Module neuroglancer/ui/annotations

High level overview of UI Annotation Module

• The annotations.ts module in neuroglancer/ui directory supports multiple operations for annotations across neuroglancer for drawing UI elements. Currently neuroglancer supports the below annotations:
  • Cell
  • Point
  • COM (Centre of Mass)
  • Polygon
  • Volume
• The annotations.ts module supports the below common functionality for all annotations:
  • Draw annotations using Tool class, each annotation has a separate tool class which inherits the base class Tool. For eg: PlacePolygonTool is the class used to draw polygons.
  • Fetch the list of landmarks (for Volume) and categories (for Cell) used for labeling various annotations.
  • Maintain all the annotations in a particular layer by storing them in a map with key as annotation id and value as annotation. Class AnnotationLayerView is used to implement this.
  • Includes utility functions/enums which are used by different annotation tools. For eg: we have an enum PolygonToolMode which takes values: DRAW, EDIT and VIEW indicating different modes in which the tool operates.