Improve organization and comment all the things!

Author: Naxum

LICENSE.md

@@ -1,4 +1,4 @@
-Copyright (c) 2016 SwiftKick Mobile LLC
+Copyright (c) 2018 SwiftKick Mobile LLC
 
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

SwiftLayout.xcodeproj/project.pbxproj

@@ -22,6 +22,11 @@
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 		22AEE3A221A1078200295C85 /* SwiftLayout.podspec in Resources */ = {isa = PBXBuildFile; fileRef = 22AEE3A121A1078200295C85 /* SwiftLayout.podspec */; };
+		61374AEF21ADF45700E543BC /* RelationalConstraintBuilder+Custom.swift in Sources */ = {isa = PBXBuildFile; fileRef = 61374AEE21ADF45700E543BC /* RelationalConstraintBuilder+Custom.swift */; };
+		61374AF121ADF4AA00E543BC /* Constrainable+Builders.swift in Sources */ = {isa = PBXBuildFile; fileRef = 61374AF021ADF4AA00E543BC /* Constrainable+Builders.swift */; };
+		61374AF321ADF4CA00E543BC /* AnchorInfo.swift in Sources */ = {isa = PBXBuildFile; fileRef = 61374AF221ADF4CA00E543BC /* AnchorInfo.swift */; };
+		61374AF521ADF4EA00E543BC /* Constrainable+Anchors.swift in Sources */ = {isa = PBXBuildFile; fileRef = 61374AF421ADF4EA00E543BC /* Constrainable+Anchors.swift */; };
+		61374AF721ADF52500E543BC /* CGFloat+SystemSpacing.swift in Sources */ = {isa = PBXBuildFile; fileRef = 61374AF621ADF52500E543BC /* CGFloat+SystemSpacing.swift */; };
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 		22AEE3A121A1078200295C85 /* SwiftLayout.podspec */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text; path = SwiftLayout.podspec; sourceTree = "<group>"; };
+		61374AEE21ADF45700E543BC /* RelationalConstraintBuilder+Custom.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "RelationalConstraintBuilder+Custom.swift"; sourceTree = "<group>"; };
+		61374AF021ADF4AA00E543BC /* Constrainable+Builders.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "Constrainable+Builders.swift"; sourceTree = "<group>"; };
+		61374AF221ADF4CA00E543BC /* AnchorInfo.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AnchorInfo.swift; sourceTree = "<group>"; };
+		61374AF421ADF4EA00E543BC /* Constrainable+Anchors.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "Constrainable+Anchors.swift"; sourceTree = "<group>"; };
+		61374AF621ADF52500E543BC /* CGFloat+SystemSpacing.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "CGFloat+SystemSpacing.swift"; sourceTree = "<group>"; };
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 			children = (
 				22AEE39421A106DB00295C85 /* Constrainable.swift */,
+				61374AF021ADF4AA00E543BC /* Constrainable+Builders.swift */,
+				61374AF421ADF4EA00E543BC /* Constrainable+Anchors.swift */,
+				61374AF221ADF4CA00E543BC /* AnchorInfo.swift */,
 				22AEE38D21A106DB00295C85 /* ConstraintBuilder.swift */,
 				22AEE39021A106DB00295C85 /* DistributiveConstraintBuilder.swift */,
 				22AEE39121A106DB00295C85 /* DistributiveConstraintBuilder+Edges.swift */,
 				22AEE39221A106DB00295C85 /* RelationalConstraintBuilder.swift */,
 				22AEE39321A106DB00295C85 /* RelationalConstraintBuilder+Dimensions.swift */,
 				22AEE39521A106DB00295C85 /* RelationalConstraintBuilder+Edges.swift */,
 				22AEE38E21A106DB00295C85 /* RelationalConstraintBuilder+Spacing.swift */,
+				61374AEE21ADF45700E543BC /* RelationalConstraintBuilder+Custom.swift */,
 				22AEE39621A106DB00295C85 /* SelfConstraintBuilder.swift */,
 				22AEE38F21A106DB00295C85 /* SelfConstraintBuilder+Dimensions.swift */,
+				61374AF621ADF52500E543BC /* CGFloat+SystemSpacing.swift */,
 				22AEE38521A1056800295C85 /* SwiftLayout.h */,
 				22AEE38621A1056800295C85 /* Info.plist */,
 			);
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+				61374AF121ADF4AA00E543BC /* Constrainable+Builders.swift in Sources */,
 				22AEE39A21A106DB00295C85 /* DistributiveConstraintBuilder.swift in Sources */,
+				61374AF521ADF4EA00E543BC /* Constrainable+Anchors.swift in Sources */,
+				61374AF721ADF52500E543BC /* CGFloat+SystemSpacing.swift in Sources */,
 				22AEE39721A106DB00295C85 /* ConstraintBuilder.swift in Sources */,
 				22AEE39D21A106DB00295C85 /* RelationalConstraintBuilder+Dimensions.swift in Sources */,
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 				22AEE3A021A106DB00295C85 /* SelfConstraintBuilder.swift in Sources */,
 				22AEE39821A106DB00295C85 /* RelationalConstraintBuilder+Spacing.swift in Sources */,
+				61374AF321ADF4CA00E543BC /* AnchorInfo.swift in Sources */,
 				22AEE39F21A106DB00295C85 /* RelationalConstraintBuilder+Edges.swift in Sources */,
 				22AEE39C21A106DB00295C85 /* RelationalConstraintBuilder.swift in Sources */,
 				22AEE39921A106DB00295C85 /* SelfConstraintBuilder+Dimensions.swift in Sources */,

SwiftLayout/AnchorInfo.swift

@@ -0,0 +1,80 @@
+//
+//  AnchorInfo.swift
+//  SwiftLayout
+//
+//  Created by Jake Sawyer on 11/27/18.
+//  Copyright © 2018 it.swiftkick. All rights reserved.
+//
+
+import UIKit
+
+//MARK: - AnchorInfo
+
+/**
+ Internal helper struct for supplying all required attributes for creating a constraint in one simple package.
+ As a bonus, you can look up an `AnchorInfo<T>` via `Constraiable.anchorInfo(xAxis/yAxis/dimension:)`
+ */
+struct AnchorInfo<AnchorType: AnyObject> {
+    var item: Constrainable
+    var attribute: NSLayoutConstraint.Attribute
+    var anchor: NSLayoutAnchor<AnchorType>
+}
+
+// MARK: - Anchor Types
+
+/**
+ Helper for writing custom constraints between two different `NSLayoutXAxisAnchor` anchors.
+ 
+ ```
+ // Constrain view's centerX anchor to another view's leading anchor
+ view.constrain(to: otherView).xAxis(.centerX, to: .leading)
+ 
+ // Modify the optional arguments to specify a more advanced constraint
+ view.constrain(to: otherView).xAxis(.centerX, to: .leading, relation: .lessThanOrEqual, constant: 0, multiplier: 0.5, activate: false)
+ 
+ // Use the constraint builder returned after each newly created constraint to access the constraints created in order
+ let constraint = view.constrain(to: otherView).xAxis(.centerX, to: .leading, constant: 0, priority: .defaultHigh, activate: false).constraints.last!
+ constraint.isActive = true // activate the constraint later
+ ```
+ */
+public enum XAxisAnchor {
+    case leading, trailing, centerX
+}
+
+/**
+ Helper for writing custom constraints between two different `NSLayoutYAxisAnchor` anchors.
+ 
+ ```
+ // Constrain view's centerY anchor to another view's bottom anchor
+ view.constrain(to: otherView).yAxis(.centerY, to: .bottom)
+ 
+ // Modify the optional arguments to specify a more advanced constraint
+ view.constrain(to: otherView).yAxis(.centerY, to: .bottom, relation: .lessThanOrEqual, constant: 0, multiplier: 0.5, activate: false)
+ 
+ // Use the constraint builder returned after each newly created constraint to access the constraints created in order
+ let constraint = view.constrain(to: otherView).yAxis(.centerY, to: .bottom, constant: 0, priority: .defaultHigh, activate: false).constraints.last!
+ constraint.isActive = true // activate the constraint later
+ ```
+ */
+public enum YAxisAnchor {
+    case top, bottom, centerY
+}
+
+/**
+ Helper for writing custom constraints between two different `NSLayoutDimension` anchors.
+ 
+ ```
+ // Constrain view's width anchor to another view's height anchor
+ view.constrain(to: otherView).dimension(.width, to: .height)
+ 
+ // Modify the optional arguments to specify a more advanced constraint
+ view.constrain(to: otherView).dimension(.width, to: .height, relation: .lessThanOrEqual, constant: 0, multiplier: 0.5, activate: false)
+ 
+ // Use the constraint builder returned after each newly created constraint to access the constraints created in order
+ let constraint = view.constrain(to: otherView).dimension(.width, to: .height, constant: 0, priority: .defaultHigh, activate: false).constraints.last!
+ constraint.isActive = true // activate the constraint later
+ ```
+ */
+public enum DimensionAnchor {
+    case width, height
+}

SwiftLayout/CGFloat+SystemSpacing.swift

@@ -0,0 +1,23 @@
+//
+//  CGFloat+SystemSpacing.swift
+//  SwiftLayout
+//
+//  Created by Jake Sawyer on 11/27/18.
+//  Copyright © 2018 it.swiftkick. All rights reserved.
+//
+
+import UIKit
+
+public extension CGFloat {
+    /**
+     This value is only useful when using SwiftLayout to define a constraint that should use system spacing.
+     It is a nonsense value of `-9999` in all other scenarios.
+     
+     ```
+     // Constrain the leading anchors of both `view` and `otherView` by the system-determined appropriate spacing.
+     view.constrain(to: otherView).leading(constant: .systemSpacing)
+     ```
+     */
+    @available(iOS 11, *)
+    public static var systemSpacing: CGFloat { return -9999 }
+}

SwiftLayout/Constrainable+Anchors.swift

@@ -0,0 +1,49 @@
+//
+//  Constrainable+Anchors.swift
+//  SwiftLayout
+//
+//  Created by Jake Sawyer on 11/27/18.
+//  Copyright © 2018 it.swiftkick. All rights reserved.
+//
+
+import UIKit
+
+// MARK: - Anchor Infos on Constrainable
+
+extension Constrainable {
+    var leadingAnchorInfo: AnchorInfo<NSLayoutXAxisAnchor> { return AnchorInfo(item: self, attribute: .leading, anchor: self.leadingAnchor) }
+    var trailingAnchorInfo: AnchorInfo<NSLayoutXAxisAnchor> { return AnchorInfo(item: self, attribute: .trailing, anchor: self.trailingAnchor) }
+    var topAnchorInfo: AnchorInfo<NSLayoutYAxisAnchor> { return AnchorInfo(item: self, attribute: .top, anchor: self.topAnchor) }
+    var bottomAnchorInfo: AnchorInfo<NSLayoutYAxisAnchor> { return AnchorInfo(item: self, attribute: .bottom, anchor: self.bottomAnchor) }
+    var widthAnchorInfo: AnchorInfo<NSLayoutDimension> { return AnchorInfo(item: self, attribute: .width, anchor: self.widthAnchor) }
+    var heightAnchorInfo: AnchorInfo<NSLayoutDimension> { return AnchorInfo(item: self, attribute: .height, anchor: self.heightAnchor) }
+    var centerXAnchorInfo: AnchorInfo<NSLayoutXAxisAnchor> { return AnchorInfo(item: self, attribute: .centerX, anchor: self.centerXAnchor) }
+    var centerYAnchorInfo: AnchorInfo<NSLayoutYAxisAnchor> { return AnchorInfo(item: self, attribute: .centerY, anchor: self.centerYAnchor) }
+}
+
+// MARK: - Getting AnchorInfos from enums
+
+extension Constrainable {
+    func anchorInfo(xAxis anchorType: XAxisAnchor) -> AnchorInfo<NSLayoutXAxisAnchor> {
+        switch anchorType {
+        case .leading: return leadingAnchorInfo
+        case .trailing: return trailingAnchorInfo
+        case .centerX: return centerXAnchorInfo
+        }
+    }
+    
+    func anchorInfo(yAxis anchorType: YAxisAnchor) -> AnchorInfo<NSLayoutYAxisAnchor> {
+        switch anchorType {
+        case .top: return topAnchorInfo
+        case .bottom: return bottomAnchorInfo
+        case .centerY: return centerYAnchorInfo
+        }
+    }
+    
+    func anchorInfo(dimension anchorType: DimensionAnchor) -> AnchorInfo<NSLayoutDimension> {
+        switch anchorType {
+        case .width: return widthAnchorInfo
+        case .height: return heightAnchorInfo
+        }
+    }
+}

SwiftLayout/Constrainable+Builders.swift

@@ -0,0 +1,94 @@
+//
+//  Constrainable+Builders.swift
+//  SwiftLayout
+//
+//  Created by Jake Sawyer on 11/27/18.
+//  Copyright © 2018 it.swiftkick. All rights reserved.
+//
+
+import Foundation
+
+public extension Constrainable {
+    /**
+     This method performs initial setup for constraining two `Constrainable`s together.
+     In general, `UIView`s will have their autoresizing masks disabled, and will become children of the other `UIView` if they don't have one yet. Unowned `UILayoutGuide`s will have their owning views set.
+     
+     # Setup process:
+     - If this is a `UIView`, its `translatesAutoresizingMaskIntoConstraints` will be disabled.
+     - If this is a `UIView` and doesn't yet have a superview, and the supplied constrainable is also a `UIView`, this view will become a child of the supplied view.
+     - If this is a `UIView` and doesn't yet have a superview, and the supplied constrainable is a `UILayoutGuide` with an owning view, this view will become the child of the supplied layout guide's owning view.
+     - If this is a `UILayoutGuide` and doesn't yet have an owning view, and the supplied constrainable is a `UIView`, this layout guide will be added to the supplied view.
+     - If this is a `UILayoutGuide` and doesn't yet have an owning view, and the supplied constrainable is also a `UILayoutGuide` with an owning view, this layout guide will add itself to the supplied layout guide's owning view.
+     
+     # Basic usage:
+     ```
+     // Constrain both leading anchors for `view` and `otherView` with an equal relationship, constant of 0, multiplier of 1, and required priority.
+     // The constraint is activated by default.
+     view.constrain(to: otherView).leading()
+     
+     // Constraint methods make heavy use of default arguments. You only need to specify arguments when setting specific values.
+     view.constrain(to: otherView).width(.lessThanOrEqual, priority: .defaultLow)
+     
+     // Some constraints invert their anchors so your constants can always be positive. This includes trailing and bottom constraints.
+     // In this example, `view` is inset inside `otherView` by 8 points from the top and 24 points from the bottom.
+     view.constrain(to: otherView).top(constant: 8).bottom(constant: 24)
+     
+     // Chain method calls to create multiple constraints easily.
+     view.constrain(to: otherView).top().bottom().width()
+     ```
+     
+     # Advanced usage:
+     ```
+     // Helper methods simplify common scenarios by defining multiple constraints at the same time.
+     view.constrain(to: otherView).centerXY().widthHeight()
+     
+     // Constrain a `view` to the `layoutMarginsGuide` of `otherView`, thus padding its edges inset from the safe areas and margins.
+     view.constrain(to: otherView.layoutMarginsGuide).leadingTrailingTopBottom(constant: 32)
+     
+     // Access the constraint builder once the constraints are made, and grab the constraints
+     let builder = view.constrain(to: otherView).leadingTrailing(constant: 16).topBottom(constant: 8)
+     print(builder.constraints) // constraints are supplied in order of declaration. In this case: leading, trailing, top, bottom.
+     
+     // Create a highly customized constraint using system spacing, without activating it, and hold onto it for later use.
+     let constraint = view.constrain(to: otherView).leading(.lessThanOrEqual, constant: .systemSpacing, multiplier: 0.5, priority: .defaultLow, activate: false).constraints.last!
+     ```
+     */
+    @discardableResult
+    func constrain(to constrainable: Constrainable) -> RelationalConstraintBuilder {
+        return RelationalConstraintBuilder(first: self, second: constrainable)
+    }
+    
+    /**
+     This method performs initial setup for distributing two `Constrainable`s vertically and/or horizontally via constraints.
+     `UIView`s will have their autoresizing masks disabled and are assumed to already have superviews.
+     `UILayoutGuide`s are assumed to already have owning views.
+     
+     # Basic usage:
+     ```
+     // Constrain `view` horizontally after `otherView` via `otherView.trailingAnchor` and `view.leadingAnchor`.
+     view.constrain(after: otherView).leadingTrailing()
+     ```
+     */
+    func constrain(after constrainable: Constrainable) -> DistributiveConstraintBuilder {
+        return DistributiveConstraintBuilder(before: constrainable, after: self)
+    }
+    
+    /**
+     This method performs initial setup for constraining a `Constrainable`'s width/height/aspect ratio.
+     `UIView`s will have their autoresizing masks disabled.
+     
+     - NOTE: `CGFloat.systemSpacing` is not an acceptable constant here.
+     
+     # Basic usage:
+     ```
+     // Constrain `view`'s width to 50 points
+     view.constrainSelf().width(constant: 50)
+     
+     // Constrain `view`'s width and height anchors to their intrinsic size at this moment
+     view.constrainSelf().widthHeight(size: view.intrinsicContentSize)
+     ```
+     */
+    func constrainSelf() -> SelfConstraintBuilder {
+        return SelfConstraintBuilder(for: self)
+    }
+}