Adaptable ScrollContainer size on UI

[lastbender]

Godot Version

v4.5.stable.official [876b29033]

Question

I have a ScrollContainer that begins empty but will have child nodes added at runtime.

I want the ScrollContainer’s height (size.y) to behave like this:

• When it has no children, its height should be 0. (Can be done by setting visibility)

• When children are added, its height should match the total height of all children combined.

• If the total child height exceeds a maximum height I define, the container should cap at that max height and then show the scrollbar.

Any suggestions how to achieve that?

[grulps]

ScrollContainer should only have one child and its size.y should be the desired max height. If you add a VBoxContainer as a child of the ScrollContainer and add the other nodes as children of the VBoxContainer, it should work as you described. Although, you may have to adjust some size flags.

[lastbender]

Yes, I actually do that, but for some reason forgot to mention it My bad!

But it still doesn’t solve my issue because sometimes the auto-sizing with containers, and changing min size doesn’t work properly together. I think I need to figure out what happens when exactly in a container. Maybe sort_children or pre_sort_children signal can help.

I’ll send more details once I’m back checking that. I appriciate the response!

[grulps]

So the scroll container is inside another container and it needs to update custom_minimum_size based on its contents? If that’s the case, I just tested and confirmed the following solution.

func _ready() -> void:
    inner_vbox.resized.connect(resize_scroll)

func resize_scroll() -> void:
    scroll.custom_minimum_size.y = minf(inner_vbox.size.y, MAX_HEIGHT)