element-ios/RiotSwiftUI/Modules/Room/CompletionSuggestion/View/CompletionSuggestionList.swift

129 lines
4.4 KiB
Swift

//
// Copyright 2021-2024 New Vector Ltd.
//
// SPDX-License-Identifier: AGPL-3.0-only
// Please see LICENSE in the repository root for full details.
//
import SwiftUI
struct CompletionSuggestionList: View {
private enum Constants {
static let topPadding: CGFloat = 8.0
static let listItemPadding: CGFloat = 4.0
static let lineSpacing: CGFloat = 10.0
static let maxHeight: CGFloat = 300.0
static let maxVisibleRows = 4
/*
As of iOS 16.0, SwiftUI's List uses `UICollectionView` instead
of `UITableView` internally, this value is an adjustment to apply
to the list items in order to be as close as possible as the
`UITableView` display.
*/
@available(iOS 16.0, *)
static let collectionViewPaddingCorrection: CGFloat = -5.0
}
// MARK: - Properties
// MARK: Private
@Environment(\.theme) private var theme: ThemeSwiftUI
@State private var prototypeListItemFrame: CGRect = .zero
// MARK: Public
@ObservedObject var viewModel: CompletionSuggestionViewModel.Context
var showBackgroundShadow = true
var body: some View {
if viewModel.viewState.items.isEmpty {
EmptyView()
} else {
ZStack {
CompletionSuggestionListItem(content: CompletionSuggestionViewStateItem.user(id: "Prototype", avatar: AvatarInput(mxContentUri: "", matrixItemId: "", displayName: "Prototype"), displayName: "Prototype"))
.background(ViewFrameReader(frame: $prototypeListItemFrame))
.hidden()
if showBackgroundShadow {
BackgroundView {
list()
}
} else {
list()
}
}
}
}
private func contentHeightForRowCount(_ count: Int) -> CGFloat {
(prototypeListItemFrame.height + (Constants.listItemPadding * 2) + Constants.lineSpacing) * CGFloat(count) + Constants.topPadding
}
private func list() -> some View {
List(viewModel.viewState.items) { item in
Button {
viewModel.send(viewAction: .selectedItem(item))
} label: {
CompletionSuggestionListItem(content: item)
.modifier(ListItemPaddingModifier(isFirst: viewModel.viewState.items.first?.id == item.id))
}
}
.listStyle(PlainListStyle())
.frame(height: min(Constants.maxHeight,
min(contentHeightForRowCount(Constants.maxVisibleRows),
contentHeightForRowCount(viewModel.viewState.items.count))))
.id(UUID()) // Rebuild the whole list on item changes. Fixes performance issues.
}
private struct ListItemPaddingModifier: ViewModifier {
private let isFirst: Bool
init(isFirst: Bool) {
self.isFirst = isFirst
}
func body(content: Content) -> some View {
var topPadding: CGFloat = isFirst ? Constants.listItemPadding + Constants.topPadding : Constants.listItemPadding
var bottomPadding: CGFloat = Constants.listItemPadding
if #available(iOS 16.0, *) {
topPadding += Constants.collectionViewPaddingCorrection
bottomPadding += Constants.collectionViewPaddingCorrection
}
return content
.padding(.top, topPadding)
.padding(.bottom, bottomPadding)
}
}
}
private struct BackgroundView<Content: View>: View {
var content: () -> Content
@Environment(\.theme) private var theme: ThemeSwiftUI
private let shadowRadius: CGFloat = 20.0
init(@ViewBuilder content: @escaping () -> Content) {
self.content = content
}
var body: some View {
content()
.background(theme.colors.background)
.clipShape(RoundedCornerShape(radius: shadowRadius, corners: [.topLeft, .topRight]))
.shadow(color: .black.opacity(0.20), radius: 20.0, x: 0.0, y: 3.0)
.mask(Rectangle().padding(.init(top: -(shadowRadius * 2), leading: 0.0, bottom: 0.0, trailing: 0.0)))
.edgesIgnoringSafeArea(.all)
}
}
// MARK: - Previews
struct CompletionSuggestion_Previews: PreviewProvider {
static let stateRenderer = MockCompletionSuggestionScreenState.stateRenderer
static var previews: some View {
stateRenderer.screenGroup()
}
}