PinLayout

PinLayout is a helper for creating auto layout contraints.

LayoutBuilder API Cheatsheet

Basics

let subview = UIView()
self.view.addSubview(subview)

self.subview.layout
	.pin(.top, .leading)
	.width(100)
	.centerX()

Edges

Layout.Edge values: .top, .bottom, .leading, .trailing (plus whatever Layout.Edge defines).

Method	Purpose
fill()	Pin all four edges (.leading, .trailing, .top, .bottom) — fills the superview.
pin(_ edges: Layout.Edge...)	Pin edges with no gap.
pin(_ edges:, insets:, gap:, priority:, relatedBy:)	Pin edges with per-edge insets (NSDirectionalEdgeInsets), a fallback gap, priority, and relation (.equal, .greaterThanOrEqual, …).
pin(_ edges:, insets:, gap: Layout.Defaults, priority:)	Gap resolved from the layout's default value for that edge.
pin(_ edge:, to otherView: UIView, gap:, priority:)	Pin one edge to another view's corresponding edge.
pin(_ edge:, to otherView:, gap: Layout.Defaults, priority:)	Same, with a library default gap.

Centering

Method	Purpose
centerX(offset:, priority:)	Center horizontally in superview, with offset.
centerX(to otherView:)	Center horizontally relative to another view.
centerY(offset:, priority:)	Center vertically in superview, with offset.
centerY(to otherView:)	Center vertically relative to another view.
center()	Both centerX + centerY in superview.
center(to otherView:)	Both centers relative to another view.

Size

Method	Purpose
width(_ constant:, priority:)	Fixed width.
height(_ constant:, priority:)	Fixed height.
minWidth(_ constant:) / minHeight(_ constant:)	Minimum size constraints.
equalWidthAndHeight(priority:)	Width == height (aspect ratio 1:1).
equalWidth(with other:, priority:, multiplier:, constant:)	Width equal (or proportional) to another view.
equalHeight(with other:, priority:, multiplier:, constant:)	Height equal (or proportional) to another view.
equalSize(with other:, priority:, multiplier:)	Both width and height equal to another view.

Alignment

Method	Purpose
align(with otherView:, to edge:, gap:)	Align this view's edge with another view's edge.

Constraint Recording (testing / teardown)

Method	Purpose
startRecording(recorder:)	Begin recording created constraints.
stopRecording()	Stop recording.
finishRecording() -> [NSLayoutConstraint]	Stop and return all recorded constraints.
findConstraint(attribute: Layout.Constant) -> NSLayoutConstraint?	Look up a constraint by attribute.
removeAllConstraints()	Remove all constraints from the view.