View

An object that manages the content for a rectangular area on the screen.

public class View: Responder 

Inheritance

Responder, Equatable, TraitEnvironment

Initializers

init(frame:)

Initializes and returns a newly allocated view object with the specified frame rectangle.

public convenience init(frame: Rect) 

Properties

backgroundColor

The view’s background color.

public var backgroundColor: Color?

isHidden

A boolean that determines if the view is hidden.

public var isHidden: Bool 

isUserInteractionEnabled

A boolean value that determines whether user events are ignored and removed from the event queue.

public var isUserInteractionEnabled: Bool 

frame

The frame rectangle, which describes the view’s location and size in it’s superview’s coordinate system.

public var frame: Rect 

bounds

The bounds rectangle, which describes the view’s location and size in its own coordinate system.

public var bounds: Rect 

center

The center point of the view’s frame rectangle

public var center: Point 

transform

Specifies the transform applied to the view, relative to the center of its bounds.

public var transform: AffineTransform = .identity 

superview

The receiver’s superview, or nil if it has none.

public private(set) weak var superview: View?

subviews

The receiver’s immediate subviews.

public private(set) var subviews: [View] = []

window

The receiver’s window object, or nil if it has none.

public private(set) weak var window: Window?

directionalLayoutMargins

The default spacing to use when laying out content in a view, taking into account the current language direction.

public var directionalLayoutMargins: DirectionalEdgeInsets 

preservesSuperviewLayoutMargins

A boolean value indicating whether the current view also respects the margins of its superview.

public var preservesSuperviewLayoutMargins: Bool = false

constraints

The constraints held by the view.

public private(set) var constraints: [LayoutConstraint] = []

bottomAnchor

A layout anchor representing the bottom edge of the view’s frame.

public var bottomAnchor: LayoutYAxisAnchor 

centerXAnchor

A layout anchor representing the horizontal center of the view’s frame.

public var centerXAnchor: LayoutXAxisAnchor 

centerYAnchor

A layout anchor representing the vertical center of the view’s frame.

public var centerYAnchor: LayoutYAxisAnchor 

firstBaselineAnchor

A layout anchor representing the baseline for the topmost line of text in the view.

public var firstBaselineAnchor: LayoutYAxisAnchor 

heightAnchor

A layout anchor representing the height of the view’s frame.

public var heightAnchor: LayoutDimension 

lastBaselineAnchor

A layout anchor representing the baseline for the bottommost line of text in the view.

public var lastBaselineAnchor: LayoutYAxisAnchor 

leadingAnchor

A layout anchor representing the leading edge of the view’s frame.

public var leadingAnchor: LayoutXAxisAnchor 

leftAnchor

A layout anchor representing the left edge of the view’s frame.

public var leftAnchor: LayoutXAxisAnchor 

rightAnchor

A layout anchor representing the right edge of the view’s frame.

public var rightAnchor: LayoutXAxisAnchor 

topAnchor

A layout anchor representing the top edge of the view’s frame.

public var topAnchor: LayoutYAxisAnchor 

trailingAnchor

A layout anchor representing the top edge of the view’s frame.

public var trailingAnchor: LayoutXAxisAnchor 

widthAnchor

A layout anchor representing the trailing edge of the view’s frame.

public var widthAnchor: LayoutDimension 

contentMode

public var contentMode: View.ContentMode = .scaleToFill

autoresizesSubviews

Determines whether the receiver automatically resizes its subviews when its bounds changes.

public var autoresizesSubviews: Bool = true

autoresizingMask

A bitmask that determines how the receiver resizes itself when its superview’s bounds changes.

public var autoresizingMask: View.AutoresizingMask = .none

contentScaleFactor

The scale factor applied to the view.

public var contentScaleFactor: Float 

requiresConstraintBasedLayout

A boolean value that indicates whether the receiver depends on the constraint-based layout system.

public class var requiresConstraintBasedLayout: Bool 

Custom views should override this to return true if they cannot layout correctly using autoresizing.

translatesAutoresizingMaskIntoConstraints

A boolean value that determines whether the view’s autoresizing mask is translated into Auto Layout constraints.

public var translatesAutoresizingMaskIntoConstraints: Bool = true

If this property’s value is true, the system creates a set of constraints that duplicate the behavior specified by the view’s autoresizing mask. This also lets you modify the view’s size and location using the view’s frame, bounds, or center properties, allowing you to create a static, frame-based layout within Auto Layout.

Note that the autoresizing mask constraints fully specify the view’s size and position; therefore, you cannot add additional constraints to modify this size or position without introducing conflicts. If you want to use Auto Layout to dynamically calculate the size and position of your view, you must set this property to false, and then provide a non ambiguous, nonconflicting set of constraints for the view.

By default, the property is set to true.

interactions

The array of interactions for the view.

public var interactions: [Interaction] = []

tag

An integer that you can use to identify view objects in your application.

public var tag: Int = 0

next

public override var next: Responder? 

traitCollection

public var traitCollection: TraitCollection 

Methods

addSubview(_:)

Add a subview to the end of the reciever’s list of subviews.

public func addSubview(_ view: View) 

bringSubviewToFront(_:)

Moves the specified subview so that it appears on top of its siblings.

public func bringSubviewToFront(_ view: View) 

sendSubviewToBack(_:)

Moves the specified subview so that it appears behind its siblings.

public func sendSubviewToBack(_ view: View) 

removeFromSuperview()

Unlinks the view from its superview and its window, and removes it from the responder chain.

public func removeFromSuperview() 

insertSubview(_:at:)

Inserts a subview at the specified index.

public func insertSubview(_ view: View, at index: Int) 

insertSubview(_:aboveSubview:)

Inserts a view above another view in the view hierarchy.

public func insertSubview(_ view: View, aboveSubview subview: View) 

insertSubview(_:belowSubview:)

Inserts a view below another view in the view hierarchy.

public func insertSubview(_ view: View, belowSubview subview: View) 

exchangeSubview(at:withSubviewAt:)

Exchanges the subviews at the specified indices.

public func exchangeSubview(at index1: Int, withSubviewAt index2: Int) 

isDescendant(of:)

Returns a boolean value indicating whether the receiver is a subview of a given view or identical to that view.

public func isDescendant(of view: View) -> Bool 

didAddSubview(_:)

Informs the view that a subview was added.

public func didAddSubview(_ subview: View) 

willRemoveSubview(_:)

Informs the view that a subview is about to be removed.

public func willRemoveSubview(_ subview: View) 

willMove(toSuperview:)

Informs the view that its superview is about to change to the specified superview.

public func willMove(toSuperview: View?) 

didMoveToSuperview()

Informs the view that its superview changed.

public func didMoveToSuperview() 

willMove(toWindow:)

Informs the view that its window object is about to change.

public func willMove(toWindow: Window?) 

didMoveToWindow()

Informs the view that its window object changed.

public func didMoveToWindow() 

layoutMarginsDidChange()

Informs the view that its layout margins changed.

public func layoutMarginsDidChange() 

addConstraint(_:)

Adds a constraint on the layout of the receiving view or its subviews.

public func addConstraint(_ constraint: LayoutConstraint) 

removeConstraint(_:)

Removes the specified constraint from the view.

public func removeConstraint(_ constraint: LayoutConstraint) 

removeConstraints(_:)

Removes the specified constraints from the view.

public func removeConstraints(_ constraints: [LayoutConstraint]) 

sizeThatFits(_:)

Asks the view to calculate and return the size that best fits the specified size.

public func sizeThatFits(_ size: Size) -> Size 

sizeToFit()

Resizes and moves the receiver view so it just encloses its subviews.

public func sizeToFit() 

draw(_:)

Draws the receiver’s image within the passed-in rectangle.

public func draw(_ rect: Rect) 

setNeedsDisplay()

Mark the receiver’s entire bounds rectangle as needing to be redrawn.

public func setNeedsDisplay() 

setNeedsDisplay(_:)

Marks the specified rectangle of the receiver as needing to be redrawn.

public func setNeedsDisplay(_ rect: Rect) 

layoutSubviews()

Lays out subviews.

public func layoutSubviews() 

The default implementation uses any constraints you have set to determine the size and position of any subviews.

Subclasses can override this method as needed to perform more precise layout of their subviews. You should override this method only if the autoresizing and constraint-based behaviors of the subviews do not offer the behavior you want. You can use your implementation to set the frame rectangles of your subviews directly.

You should not call this method directly. If you want to force a layout update, call the setNeedsLayout() method instead to do so prior to the next drawing update. If you want to update the layout of your views immediately, call the layoutIfNeeded() method.

setNeedsLayout()

Invalidates the current layout of the receiver and triggers a layout update during the next update cycle.

public func setNeedsLayout() 

Call this method on your application’s main thread when you want to adjust the layout of a view’s subviews. This method makes a note of the request and returns immediately. Because this method does not force an immediate update, but instead waits for the next update cycle, you can use it to invalidate the layout of multiple views before any of those views are updated. This behavior allows you to consolidate all of your layout updates to one update cycle, which is usually better for performance.

layoutIfNeeded()

Lays out the subviews immediately, if layout updates are pending.

public func layoutIfNeeded() 

Use this method to force the view to update its layout immediately. When using Auto Layout, the layout engine updates the position of views as needed to satisfy changes in constraints. Using the view that receives the message as the root view, this method lays out the view subtree starting at the root. If no layout updates are pending, this method exits without modifying the layout or calling any layout-related callbacks.

addInteraction(_:)

Adds an interaction to the view.

public func addInteraction(_ interaction: Interaction) 

removeInteraction(_:)

Removes an interaction from the view.

public func removeInteraction(_ interaction: Interaction) 

viewWithTag(_:)

Returns the view whose tag matches the specified value.

public func viewWithTag(_ tag: Int) -> View? 

convert(_:to:)

Converts a point from the receiver’s coordinate system to that of the specified view.

public func convert(_ point: Point, to view: View?) -> Point 

convert(_:from:)

Converts a point from the coordinate system of a given view to that of the receiver.

public func convert(_ point: Point, from view: View?) -> Point 

convert(_:to:)

Converts a rectangle from the receiver’s coordinate system to that of another view.

public func convert(_ rect: Rect, to view: View?) -> Rect 

convert(_:from:)

Converts a rectangle from the coordinate system of another view to that of the receiver.

public func convert(_ rect: Rect, from view: View?) -> Rect 

traitCollectionDidChange(_:)

public func traitCollectionDidChange(_ previousTraitCollection: TraitCollection?) 

Operators

==

public static func ==(_ lhs: View, _ rhs: View) -> Bool