vds_ios/VDS/Components/Carousel/Carousel.swift

323 lines
11 KiB
Swift

//
// Carousel.swift
// VDS
//
// Created by Kanamarlapudi, Vasavi on 29/05/24.
//
import Foundation
import UIKit
import VDSTokens
import Combine
/// A carousel is a collection of related content in a row that a customer can navigate through horizontally.
/// Use this component to show content that is supplementary, not essential for task completion.
@objc(VDSCarousel)
open class Carousel: View {
//--------------------------------------------------
// MARK: - Initializers
//--------------------------------------------------
required public init() {
super.init(frame: .zero)
}
public override init(frame: CGRect) {
super.init(frame: .zero)
}
public required init?(coder: NSCoder) {
super.init(coder: coder)
}
//--------------------------------------------------
// MARK: - Public Properties
//--------------------------------------------------
/// Aspect-ratio options for tilelet in the carousel. If 'none' is passed, the tilelet will take the height of the tallest item in the carousel.
open var aspectRatio: AspectRatio = .ratio1x1 { didSet { setNeedsUpdate() } }
/// Data used to render tilelets in the carousel.
open var data: [Any] = [] { didSet { setNeedsUpdate() } }
/// Space between each tile. The default value will be 24px in tablet and 12px in mobile.
open var gutter: Gutter {
get { return _gutter }
set {
_gutter = newValue
setNeedsUpdate()
}
}
/// The amount of slides visible in the carousel container at one time. The default value will be 3UP in tablet and 1UP in mobile.
open var layout: Layout {
get { return _layout }
set {
_layout = newValue
setNeedsUpdate()
}
}
/// A callback when moving the carousel. Returns event object and selectedGroupIndex.
open var onChange: ((Int) -> Void)? { // TO DO: return object and index
get { nil }
set {
onChangeCancellable?.cancel()
if let newValue {
onChangeCancellable = onChangePublisher
.sink { c in
newValue(c)
}
}
}
}
/// Config object for pagination.
open var pagination: CarouselPaginationModel {
get { return _pagination }
set {
_pagination = newValue
setNeedsUpdate()
}
}
/// If provided, will determine the conditions to render the pagination arrows.
open var paginationDisplay: PaginationDisplay {
get { return _paginationDisplay }
set {
_paginationDisplay = newValue
setNeedsUpdate()
}
}
/// If provided, will apply margin to pagination arrows. Can be set to either positive or negative values.
/// The default value will be 12px in tablet and 8px in mobile.
open var paginationInset: CGFloat {
get { return _paginationInset }
set {
_paginationInset = newValue
setNeedsUpdate()
}
}
/// Options for user to configure the partially-visible tile in group. Setting peek to 'none' will display arrow navigation icons on mobile devices.
open var peek: Peek {
get { return _peek }
set {
_peek = newValue
setNeedsUpdate()
}
}
/// The initial visible slide's index in the carousel.
open var selectedIndex: Int? { didSet { setNeedsUpdate() } }
/// If provided, will set the alignment for slot content when the slots has different heights.
open var slotAlignment: [CarouselSlotAlignmentModel] = [] { didSet { setNeedsUpdate() } }
//--------------------------------------------------
// MARK: - Enums
//--------------------------------------------------
/// Enum used to describe the aspect ratios used for this component.
public enum AspectRatio: String, CaseIterable {
case ratio1x1 = "1:1"
case ratio3x4 = "3:4"
case ratio4x3 = "4:3"
case ratio2x3 = "2:3"
case ratio3x2 = "3:2"
case ratio9x16 = "9:16"
case ratio16x9 = "16:9"
case ratio1x2 = "1:2"
case ratio2x1 = "2:1"
case none
}
/// Enum used to describe the number of slides visible in the carousel container at one time. The default value will be 3UP in tablet and 1UP in mobile.
public enum Layout: String, CaseIterable {
case oneUP = "1UP"
case twoUP = "2UP"
case threeUP = "3UP"
case fourUP = "4UP"
case fiveUP = "5UP"
case sixUP = "6UP"
var value: Int {
switch self {
case .oneUP:
1
case .twoUP:
2
case .threeUP:
3
case .fourUP:
4
case .fiveUP:
5
case .sixUP:
6
}
}
}
/// Enum used to describe the number of slides visible in the carousel container at one time. The default value will be 3UP in tablet and 1UP in mobile.
public enum Gutter: String, CaseIterable {
case twelvePX = "12px"
case twentyFourPX = "24px"
var value: CGFloat {
switch self {
case .twelvePX:
VDSLayout.space12X
case .twentyFourPX:
VDSLayout.space24X
}
}
}
/// Enum used to describe the pagination display for this component.
public enum PaginationDisplay: String, CaseIterable {
case onHover, persistent, none
}
/// Enum used to describe the peek for this component. Options for user to configure the partially-visible tile in group. Setting peek to 'none' will display arrow navigation icons on mobile devices.
public enum Peek: String, CaseIterable {
case standard, minimum, none
}
// TO DO: move to model class
/// Enum used to describe the vertical of slotAlignment.
public enum Vertical: String, CaseIterable {
case top, middle, bottom
}
/// Enum used to describe the horizontal of slotAlignment.
public enum Horizontal: String, CaseIterable {
case left, center, right
}
//--------------------------------------------------
// MARK: - Private Properties
//--------------------------------------------------
// Sizes are from InVision design specs.
internal var containerSize: CGSize { CGSize(width: 320, height: 44) }
private let contentStackView = UIStackView().with {
$0.translatesAutoresizingMaskIntoConstraints = false
$0.axis = .vertical
$0.distribution = .fill
$0.spacing = UIDevice.isIPad ? VDSLayout.space8X : VDSLayout.space6X
$0.backgroundColor = .clear
}
internal var carouselScrollBar = CarouselScrollbar().with {
$0.layout = UIDevice.isIPad ? .threeUP : .oneUP
$0.position = 0
$0.backgroundColor = .clear
}
internal var containerView = View().with {
$0.clipsToBounds = true
$0.backgroundColor = .clear
}
internal var scrollContainerView = View().with {
$0.clipsToBounds = true
$0.backgroundColor = .clear
}
private var scrollView = UIScrollView().with {
$0.translatesAutoresizingMaskIntoConstraints = false
$0.backgroundColor = .clear
}
/// A publisher for when the scrubber position changes. Passes parameters (position).
open var onChangePublisher = PassthroughSubject<Int, Never>()
private var onChangeCancellable: AnyCancellable?
internal var _layout: Layout = UIDevice.isIPad ? .threeUP : .oneUP
internal var _pagination: CarouselPaginationModel = .init(kind: .lowContrast, floating: true)
internal var _paginationDisplay: PaginationDisplay = .none
internal var _paginationInset: CGFloat = UIDevice.isIPad ? VDSLayout.space12X : VDSLayout.space8X
internal var _gutter: Gutter = UIDevice.isIPad ? .twentyFourPX : .twelvePX
internal var _peek: Peek = .none
internal var _numberOfSlides: Int = 1
private var selectedGroupIndex: Int? { didSet { setNeedsUpdate() } }
private var containerStackHeightConstraint: NSLayoutConstraint?
private var containerViewHeightConstraint: NSLayoutConstraint?
// The scrollbar has top 5X space. So the expected top space is adjusted for tablet and mobile.
let space = UIDevice.isIPad ? VDSLayout.space3X : VDSLayout.space1X
//--------------------------------------------------
// MARK: - Lifecycle
//--------------------------------------------------
open override func initialSetup() {
super.initialSetup()
}
open override func setup() {
super.setup()
isAccessibilityElement = false
// add containerView
addSubview(containerView)
containerView
.pinTop()
.pinBottom()
.pinLeading()
.pinTrailing()
.heightGreaterThanEqualTo(containerSize.height)
containerView.centerXAnchor.constraint(equalTo: centerXAnchor).activate()
// add content stackview
containerView.addSubview(contentStackView)
// add scrollview
scrollContainerView.addSubview(scrollView)
// add pagination button icons
scrollContainerView.addSubview(pagination.previousButton)
pagination.previousButton
.pinLeading(paginationInset)
.pinCenterY()
scrollContainerView.addSubview(pagination.nextButton)
pagination.nextButton
.pinTrailing(paginationInset)
.pinCenterY()
// add scroll container view & carousel scrollbar
contentStackView.addArrangedSubview(scrollContainerView)
contentStackView.addArrangedSubview(carouselScrollBar)
contentStackView.setCustomSpacing(space, after: scrollContainerView)
contentStackView
.pinTop()
.pinBottom()
.pinLeading()
.pinTrailing()
.heightGreaterThanEqualTo(space+containerSize.height)
contentStackView.centerXAnchor.constraint(equalTo: centerXAnchor).activate()
}
open override func updateView() {
containerViewHeightConstraint?.isActive = false
super.updateView()
containerViewHeightConstraint = containerView.heightAnchor.constraint(equalToConstant: 200)
containerViewHeightConstraint?.isActive = true
pagination.previousButton.isHidden = (paginationDisplay == .none)
pagination.nextButton.isHidden = (paginationDisplay == .none)
layoutIfNeeded()
}
open override func reset() {
// for subview in subviews {
// for recognizer in subview.gestureRecognizers ?? [] {
// subview.removeGestureRecognizer(recognizer)
// }
// }
super.reset()
}
}