ui-toolkit

Unity UI Toolkit screens are built by defining layout structure in UXML and applying flex-based styling with USS variables, then querying elements via UQuery to wire runtime events. This pattern enables maintainable main menus and HUDs by separating visual structure from logic.

ListView virtualization handles large scrolling lists in Unity UI Toolkit by configuring fixedItemHeight and using makeItem/bindItem patterns. This reuses visual elements instead of instantiating them all, ensuring performance for inventory-like UI with large datasets.

UQuery works by querying the UIDocument.rootVisualElement to locate child elements by name, class, or type using Q and Query methods. After locating the target VisualElement, you attach event callbacks directly to handle clicks and slider changes at runtime.

You can switch UI themes dynamically at runtime in Unity by managing stylesheets on the root visual element. This allows toggling between dark and light palettes by adding or removing USS stylesheet references without rebuilding the UXML structure.

Animate UI transitions in Unity UI Toolkit by toggling USS classes on VisualElements to trigger transitions defined in USS. You can chain animations or clean up states by listening for the TransitionEndEvent callback after the visual transition completes.

Unity UI Toolkit supports custom reusable VisualElement components via UxmlFactory. This encapsulates specific styling and behavior into a single element that can be instantiated and queried directly within UXML files like built-in controls.