Bug 36518 call hierarchy: 'refresh' should available only in dropdown menu
toolbar button is not conventional and not accessible we should remove it from there and put in the dropdown menu (context menu is ok, i guess)
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/callhierarchy/CallHierarchyViewPart.java
new CallHierarchyTransferDropAdapter(this, viewer)
        };
        viewer.addDropSupport(ops, transfers, new DelegatingDropAdapter(dropListeners));
    }
    private void addDragAdapters(StructuredViewer viewer, int ops, Transfer[] transfers) {
        TransferDragSourceListener[] dragListeners= new TransferDragSourceListener[] {
            new SelectionTransferDragAdapter(new SelectionProviderAdapter(viewer))
        };
        viewer.addDragSupport(ops, transfers, new JdtViewerDragAdapter(viewer, dragListeners));
    }   
            
    public void createPartControl(Composite parent) {
        fPagebook = new PageBook(parent, SWT.NONE);
        
        createHierarchyLocationSplitter(fPagebook);
        createCallHierarchyViewer(fHierarchyLocationSplitter);
        createLocationViewer(fHierarchyLocationSplitter);
        
        fNoHierarchyShownLabel = new Label(fPagebook, SWT.TOP + SWT.LEFT + SWT.WRAP);
        fNoHierarchyShownLabel.setText(CallHierarchyMessages.getString(
                "CallHierarchyViewPart.empty"));    
        showPage(PAGE_EMPTY);
        WorkbenchHelp.setHelp(fPagebook, IJavaHelpContextIds.CALL_HIERARCHY_VIEW);
        
        fSelectionProviderMediator = new SelectionProviderMediator(new Viewer[] {
                    fCallHierarchyViewer, fLocationViewer
                });
        IStatusLineManager slManager = getViewSite().getActionBars().getStatusLineManager();
        fSelectionProviderMediator.addSelectionChangedListener(new StatusBarUpdater(
                slManager));