> For the complete documentation index, see [llms.txt](https://santutu.gitbook.io/rts-selection-system/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://santutu.gitbook.io/rts-selection-system/extra-customization/selectioninputhandler.cs.md).

# SelectionInputHandler.cs

It manages both single-click and drag selection of game objects, with support for:

* Single/Multiple unit selection
* Modifier keys (Shift, Ctrl) for adding/removing units
* Double-click to select similar units
* Tab cycling through unit groups
* Customizable selection priorities
* Drag box selection

Key customization points:

* Inherit this class to customize selection behavior by overriding virtual methods like`HandleClickEvent` and `HandleDragReleaseEvent`.