add methods to determine if we should allow dragging and dropping

src/app/sortable-list.coffee

@@ -14,6 +14,8 @@ class SortableList extends View
     @on 'drop',      '.sortable', @onDrop
 
   onDragStart: (event) =>
+    return false if !@shouldAllowDrag()
+
     el = @getSortableElement(event)
     el.addClass 'is-dragging'
     event.originalEvent.dataTransfer.setData 'sortable-index', el.index()
@@ -32,9 +34,16 @@ class SortableList extends View
     @getSortableElement(event).removeClass 'is-drop-target'
 
   onDrop: (event) =>
+    return false if !@shouldAllowDrop()
     event.stopPropagation()
     @find('.is-drop-target').removeClass 'is-drop-target'
 
+  shouldAllowDrag: ->
+    true
+
+  shouldAllowDrop: ->
+    true
+
   getDroppedElement: (event) ->
     idx = event.originalEvent.dataTransfer.getData 'sortable-index'
     @find ".sortable:eq(#{idx})"

src/packages/tabs/lib/tabs-view.coffee

@@ -45,6 +45,10 @@ class Tabs extends SortableList
   removeTabAtIndex: (index) ->
     @find(".tab:eq(#{index})").remove()
 
+  shouldAllowDrag: ->
+    panes = rootView.find('.pane')
+    panes.length == 1 && panes.find('.sortable').length > 0
+
   onDragStart: (event) =>
     super
     pane = $(event.target).closest('.pane')
@@ -75,10 +79,11 @@ class Tabs extends SortableList
     draggedTab.insertAfter(droppedNearTab)
 
     currentDraggedTabIndex = draggedTab.index()
-
+    #console.log ".#{Tabs.viewClass()} .sortable:eq(#{previousDraggedTabIndex})"
     toEditor.editSessions.splice(currentDraggedTabIndex, 0, fromEditor.editSessions.splice(previousDraggedTabIndex, 1)[0])
 
     @setActiveTab(currentDraggedTabIndex)
-    fromEditor.setActiveEditSessionIndex(0)
+    console.log fromPaneIndex, toPaneIndex, currentDraggedTabIndex
+    fromEditor.setActiveEditSessionIndex(0) if fromPaneIndex != toPaneIndex
     toEditor.setActiveEditSessionIndex(currentDraggedTabIndex)
     toEditor.focus()