SnapKit/Source/Constraint.swift

735 lines
29 KiB
Swift

//
// Snap
//
// Copyright (c) 2011-2014 Masonry Team - https://github.com/Masonry
//
// 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:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
#if os(iOS)
import UIKit
#else
import AppKit
#endif
/**
* Constraint is a single item that defines all the properties for a single ConstraintMaker chain
*/
final public class Constraint {
public var left: Constraint { return self.addConstraint(ConstraintAttributes.Left) }
public var top: Constraint { return self.addConstraint(ConstraintAttributes.Top) }
public var right: Constraint { return self.addConstraint(ConstraintAttributes.Right) }
public var bottom: Constraint { return self.addConstraint(ConstraintAttributes.Bottom) }
public var leading: Constraint { return self.addConstraint(ConstraintAttributes.Leading) }
public var trailing: Constraint { return self.addConstraint(ConstraintAttributes.Trailing) }
public var width: Constraint { return self.addConstraint(ConstraintAttributes.Width) }
public var height: Constraint { return self.addConstraint(ConstraintAttributes.Height) }
public var centerX: Constraint { return self.addConstraint(ConstraintAttributes.CenterX) }
public var centerY: Constraint { return self.addConstraint(ConstraintAttributes.CenterY) }
public var baseline: Constraint { return self.addConstraint(ConstraintAttributes.Baseline) }
public var and: Constraint {
if self.relation != nil {
fatalError("And is semantic only and can only be used before a relation is set.")
}
return self
}
public var with: Constraint { return self }
// MARK: initializer
internal init(fromItem: ConstraintItem) {
self.fromItem = fromItem
self.toItem = ConstraintItem(object: nil, attributes: ConstraintAttributes.None)
}
// MARK: equalTo
public func equalTo(other: ConstraintItem) -> Constraint {
return self.constrainTo(other, relation: .Equal)
}
public func equalTo(other: View) -> Constraint {
return self.constrainTo(other, relation: .Equal)
}
#if os(iOS)
public func equalTo(other: UILayoutSupport) -> Constraint {
return self.constrainTo(other, relation: .Equal)
}
#endif
public func equalTo(other: Float) -> Constraint {
return self.constrainTo(other, relation: .Equal)
}
public func equalTo(other: Double) -> Constraint {
return self.constrainTo(Float(other), relation: .Equal)
}
public func equalTo(other: CGFloat) -> Constraint {
return self.constrainTo(Float(other), relation: .Equal)
}
public func equalTo(other: Int) -> Constraint {
return self.constrainTo(Float(other), relation: .Equal)
}
public func equalTo(other: UInt) -> Constraint {
return self.constrainTo(Float(other), relation: .Equal)
}
public func equalTo(other: CGSize) -> Constraint {
return self.constrainTo(other, relation: .Equal)
}
public func equalTo(other: CGPoint) -> Constraint {
return self.constrainTo(other, relation: .Equal)
}
public func equalTo(other: EdgeInsets) -> Constraint {
return self.constrainTo(other, relation: .Equal)
}
// MARK: lessThanOrEqualTo
public func lessThanOrEqualTo(other: ConstraintItem) -> Constraint {
return self.constrainTo(other, relation: .LessThanOrEqualTo)
}
public func lessThanOrEqualTo(other: View) -> Constraint {
return self.constrainTo(other, relation: .LessThanOrEqualTo)
}
#if os(iOS)
public func lessThanOrEqualTo(other: UILayoutSupport) -> Constraint {
return self.constrainTo(other, relation: .LessThanOrEqualTo)
}
#endif
public func lessThanOrEqualTo(other: Float) -> Constraint {
return self.constrainTo(other, relation: .LessThanOrEqualTo)
}
public func lessThanOrEqualTo(other: Double) -> Constraint {
return self.constrainTo(Float(other), relation: .LessThanOrEqualTo)
}
public func lessThanOrEqualTo(other: CGFloat) -> Constraint {
return self.constrainTo(Float(other), relation: .LessThanOrEqualTo)
}
public func lessThanOrEqualTo(other: Int) -> Constraint {
return self.constrainTo(Float(other), relation: .LessThanOrEqualTo)
}
public func lessThanOrEqualTo(other: UInt) -> Constraint {
return self.constrainTo(Float(other), relation: .LessThanOrEqualTo)
}
public func lessThanOrEqualTo(other: CGSize) -> Constraint {
return self.constrainTo(other, relation: .LessThanOrEqualTo)
}
public func lessThanOrEqualTo(other: CGPoint) -> Constraint {
return self.constrainTo(other, relation: .LessThanOrEqualTo)
}
public func lessThanOrEqualTo(other: EdgeInsets) -> Constraint {
return self.constrainTo(other, relation: .LessThanOrEqualTo)
}
// MARK: greaterThanOrEqualTo
public func greaterThanOrEqualTo(other: ConstraintItem) -> Constraint {
return self.constrainTo(other, relation: .GreaterThanOrEqualTo)
}
public func greaterThanOrEqualTo(other: View) -> Constraint {
return self.constrainTo(other, relation: .GreaterThanOrEqualTo)
}
#if os(iOS)
public func greaterThanOrEqualTo(other: UILayoutSupport) -> Constraint {
return self.constrainTo(other, relation: .GreaterThanOrEqualTo)
}
#endif
public func greaterThanOrEqualTo(other: Float) -> Constraint {
return self.constrainTo(other, relation: .GreaterThanOrEqualTo)
}
public func greaterThanOrEqualTo(other: Double) -> Constraint {
return self.constrainTo(Float(other), relation: .GreaterThanOrEqualTo)
}
public func greaterThanOrEqualTo(other: CGFloat) -> Constraint {
return self.constrainTo(Float(other), relation: .GreaterThanOrEqualTo)
}
public func greaterThanOrEqualTo(other: Int) -> Constraint {
return self.constrainTo(Float(other), relation: .GreaterThanOrEqualTo)
}
public func greaterThanOrEqualTo(other: UInt) -> Constraint {
return self.constrainTo(Float(other), relation: .GreaterThanOrEqualTo)
}
public func greaterThanOrEqualTo(other: CGSize) -> Constraint {
return self.constrainTo(other, relation: .GreaterThanOrEqualTo)
}
public func greaterThanOrEqualTo(other: CGPoint) -> Constraint {
return self.constrainTo(other, relation: .GreaterThanOrEqualTo)
}
public func greaterThanOrEqualTo(other: EdgeInsets) -> Constraint {
return self.constrainTo(other, relation: .GreaterThanOrEqualTo)
}
// MARK: multiplier
public func multipliedBy(amount: Float) -> Constraint {
self.multiplier = amount
return self
}
public func multipliedBy(amount: Double) -> Constraint {
return self.multipliedBy(Float(amount))
}
public func multipliedBy(amount: CGFloat) -> Constraint {
return self.multipliedBy(Float(amount))
}
public func multipliedBy(amount: Int) -> Constraint {
return self.multipliedBy(Float(amount))
}
public func multipliedBy(amount: UInt) -> Constraint {
return self.multipliedBy(Float(amount))
}
public func dividedBy(amount: Float) -> Constraint {
self.multiplier = 1.0 / amount;
return self
}
public func dividedBy(amount: Double) -> Constraint {
return self.dividedBy(Float(amount))
}
public func dividedBy(amount: CGFloat) -> Constraint {
return self.dividedBy(Float(amount))
}
public func dividedBy(amount: Int) -> Constraint {
return self.dividedBy(Float(amount))
}
public func dividedBy(amount: UInt) -> Constraint {
return self.dividedBy(Float(amount))
}
// MARK: priority
public func priority(priority: Float) -> Constraint {
self.priority = priority
return self
}
public func priority(priority: Double) -> Constraint {
return self.priority(Float(priority))
}
public func priority(priority: CGFloat) -> Constraint {
return self.priority(Float(priority))
}
public func priority(priority: UInt) -> Constraint {
return self.priority(Float(priority))
}
public func priority(priority: Int) -> Constraint {
return self.priority(Float(priority))
}
public func priorityRequired() -> Constraint {
return self.priority(1000.0)
}
public func priorityHigh() -> Constraint {
return self.priority(750.0)
}
public func priorityMedium() -> Constraint {
#if os(iOS)
return self.priority(500.0)
#else
return self.priority(501.0)
#endif
}
public func priorityLow() -> Constraint {
return self.priority(250.0)
}
// MARK: offset
public func offset(amount: Float) -> Constraint {
self.offset = amount
return self
}
public func offset(amount: Double) -> Constraint {
return self.offset(Float(amount))
}
public func offset(amount: CGFloat) -> Constraint {
return self.offset(Float(amount))
}
public func offset(amount: Int) -> Constraint {
return self.offset(Float(amount))
}
public func offset(amount: UInt) -> Constraint {
return self.offset(Float(amount))
}
public func offset(amount: CGPoint) -> Constraint {
self.offset = amount
return self
}
public func offset(amount: CGSize) -> Constraint {
self.offset = amount
return self
}
public func offset(amount: EdgeInsets) -> Constraint {
self.offset = amount
return self
}
// MARK: insets
public func insets(amount: EdgeInsets) -> Constraint {
self.offset = amount
return self
}
// MARK: install / uninstall
public func install() -> [LayoutConstraint] {
return self.installOnView(updateExisting: false)
}
public func uninstall() {
self.uninstallFromView()
}
public func activate() {
if NSLayoutConstraint.respondsToSelector("activateConstraints:") && self.installInfo != nil {
let layoutConstraints = self.installInfo!.layoutConstraints.allObjects as! [LayoutConstraint]
if layoutConstraints.count > 0 {
NSLayoutConstraint.activateConstraints(layoutConstraints)
}
} else {
self.install()
}
}
public func deactivate() {
if NSLayoutConstraint.respondsToSelector("deactivateConstraints:") && self.installInfo != nil {
let layoutConstraints = self.installInfo!.layoutConstraints.allObjects as! [LayoutConstraint]
if layoutConstraints.count > 0 {
NSLayoutConstraint.deactivateConstraints(layoutConstraints)
}
} else {
self.uninstall()
}
}
// MARK: internal
internal func installOnView(updateExisting: Bool = false) -> [LayoutConstraint] {
var installOnView: View? = nil
if self.toItem.view != nil {
installOnView = Constraint.closestCommonSuperviewFromView(self.fromItem.view, toView: self.toItem.view)
if installOnView == nil {
NSException(name: "Cannot Install Constraint", reason: "No common superview between views", userInfo: nil).raise()
return []
}
} else {
installOnView = self.fromItem.view?.superview
if installOnView == nil {
if self.fromItem.attributes == ConstraintAttributes.Width || self.fromItem.attributes == ConstraintAttributes.Height {
installOnView = self.fromItem.view
}
if installOnView == nil {
NSException(name: "Cannot Install Constraint", reason: "Missing superview", userInfo: nil).raise()
return []
}
}
}
if let installedOnView = self.installInfo?.view {
if installedOnView != installOnView {
NSException(name: "Cannot Install Constraint", reason: "Already installed on different view.", userInfo: nil).raise()
return []
}
return self.installInfo?.layoutConstraints.allObjects as? [LayoutConstraint] ?? []
}
var newLayoutConstraints = [LayoutConstraint]()
let layoutFromAttributes = self.fromItem.attributes.layoutAttributes
let layoutToAttributes = self.toItem.attributes.layoutAttributes
// get layout from
let layoutFrom: View? = self.fromItem.view
// get layout relation
let layoutRelation: NSLayoutRelation = (self.relation != nil) ? self.relation!.layoutRelation : .Equal
for layoutFromAttribute in layoutFromAttributes {
// get layout to attribute
let layoutToAttribute = (layoutToAttributes.count > 0) ? layoutToAttributes[0] : layoutFromAttribute
// get layout constant
var layoutConstant: CGFloat = layoutToAttribute.snp_constantForValue(self.constant)
layoutConstant += layoutToAttribute.snp_offsetForValue(self.offset)
// get layout to
var layoutTo: View? = self.toItem.view
if layoutTo == nil && layoutToAttribute != .Width && layoutToAttribute != .Height {
layoutTo = installOnView
}
// create layout constraint
let layoutConstraint = LayoutConstraint(
item: layoutFrom!,
attribute: layoutFromAttribute,
relatedBy: layoutRelation,
toItem: layoutTo,
attribute: layoutToAttribute,
multiplier: CGFloat(self.multiplier),
constant: layoutConstant)
// set priority
layoutConstraint.priority = self.priority
// set constraint
layoutConstraint.snp_constraint = self
newLayoutConstraints.append(layoutConstraint)
}
// special logic for updating
if updateExisting {
// get existing constraints for this view
let existingLayoutConstraints = reverse(layoutFrom!.snp_installedLayoutConstraints)
// array that will contain only new layout constraints to keep
var newLayoutConstraintsToKeep = [LayoutConstraint]()
// begin looping
for layoutConstraint in newLayoutConstraints {
// layout constraint that should be updated
var updateLayoutConstraint: LayoutConstraint? = nil
// loop through existing and check for match
for existingLayoutConstraint in existingLayoutConstraints {
if existingLayoutConstraint == layoutConstraint {
updateLayoutConstraint = existingLayoutConstraint
break
}
}
// if we have existing one lets just update the constant
if updateLayoutConstraint != nil {
updateLayoutConstraint!.constant = layoutConstraint.constant
}
// otherwise add this layout constraint to new keep list
else {
newLayoutConstraintsToKeep.append(layoutConstraint)
}
}
// set constraints to only new ones
newLayoutConstraints = newLayoutConstraintsToKeep
}
// add constraints
installOnView!.addConstraints(newLayoutConstraints)
// set install info
self.installInfo = ConstraintInstallInfo(view: installOnView, layoutConstraints: NSHashTable.weakObjectsHashTable())
// store which layout constraints are installed for this constraint
for layoutConstraint in newLayoutConstraints {
self.installInfo!.layoutConstraints.addObject(layoutConstraint)
}
// store the layout constraints against the layout from view
layoutFrom!.snp_installedLayoutConstraints += newLayoutConstraints
// return the new constraints
return newLayoutConstraints
}
internal func uninstallFromView() {
if let installInfo = self.installInfo,
let installedLayoutConstraints = installInfo.layoutConstraints.allObjects as? [LayoutConstraint] {
if installedLayoutConstraints.count > 0 {
if let installedOnView = installInfo.view {
// remove the constraints from the UIView's storage
installedOnView.removeConstraints(installedLayoutConstraints)
}
// remove the constraints from the from item view
if let fromView = self.fromItem.view {
fromView.snp_installedLayoutConstraints = fromView.snp_installedLayoutConstraints.filter {
return !contains(installedLayoutConstraints, $0)
}
}
}
}
self.installInfo = nil
}
// MARK: private
private let fromItem: ConstraintItem
private var toItem: ConstraintItem
private var relation: ConstraintRelation?
private var constant: Any = Float(0.0)
private var multiplier: Float = 1.0
private var priority: Float = 1000.0
private var offset: Any = Float(0.0)
private var installInfo: ConstraintInstallInfo?
private func addConstraint(attributes: ConstraintAttributes) -> Constraint {
if self.relation == nil {
self.fromItem.attributes += attributes
}
return self
}
private func constrainTo(other: ConstraintItem, relation: ConstraintRelation) -> Constraint {
if other.attributes != ConstraintAttributes.None {
let toLayoutAttributes = other.attributes.layoutAttributes
if toLayoutAttributes.count > 1 {
let fromLayoutAttributes = self.fromItem.attributes.layoutAttributes
if toLayoutAttributes != fromLayoutAttributes {
NSException(name: "Invalid Constraint", reason: "Cannot constrain to multiple non identical attributes", userInfo: nil).raise()
return self
}
other.attributes = ConstraintAttributes.None
}
}
self.toItem = other
self.relation = relation
return self
}
private func constrainTo(other: View, relation: ConstraintRelation) -> Constraint {
return constrainTo(ConstraintItem(object: other, attributes: ConstraintAttributes.None), relation: relation)
}
#if os(iOS)
private func constrainTo(other: UILayoutSupport, relation: ConstraintRelation) -> Constraint {
return constrainTo(ConstraintItem(object: other, attributes: ConstraintAttributes.None), relation: relation)
}
#endif
private func constrainTo(other: Float, relation: ConstraintRelation) -> Constraint {
self.constant = other
return constrainTo(ConstraintItem(object: nil, attributes: ConstraintAttributes.None), relation: relation)
}
private func constrainTo(other: Double, relation: ConstraintRelation) -> Constraint {
self.constant = other
return constrainTo(ConstraintItem(object: nil, attributes: ConstraintAttributes.None), relation: relation)
}
private func constrainTo(other: CGSize, relation: ConstraintRelation) -> Constraint {
self.constant = other
return constrainTo(ConstraintItem(object: nil, attributes: ConstraintAttributes.None), relation: relation)
}
private func constrainTo(other: CGPoint, relation: ConstraintRelation) -> Constraint {
self.constant = other
return constrainTo(ConstraintItem(object: nil, attributes: ConstraintAttributes.None), relation: relation)
}
private func constrainTo(other: EdgeInsets, relation: ConstraintRelation) -> Constraint {
self.constant = other
return constrainTo(ConstraintItem(object: nil, attributes: ConstraintAttributes.None), relation: relation)
}
private class func closestCommonSuperviewFromView(fromView: View?, toView: View?) -> View? {
var views = Set<View>()
var fromView = fromView
var toView = toView
do {
if let view = toView {
if views.contains(view) {
return view
}
views.insert(view)
toView = view.superview
}
if let view = fromView {
if views.contains(view) {
return view
}
views.insert(view)
fromView = view.superview
}
} while (fromView != nil || toView != nil)
return nil
}
}
private extension NSLayoutAttribute {
private func snp_offsetForValue(value: Any?) -> CGFloat {
// Float
if let float = value as? Float {
return CGFloat(float)
}
// Double
else if let double = value as? Double {
return CGFloat(double)
}
// UInt
else if let int = value as? Int {
return CGFloat(int)
}
// Int
else if let uint = value as? UInt {
return CGFloat(uint)
}
// CGFloat
else if let float = value as? CGFloat {
return float
}
// CGSize
else if let size = value as? CGSize {
if self == .Width {
return size.width
} else if self == .Height {
return size.height
}
}
// CGPoint
else if let point = value as? CGPoint {
#if os(iOS)
switch self {
case .Left, .CenterX, .LeftMargin, .CenterXWithinMargins: return point.x
case .Top, .CenterY, .TopMargin, .CenterYWithinMargins, .Baseline, .FirstBaseline: return point.y
case .Right, .RightMargin: return -point.x
case .Bottom, .BottomMargin: return -point.y
case .Leading, .LeadingMargin: return (Config.interfaceLayoutDirection == .LeftToRight) ? point.x : -point.x
case .Trailing, .TrailingMargin: return (Config.interfaceLayoutDirection == .LeftToRight) ? -point.x : point.x
case .Width, .Height, .NotAnAttribute: return CGFloat(0)
}
#else
switch self {
case .Left, .CenterX: return point.x
case .Top, .CenterY, .Baseline: return point.y
case .Right: return -point.x
case .Bottom: return -point.y
case .Leading: return (Config.interfaceLayoutDirection == .LeftToRight) ? point.x : -point.x
case .Trailing: return (Config.interfaceLayoutDirection == .LeftToRight) ? -point.x : point.x
case .Width, .Height, .NotAnAttribute: return CGFloat(0)
}
#endif
}
// EdgeInsets
else if let insets = value as? EdgeInsets {
#if os(iOS)
switch self {
case .Left, .CenterX, .LeftMargin, .CenterXWithinMargins: return insets.left
case .Top, .CenterY, .TopMargin, .CenterYWithinMargins, .Baseline, .FirstBaseline: return insets.top
case .Right, .RightMargin: return -insets.right
case .Bottom, .BottomMargin: return -insets.bottom
case .Leading, .LeadingMargin: return (Config.interfaceLayoutDirection == .LeftToRight) ? insets.left : -insets.right
case .Trailing, .TrailingMargin: return (Config.interfaceLayoutDirection == .LeftToRight) ? -insets.right : insets.left
case .Width, .Height, .NotAnAttribute: return CGFloat(0)
}
#else
switch self {
case .Left, .CenterX: return insets.left
case .Top, .CenterY, .Baseline: return insets.top
case .Right: return -insets.right
case .Bottom: return -insets.bottom
case .Leading: return (Config.interfaceLayoutDirection == .LeftToRight) ? insets.left : -insets.right
case .Trailing: return (Config.interfaceLayoutDirection == .LeftToRight) ? -insets.right : insets.left
case .Width, .Height, .NotAnAttribute: return CGFloat(0)
}
#endif
}
return CGFloat(0)
}
private func snp_constantForValue(value: Any?) -> CGFloat {
// Float
if let float = value as? Float {
return CGFloat(float)
}
// Double
else if let double = value as? Double {
return CGFloat(double)
}
// UInt
else if let int = value as? Int {
return CGFloat(int)
}
// Int
else if let uint = value as? UInt {
return CGFloat(uint)
}
// CGFloat
else if let float = value as? CGFloat {
return float
}
// CGSize
else if let size = value as? CGSize {
if self == .Width {
return size.width
} else if self == .Height {
return size.height
}
}
// CGPoint
else if let point = value as? CGPoint {
#if os(iOS)
switch self {
case .Left, .CenterX, .LeftMargin, .CenterXWithinMargins: return point.x
case .Top, .CenterY, .TopMargin, .CenterYWithinMargins, .Baseline, .FirstBaseline: return point.y
case .Right, .RightMargin: return point.x
case .Bottom, .BottomMargin: return point.y
case .Leading, .LeadingMargin: return point.x
case .Trailing, .TrailingMargin: return point.x
case .Width, .Height, .NotAnAttribute: return CGFloat(0)
}
#else
switch self {
case .Left, .CenterX: return point.x
case .Top, .CenterY, .Baseline: return point.y
case .Right: return point.x
case .Bottom: return point.y
case .Leading: return point.x
case .Trailing: return point.x
case .Width, .Height, .NotAnAttribute: return CGFloat(0)
}
#endif
}
// EdgeInsets
else if let insets = value as? EdgeInsets {
#if os(iOS)
switch self {
case .Left, .CenterX, .LeftMargin, .CenterXWithinMargins: return insets.left
case .Top, .CenterY, .TopMargin, .CenterYWithinMargins, .Baseline, .FirstBaseline: return insets.top
case .Right, .RightMargin: return insets.right
case .Bottom, .BottomMargin: return insets.bottom
case .Leading, .LeadingMargin: return (Config.interfaceLayoutDirection == .LeftToRight) ? insets.left : insets.right
case .Trailing, .TrailingMargin: return (Config.interfaceLayoutDirection == .LeftToRight) ? insets.right : insets.left
case .Width, .Height, .NotAnAttribute: return CGFloat(0)
}
#else
switch self {
case .Left, .CenterX: return insets.left
case .Top, .CenterY, .Baseline: return insets.top
case .Right: return insets.right
case .Bottom: return insets.bottom
case .Leading: return (Config.interfaceLayoutDirection == .LeftToRight) ? insets.left : insets.right
case .Trailing: return (Config.interfaceLayoutDirection == .LeftToRight) ? insets.right : insets.left
case .Width, .Height, .NotAnAttribute: return CGFloat(0)
}
#endif
}
return CGFloat(0);
}
}
private struct ConstraintInstallInfo {
weak var view: View? = nil
let layoutConstraints: NSHashTable
}
internal func ==(left: Constraint, right: Constraint) -> Bool {
return (left.fromItem == right.fromItem &&
left.toItem == right.toItem &&
left.relation == right.relation &&
left.multiplier == right.multiplier &&
left.priority == right.priority)
}