Impressia/Vernissage/Widgets/ImagesCarousel.swift

124 lines
4.5 KiB
Swift

//
// https://mczachurski.dev
// Copyright © 2023 Marcin Czachurski and the repository contributors.
// Licensed under the MIT License.
//
import SwiftUI
import MastodonKit
struct ImagesCarousel: View {
@State public var attachments: [AttachmentModel]
@State private var imageHeight: Double
@State private var imageWidth: Double
@State private var selected: String
@State private var heightWasPrecalculated: Bool
@Binding public var selectedAttachmentId: String?
@Binding public var exifCamera: String?
@Binding public var exifExposure: String?
@Binding public var exifCreatedDate: String?
@Binding public var exifLens: String?
init(attachments: [AttachmentModel],
selectedAttachmentId: Binding<String?>,
exifCamera: Binding<String?>,
exifExposure: Binding<String?>,
exifCreatedDate: Binding<String?>,
exifLens: Binding<String?>
) {
_selectedAttachmentId = selectedAttachmentId
_exifCamera = exifCamera
_exifExposure = exifExposure
_exifCreatedDate = exifCreatedDate
_exifLens = exifLens
self.attachments = attachments
self.selected = String.empty()
let highestImage = attachments.getHighestImage()
let imgHeight = Double((highestImage?.meta as? ImageMetadata)?.original?.height ?? 0)
let imgWidth = Double((highestImage?.meta as? ImageMetadata)?.original?.width ?? 0)
// Calculate size of frame (first from cache, then from metadata).
if let highestImage, let size = ImageSizeService.shared.get(for: highestImage.url) {
self.imageWidth = size.width
self.imageHeight = size.height
self.heightWasPrecalculated = true
} else if let highestImage, imgHeight > 0 && imgWidth > 0 {
let size = ImageSizeService.shared.calculate(for: highestImage.url, width: imgWidth, height: imgHeight)
self.imageWidth = size.width
self.imageHeight = size.height
self.heightWasPrecalculated = true
} else {
self.imageWidth = UIScreen.main.bounds.width
self.imageHeight = UIScreen.main.bounds.width * 0.75
self.heightWasPrecalculated = false
}
}
var body: some View {
TabView(selection: $selected) {
ForEach(attachments, id: \.id) { attachment in
ImageCarouselPicture(attachment: attachment) { (attachment, imageData) in
withAnimation {
self.recalculateImageHeight(attachment: attachment, imageData: imageData)
}
DispatchQueue.main.asyncAfter(deadline: .now() + 0.4) {
attachment.set(data: imageData)
}
}
.tag(attachment.id)
}
}
.frame(height: self.imageHeight)
.tabViewStyle(PageTabViewStyle())
.onChange(of: selected, perform: { index in
self.selectedAttachmentId = selected
if let attachment = attachments.first(where: { item in item.id == index }) {
self.exifCamera = attachment.exifCamera
self.exifExposure = attachment.exifExposure
self.exifCreatedDate = attachment.exifCreatedDate
self.exifLens = attachment.exifLens
}
})
.onAppear {
self.selected = self.attachments.first?.id ?? String.empty()
}
}
private func recalculateImageHeight(attachment: AttachmentModel, imageData: Data) {
guard heightWasPrecalculated == false else {
return
}
var imageHeight = 0.0
var imageWidth = 0.0
for item in attachments {
if let data = item.data, let image = UIImage(data: data) {
if image.size.height > imageHeight {
imageHeight = image.size.height
imageWidth = image.size.width
}
}
}
if let image = UIImage(data: imageData) {
if image.size.height > imageHeight {
imageHeight = image.size.height
imageWidth = image.size.width
}
}
let size = ImageSizeService.shared.calculate(for: attachment.url, width: imageWidth, height: imageHeight)
self.imageWidth = size.width
self.imageHeight = size.height
}
}