I have a container that I want to put a shape in, and I want it to stretch the full length of the container and be pressed to the top.

I can just place the shape at the coordinates and then it will be pressed to the top like I want, but then it won’t stretch to the full width.
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You can also select layout from the parent element, in which case the form I want will stretch to full width, but it won’t be pinned to the top.
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I’ve tried setting the form style to width: 100%, but apparently I’m misunderstanding something and it doesn’t work here.

So the questions is: How do I stretch an object to its full width while pinning it to the top in QT Designer?

Program structure:
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