Store cursor & line position when switching editor

When tearing down the source editor, we need to store the updated cursor
position, so that the position can be moved to when opening the rich
text editor.

services/web/public/coffee/ide/editor/directives/aceEditor.coffee

@@ -516,6 +516,7 @@ define [
 
 				scope.$on '$destroy', () ->
 					if scope.sharejsDoc?
+						scope.$broadcast('changeEditor')
 						tearDownSpellCheck()
 						tearDownCursorPosition()
 						detachFromAce(scope.sharejsDoc)

services/web/public/coffee/ide/editor/directives/aceEditor/cursor-position/CursorPositionManager.coffee

@@ -3,12 +3,12 @@ define [], () ->
 		constructor: (@$scope, @adapter, @localStorage) ->
 			@$scope.$on 'editorInit', @jumpToPositionInNewDoc
 
-			@$scope.$on 'beforeChangeDocument', () =>
-				@storeCursorPosition()
-				@storeFirstVisibleLine()
+			@$scope.$on 'beforeChangeDocument', @storePositionAndLine
 
 			@$scope.$on 'afterChangeDocument', @jumpToPositionInNewDoc
 
+			@$scope.$on 'changeEditor', @storePositionAndLine
+
 			@$scope.$on "#{@$scope.name}:gotoLine", (e, line, column) =>
 				if line?
 					setTimeout () =>
@@ -24,6 +24,10 @@ define [], () ->
 			@$scope.$on "#{@$scope.name}:clearSelection", (e) =>
 				@adapter.clearSelection()
 
+		storePositionAndLine: () =>
+			@storeCursorPosition()
+			@storeFirstVisibleLine()
+
 		jumpToPositionInNewDoc: () =>
 			@doc_id = @$scope.sharejsDoc?.doc_id
 			setTimeout () =>