RoboFont’s Glyph Editor comes with a few core tools for manipulating glyphs: the Editing, Bezier, Slice and Measurement tools. These interactive tools are built around macOS NSEvent objects, which represent input actions such as mouse clicks and position, pressed keys, etc.
Custom interactive tools can be created by subclassing the
BaseEventTool or one of the other core tools which are available from the
# subclass base tool from mojo.events import BaseEventTool # or one of the core tools from mojo.events import EditingTool, BezierDrawingTool, SliceTool, MeasurementTool