How to use:

Activating the Tool: To use the Ellipse Tool, the user clicks on add feature, then click on the "Ellipse Tool" button in the toolbar. This activates the tool and enables the user to create or modify ellipses.

Creating an Ellipse: With the Ellipse Tool active, the user can create a new ellipse by clicking and dragging on the canvas. When the user clicks the mouse and holds it, a temporary ellipse shape is displayed. As the user drags the mouse, the ellipse shape dynamically adjusts its size and position based on the drag distance. The user can release the mouse click to finalize the ellipse creation.

Modifying an Ellipse: Once an ellipse is created or selected, the user can modify it. To modify an ellipse, the user can click and drag on one of the control points of the ellipse (located at the four cardinal points). When a control point is dragged, the ellipse adjusts its size while maintaining its center.

Proportional Scaling: While dragging the control point, if the user holds the "Command" or "Control" key (on Mac or Windows, respectively), the ellipse will scale proportionally. This means both the horizontal and vertical radii of the ellipse will change proportionally, preserving the elliptical shape.

Non-proportional Scaling: If the user drags the control point without holding the "Command" or "Control" key, the ellipse will scale non-proportionally. This means only one radius (either horizontal or vertical) will change, allowing the user to deform the ellipse into an ellipse-like shape.