Rounded Corner Handles

Overview

When a single rectangle is selected, corner radius handles appear inside each corner. Drag a handle to change the radius. While dragging, a numeric label shows the current radius in pixels next to the active handle.

Steps

1. Select a rectangle.
2. Drag any corner radius handle.
3. Watch the value label update in real time.

Behavior

• Shift-click handles to toggle which corners are linked. Only selected handles update.
• Alt/Ctrl/Meta while dragging temporarily restricts the change to the active corner.
• The label follows the active handle and stays readable across zoom and pan.
• Undo/redo stores the change as a single history entry.

Constraints

• Corner radius controls appear only for a single rectangle selection.
• Very small rectangles (about 40px on screen) hide the handles.
• Corner radius is clamped to half the shortest side of the rectangle.