*/ return ep; } Step 5: Return the required DnD command from the corresponding Edit Part /** * @generated NOT */ @Override public Command getCommand(Request _request) { if(_request instanceof DropObjectsRequest) {
• 3.
  return getDnDEditPolicy().getCommand(_request); }else { return super.getCommand(_request); } } /** * @generated NOT * @return */ private EditPolicy getDnDEditPolicy() { EditPolicy dndPolicy = null; EditPolicyIterator i = getEditPolicyIterator(); while (i.hasNext()) { EditPolicy tempPolicy = i.next(); if (tempPolicy instanceof DragDropEditPolicy) { dndPolicy = tempPolicy; break; } } return dndPolicy; } // Custom Edit Policy public class BOMADragDropEditPolicy extends DragDropEditPolicy { @Override protected Command getDropElementCommand(EObject element, DropObjectsRequest request) { EObject modelObj = getHostObject(); TransactionalEditingDomain editDomain = (TransactionalEdit ingDomain)WorkingCopyUtil.getWorkingCopyFor(modelObj).getEditingDomain(); return getGMFWrapper(new BOMADragDropCommand(editDomain,request,modelObj,element)); } private Command getGMFWrapper(ICommand gmfCommand){ return new ICommandProxy(gmfCommand); } //------ } Step 6 : Execute the DnD Command to create the Concepts through corresponding Generator class
• 4.
  public class BOMADragDropCommandextends AbstractTransactionalCommand{ private EObject modelObj; private EObject element; private IDataModelGenerator modelGen; /** * * @param editDomain * @param request * @param modelObj * @param element */ public BOMADragDropCommand (TransactionalEditingDomain editDomain,DropObjectsRequest request,EObject modelObj,EObject element){ super(editDomain,"DND",getAffectedFiles(request)); this.modelObj = modelObj; this.element = element; } @Override protected CommandResult doExecuteWithResult(IProgressMonitor monitor, IAdaptable info) throws ExecutionException { Model model = null; // if(modelObj != null){ if(modelObj instanceof Model){ model = (Model)modelObj; int elementType = DropElementTypeResolver.getElementType(element); switch(elementType){ case DropElementTypeResolver.CONCEPT_TYPE: modelGen = new ConceptModelGenerator((Model)modelObj); modelGen.generateUMLModel(element); modelGen.setRelationships(); break; case DropElementTypeResolver.DB_TYPE: modelGen = new DB2UMLModelGenerator((Model)modelObj); modelGen.generateUMLModel(element); modelGen.setRelationships(); break; case DropElementTypeResolver.JAVA_TYPE: break; case DropElementTypeResolver.XSD_TYPE:
• 5.
  break; } } } return CommandResult.newOKCommandResult(); } private static List getAffectedFiles(Request request){ return null; } }