Layout breaks view arrangements

[mohpor]

Hi,

In Material 2.x when we used Layout, we considered the child as free and the layout function would add it to the parent, and it is done through addSubview, there were cases that this was not the desired effect, for example when I add a blur view in my code, I want it to be at the bottom, so, first I would've inserted the child at 0, and then lay it out:

parent.insertSubview(child, at: 0)
parent.layout(child).edges()

Material 3 breaks this simple rule and adds the child to super view, without checking to see if the child already has a parent, and therefore breaks the arrangement the developer might have desired.

There is workaround for this, you can simply arrange the view afterwards, but now I have to look for every instance I've done it! This is a breaking change.

P.S.: I did the Material 2's Layout, although it has been erased from git's history due to restructuring.

[mohpor]

This is a serious problem.
I'm sure many developers would see views that has been laid out using Layout out of order, without being able to detect why this is happening!

[OrkhanAlikhanov]

So the problem is that order of inserted view changes? The reason might be we don't check if the view is already child.

Material/Sources/iOS/Layout/Layout.swift

Lines 43 to 47 in 3677b26

	func layout(_ child: UIView) -> Layout {
	addSubview(child)
	child.translatesAutoresizingMaskIntoConstraints = false
	return child.layout
	}

[mohpor]

Exactly,
In the previous versions, in the layout function, we added the subview ONLY if the parent was missing!

[OrkhanAlikhanov]

I submitted PR for this. Thank you for reporting 💪

[OrkhanAlikhanov]

Btw, you could workaround it by:

parent.insertSubview(child, at: 0)
child.translatesAutoresizingMaskIntoConstraints = false
child.layout.edges()

:)

[daniel-jonathan]

@mohpor please find your fix here and thank you for bringing this to our attention: https://github.com/CosmicMind/Material/releases/tag/3.1.2, thank you @OrkhanAlikhanov :)