smnbck/QuickLayout

Written in pure Swift, QuickLayout offers a simple and easy way to manage Auto Layout in code.

QuickLayout

QuickLayout offers an additional way, to easily manage the Auto Layout using only code. You can harness the power of QuickLayout to align your interface programmatically without even creating constraints explicitly.

• The WHY
• Naming Convension
• Features
• Example Project
• Requirements
• Installation
  • CocoaPods
  • Carthage
  • Manually
• Usage
  • Constant edges
  • Layout to Superview
    • Layout edge-x to superview edge-x
    • Using the applied constraint
    • Ratio
    • Offset
    • Center
    • Size
    • Fill
    • Axis
  • Layout to View
    • Edge-x to edge-x of another view
    • Multiple edges
  • Content Wrap
  • Array of QLView Elements
    • Constant edges
    • Axis
    • Multiple edges
    • Spread views
  • More
    • Priority
    • Relation
    • Ratio
    • Offset
  • Explicit Layout

The WHY

Why should you use QuickLayout?

• QuickLayout drastically shortens the amount of code in case you ever need to write the view hierarchy.
• It provides a common Auto Layout API for iOS, tvOS and macOS.
• QuickLayout contains most of the Auto Layout constructs an iOS App requires.
• The QuickLayout method declarations are very descriptive and clear. It is fully documented!
• Layout a UIView or NSView or an array of views using the instances themselves, without even creating a single NSLayoutConstraint instance.

Naming Convension

As of version 2.0.0, QuickLayout supports tvOS and macOS as well as iOS. Therefore, a few adjustments have been made.

• QLView replaces UIView or NSView.
• QLPriority replaces NSLayoutConstraint.Priority and UILayoutPriority
• QLAttribute replaces NSLayoutConstraint.Attribute and NSLayoutAttribute
• QLRelation replaces NSLayoutConstraint.Relation and NSLayoutRelation

Features

• Extension to QLView that contains functionality that allows you to set constraints directly from the view itself.
• Extension to Array of QLView that contains functionality that allows you to set constraints directly from an array of views.

Example Project

The example project demonstrates the benefits of using QuickLayout with several common use cases. Have a look! 😎

Requirements

Swift 4.0 or any higher version.

Installation

CocoaPods

CocoaPods is a dependency manager for Cocoa projects. You can install it with the following command:

$ gem install cocoapods

To integrate QuickLayout into your Xcode project using CocoaPods, specify the following in your Podfile:

pod 'QuickLayout', '3.0.0'

Then, run the following command:

$ pod install

Carthage

Carthage is a decentralized dependency manager that builds your dependencies and provides you with binary frameworks.

You can install Carthage with Homebrew using the following command:

$ brew update
$ brew install carthage

To integrate QuickLayout into your Xcode project using Carthage, specify the following in your Cartfile:

github "huri000/QuickLayout" == 3.0.0

Manually

Add the source files to your project.

Usage

Using QuickLayout is easy. No setup or preparation is required. All the necessary methods are already available in any of the QLView instances, and are fully documented and highly descriptive.

First, some boilerplate code: Define simpleView of type QLView and add it to the view hierarchy.

// Create a view, add it to view hierarchy, and customize it
let simpleView = QLView()
simpleView.backgroundColor = .gray
parentView.addSubview(simpleView)

Constant edges

Set a constant edge of a view:

simpleView.set(.height, of: 50)

You can set multiple constant edges using variadic parameters:

simpleView.set(.width, .height, of: 100)

Layout to Superview

You can easily layout a view directly to its superview as long as it has one.

Layout edge-x to superview edge-x

Layout the top of a view to the top of its superview:

simpleView.layoutToSuperview(.top)

Layout the centerX of a view to the centerX of its superview:

simpleView.layoutToSuperview(.centerX)

Multiple edges

You can also layout multiple edges likewise, using variadic parameters:

simpleView.layoutToSuperview(.top, .bottom, .centerX, .width)

Using the applied constraint

All the layout methods return the applied constraints, but the returned values are discardable so you can simply ignore them if you don't need them.

let topConstraint = simpleView.layoutToSuperview(.top)

// Change the offset value by adding 10pts to it
topConstraint.constant += 10

Ratio

You can layout a view to 80% its superview width:

simpleView.layoutToSuperview(.width, ratio: 0.8)

Offset

You can layout a view to it's superview width minus 10pts offset:

simpleView.layoutToSuperview(.width, offset: -10)

Center

Layout view to the center of superview:

let center = simpleView.centerInSuperview()

You can optionally retreive the returned QLCenterConstraints instance.

center?.y.constant = 20

That is the equivalent of doing the following, without getting the QLCenterConstraints instance (but an array of NSLayoutConstraint instead).

simpleView.layoutToSuperview(.centerX, .centerY)

Size

Size to superview with optional ratio - It means that simpleView is 80% its superview size.

let size = simpleView.sizeToSuperview(withRatio: 0.8)

You can optionally retreive the returned QLSizeConstraints instance.

size?.width.constant = -20

That is the equivalent of doing the following, without getting the QLSizeConstraints instance (but an array of NSLayoutConstraint instead).

simpleView.layoutToSuperview(.width, .height, ratio: 0.8)

Fill

let fillConstraints = simpleView.fillSuperview()

You can optionally retreive the returned QLFillConstraints instance.

fillConstraints?.center.y.constant = 5

Axis:

You can layout view to a certain axis, for example:

Horizontally:

let axis = simpleView.layoutToSuperview(axis: .horizontally)

Vertically:

simpleView.layoutToSuperview(axis: .vertically)

That is equivalent to (Horizontally):

simpleView.layoutToSuperview(.left, .right)

Or (Vertically):

simpleView.layoutToSuperview(.top, .bottom)

You can reteive the QLAxisConstraints instance as well and use it.

Layout to View

It is possible to layout one view to another inside the view hierarchy.

Layout edge-x to edge-y of another view

You can layout an edge of a view to another. For example:

Layout simpleView's left edge to the right edge of anotherView, with 20pts right offset.

simpleView.layout(.left, to: .right, of: anotherView, offset: 20)

Edge-x to edge-x of another view

Layout simpleView's top edge to the top edge of anotherView

simpleView.layout(to: .top, of: anotherView)

Multiple edges

Layout simpleView's left, right and centerY to anotherView's left, right and centerY, respectively.

simpleView.layout(.left, .right, .centerY, to: anotherView)

Content Wrap

Content Hugging Oriority and Content Compression Resistance can be also mutated in code

Vertical example:

let label = UILabel()
label.text = "Hi There!"
label.verticalCompressionResistancePriority = .required
label.verticalHuggingPriority = .required

You can set the compression resistence and the hugging priority, together. Thus, forcing both to be .required vertically and horizontally.

label.forceContentWrap()

You can force content wrap a specific axis:

label.forceContentWrap(.vertically)

Array of QLView Elements

You can generate an array of views and apply constraints on them all in one shot.

// Create array of views and customize it
var viewsArray: [QLView] = []
for _ in 0...4 {
    let simpleView = QLView()
    view.addSubview(simpleView)
    viewsArray.append(simpleView)
}

Constant edges

Each element gets height of 50pts, using this single line of code.

viewsArray.set(.height, of: 50)

Axis

Each element cling to left and right of its superview.

viewsArray.layoutToSuperview(axis: .horizontally, offset: 30)

Multiple edges

Each element left, right, top, bottom edges is exactly fits another view.

viewsArray.layout(.left, .right, .top, .bottom, to: parentView)

Spread views

You can spread the elements one below the other (vertically), the first stretches to the top of the superview and the last stretchs to the bottom of the superview. There is an offset of 1pt between each element.

viewsArray.spread(.vertically, stretchEdgesToSuperview: true, offset: 1)

More

Every layout method has several optional parameters - see below:

Priority

• The priority of the applied constraint.
• Included by all the layout methods.
• Default value: .required.

Other than the default system priorities, QuickLayout offers one more - it has 999 value and it's called .must.

You can tweak the priorities as you like in order to deal with breakage and redundancies.

Example for setting the constraints priority:

let width = simpleView.set(.width, of: 100, priority: .must)

Relation

• The relation of a view to another view.
• Included by most of the layout methods.
• Default value: .equal

Ratio

• The ratio of a view to another view.
• Included by most of the layout methods.
• Default value: 1

Offset

• The offset of a view to another view.
• Included by most of the layout methods.
• Default value: 0

Explicit Layout

You can layout a view/s explicitly to a superview or another view when you need to. Most paramters have a default value.

simpleView.layout(.height, to: .width, of: anotherView, relation: .lessThanOrEqual, ratio: 0.5, offset: 10, priority: .defaultHigh)

Contributing

Forks, patches and other feedback are welcome.

Author

Daniel Huri (huri000@gmail.com)

License

QuickLayout is available under the MIT license. See the LICENSE file for more info.