Drafter

Drafter is a set of simple wrapper calls around creating and accessing NSLayoutConstraints which makes it much less verbose when creating them progromatically. It allows for many of the common constraint creation operations to be expressed in a more concise way compared to the standard NSLayoutConstraint creation methods

To run the example project, clone the repo, and run pod install from the Example directory first.

Usage

Make sure you import the Drafter Module. import Drafter

The methods are all a category on UIView therefor you want to call these methods on the view you want affected.

Access

All access to constraint right now are presented with a variable interface. These iterate through the appropriate constraints locating the right correct one

Pinned container constraints

view.pinedLeftConstraint
view.pinnedRightConstraint
view.pinnedTopConstraint
view.pinnedBottomConstraint

Size constraints

// Note these only access height constraints that are to a constant, not bounded to a view.
view.pinnedHeightConstraint
view.pinnedWidthConstraint

Coming Soon

• Max and Min size constraints access
• Max and Min pinned padding constraints access

Creation

All Creation Methods have optional parameters:
active, Default true priority, Default UILayoutPriorityRequired
They also all return NSLayoutConstraint unless otherwise noted

Pinning sides to container

Pins the view side to it’s container respectively. These will crash if the caller doesn’t have a superview Pinning methods have an optional parameter of padding, Default 0.0

view.pinTopSpaceToContainer()
view.pinLeftSpaceToConainer()
view.pinRightSpaceToContainer()
view.pinBottomSpaceToContainer()

The fill method are a mass Pinning to Container functional for ease of use
The fill has an optional parameter insets, Default UIEdgeInsetsZero

// NOTE: This method returns a named tuple mimicking `UIEdgeInsets` but with constraints
view.fillContainer()

Centering in container

The centering interface is very similar to the pinning however it is centering based on the axis you specify, if no axis is specified it will center in both dimensions. These will crash if the caller doesn’t have a superview.
Centering constraints have an optional parameter offset. Default 0.0

view.centerInContainer(.Horizontal)
view.centerInContainer(.Vertical)


// NOTE: This method returns a named tuple mimicking `CGPoint` but with constraints
view.centerInContainer() 

Setting Size (width, height)

You can either set the size of the view directly or bind it to another view.
The view binding functions have an optional parameter multiplier. Default 1.0

view.pinHeight(toView: v)
view.pinHeight(toHeight: h)
view.pinWidth(toView: v)
view.pinWidth(toWidth: w)

// NOTE: This method returns a named tuple mimicking `CGSize` but with constraints.
// this method doesn't take a multiplier
view.pinSize(toSize: s)

Aligning & Attaching views

This interface requires you to pass in the view you are aligning the caller to. We don’t enforce the two views being in the same heirarchy so you have to be careful about that.
These have an optional parameter offset. Default 0.0

view.alignLeft(toLeftOfView: v)
view.alignRight(toRightOfView: v)
view.alignBottom(toBottomOfView: v)
view.alignTop(toTopOfView: v)

view.attachLeft(toRightOfView: v)   
view.attachRight(toLeftOfView: v)
view.attachBottom(toTopOfView: v)   
view.attachTop(toBottomOfView: v)

// NOTE the following return an array of constraints
// these have an optional param realtion. Default .Equal
view.align(subviews: vs, attribute: NSLayoutAttribute)
view.space(subviews: vs, alongAxis: UILayoutConstraintAxis,
            isPositive: true) // optional: defaults to true 

Coming Soon

• Min/Max Size Constraints
• Min/Max Padding to container

Authors

github: @mattThousand, email: [email protected], twitter: @mattThousand
github: @dostrander, email: [email protected], twitter: @_derko

License

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