Use the editor toolbar role on iOS 26 instead of left aligning the header by frame. (#4647)

The weird back button animation doesn't happen anymore 🥳

ElementX/Sources/Other/SwiftUI/Views/RoomHeaderView.swift

@@ -19,13 +19,14 @@ struct RoomHeaderView: View {
     let mediaProvider: MediaProviderProtocol?
     
     var body: some View {
-        if ProcessInfo.isRunningAccessibilityTests || ProcessInfo.processInfo.isiOSAppOnMac {
-            // Accessibility tests scale up the dynamic size in real time which may break the view.
-            // macOS really doesn't like the greedy size and does weird things to it.
+        if #available(iOS 26.0, *) {
+            // On iOS 26+ we use the toolbarRole(.editor) to leading align.
             content
         } else {
+            // On iOS 18 and lower, the editor role causes an animation glitch with the back button whenever
+            // you push a screen whilst the large title is visible on the room screen.
             content
-                // Take up as much space as possible, with a leading alignment for use in the principal toolbar position
+                // So take up as much space as possible, with a leading alignment for use in the default principal toolbar position
                 .frame(idealWidth: .greatestFiniteMagnitude, maxWidth: .infinity, alignment: .leading)
         }
     }
@@ -64,9 +65,19 @@ struct RoomHeaderView: View {
     }
 }
 
+extension RoomHeaderView {
+    static var toolbarRole: ToolbarRole {
+        if #available(iOS 26.0, *) {
+            .editor
+        } else {
+            .automatic
+        }
+    }
+}
+
 struct RoomHeaderView_Previews: PreviewProvider, TestablePreview {
     static var previews: some View {
-        VStack(spacing: 8) {
+        VStack(alignment: .leading, spacing: 8) {
             makeHeader(avatarURL: nil, verificationState: .notVerified)
             makeHeader(avatarURL: .mockMXCAvatar, verificationState: .notVerified)
             makeHeader(avatarURL: .mockMXCAvatar, verificationState: .verified)

ElementX/Sources/Screens/JoinRoomScreen/View/JoinRoomScreen.swift

@@ -40,6 +40,7 @@ struct JoinRoomScreen: View {
         .alert(item: $context.alertInfo)
         .background()
         .backgroundStyle(.compound.bgCanvasDefault)
+        .toolbarRole(RoomHeaderView.toolbarRole)
         .navigationBarTitleDisplayMode(.inline)
         .toolbar { toolbar }
         .shouldScrollOnKeyboardDidShow(focus == .knockMessage, to: Focus.knockMessage)

ElementX/Sources/Screens/RoomScreen/View/RoomScreen.swift

@@ -66,6 +66,7 @@ struct RoomScreen: View {
                         .environment(\.shouldAutomaticallyLoadImages, !timelineContext.viewState.hideTimelineMedia)
                 }
             }
+            .toolbarRole(RoomHeaderView.toolbarRole)
             .navigationTitle(L10n.screenRoomTitle) // Hidden but used for back button text.
             .navigationBarTitleDisplayMode(.inline)
             .toolbar { toolbar }

ElementX/Sources/Screens/Spaces/SpaceScreen/View/SpaceScreen.swift

@@ -21,6 +21,7 @@ struct SpaceScreen: View {
             }
         }
         .background(Color.compound.bgCanvasDefault.ignoresSafeArea())
+        .toolbarRole(RoomHeaderView.toolbarRole)
         .navigationTitle(context.viewState.space.name)
         .navigationBarTitleDisplayMode(.inline)
         .toolbar { toolbar }

ElementX/Sources/Screens/ThreadTimelineScreen/View/ThreadTimelineScreen.swift

@@ -24,10 +24,11 @@ struct ThreadTimelineScreen: View {
         
     var body: some View {
         TimelineView(timelineContext: timelineContext)
+            .background(.compound.bgCanvasDefault)
+            .toolbarRole(RoomHeaderView.toolbarRole)
             .navigationTitle(L10n.commonThread)
             .navigationBarTitleDisplayMode(.inline)
             .toolbar { toolbar }
-            .background(.compound.bgCanvasDefault)
             .toolbarBackground(.visible, for: .navigationBar) // Fix the toolbar's background.
             .timelineMediaPreview(viewModel: $context.mediaPreviewViewModel)
             .overlay(alignment: .bottomTrailing) {

PreviewTests/Sources/__Snapshots__/PreviewTests/roomHeaderView.iPad-en-GB-0.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:d3642081cbd670f8cd3db79b211081f6b8f780da486ae6d3c388d05931efed0e
-size 96541
+oid sha256:06bdbba08a5d7d53d356b4a02eb94b090588b90683cf574239c868252ab8ee14
+size 97107

PreviewTests/Sources/__Snapshots__/PreviewTests/roomHeaderView.iPad-pseudo-0.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:d3642081cbd670f8cd3db79b211081f6b8f780da486ae6d3c388d05931efed0e
-size 96541
+oid sha256:06bdbba08a5d7d53d356b4a02eb94b090588b90683cf574239c868252ab8ee14
+size 97107

PreviewTests/Sources/__Snapshots__/PreviewTests/roomHeaderView.iPhone-16-en-GB-0.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:cad5aff3deb96a20f9b1eec7d40112c33b288b7c5c60d5d5c755f9011a9dfaa6
-size 74246
+oid sha256:e57968b4e8159f7bae287d25c095f0f50592876e8d53b0f74016a184d1fd6a0c
+size 74497

PreviewTests/Sources/__Snapshots__/PreviewTests/roomHeaderView.iPhone-16-pseudo-0.png

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:cad5aff3deb96a20f9b1eec7d40112c33b288b7c5c60d5d5c755f9011a9dfaa6
-size 74246
+oid sha256:e57968b4e8159f7bae287d25c095f0f50592876e8d53b0f74016a184d1fd6a0c
+size 74497