vds_ios/VDS/Components/CarouselScrollbar/CarouselScrollbar.swift
Matt Bruce c64caa7a9f added publishers/cancellables
Signed-off-by: Matt Bruce <matt.bruce@verizon.com>
2024-03-27 15:24:40 -05:00

437 lines
18 KiB
Swift

//
// CarouselScrollbar.swift
// VDS
//
// Created by Kanamarlapudi, Vasavi on 12/03/24.
//
import Foundation
import UIKit
import VDSColorTokens
import VDSFormControlsTokens
import Combine
/// A carousel scrollbar is a control that allows to navigate between items in a carousel.
/// It's also a status indicator that conveys the relative amount of content in a carousel and a location within it.
@objc(VDSCarouselScrollbar)
open class CarouselScrollbar: 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
//--------------------------------------------------
/// Used to set total number of slides within carousel
open var numberOfSlides: Int {
get { return _numberOfSlides }
set {
_numberOfSlides = newValue
setThumbWidth()
scrollThumbToPosition(position)
setNeedsUpdate()
}
}
/// The number of slides that can appear at once in a set in a carousel container.
open var selectedLayout: Layout? {
get { return _selectedLayout }
set {
if let newValue {
_selectedLayout = newValue
} else {
_selectedLayout = .oneUP
}
setThumbWidth()
scrollThumbToPosition(position)
setNeedsUpdate()
}
}
/// Enum used to describe the number of slides that can appear at once in a set in a carousel container.
public enum Layout: String, CaseIterable {
case oneUP = "1UP"
case twoUP = "2UP"
case threeUP = "3UP"
case fourUP = "4UP"
case fiveUP = "5UP"
case sixUP = "6UP"
case eightUP = "8UP"
var value: Int {
switch self {
case .oneUP:
1
case .twoUP:
2
case .threeUP:
3
case .fourUP:
4
case .fiveUP:
5
case .sixUP:
6
case .eightUP:
8
}
}
}
/// Used to set the position of the thumb(scrubber). This is used when the carousel container changes position, it will align the position of thumb(scrubber).
open var position: Int {
get { return _position }
set {
checkPositions()
_position = (newValue > totalPositions) ? totalPositions : newValue
scrollThumbToPosition(position)
setNeedsUpdate()
}
}
/// Allows a unique id to be passed into the thumb and track of the thumb(scrubber).
open var scrubberId: Int? { didSet { setNeedsUpdate() } }
/// A callback when the scrubber position changes. Passes parameters (position).
open var onScrubberDrag: ((Int) -> Void)? {
get { nil }
set {
onScrubberDragCancellable?.cancel()
if let newValue {
onScrubberDragCancellable = onScrubberDragPublisher
.sink { c in
newValue(c)
}
}
}
}
/// A publisher for when the scrubber position changes. Passes parameters (position).
open var onScrubberDragPublisher = PassthroughSubject<Int, Never>()
private var onScrubberDragCancellable: AnyCancellable?
/// A callback when the thumb move forward. Passes parameters (position).
open var onMoveForward: ((Int) -> Void)? {
get { nil }
set {
onMoveForwardCancellable?.cancel()
if let newValue {
onMoveForwardCancellable = onMoveForwardPublisher
.sink { c in
newValue(c)
}
}
}
}
/// A publisher for when the thumb move forward. Passes parameters (position).
open var onMoveForwardPublisher = PassthroughSubject<Int, Never>()
private var onMoveForwardCancellable: AnyCancellable?
/// A callback when the thumb move backward. Passes parameters (position).
open var onMoveBackward: ((Int) -> Void)? {
get { nil }
set {
onMoveBackwardCancellable?.cancel()
if let newValue {
onMoveBackwardCancellable = onMoveBackwardPublisher
.sink { c in
newValue(c)
}
}
}
}
/// A publisher for when the thumb move backward. Passes parameters (position).
open var onMoveBackwardPublisher = PassthroughSubject<Int, Never>()
private var onMoveBackwardCancellable: AnyCancellable?
/// A callback when the thumb touch start. Passes parameters (position).
open var onThumbTouchStart: ((Int) -> Void)? {
get { nil }
set {
onThumbTouchStartCancellable?.cancel()
if let newValue {
onThumbTouchStartCancellable = onThumbTouchStartPublisher
.sink { c in
newValue(c)
}
}
}
}
/// A publisher for when the thumb touch start. Passes parameters (position).
open var onThumbTouchStartPublisher = PassthroughSubject<Int, Never>()
private var onThumbTouchStartCancellable: AnyCancellable?
/// A callback when the thumb touch end. Passes parameters (position).
open var onThumbTouchEnd: ((Int) -> Void)? {
get { nil }
set {
onThumbTouchEndCancellable?.cancel()
if let newValue {
onThumbTouchEndCancellable = onThumbTouchEndPublisher
.sink { c in
newValue(c)
}
}
}
}
/// A publisher for when the thumb touch end. Passes parameters (position).
open var onThumbTouchEndPublisher = PassthroughSubject<Int, Never>()
private var onThumbTouchEndCancellable: AnyCancellable?
//--------------------------------------------------
// MARK: - Private Properties
//--------------------------------------------------
// Sizes are from InVision design specs.
internal var containerSize: CGSize { CGSize(width: 45, height: 44) }
internal var _selectedLayout: Layout = .oneUP
internal var _numberOfSlides: Int = 1
internal var totalPositions: Int = 1
internal var _position: Int = 1
internal var trayOriginalCenter: CGPoint!
private let trackViewWidth = 96
private let trackViewHeight: CGFloat = 4
private let minThumbWidth: Float = 16.0
private var thumbWidth: Float = 16.0
private var computedWidth: Float = 0.0
private let cornerRadius: CGFloat = 2.0
private let activeOpacity: Float = 0.15
private let defaultOpacity: Float = 1
internal var containerView = View().with {
$0.clipsToBounds = true
}
internal var trackView = View()
internal var leftActiveOverlay = View()
internal var rightActiveOverlay = View()
internal var thumbView = View()
internal var rightActiveOverlayLayer: CALayer = CALayer()
internal var leftActiveOverlayLayer: CALayer = CALayer()
internal var thumbViewLayer: CALayer = CALayer()
//--------------------------------------------------
// MARK: - Configuration
//--------------------------------------------------
private var thumbColorConfiguration = SurfaceColorConfiguration(VDSColor.interactiveScrollthumbOnlight , VDSColor.interactiveScrollthumbOndark)
private var trackColorConfiguration = SurfaceColorConfiguration(VDSColor.interactiveScrolltrackOnlight , VDSColor.interactiveScrolltrackOndark)
private var activeOverlayColorConfiguration = SurfaceColorConfiguration(VDSColor.paletteBlack, VDSColor.paletteWhite)
//--------------------------------------------------
// MARK: - Lifecycle
//--------------------------------------------------
open override func initialSetup() {
super.initialSetup()
}
open override func setup() {
super.setup()
isAccessibilityElement = true
accessibilityLabel = "Carousel Scrollbar"
addSubview(containerView)
containerView
.pinTop()
.pinBottom()
.pinLeadingGreaterThanOrEqualTo()
.pinTrailingLessThanOrEqualTo()
.height(containerSize.height)
.width(CGFloat(trackViewWidth))
containerView.centerXAnchor.constraint(equalTo: centerXAnchor).activate()
//Trackview
trackView.frame = CGRectMake(0, 20, CGFloat(trackViewWidth), trackViewHeight)
trackView.layer.cornerRadius = cornerRadius
containerView.addSubview(trackView)
///Left active overlay
leftActiveOverlay.frame = CGRectMake(trackView.frame.origin.x, 0, CGFloat(trackViewWidth), containerSize.height)
leftActiveOverlay.isUserInteractionEnabled = true
leftActiveOverlay.backgroundColor = .clear
let leftPressRecognizer = UILongPressGestureRecognizer(target: self, action: #selector(onLeftViewLongPressRecognizer(_:)))
leftPressRecognizer.minimumPressDuration = 0
leftActiveOverlay.addGestureRecognizer(leftPressRecognizer)
containerView.addSubview(leftActiveOverlay)
leftActiveOverlay.layer.addSublayer(leftActiveOverlayLayer)
leftActiveOverlayLayer.cornerRadius = cornerRadius
leftActiveOverlayLayer.frame = .init(origin: .zero, size: .init(width: leftActiveOverlayLayer.frame.size.width, height: trackViewHeight))
///Right active overlay
rightActiveOverlay.frame = CGRectMake(thumbView.frame.origin.x + thumbView.frame.size.width, 0, CGFloat(trackViewWidth), containerSize.height)
rightActiveOverlay.isUserInteractionEnabled = true
rightActiveOverlay.backgroundColor = .clear
let rightPressRecognizer = UILongPressGestureRecognizer(target: self, action: #selector(onRightViewLongPressRecognizer(_:)))
rightPressRecognizer.minimumPressDuration = 0
rightActiveOverlay.addGestureRecognizer(rightPressRecognizer)
containerView.addSubview(rightActiveOverlay)
rightActiveOverlay.layer.addSublayer(rightActiveOverlayLayer)
rightActiveOverlayLayer.cornerRadius = cornerRadius
rightActiveOverlayLayer.frame = .init(origin: .zero, size: .init(width: rightActiveOverlay.frame.size.width, height: trackViewHeight))
//Thumbview
thumbView.frame = CGRectMake(0, 0, CGFloat(thumbWidth), containerSize.height)
thumbView.backgroundColor = .clear
thumbView.addGestureRecognizer(UIPanGestureRecognizer(target: self, action:(#selector(onScrubberChange(_:)))))
containerView.addSubview(thumbView)
updateActiveOverlays()
thumbViewLayer.cornerRadius = cornerRadius
thumbViewLayer.backgroundColor = thumbColorConfiguration.getColor(surface).cgColor
thumbViewLayer.frame = .init(origin: .init(x: 0, y: 20), size: .init(width: CGFloat(thumbWidth), height: trackViewHeight))
thumbView.layer.addSublayer(thumbViewLayer)
}
open override func updateView() {
super.updateView()
trackView.backgroundColor = trackColorConfiguration.getColor(surface)
thumbViewLayer.backgroundColor = thumbColorConfiguration.getColor(surface).cgColor
}
open override func updateAccessibility() {
super.updateAccessibility()
}
open override func reset() {
for subview in subviews {
for recognizer in subview.gestureRecognizers ?? [] {
subview.removeGestureRecognizer(recognizer)
}
}
super.reset()
}
//--------------------------------------------------
// MARK: - Private Methods
//--------------------------------------------------
func movePositionBackward() {
position = position - 1
scrollThumbToPosition(position)
onMoveBackwardPublisher.send(position)
}
func movePositionForward() {
position = position + 1
scrollThumbToPosition(position)
onMoveForwardPublisher.send(position)
}
// Compute track width and should maintain minimum thumb width if needed
private func setThumbWidth() {
let width = (Float(trackViewWidth) / Float(numberOfSlides)) * Float(_selectedLayout.value)
computedWidth = (width > Float(trackViewWidth)) ? Float(trackViewWidth) : width
thumbWidth = (width <= Float(trackViewWidth) && width > minThumbWidth) ? width : ((width > Float(trackViewWidth)) ? Float(trackViewWidth) : minThumbWidth)
thumbView.frame.size.width = CGFloat(thumbWidth)
thumbView.frame.origin.x = trackView.frame.origin.x
thumbViewLayer.frame.size.width = thumbView.frame.size.width
checkPositions()
updateActiveOverlays()
}
// Incomplete set moves a shorter distance than the standard increment value.
// Update active overlay frames according to thumb position.
private func updateActiveOverlays() {
// adjusting thumb position if it goes beyond trackView on left/right.
let thumbPosition = thumbView.frame.origin.x + thumbView.frame.size.width
let trackPosition = trackView.frame.origin.x + trackView.frame.size.width
if thumbPosition > trackPosition {
thumbView.frame.origin.x = trackPosition - thumbView.frame.size.width
} else if thumbView.frame.origin.x < trackView.frame.origin.x {
thumbView.frame.origin.x = trackView.frame.origin.x
}
//left active overlay position update
leftActiveOverlay.frame.size.width = thumbView.frame.origin.x - trackView.frame.origin.x + cornerRadius
leftActiveOverlayLayer.frame = .init(origin: .init(x: 0, y: 20), size: .init(width: leftActiveOverlay.frame.size.width, height: trackViewHeight))
//right active overlay position update
rightActiveOverlay.frame.origin.x = thumbView.frame.origin.x + thumbView.frame.size.width - cornerRadius
rightActiveOverlay.frame.size.width = (trackView.frame.origin.x + trackView.frame.size.width) - (thumbView.frame.origin.x + thumbView.frame.size.width) + cornerRadius
rightActiveOverlayLayer.frame = .init(origin: .init(x: 0, y: 20), size: .init(width: rightActiveOverlay.frame.size.width, height: trackViewHeight))
}
private func checkPositions() {
totalPositions = Int (ceil (Double(numberOfSlides) / Double(_selectedLayout.value)))
}
private func scrollThumbToPosition(_ position: Int) {
setThumb(at: position)
onScrubberDragPublisher.send(position)
}
private func setThumb(at position: Int) {
UIView.animate(withDuration: 0.1, delay: 0.0, options: .curveLinear, animations: { [weak self] in
guard let self else { return }
self.thumbView.frame.origin.x = CGFloat(Float((position) - 1) * self.computedWidth) + self.trackView.frame.origin.x
self.updateActiveOverlays()
})
}
//--------------------------------------------------
// MARK: - Gesture Methods
//--------------------------------------------------
// Drag scrollbar thumb to move it to the left or right.
// Upon releases of drag, the scrollbar thumb snaps to the closest full position and the scrollbar returns to original size without delay.
@objc func onScrubberChange(_ sender: UIPanGestureRecognizer) {
let translation = sender.translation(in: thumbView)
if sender.state == UIGestureRecognizer.State.began {
trayOriginalCenter = thumbView.center
onThumbTouchStartPublisher.send(position)
} else if sender.state == UIGestureRecognizer.State.changed {
let draggedPositions = Int (ceil (Double(translation.x) / Double(computedWidth)))
setThumb(at: position + draggedPositions)
}
else if sender.state == UIGestureRecognizer.State.cancelled || sender.state == UIGestureRecognizer.State.ended {
let draggedPositions = Int (ceil (Double(translation.x) / Double(computedWidth)))
position = ((position + draggedPositions) < 1) ? 1 : (position + draggedPositions)
if sender.state == UIGestureRecognizer.State.ended {
onThumbTouchEndPublisher.send(position)
}
}
}
// Move the scrollbar thumb to the left while tapping on the left side of the scrubber.
@objc func onLeftViewLongPressRecognizer(_ gesture: UILongPressGestureRecognizer) {
animateOverlay(layer: leftActiveOverlayLayer, with: gesture, onGestureEnd: movePositionBackward)
}
// Move the scrollbar thumb to the right while tapping on the right side of the scrubber.
@objc func onRightViewLongPressRecognizer(_ gesture: UILongPressGestureRecognizer) {
animateOverlay(layer: rightActiveOverlayLayer, with: gesture, onGestureEnd: movePositionForward)
}
private func animateOverlay(layer: CALayer, with gesture: UILongPressGestureRecognizer, onGestureEnd: @escaping(() -> Void)) {
UIView.animate(withDuration: 0.1, delay: 0.0, options: .curveLinear, animations: { [weak self] in
guard let self else { return }
if gesture.state == .began {
layer.backgroundColor = activeOverlayColorConfiguration.getColor(self).cgColor
layer.opacity = activeOpacity
} else if gesture.state == .cancelled {
layer.backgroundColor = UIColor.clear.cgColor
layer.opacity = defaultOpacity
} else if gesture.state == .ended {
layer.backgroundColor = UIColor.clear.cgColor
layer.opacity = defaultOpacity
onGestureEnd()
}
})
}
}