Arc Angles & Radius Scaling

Overview

Arc shapes render a full circle when startAngle equals endAngle, and resizing updates both radius and innerRadius to keep proportions.

A selected circle also exposes the same sweep model through its single arc handle:

• The handle starts on the right side of the circle.
• Dragging the handle up or down opens a gap continuously from a full circle toward a smaller sweep.
• The handle stays anchored on the circle radius during drag.
• Releasing the drag commits the conversion to shapeType = 'arc' with startAngle = 0 and innerRadius = 0.

API

editor.updateObjectProperty(arcId, 'startAngle', 45)
editor.updateObjectProperty(arcId, 'endAngle', 45)

editor.setObjectSize(arcId, 200, 200)

Notes

• When startAngle equals endAngle, the arc renders a full 360° sweep.
• Resizing updates radius and preserves the existing inner/outer radius ratio.
• Circle-to-arc conversion previews the sweep during dragmove and saves the final arc geometry on dragend.