Proposal: Before Pool Request GameObject.SetActive(true) have a Callback or even better RequestInactive

[IAFahim]

In Unity optimization guidebook (I think I read it) it says. When we pool a UI element, we often set it active then modify it, causing double render.

So having an optional Action callback to setup elements before setting it active only when the object is from pool (not when created first time) would provide performance improvements.

Like this

prefab.Request(_ , OnGetFromPool)

Callback has limitations like what if you spawn 20 items in a GridLayout for each item it would redraw full canvas.

So having a new method RequestInactive would be the best solution. Or we can just spawn UI element with parent null then attach to canvas. (Have to call set TransformSetIndex later)

I am saying it because when we build a complex ui with lots of item setActive it can add up.

Let me know if it's crazy talk or not.

[aprius]

This is absolutely correct, this approach could indeed improve performance in Unity when working with complex UI elements. Unity's rendering system does have specific ways of handling active/inactive UI elements, and calling SetActive frequently especially when modifying pooled objects can lead to costly recalculations in layouts and canvas batches.

RequestInactive method will give more flexibility in editing because then you can do whatever you want after Request. Like request UI element with no parent then configure it and then attaching it to the parent canvas after setup. It ensures that layout updates happen only after the element is fully ready. You could call the SetTransformIndex method afterwards to maintain the correct order without disrupting the layout during setup, but this seems a bit overkill.

Finaly call SetActive(true) to active gameObject