SnapKit/Source/Constraint.swift

467 lines
19 KiB
Swift

//
// SnapKit
//
// Copyright (c) 2011-Present SnapKit Team - https://github.com/SnapKit
//
// 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
/**
Used to expose API's for a Constraint
*/
public class Constraint {
public func install() -> [LayoutConstraint] { fatalError("Must be implemented by Concrete subclass.") }
public func uninstall() -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func activate() -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func deactivate() -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func updateOffset(amount: Float) -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func updateOffset(amount: Double) -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func updateOffset(amount: CGFloat) -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func updateOffset(amount: Int) -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func updateOffset(amount: UInt) -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func updateOffset(amount: CGPoint) -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func updateOffset(amount: CGSize) -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func updateOffset(amount: EdgeInsets) -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func updateInsets(amount: EdgeInsets) -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func updatePriority(priority: Float) -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func updatePriority(priority: Double) -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func updatePriority(priority: CGFloat) -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func updatePriority(priority: UInt) -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func updatePriority(priority: Int) -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func updatePriorityRequired() -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func updatePriorityHigh() -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func updatePriorityMedium() -> Void { fatalError("Must be implemented by Concrete subclass.") }
public func updatePriorityLow() -> Void { fatalError("Must be implemented by Concrete subclass.") }
}
/**
Used internally to implement a ConcreteConstraint
*/
internal class ConcreteConstraint: Constraint {
internal override func updateOffset(amount: Float) -> Void {
self.constant = amount
}
internal override func updateOffset(amount: Double) -> Void {
self.updateOffset(Float(amount))
}
internal override func updateOffset(amount: CGFloat) -> Void {
self.updateOffset(Float(amount))
}
internal override func updateOffset(amount: Int) -> Void {
self.updateOffset(Float(amount))
}
internal override func updateOffset(amount: UInt) -> Void {
self.updateOffset(Float(amount))
}
internal override func updateOffset(amount: CGPoint) -> Void {
self.constant = amount
}
internal override func updateOffset(amount: CGSize) -> Void {
self.constant = amount
}
internal override func updateOffset(amount: EdgeInsets) -> Void {
self.constant = amount
}
internal override func updateInsets(amount: EdgeInsets) -> Void {
self.constant = EdgeInsets(top: amount.top, left: amount.left, bottom: -amount.bottom, right: -amount.right)
}
internal override func updatePriority(priority: Float) -> Void {
self.priority = priority
}
internal override func updatePriority(priority: Double) -> Void {
self.updatePriority(Float(priority))
}
internal override func updatePriority(priority: CGFloat) -> Void {
self.updatePriority(Float(priority))
}
internal override func updatePriority(priority: UInt) -> Void {
self.updatePriority(Float(priority))
}
internal override func updatePriority(priority: Int) -> Void {
self.updatePriority(Float(priority))
}
internal override func updatePriorityRequired() -> Void {
self.updatePriority(Float(1000.0))
}
internal override func updatePriorityHigh() -> Void {
self.updatePriority(Float(750.0))
}
internal override func updatePriorityMedium() -> Void {
#if os(iOS)
self.updatePriority(Float(500.0))
#else
self.updatePriority(Float(501.0))
#endif
}
internal override func updatePriorityLow() -> Void {
self.updatePriority(Float(250.0))
}
internal override func install() -> [LayoutConstraint] {
return self.installOnViewUpdatingExisting(false)
}
internal override func uninstall() -> Void {
self.uninstallFromView()
}
internal override func activate() -> Void {
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()
}
}
internal override func deactivate() -> Void {
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()
}
}
private let fromItem: ConstraintItem
private let toItem: ConstraintItem
private let relation: ConstraintRelation
private let multiplier: Float
private var constant: Any {
didSet {
if let installInfo = self.installInfo {
for layoutConstraint in installInfo.layoutConstraints.allObjects as! [LayoutConstraint] {
let attribute = (layoutConstraint.secondAttribute == .NotAnAttribute) ? layoutConstraint.firstAttribute : layoutConstraint.secondAttribute
layoutConstraint.constant = attribute.snp_constantForValue(self.constant)
}
}
}
}
private var priority: Float {
didSet {
if let installInfo = self.installInfo {
for layoutConstraint in installInfo.layoutConstraints.allObjects as! [LayoutConstraint] {
layoutConstraint.priority = self.priority
}
}
}
}
private var installInfo: ConcreteConstraintInstallInfo? = nil
internal init(fromItem: ConstraintItem, toItem: ConstraintItem, relation: ConstraintRelation, constant: Any, multiplier: Float, priority: Float) {
self.fromItem = fromItem
self.toItem = toItem
self.relation = relation
self.constant = constant
self.multiplier = multiplier
self.priority = priority
}
internal func installOnViewUpdatingExisting(updateExisting: Bool = false) -> [LayoutConstraint] {
var installOnView: View? = nil
if self.toItem.view != nil {
installOnView = 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.layoutRelation
for layoutFromAttribute in layoutFromAttributes {
// get layout to attribute
let layoutToAttribute = (layoutToAttributes.count > 0) ? layoutToAttributes[0] : layoutFromAttribute
// get layout constant
let layoutConstant: CGFloat = layoutToAttribute.snp_constantForValue(self.constant)
// 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 = layoutFrom!.snp_installedLayoutConstraints.reverse()
// 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 = ConcreteConstraintInstallInfo(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 !installedLayoutConstraints.contains($0)
}
}
}
}
self.installInfo = nil
}
}
private struct ConcreteConstraintInstallInfo {
weak var view: View? = nil
let layoutConstraints: NSHashTable
}
private extension NSLayoutAttribute {
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)
default: 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)
default: return CGFloat(0)
}
#endif
}
return CGFloat(0);
}
}
private func closestCommonSuperviewFromView(fromView: View?, toView: View?) -> View? {
var views = Set<View>()
var fromView = fromView
var toView = toView
repeat {
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 func ==(left: ConcreteConstraint, right: ConcreteConstraint) -> Bool {
return (left.fromItem == right.fromItem &&
left.toItem == right.toItem &&
left.relation == right.relation &&
left.multiplier == right.multiplier &&
left.priority == right.priority)
}