Media loading flow changes (#483)

* Use an imageProvider directly from the view in the home screen

* Add support for media request coalescing

* Rename MediaProxy to MediaLoader

* Add new image loading mechanism to the room details screen avatar.

* Use the `SettingsScreen` prefix for all settings screen related components

* Add new image loading mechanism to the room header

* Add new image loading mechanism to the room member details screen

* Introduce a LoadableImage SwiftUI view that will automatically handle image loading

* Adopt the new LoadableImage where possible

* Fix LoadableImage not using/storing loaded images properly

* Simplify media loader enqueueing

* Made LodableImage load content after mediaSource updates. Adopt it on the home and settings screens

* Introduce a LoadableAvatarImage component and reuse it throughout the app

* Small logging tweaks, made some LoadableImage properties private

* Fix redacted skeletons avatar background color

* Fix placeholder avatars changing when backgrounding the app

* PR comments.

- Trim the @ sign off of mxid placeholders.
- Only expose AvatarSize on the avatar image, use CGSize elsewhere.

Co-authored-by: Doug <douglase@element.io>

ElementX/Sources/Screens/HomeScreen/HomeScreenViewModel.swift

@@ -37,7 +37,7 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
     
     // MARK: - Setup
     
-    // swiftlint:disable:next function_body_length cyclomatic_complexity
+    // swiftlint:disable:next function_body_length
     init(userSession: UserSessionProtocol, attributedStringBuilder: AttributedStringBuilderProtocol) {
         self.userSession = userSession
         self.attributedStringBuilder = attributedStringBuilder
@@ -45,7 +45,8 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
         visibleRoomsSummaryProvider = userSession.clientProxy.visibleRoomsSummaryProvider
         allRoomsSummaryProvider = userSession.clientProxy.allRoomsSummaryProvider
         
-        super.init(initialViewState: HomeScreenViewState(userID: userSession.userID))
+        super.init(initialViewState: HomeScreenViewState(userID: userSession.userID),
+                   imageProvider: userSession.mediaProvider)
         
         userSession.callbacks
             .receive(on: DispatchQueue.main)
@@ -71,9 +72,7 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
         
         Task {
             if case let .success(url) = await userSession.clientProxy.loadUserAvatarURL() {
-                if case let .success(avatar) = await userSession.mediaProvider.loadImageFromURL(url, avatarSize: .user(on: .home)) {
-                    state.userAvatar = avatar
-                }
+                state.userAvatarURL = url
             }
         }
         
@@ -139,13 +138,8 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
     
     // MARK: - Public
     
-    // swiftlint:disable:next cyclomatic_complexity
     override func process(viewAction: HomeScreenViewAction) async {
         switch viewAction {
-        case .loadRoomData(let roomIdentifier):
-            if state.roomListMode != .skeletons {
-                loadDataForRoomIdentifier(roomIdentifier)
-            }
         case .selectRoom(let roomIdentifier):
             callback?(.presentRoom(roomIdentifier: roomIdentifier))
         case .userMenu(let action):
@@ -178,27 +172,7 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
     }
     
     // MARK: - Private
-    
-    private func loadDataForRoomIdentifier(_ identifier: String) {
-        guard let room = roomsForIdentifiers[identifier],
-              room.avatar == nil,
-              let avatarURL = room.avatarURL else {
-            return
-        }
         
-        Task {
-            if case let .success(image) = await userSession.mediaProvider.loadImageFromURL(avatarURL, avatarSize: .room(on: .home)) {
-                guard let roomIndex = state.rooms.firstIndex(where: { $0.roomId == identifier }) else {
-                    return
-                }
-                
-                var room = state.rooms[roomIndex]
-                room.avatar = image
-                state.rooms[roomIndex] = room
-            }
-        }
-    }
-    
     /// This method will update all view state rooms by merging the data from both summary providers
     /// If a room is empty in the visible room summary provider it will try to get it from the allRooms one
     /// This ensures that we show as many room details as possible without loading up timelines
@@ -256,10 +230,6 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
         room.hasUnreads = details.unreadNotificationCount > 0
         room.lastMessage = details.lastMessage
         
-        if let avatarURL = details.avatarURL {
-            room.avatar = userSession.mediaProvider.imageFromURL(avatarURL, avatarSize: .room(on: .home))
-        }
-        
         if let lastMessageTimestamp = details.lastMessageTimestamp {
             room.timestamp = lastMessageTimestamp.formattedMinimal()
         }