session-ios/Session/Conversations/Message Cells/Content Views/MediaView.swift

472 lines
16 KiB
Swift

// Copyright © 2022 Rangeproof Pty Ltd. All rights reserved.
import UIKit
import YYImage
import SessionUIKit
import SessionMessagingKit
public class MediaView: UIView {
static let contentMode: UIView.ContentMode = .scaleAspectFill
private enum MediaError {
case missing
case invalid
case failed
}
// MARK: -
private let mediaCache: NSCache<NSString, AnyObject>
public let attachment: Attachment
private let isOutgoing: Bool
private let maxMessageWidth: CGFloat
private var loadBlock: (() -> Void)?
private var unloadBlock: (() -> Void)?
// MARK: - LoadState
// The loadState property allows us to:
//
// * Make sure we only have one load attempt
// enqueued at a time for a given piece of media.
// * We never retry media that can't be loaded.
// * We skip media loads which are no longer
// necessary by the time they reach the front
// of the queue.
enum LoadState {
case unloaded
case loading
case loaded
case failed
}
private let loadState: Atomic<LoadState> = Atomic(.unloaded)
// MARK: - Initializers
public required init(
mediaCache: NSCache<NSString, AnyObject>,
attachment: Attachment,
isOutgoing: Bool,
maxMessageWidth: CGFloat
) {
self.mediaCache = mediaCache
self.attachment = attachment
self.isOutgoing = isOutgoing
self.maxMessageWidth = maxMessageWidth
super.init(frame: .zero)
backgroundColor = Colors.unimportant
clipsToBounds = true
createContents()
}
@available(*, unavailable, message: "use other init() instead.")
required public init?(coder aDecoder: NSCoder) {
notImplemented()
}
deinit {
loadState.mutate { $0 = .unloaded }
}
// MARK: -
private func createContents() {
AssertIsOnMainThread()
guard attachment.state != .pendingDownload && attachment.state != .downloading else {
addDownloadProgressIfNecessary()
return
}
guard attachment.state != .failedDownload else {
configure(forError: .failed)
return
}
guard attachment.isValid else {
configure(forError: .invalid)
return
}
if attachment.isAnimated {
configureForAnimatedImage(attachment: attachment)
}
else if attachment.isImage {
configureForStillImage(attachment: attachment)
}
else if attachment.isVideo {
configureForVideo(attachment: attachment)
}
else {
owsFailDebug("Attachment has unexpected type.")
configure(forError: .invalid)
}
}
private func addDownloadProgressIfNecessary() {
guard attachment.state != .failedDownload else {
configure(forError: .failed)
return
}
guard attachment.state != .uploading && attachment.state != .uploaded else {
// TODO: Show "restoring" indicator and possibly progress.
configure(forError: .missing)
return
}
backgroundColor = (isDarkMode ? .ows_gray90 : .ows_gray05)
let loader = MediaLoaderView()
addSubview(loader)
loader.pin([ UIView.HorizontalEdge.left, UIView.VerticalEdge.bottom, UIView.HorizontalEdge.right ], to: self)
}
private func addUploadProgressIfNecessary(_ subview: UIView) -> Bool {
guard isOutgoing else { return false }
guard attachment.state != .failedUpload else {
configure(forError: .failed)
return false
}
// If this message was uploaded on a different device it'll now be seen as 'downloaded' (but
// will still be outgoing - we don't want to show a loading indicator in this case)
guard attachment.state != .uploaded && attachment.state != .downloaded else { return false }
let loader = MediaLoaderView()
addSubview(loader)
loader.pin([ UIView.HorizontalEdge.left, UIView.VerticalEdge.bottom, UIView.HorizontalEdge.right ], to: self)
return true
}
private func configureForAnimatedImage(attachment: Attachment) {
let animatedImageView: YYAnimatedImageView = YYAnimatedImageView()
// We need to specify a contentMode since the size of the image
// might not match the aspect ratio of the view.
animatedImageView.contentMode = MediaView.contentMode
// Use trilinear filters for better scaling quality at
// some performance cost.
animatedImageView.layer.minificationFilter = .trilinear
animatedImageView.layer.magnificationFilter = .trilinear
animatedImageView.backgroundColor = Colors.unimportant
animatedImageView.isHidden = !attachment.isValid
addSubview(animatedImageView)
animatedImageView.autoPinEdgesToSuperviewEdges()
_ = addUploadProgressIfNecessary(animatedImageView)
loadBlock = { [weak self] in
AssertIsOnMainThread()
if animatedImageView.image != nil {
owsFailDebug("Unexpectedly already loaded.")
return
}
self?.tryToLoadMedia(
loadMediaBlock: { applyMediaBlock in
guard attachment.isValid else {
self?.configure(forError: .invalid)
return
}
guard let filePath: String = attachment.originalFilePath else {
owsFailDebug("Attachment stream missing original file path.")
self?.configure(forError: .invalid)
return
}
applyMediaBlock(YYImage(contentsOfFile: filePath))
},
applyMediaBlock: { media in
AssertIsOnMainThread()
guard let image: YYImage = media as? YYImage else {
owsFailDebug("Media has unexpected type: \(type(of: media))")
self?.configure(forError: .invalid)
return
}
// FIXME: Animated images flicker when reloading the cells (even though they are in the cache)
animatedImageView.image = image
},
cacheKey: attachment.id
)
}
unloadBlock = {
AssertIsOnMainThread()
animatedImageView.image = nil
}
}
private func configureForStillImage(attachment: Attachment) {
let stillImageView = UIImageView()
// We need to specify a contentMode since the size of the image
// might not match the aspect ratio of the view.
stillImageView.contentMode = MediaView.contentMode
// Use trilinear filters for better scaling quality at
// some performance cost.
stillImageView.layer.minificationFilter = .trilinear
stillImageView.layer.magnificationFilter = .trilinear
stillImageView.backgroundColor = Colors.unimportant
stillImageView.isHidden = !attachment.isValid
addSubview(stillImageView)
stillImageView.autoPinEdgesToSuperviewEdges()
_ = addUploadProgressIfNecessary(stillImageView)
loadBlock = { [weak self] in
AssertIsOnMainThread()
if stillImageView.image != nil {
owsFailDebug("Unexpectedly already loaded.")
return
}
self?.tryToLoadMedia(
loadMediaBlock: { applyMediaBlock in
guard attachment.isValid else {
self?.configure(forError: .invalid)
return
}
attachment.thumbnail(
size: .large,
success: { image, _ in applyMediaBlock(image) },
failure: {
Logger.error("Could not load thumbnail")
self?.configure(forError: .invalid)
}
)
},
applyMediaBlock: { media in
AssertIsOnMainThread()
guard let image: UIImage = media as? UIImage else {
owsFailDebug("Media has unexpected type: \(type(of: media))")
self?.configure(forError: .invalid)
return
}
stillImageView.image = image
},
cacheKey: attachment.id
)
}
unloadBlock = {
AssertIsOnMainThread()
stillImageView.image = nil
}
}
private func configureForVideo(attachment: Attachment) {
let stillImageView = UIImageView()
// We need to specify a contentMode since the size of the image
// might not match the aspect ratio of the view.
stillImageView.contentMode = MediaView.contentMode
// Use trilinear filters for better scaling quality at
// some performance cost.
stillImageView.layer.minificationFilter = .trilinear
stillImageView.layer.magnificationFilter = .trilinear
stillImageView.backgroundColor = Colors.unimportant
stillImageView.isHidden = !attachment.isValid
addSubview(stillImageView)
stillImageView.autoPinEdgesToSuperviewEdges()
if !addUploadProgressIfNecessary(stillImageView) {
let videoPlayIcon = UIImage(named: "CirclePlay")
let videoPlayButton = UIImageView(image: videoPlayIcon)
videoPlayButton.set(.width, to: 72)
videoPlayButton.set(.height, to: 72)
stillImageView.addSubview(videoPlayButton)
videoPlayButton.autoCenterInSuperview()
}
loadBlock = { [weak self] in
AssertIsOnMainThread()
if stillImageView.image != nil {
owsFailDebug("Unexpectedly already loaded.")
return
}
self?.tryToLoadMedia(
loadMediaBlock: { applyMediaBlock in
guard attachment.isValid else {
self?.configure(forError: .invalid)
return
}
attachment.thumbnail(
size: .medium,
success: { image, _ in applyMediaBlock(image) },
failure: {
Logger.error("Could not load thumbnail")
self?.configure(forError: .invalid)
}
)
},
applyMediaBlock: { media in
AssertIsOnMainThread()
guard let image: UIImage = media as? UIImage else {
owsFailDebug("Media has unexpected type: \(type(of: media))")
self?.configure(forError: .invalid)
return
}
stillImageView.image = image
},
cacheKey: attachment.id
)
}
unloadBlock = {
AssertIsOnMainThread()
stillImageView.image = nil
}
}
private func configure(forError error: MediaError) {
// When there is a failure in the 'loadMediaBlock' closure this can be called
// on a background thread - rather than dispatching in every 'loadMediaBlock'
// usage we just do so here
guard Thread.isMainThread else {
DispatchQueue.main.async {
self.configure(forError: error)
}
return
}
let icon: UIImage
switch error {
case .failed:
guard let asset = UIImage(named: "media_retry") else {
owsFailDebug("Missing image")
return
}
icon = asset
case .invalid:
guard let asset = UIImage(named: "media_invalid") else {
owsFailDebug("Missing image")
return
}
icon = asset
case .missing: return
}
backgroundColor = (isDarkMode ? .ows_gray90 : .ows_gray05)
// For failed ougoing messages add an overlay to make the icon more visible
if isOutgoing {
let attachmentOverlayView: UIView = UIView()
attachmentOverlayView.backgroundColor = Colors.navigationBarBackground
.withAlphaComponent(Values.lowOpacity)
addSubview(attachmentOverlayView)
attachmentOverlayView.pin(to: self)
}
let iconView = UIImageView(image: icon.withRenderingMode(.alwaysTemplate))
iconView.tintColor = Colors.text
.withAlphaComponent(Values.mediumOpacity)
addSubview(iconView)
iconView.autoCenterInSuperview()
}
private func tryToLoadMedia(
loadMediaBlock: @escaping (@escaping (AnyObject?) -> Void) -> Void,
applyMediaBlock: @escaping (AnyObject) -> Void,
cacheKey: String
) {
// It's critical that we update loadState once
// our load attempt is complete.
let loadCompletion: (AnyObject?) -> Void = { [weak self] possibleMedia in
guard self?.loadState.wrappedValue == .loading else {
Logger.verbose("Skipping obsolete load.")
return
}
guard let media: AnyObject = possibleMedia else {
self?.loadState.mutate { $0 = .failed }
// TODO:
// [self showAttachmentErrorViewWithMediaView:mediaView];
return
}
applyMediaBlock(media)
self?.mediaCache.setObject(media, forKey: cacheKey as NSString)
self?.loadState.mutate { $0 = .loaded }
}
guard loadState.wrappedValue == .loading else {
owsFailDebug("Unexpected load state: \(loadState)")
return
}
if let media: AnyObject = self.mediaCache.object(forKey: cacheKey as NSString) {
Logger.verbose("media cache hit")
guard Thread.isMainThread else {
DispatchQueue.main.async {
loadCompletion(media)
}
return
}
loadCompletion(media)
return
}
Logger.verbose("media cache miss")
MediaView.loadQueue.async { [weak self] in
guard self?.loadState.wrappedValue == .loading else {
Logger.verbose("Skipping obsolete load.")
return
}
loadMediaBlock { media in
guard Thread.isMainThread else {
DispatchQueue.main.async {
loadCompletion(media)
}
return
}
loadCompletion(media)
}
}
}
// We use this queue to perform the media loads.
// These loads are expensive, so we want to:
//
// * Do them off the main thread.
// * Only do one at a time.
// * Avoid this work if possible (obsolete loads for
// views that are no longer visible, redundant loads
// of media already being loaded, don't retry media
// that can't be loaded, etc.).
// * Do them in _reverse_ order. More recently enqueued
// loads more closely reflect the current view state.
// By processing in reverse order, we improve our
// "skip rate" of obsolete loads.
private static let loadQueue = ReverseDispatchQueue(label: "org.signal.asyncMediaLoadQueue")
public func loadMedia() {
switch loadState.wrappedValue {
case .unloaded:
loadState.mutate { $0 = .loading }
loadBlock?()
case .loading, .loaded, .failed: break
}
}
public func unloadMedia() {
loadState.mutate { $0 = .unloaded }
unloadBlock?()
}
}