A Size Change Tracker informs all Affected Objects about changes of the size of the object it is appended to. 

since Better UI 2.5:

The Size Change Tracker must be attached to an object that also has a component which implements ILayoutElement. This is usually the case for all visual elements like Images or Texts.

(This requirement was introduced because of very poor performance of the previous implementation)

You can change the following properties:

  • Size Mode: Either use "Preferred Size" or "Min Size" provided by the ILayoutElement component
  • Affected Axis: Tracks size changes of the specified axis. Can be Horizontal, Vertical or both.
  • Affected Objects: A list of objects that are informed about size changes.
    All components attached to these objects which implement ILayoutChildDependency will be informed about size changes (right now only Better Content Size Fitter implements this).

For more information about the use case of the Size Change Tracker, please read the Tutorial How to Resize Parent to Text Content.