# TZStackView [![Carthage compatible](https://img.shields.io/badge/Carthage-compatible-4BC51D.svg?style=flat)](https://github.com/Carthage/Carthage) ![Swift 3.0.x](https://img.shields.io/badge/Swift-3.0.x-orange.svg)
A wonderful layout component called the [`UIStackView` was introduced with *iOS 9*](https://developer.apple.com/library/prerelease/ios/documentation/UIKit/Reference/UIStackView_Class_Reference/). With this component it is really easy to layout components in a row both horizontally and vertically. Apple recommends using the `UIStackView` wherever possible and resort to explicit `NSLayoutConstraints` only when there is no way to do it with `UIStackView`. This saves you lots of boiler plate `NSLayoutConstraint` creation code.

`UIStackView` requires *iOS 9*, but we're not ready to make our apps require *iOS 9+* just yet. In the meanwhile, we developers are eager to try this component in our apps right now! This is why I created this replica of the `UIStackView`, called the `TZStackView` (TZ = Tom van Zummeren, my initials). I created this component very carefully, tested every single corner case and matched the results against the *real* `UIStackView` with automated `XCTestCases`.

## Features
- ✅ Compatible with **iOS 7.x** and **iOS 8.x**
- ✅ Supports the complete API of `UIStackView` including **all** *distribution* and *alignment* options
- ✅ Supports animating the `hidden` property of the *arranged subviews*
- ❌ Supports *Storyboard*

So this implementation does **not** support Storyboard. It is meant for iOS developers who, like me, want to use the `UIStackView` in our existing apps and like to layout their components in code as opposed to using *Storyboard*.

## Setup
You basically have two options to include the `TZStackView` in your *Xcode* project:

### Use [CocoaPods](http://cocoapods.org/)
Example `Podfile`:
```ruby
source 'https://github.com/CocoaPods/Specs.git'
platform :ios, "8.0"
use_frameworks!

pod "TZStackView", "1.2.0"
```
Unfortunately, using CocoaPods with a Swift pod requires iOS 8.

### Use [Carthage](https://github.com/Carthage/Carthage)

Example `Cartfile`:
```
github "tomvanzummeren/TZStackView" ~> 1.2.0
```

Run `carthage` to build the framework and drag the built `TZStackView.framework` into your Xcode project.

### Drag files directly into your project
Alternatively (when you do want to support iOS 7) drag in the following classes from the *Example* folder directly into your *Xcode* project
  * `TZStackView`
  * `TZSpacerView`
  * `TZStackViewAlignment`
  * `TZStackViewDistribution`

## Example usage
Given `view1`, `view2` and `view3` who have intrinsic content sizes set to *100x100*, *80x80* and *60x60* respectively.

```swift
let stackView = TZStackView(arrangedSubviews: [view1, view2, view3])
stackView.distribution = .FillEqually
stackView.alignment = .Center
stackView.axis = .Vertical
stackView.spacing = 25
```

This would produce the following layout:

![TZStackView Layout example](/assets/layout-example.png)

See the [developer documentation for `UIStackView`](https://developer.apple.com/library/prerelease/ios/documentation/UIKit/Reference/UIStackView_Class_Reference/) for all other combinatins of distributions, alignments and axis. `TZStackView` works and behaves exactly the same way as the `UIStackView` except for not supporting Storyboard. If you do find a case where it does not behave the same way, please file a bug report.

To animate adding a view to or removing a view from the arranged subviews, simply hide or show them by adjusting the `hidden` property within an animation block (as described by the `UIStackView` reference docs as well):

```swift
UIView.animateWithDuration(0.5, animations: {
	self.view2.hidden = true
})
```
![TZStackView hidden animation example](/assets/TZStackView-hide-animation.gif)

## Migrating to UIStackView
If at a later point you decide to make *iOS 9* the minimum requirement of your app (it will happen sooner or later), you will want to migrate to the real `UIStackView` instead of using this implementation. Because the `TZStackView` is a drop-in replacement for `UIStackView`, you simply replace:

```swift
let stackView = TZStackView(arrangedSubviews: views)
```

with ...

```swift
let stackView = UIStackView(arrangedSubviews: views)
```

... and you're good to go! You will not need to make any other changes and everything will simply work the way it worked before.

## License
TZStackView is released under the MIT license. See LICENSE for details.