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// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
import Common
import Foundation
import UIKit
import ComponentLibrary
struct SummaryViewModel {
let title: String?
let titleA11yId: String
let compactTitleA11yId: String
let brandViewModel: BrandViewModel
let summary: NSAttributedString?
let summaryA11yId: String
let scrollContentBottomInset: CGFloat
}
final class SummaryView: UIView, UITableViewDataSource, UITableViewDelegate, ThemeApplicable {
private struct UX {
static let tableViewHorizontalPadding: CGFloat = 16.0
static let titleVisbilityThreshold: CGFloat = 30.0
static let titleVisibilityAnimationDuration: CGFloat = 0.1
}
private enum Section: Int, CaseIterable {
case title, brand, summary
}
private let tableView: UITableView = .build {
$0.backgroundColor = .clear
$0.separatorStyle = .none
$0.allowsSelection = false
$0.showsVerticalScrollIndicator = false
$0.alpha = 0.0
}
private var theme: Theme?
private var model: SummaryViewModel?
/// A closure that is called in response to the tableView scroll.
/// The paramater provided is true when the title cell is showed.
var onDidChangeTitleCellVisibility: ((Bool) -> Void)?
override init(frame: CGRect) {
super.init(frame: frame)
setup()
}
required init?(coder: NSCoder) {
fatalError("init(coder:) has not been implemented")
}
private func setup() {
tableView.dataSource = self
tableView.delegate = self
tableView.register(cellType: SummaryTitleCell.self)
tableView.register(cellType: SummaryBrandCell.self)
tableView.register(cellType: SummaryTextCell.self)
addSubviews(tableView)
NSLayoutConstraint.activate([
tableView.leadingAnchor.constraint(equalTo: leadingAnchor, constant: UX.tableViewHorizontalPadding),
tableView.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -UX.tableViewHorizontalPadding),
tableView.topAnchor.constraint(equalTo: topAnchor),
tableView.bottomAnchor.constraint(equalTo: bottomAnchor),
])
}
// MARK: - UITableViewDataSource
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return Section.allCases.count
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
guard let section = Section(rawValue: indexPath.row), let model else {
return UITableViewCell()
}
let cell: UITableViewCell
switch section {
case .title:
cell = tableView.dequeueReusableCell(withIdentifier: SummaryTitleCell.cellIdentifier, for: indexPath)
if let cell = cell as? SummaryTitleCell {
cell.configure(text: model.title, a11yId: model.titleA11yId)
}
case .brand:
cell = tableView.dequeueReusableCell(withIdentifier: SummaryBrandCell.cellIdentifier, for: indexPath)
if let cell = cell as? SummaryBrandCell {
cell.configure(
text: model.brandViewModel.brandLabel,
textA11yId: model.brandViewModel.brandLabelA11yId,
logo: model.brandViewModel.brandImage,
logoA11yId: model.brandViewModel.brandImageA11yId
)
}
case .summary:
cell = tableView.dequeueReusableCell(withIdentifier: SummaryTextCell.cellIdentifier, for: indexPath)
if let cell = cell as? SummaryTextCell {
cell.configure(text: model.summary, a11yId: model.summaryA11yId)
}
}
if let cell = cell as? ThemeApplicable, let theme {
cell.applyTheme(theme: theme)
}
return cell
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return UITableView.automaticDimension
}
func configure(model: SummaryViewModel) {
self.model = model
tableView.contentInset = UIEdgeInsets(
top: 0.0,
left: 0.0,
bottom: model.scrollContentBottomInset,
right: 0.0
)
tableView.reloadData()
}
func showContent() {
tableView.alpha = 1.0
}
// MARK: - UIScrollViewDelegate
func scrollViewDidScroll(_ scrollView: UIScrollView) {
guard let titleCell = tableView.cellForRow(at: IndexPath(row: 0, section: 0)) else { return }
// Determine the threshold for showing/hiding the compact title.
// The threshold must include both the table view’s top contentInset
// and its safe area inset, since the contentOffset.y does not start
// at 0 but instead reflects these insets.
let topInset = abs(tableView.contentInset.top) + abs(tableView.safeAreaInsets.top)
let offset = scrollView.contentOffset.y + topInset - titleCell.frame.height
// hide or show the title cell gradually as the table view scrolls.
let titleCellAlpha = abs(offset / (titleCell.frame.height))
let isShowingTitleCell = offset < -UX.titleVisbilityThreshold
UIView.animate(withDuration: UX.titleVisibilityAnimationDuration) {
titleCell.alpha = titleCellAlpha
self.onDidChangeTitleCellVisibility?(isShowingTitleCell)
}
}
// MARK: - ThemeApplicable
func applyTheme(theme: any Theme) {
self.theme = theme
}
}