SimplyLayout 1.2.0

SimplyLayout 1.2.0

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由 Su, Hsing-Yu 维护。

SimplyLayout 1.2.0

  • 由
  • Su, Hsing-Yu

SimplyLayout

基于锚点的 Auto Layout 的 Swift 语法糖

安装

CocoaPod

# Swift 4 with full functions, including `Core`, `Anchor` and `Group`
pod 'SimplyLayout'

# Swift 4 with syntactic sugar only
pod 'SimplyLayout/Core'

# Swift 4 with convenience virtual anchors (CenterAnchor, EdgeAnchor, etc.)
pod 'SimplyLayout/Anchor'

# Swift 4 with constraint grouping functions
pod 'SimplyLayout/Group'

# Swift 3
pod 'SimplyLayout', :git => 'https://github.com/aipeople/SimplyLayout.git', :tag => 'swift3-1.0.1'

使用

操作符

  • +, - -> 设置常量
  • * -> 设置倍数
  • ~ -> 设置优先级

示例

import SimplyLayout

view.widthAnchor == 100
// view.widthAnchor.constraint(equalToConstant: 100).isActive = true
// view.translatesAutoresizingMaskIntoConstraints = false

view.heightAnchor == view.superview!.heightAnchor * 0.25 + 40 ~ .defautHigh
// let constraint = view.heightAnchor.constraint(equalTo: view.superview!.heightAnchor, multiplier: 0.25, constant: 40)
// constraint.priority = .defaultHigh
// constraint.isActive = true
// view.translatesAutoresizingMaskIntoConstraints = false

激活

约束将自动激活。您可以通过设置 SimplyLayout.config.defaultActivation 为 false 来关闭此功能。由于某些原因，您可能想要创建具有不同激活状态的约束。《++》和--, 可以帮您移除默认配置。

示例

SimplyLayout.config.defaultActivation = true

view.widthAnchor == 100
// view.widthAnchor.constraint(equalToConstant: 100).isActive = true

view.widthAnchor == --100
// view.widthAnchor.constraint(equalToConstant: 100)

SimplyLayout.config.defaultActivation = false

view.heightAnchor == view.superview!.heightAnchor * 0.25
// let constraint = view.heightAnchor.constraint(equalTo: view.superview!.heightAnchor, multiplier: 0.25)

view.heightAnchor == ++view.superview!.heightAnchor * 0.25
// let constraint = view.heightAnchor.constraint(equalTo: view.superview!.heightAnchor, multiplier: 0.25)
// constraint.isActive = true

访问约束

可以通过使用 = 运算符轻松访问新创建的约束。

示例

let constraint = view.heightAnchor == view.superview!.heightAnchor * 0.25

虚拟锚点

虚拟锚点不是真实的 NSLayoutAnchor。这些锚点只是为了帮助您更容易地创建约束。

  • 中心锚点
view.centerAnchor == view.superview!.centerAnchor + CGPoint(x: 10, y: 10)
// view.centerXAnchor == view.superview!.centerXAnchor + 10
// view.centerYAnchor == view.superview!.centerYAnchor + 10
  • 边缘锚点
view.edgeAnchor == view.superview!.edgeAnchor
// view.topAnchor      == view.superview!.topAnchor
// view.leadingAnchor  == view.superview!.leadingAnchor
// view.bottomAnchor   == view.superview!.bottomAnchor
// view.trailingAnchor == view.superview!.trailingAnchor

view.edgeAnchor == view.superview!.edgeAnchor.insetBy(top: 10, left: 20, bottom: 10, right: 20)
// view.edgeAnchor == view.superview!.edgeAnchor + UIEdgeInsets(top: 10, left: 20, bottom: 10, right: 20)
// -----------------------(equals to)------------------------
// view.topAnchor      == view.superview!.topAnchor      + 10
// view.leadingAnchor  == view.superview!.leadingAnchor  + 20
// view.bottomAnchor   == view.superview!.bottomAnchor   - 10
// view.trailingAnchor == view.superview!.trailingAnchor - 20

分组

分组函数需要 SimplyLayout/Group 子模块。它提供了一个方便地将多个约束组合在一起的方法。一组约束由一个 NSLayoutConstraint 数组表示，可以一起激活/关闭。

示例

let boxA = UIView()
let boxB = UIView()

// `verticalConstraintGroup` is an array with NSLayoutConstraint.
// In the following case, it will contains two constraints.
let verticalConstraintGroup = NSLayoutConstraint.group {
    boxA.centerXAnchor == boxA.superview!.centerXAnchor
    boxB.centerXAnchor == boxB.superview!.centerXAnchor
}
 
// All the constraints created in the block won't be activated 
let horizontalConstraintGroup = NSLayoutConstraint.group(activated: false) {
    boxA.centerYAnchor == boxA.superview!.centerYAnchor
    boxB.centerYAnchor == boxB.superview!.centerYAnchor
}

// Deactivate all constraints in the group
verticalConstraintGroup.deactivateAll()

// Activate all constraints in the group
horizontalConstraintGroup.activateAll()

配置

  • postNotificationWhenConstrantCreate：当使用 SimplyLayout 语法设置约束后，将立即发布名为 SimplyLayout.constraintCreatedNotification 的通知。默认值为 false。

可以在 SimplyLayout.config 中设置与约束相关的行为。

  • defaultPriority：默认值是 .required
  • defaultActivation：默认值是 true