UGTK / Toolkit / Ui Module / Mouse Over System Completed

Mouse Over System

Summary

The Mouse Over System swaps the hardware cursor while the pointer is over an object, and puts the system one back when it leaves.

It is the "this is clickable" hint: a hand over a button, crosshairs over a target, a magnifier over a zoomable map. One component per object, no script to write.

Modules Dependencies

None inside UGTK. It uses Unity's EventSystem and Cursor.SetCursor.

Setup

Add Mn_MouseOver to the object that should change the cursor.
Assign Cursor Texture in the inspector.

The object has to be reachable by the EventSystem, which means one of two things: a Graphic with Raycast Target on if it lives on a canvas, or a collider plus a Physics Raycaster on the camera if it is a world object. Without that the pointer events never arrive and the component does nothing at all — there is no error to tell you.

How To Use

There is nothing to call: the component reacts to the pointer entering and leaving on its own.

Three things are worth knowing before you ship it.

With no texture assigned the cursor is hidden, not changed. That is a legitimate effect — it is how you hide the pointer over a custom-drawn cursor — but it also happens when you simply forgot to fill the field, and the two look identical.
The texture must have Read/Write enabled in its import settings. Without it Cursor.SetCursor refuses the texture and the system cursor stays exactly as it was, silently.
The hotspot is the top-left corner. The component passes Vector2.zero, so a crosshair drawn in the middle of its texture will point at its corner, not at its centre. If you need the click point elsewhere, that is a change to the component.

Keep the texture small. A cursor is drawn by the OS at its native size, so a 512×512 image does not give a crisper pointer — it gives a huge one.

Testing Scene

The inspector also carries an Editor Test Tools block that simulates the pointer entering and leaving, so the texture can be checked without entering Play Mode and hovering by hand. It previews the assigned cursor at its real size and warns about the two traps above — no texture assigned, and Read/Write disabled.

Technical Info

Path	Content
`Scripts/Mn_MouseOver.cs`	The component. Implements `IPointerEnterHandler` and `IPointerExitHandler`; applies the texture on enter and restores the system cursor on exit
`Scripts/Editor/Mn_MouseOverEditor.cs`	Inspector: cursor preview, the Read/Write check, and the two simulate buttons