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>
2026-11-04 00:49:44 +00:00 · 2023-01-25 19:45:01 +02:00
parent 3a74f13097
commit bd4c0b72cb
58 changed files with 875 additions and 830 deletions
@@ -36,6 +36,10 @@ class ViewModelContext<ViewState: BindableState, ViewAction>: ObservableObject {

    /// Get-able/Observable `Published` property for the `ViewState`
    @Published fileprivate(set) var viewState: ViewState
+    
+    /// An optional image loading service so that views can manage themselves
+    /// Intentionally non-generic so that it doesn't grow uncontrollably
+    let imageProvider: ImageProviderProtocol?

    /// Set-able/Bindable access to the bindable state.
    subscript<T>(dynamicMember keyPath: WritableKeyPath<ViewState.BindStateType, T>) -> T {
@@ -43,9 +47,10 @@ class ViewModelContext<ViewState: BindableState, ViewAction>: ObservableObject {
        set { viewState.bindings[keyPath: keyPath] = newValue }
    }
    
-    init(initialViewState: ViewState) {
+    init(initialViewState: ViewState, imageProvider: ImageProviderProtocol?) {
        self.viewActions = PassthroughSubject()
        self.viewState = initialViewState
+        self.imageProvider = imageProvider
    }

    /// Send a `ViewAction` to the `ViewModel` for processing.
@@ -78,8 +83,8 @@ class StateStoreViewModel<State: BindableState, ViewAction> {
        set { context.viewState = newValue }
    }

-    init(initialViewState: State) {
-        context = Context(initialViewState: initialViewState)
+    init(initialViewState: State, imageProvider: ImageProviderProtocol? = nil) {
+        context = Context(initialViewState: initialViewState, imageProvider: imageProvider)
        context.viewActions
            .sink { [weak self] action in
                guard let self else { return }
@@ -0,0 +1,50 @@
+//
+// Copyright 2023 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import SwiftUI
+
+struct LoadableAvatarImage: View {
+    private let url: URL?
+    private let name: String?
+    private let contentID: String?
+    private let avatarSize: AvatarSize
+    private let imageProvider: ImageProviderProtocol?
+    
+    @ScaledMetric private var frameSize: CGFloat
+    
+    init(url: URL?, name: String?, contentID: String?, avatarSize: AvatarSize, imageProvider: ImageProviderProtocol?) {
+        self.url = url
+        self.name = name
+        self.contentID = contentID
+        self.avatarSize = avatarSize
+        self.imageProvider = imageProvider
+        
+        _frameSize = ScaledMetric(wrappedValue: avatarSize.value)
+    }
+    
+    var body: some View {
+        LoadableImage(url: url,
+                      size: avatarSize.scaledSize,
+                      imageProvider: imageProvider) { image in
+            image
+                .scaledToFill()
+        } placeholder: {
+            PlaceholderAvatarImage(name: name, contentID: contentID)
+        }
+        .frame(width: frameSize, height: frameSize)
+        .clipShape(Circle())
+    }
+}
@@ -0,0 +1,102 @@
+//
+// Copyright 2023 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import SwiftUI
+
+struct LoadableImage<TransformerView: View, PlaceholderView: View>: View {
+    private let mediaSource: MediaSourceProxy?
+    private let blurhash: String?
+    private let size: CGSize?
+    private let imageProvider: ImageProviderProtocol?
+    
+    private var transformer: (Image) -> TransformerView
+    private let placeholder: () -> PlaceholderView
+    
+    @State private var cachedImage: UIImage?
+    
+    /// A SwiftUI view that automatically fetches images
+    /// It will try fetching the image from in-memory cache and if that's not available
+    /// it will fire a task to load it through the image provider
+    /// - Parameters:
+    ///   - mediaSource: the source of the image
+    ///   - blurhash: an optional blurhash
+    ///   - transformer: entry point for configuring the resulting image view
+    ///   - placeholder: a view to show while the image or blurhash are not available
+    init(mediaSource: MediaSourceProxy?,
+         blurhash: String? = nil,
+         size: CGSize? = nil,
+         imageProvider: ImageProviderProtocol?,
+         transformer: @escaping (Image) -> TransformerView = { $0 },
+         placeholder: @escaping () -> PlaceholderView) {
+        self.mediaSource = mediaSource
+        self.blurhash = blurhash
+        self.size = size
+        self.imageProvider = imageProvider
+        
+        self.transformer = transformer
+        self.placeholder = placeholder
+    }
+    
+    init(url: URL?,
+         blurhash: String? = nil,
+         size: CGSize? = nil,
+         imageProvider: ImageProviderProtocol?,
+         transformer: @escaping (Image) -> TransformerView = { $0 },
+         placeholder: @escaping () -> PlaceholderView) {
+        let mediaSource = url.map(MediaSourceProxy.init)
+        
+        self.init(mediaSource: mediaSource,
+                  blurhash: blurhash,
+                  size: size,
+                  imageProvider: imageProvider,
+                  transformer: transformer,
+                  placeholder: placeholder)
+    }
+    
+    var body: some View {
+        let _ = Task {
+            // Future improvement: Does guarding against a nil image prevent the image being updated when the URL changes?
+            guard image == nil, let mediaSource else { return }
+            
+            if case let .success(image) = await imageProvider?.loadImageFromSource(mediaSource, size: size) {
+                self.cachedImage = image
+            }
+        }
+        
+        ZStack {
+            if let image {
+                transformer(
+                    Image(uiImage: image)
+                        .resizable()
+                )
+            } else if let blurhash,
+                      // Build a small blurhash image so that it's fast
+                      let image = UIImage(blurHash: blurhash, size: .init(width: 10.0, height: 10.0)) {
+                transformer(
+                    Image(uiImage: image)
+                        .resizable()
+                )
+            } else {
+                placeholder()
+            }
+        }
+        .animation(.elementDefault, value: image)
+    }
+    
+    private var image: UIImage? {
+        cachedImage ?? imageProvider?.imageFromSource(mediaSource, size: size)
+    }
+}
@@ -0,0 +1,76 @@
+//
+// Copyright 2022 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import SwiftUI
+
+struct PlaceholderAvatarImage: View {
+    @Environment(\.redactionReasons) var redactionReasons
+
+    private let textForImage: String
+    private let contentID: String?
+    
+    var body: some View {
+        ZStack {
+            bgColor
+            
+            // This text's frame doesn't look right when redacted
+            if redactionReasons != .placeholder {
+                Text(textForImage)
+                    .padding(4)
+                    .foregroundColor(.white)
+                    .font(.system(size: 200).weight(.semibold))
+                    .minimumScaleFactor(0.001)
+            }
+        }
+        .aspectRatio(1, contentMode: .fill)
+    }
+
+    init(name: String?, contentID: String?) {
+        let baseName = name ?? contentID?.trimmingCharacters(in: .punctuationCharacters)
+        textForImage = baseName?.first?.uppercased() ?? ""
+        self.contentID = contentID
+    }
+
+    private var bgColor: Color {
+        if redactionReasons == .placeholder {
+            return .element.systemGray4
+        }
+
+        guard let contentID else {
+            return .element.accent
+        }
+
+        return .element.avatarBackground(for: contentID)
+    }
+}
+
+struct PlaceholderAvatarImage_Previews: PreviewProvider {
+    static var previews: some View {
+        VStack(spacing: 75) {
+            PlaceholderAvatarImage(name: "Xavier", contentID: "@userid1:matrix.org")
+                .clipShape(Circle())
+                .frame(width: 150, height: 100)
+            
+            PlaceholderAvatarImage(name: "@*~AmazingName~*@", contentID: "@userid2:matrix.org")
+                .clipShape(Circle())
+                .frame(width: 150, height: 100)
+            
+            PlaceholderAvatarImage(name: nil, contentID: "@userid3:matrix.org")
+                .clipShape(Circle())
+                .frame(width: 150, height: 100)
+        }
+    }
+}