AutomaticSize with UIListLayouts is completely broken

If you’re using AutomaticSize and a UIListLayout, it continuously offsets children
Can see each subsequent child if being offset more and more





ListLayout bug.rbxm (7.0 KB)

And applying contents to an object causes the whole frame to adjust? This should NOT be the case. The sub contents should have NO effect the list layout


Inserting a TextLabel (which is in the other frames btw) causes the only frame to adjust

Expected behavior

It should automatically scale as one would expected, contents shouldn’t be getting offset

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This is because AutomaticSize is made for use primarily with offset. Youre size values use Scale.

Scale bases it’s value off the parents AbsoluteSize, and AutomaticSize bases it’s value off of the childrens AbsoluteSize. It’s a cyclical dependency, which causes unexpected behaviour.

Research usePx implementation, to see how you can get proper scaling at different screen sizes, while retaining proper functionality accross youre UI, such as UIListLayouts, by being able to use Offset values.

The automatic size is ONLY for the X scale. All contents uses RelativeYY, thus it should work as expected, as the X values will not change regardless of how much the automatic sizing does

This doesn’t change anything; It’s still a cyclical dependency. You want your Slot element to be 1:1 scale with something on the X, but when the parent is Automatically sized on the X, what will it attach onto?

I reiterate; Scale is not practical to be used how you’re using it; A px implementation lets you pass px values (like CSS), which scale with the screen size.

Use one

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If its based off AbsoluteSize, then why does it change, even tho AbsoluteSize does not change?

Hi @NinjoOnline thank you for the bug report. Unfortunately AutomaticSize behavior becomes hard to define when you have an automatically sized part and a child with scale-based sizing, because the sizing relationship becomes dependent on the other:

  • Automatic Size: parent’s size changes according to children sizes
  • UDim2 Scale sizing and positioning: child’s size/pos changes relative to parent size

Because of UI’s reliance on UDim2 as a foundational type, we hope to revisit this behavior in the near future, but we don’t have an ETA just yet.

The child’s size is RelativeYY though… the Y scale never changes, thus it’s irrelevant what the parents X size is (the automatic size)

And this definitely feels like a bug, cause it’s a single frame that’s affecting everything…


It’s not even the first frame in layout either… it’s just this one frame that breaks everything. It’s like it’s requiring me to have atleast 1 frame using offset…

Here’s a temporary fix I found (knowing the info above)

Just have 2 filler frames at the start and end, with (0, 0, 1, 0)

For your inner list layout, try changing ItemLineAlignment to Center. This completely fixed a bug I was experiencing a few weeks ago.