Add margin constraints methods

Sources/Layout/UIKit/UIView+AutoLayout.swift

@@ -7,6 +7,8 @@
 //  See https://github.com/Tinder/Layout/blob/main/LICENSE for license information.
 //
 
+// swiftlint:disable file_length
+
 import UIKit
 
 extension UIView {
@@ -372,4 +374,75 @@ extension UIView {
             right.constraint(to: superview.right, constant: -inset)
         ]
     }
+
+    // MARK: - Margins
+
+    /// Creates constraints aligning the edges of the receiver to the margins of the superview with an inset.
+    ///
+    /// - Parameter inset: The inset value.
+    ///
+    /// - Returns: The created constraints.
+    public func marginConstraints(
+        inset: CGFloat = 0
+    ) -> [NSLayoutConstraint] {
+        marginConstraints(insets: UIEdgeInsets(top: inset, left: inset, bottom: inset, right: inset))
+    }
+
+    /// Creates constraints aligning the edges of the receiver to the margins of the superview with directional insets
+    /// ([`NSDirectionalEdgeInsets`](https://developer.apple.com/documentation/uikit/nsdirectionaledgeinsets)).
+    ///
+    /// - Parameter insets: The directional insets.
+    ///
+    /// - Returns: The created constraints.
+    public func marginConstraints(
+        insets: DirectionalInsets
+    ) -> [NSLayoutConstraint] {
+        assert(superview != nil, "marginConstraints(insets:) requires superview")
+        guard let superview: UIView
+        else { return [] }
+        return [
+            leading.constraint(to: superview.margins.leading, constant: insets.leading),
+            trailing.constraint(to: superview.margins.trailing, constant: -insets.trailing),
+            top.constraint(to: superview.margins.top, constant: insets.top),
+            bottom.constraint(to: superview.margins.bottom, constant: -insets.bottom)
+        ]
+    }
+
+    /// Creates constraints aligning the edges of the receiver to the margins of the superview with canonical insets
+    /// ([`UIEdgeInsets`](https://developer.apple.com/documentation/uikit/uiedgeinsets)).
+    ///
+    /// - Parameter insets: The canonical insets.
+    ///
+    /// - Returns: The created constraints.
+    public func marginConstraints(
+        insets: CanonicalInsets
+    ) -> [NSLayoutConstraint] {
+        assert(superview != nil, "marginConstraints(insets:) requires superview")
+        guard let superview: UIView
+        else { return [] }
+        return [
+            left.constraint(to: superview.margins.left, constant: insets.left),
+            right.constraint(to: superview.margins.right, constant: -insets.right),
+            top.constraint(to: superview.margins.top, constant: insets.top),
+            bottom.constraint(to: superview.margins.bottom, constant: -insets.bottom)
+        ]
+    }
+
+    /// Creates constraints aligning the left and right edges of the receiver to the corresponding margins of the
+    /// superview with an inset.
+    ///
+    /// - Parameter inset: The inset value.
+    ///
+    /// - Returns: The created constraints.
+    public func sideMarginConstraints(
+        inset: CGFloat = 0
+    ) -> [NSLayoutConstraint] {
+        assert(superview != nil, "sideMarginConstraints(inset:) requires superview")
+        guard let superview: UIView
+        else { return [] }
+        return [
+            left.constraint(to: superview.margins.left, constant: inset),
+            right.constraint(to: superview.margins.right, constant: -inset)
+        ]
+    }
 }

Tests/LayoutTests/UIKit/UIView+AutoLayoutTests.swift

@@ -8,7 +8,7 @@
 //  See https://github.com/Tinder/Layout/blob/main/LICENSE for license information.
 //
 
-import Layout
+@testable import Layout
 import Nimble
 import UIKit
 import XCTest
@@ -855,4 +855,136 @@ final class UIViewAutoLayoutTests: XCTestCase {
         expect(constraints[0]).to(match(view.left.constraint(to: superview.left, constant: inset)))
         expect(constraints[1]).to(match(view.right.constraint(to: superview.right, constant: -inset)))
     }
+
+    // MARK: - Margins
+
+    func testMarginConstraintsInset() {
+
+        // GIVEN
+
+        let superview: UIView = .init()
+        let view: UIView = .init()
+        superview.addSubview(view)
+
+        // WHEN
+
+        let constraints: [NSLayoutConstraint] = view.marginConstraints()
+
+        // THEN
+
+        expect(constraints.count) == 4
+        expect(constraints[0]).to(match(view.left.constraint(to: superview.margins.left)))
+        expect(constraints[1]).to(match(view.right.constraint(to: superview.margins.right)))
+        expect(constraints[2]).to(match(view.top.constraint(to: superview.margins.top)))
+        expect(constraints[3]).to(match(view.bottom.constraint(to: superview.margins.bottom)))
+    }
+
+    func testMarginConstraintsInset_givenInset() {
+
+        // GIVEN
+
+        let superview: UIView = .init()
+        let view: UIView = .init()
+        superview.addSubview(view)
+        let inset: CGFloat = 10
+
+        // WHEN
+
+        let constraints: [NSLayoutConstraint] = view.marginConstraints(inset: inset)
+
+        // THEN
+
+        expect(constraints.count) == 4
+        expect(constraints[0]).to(match(view.left.constraint(to: superview.margins.left, constant: inset)))
+        expect(constraints[1]).to(match(view.right.constraint(to: superview.margins.right, constant: -inset)))
+        expect(constraints[2]).to(match(view.top.constraint(to: superview.margins.top, constant: inset)))
+        expect(constraints[3]).to(match(view.bottom.constraint(to: superview.margins.bottom, constant: -inset)))
+    }
+
+    func testMarginConstraintsInsetsDirectional() {
+
+        // GIVEN
+
+        let superview: UIView = .init()
+        let view: UIView = .init()
+        superview.addSubview(view)
+        let insets: NSDirectionalEdgeInsets = .init(top: 1, leading: 2, bottom: 3, trailing: 4)
+
+        // WHEN
+
+        let constraints: [NSLayoutConstraint] = view.marginConstraints(insets: insets)
+
+        // THEN
+
+        expect(constraints.count) == 4
+        expect(constraints[0])
+            .to(match(view.leading.constraint(to: superview.margins.leading, constant: insets.leading)))
+        expect(constraints[1])
+            .to(match(view.trailing.constraint(to: superview.margins.trailing, constant: -insets.trailing)))
+        expect(constraints[2])
+            .to(match(view.top.constraint(to: superview.margins.top, constant: insets.top)))
+        expect(constraints[3])
+            .to(match(view.bottom.constraint(to: superview.margins.bottom, constant: -insets.bottom)))
+    }
+
+    func testMarginConstraintsInsetsCanonical() {
+
+        // GIVEN
+
+        let superview: UIView = .init()
+        let view: UIView = .init()
+        superview.addSubview(view)
+        let insets: UIEdgeInsets = .init(top: 1, left: 2, bottom: 3, right: 4)
+
+        // WHEN
+
+        let constraints: [NSLayoutConstraint] = view.marginConstraints(insets: insets)
+
+        // THEN
+
+        expect(constraints.count) == 4
+        expect(constraints[0]).to(match(view.left.constraint(to: superview.margins.left, constant: insets.left)))
+        expect(constraints[1]).to(match(view.right.constraint(to: superview.margins.right, constant: -insets.right)))
+        expect(constraints[2]).to(match(view.top.constraint(to: superview.margins.top, constant: insets.top)))
+        expect(constraints[3]).to(match(view.bottom.constraint(to: superview.margins.bottom, constant: -insets.bottom)))
+    }
+
+    func testSideMarginConstraintsInset() {
+
+        // GIVEN
+
+        let superview: UIView = .init()
+        let view: UIView = .init()
+        superview.addSubview(view)
+
+        // WHEN
+
+        let constraints: [NSLayoutConstraint] = view.sideMarginConstraints()
+
+        // THEN
+
+        expect(constraints.count) == 2
+        expect(constraints[0]).to(match(view.left.constraint(to: superview.margins.left)))
+        expect(constraints[1]).to(match(view.right.constraint(to: superview.margins.right)))
+    }
+
+    func testSideMarginConstraintsInset_givenInset() {
+
+        // GIVEN
+
+        let superview: UIView = .init()
+        let view: UIView = .init()
+        superview.addSubview(view)
+        let inset: CGFloat = 10
+
+        // WHEN
+
+        let constraints: [NSLayoutConstraint] = view.sideMarginConstraints(inset: inset)
+
+        // THEN
+
+        expect(constraints.count) == 2
+        expect(constraints[0]).to(match(view.left.constraint(to: superview.margins.left, constant: inset)))
+        expect(constraints[1]).to(match(view.right.constraint(to: superview.margins.right, constant: -inset)))
+    }
 }

cheatsheet.html

@@ -335,6 +335,14 @@ <h3>Edges</h3>
                         <pre>edgeConstraints(insets: canonical)</pre>
                         <pre>sideEdgeConstraints()</pre>
                         <pre>sideEdgeConstraints(inset: 100)</pre>
+                        <h3>Margins</h3>
+                        <p>Constrains to superview margins.<p>
+                        <pre>marginConstraints()</pre>
+                        <pre>marginConstraints(inset: 100)</pre>
+                        <pre>marginConstraints(insets: directional)</pre>
+                        <pre>marginConstraints(insets: canonical)</pre>
+                        <pre>sideMarginConstraints()</pre>
+                        <pre>sideMarginConstraints(inset: 100)</pre>
                         <h2>Auto Layout</h2>
                         <h3>NSLayoutConstraint</h3>
                         <pre>activate()</pre>