HorizontalLayoutGroup

HorizontalLayoutGroup is a component in the Unity game engine's UI system, specifically within the UI Toolkit and formerly uGUI. It is used to arrange child UI elements horizontally. When added to a parent GameObject with a RectTransform, it automatically positions and sizes its children to align them in a row.

The HorizontalLayoutGroup offers several configurable properties to control the layout. These include Padding, which adds space around the edges of the group's content, and Spacing, which defines the gap between individual child elements. Child Alignment determines how the children are positioned within the group if their combined size is smaller than the group's width. Control Child Size allows the group to force its children to resize to match the group's dimensions, either by width, height, or both. Use Child Scale is similar to Control Child Size but uses scaling instead of resizing.

This component is invaluable for creating responsive and organized user interfaces. It simplifies the process of laying out buttons, text fields, images, and other UI elements in a linear fashion, ensuring they remain visually consistent across different screen resolutions. For example, it can be used to create a row of icons, a series of input fields, or a menu bar. The group recalculates its children's positions and sizes whenever changes occur to the group's properties or its children.