Split the corner layout on the hinge when partially open

On a half-open foldable the side column takes exactly the trailing half,
so the split lands on the hinge. Fully open, the column can now be
resized up to half the width. A re-presented player seeds the hinge
state from the last report so it doesn't animate into the split.

Yattee/Views/Player/CornerPlayerLayout.swift

@@ -28,6 +28,10 @@ struct CornerPlayerLayout<PlayerContent: View>: View {
 
     let onChannelTap: (() -> Void)?
     var onFullscreen: (() -> Void)? = nil
+    /// Foldable hinge partially open (iPhone Duo, book posture): the side
+    /// column (grabber included) takes exactly the trailing half so the
+    /// split lands on the hinge. Not resizable then — only overdrag-hide.
+    var isHingeSplit = false
 
     /// Seed the panel visibility BEFORE the first frame — applying the
     /// preset's default visibility via onAppear/onChange animates the panels
@@ -44,8 +48,10 @@ struct CornerPlayerLayout<PlayerContent: View>: View {
             _ height: CGFloat
         ) -> PlayerContent,
         onChannelTap: (() -> Void)?,
-        onFullscreen: (() -> Void)? = nil
+        onFullscreen: (() -> Void)? = nil,
+        isHingeSplit: Bool = false
     ) {
+        self.isHingeSplit = isHingeSplit
         self.playerControlsLayout = playerControlsLayout
         self.playerContent = playerContent
         self.onChannelTap = onChannelTap
@@ -179,9 +185,10 @@ struct CornerPlayerLayout<PlayerContent: View>: View {
     }
 
     private func clampColumnWidth(_ width: CGFloat, availableWidth: CGFloat) -> CGFloat {
+        // Up to half the window, grabber included
         let maxWidth = max(
             Self.minColumnWidth,
-            min(Self.maxColumnWidthCap, availableWidth * 0.45, availableWidth - Self.minVideoColumnWidth)
+            min(Self.maxColumnWidthCap, availableWidth / 2 - Self.grabberWidth, availableWidth - Self.minVideoColumnWidth)
         )
         return min(max(width, Self.minColumnWidth), maxWidth)
     }
@@ -227,10 +234,12 @@ struct CornerPlayerLayout<PlayerContent: View>: View {
             // away on its own while the panel stays nominally visible.
             let showsAnyRegion = showsSideColumn || showsBelowVideo
 
-            let effectiveColumnWidth = clampColumnWidth(columnWidth, availableWidth: width)
             // Grabber sits on the column's leading edge, inside the column
             // background — narrow strip matching the panel drag handle look.
             let grabberWidth = Self.grabberWidth
+            // Hinge split ignores (and never overwrites) the saved width.
+            let hingeColumnWidth = max(Self.minColumnWidth, width / 2 - grabberWidth)
+            let effectiveColumnWidth = isHingeSplit ? hingeColumnWidth : clampColumnWidth(columnWidth, availableWidth: width)
             let totalColumnWidth = effectiveColumnWidth + grabberWidth
 
             // Panels never move. Both sit at their home positions (column on
@@ -315,9 +324,9 @@ struct CornerPlayerLayout<PlayerContent: View>: View {
                 if hasSideColumn, let video {
                     HStack(spacing: 0) {
                         PanelResizeGrabber(
-                            panelWidth: $columnWidth,
-                            minWidth: Self.minColumnWidth,
-                            maxWidth: clampColumnWidth(.infinity, availableWidth: width),
+                            panelWidth: isHingeSplit ? .constant(hingeColumnWidth) : $columnWidth,
+                            minWidth: isHingeSplit ? hingeColumnWidth : Self.minColumnWidth,
+                            maxWidth: isHingeSplit ? hingeColumnWidth : clampColumnWidth(.infinity, availableWidth: width),
                             panelSide: .right,
                             isPinned: true,
                             isDragActive: $isGrabberActive,

Yattee/Views/Player/ExpandedPlayerSheet+Layouts.swift

@@ -1364,10 +1364,20 @@ extension ExpandedPlayerSheet {
                 #if os(iOS)
                 self.toggleFullscreen()
                 #endif
-            }
+            },
+            isHingeSplit: isHingeSplitActive
         )
     }
 
+    /// The corner layout splits on the hinge while it's partially open.
+    private var isHingeSplitActive: Bool {
+        #if os(iOS)
+        isTabletopHinge
+        #else
+        false
+        #endif
+    }
+
     // MARK: - Widescreen Player Area
 
     /// Player area for widescreen layout with panel support.

Yattee/Views/Player/ExpandedPlayerSheet.swift

@@ -100,7 +100,9 @@ struct ExpandedPlayerSheet: View {
     /// Foldable hinge partially open (iPhone Duo laptop position): the
     /// fullscreen portrait layout keeps the video on the upper half and
     /// moves every control to the lower half.
-    @State var isTabletopHinge = false
+    /// Seeded from the last hinge report so a re-presented player starts in
+    /// the right layout instead of animating into it.
+    @State var isTabletopHinge = HingeLayoutObserver.lastKnownTabletop
     #endif
 
     #if os(iOS) || os(macOS)

Yattee/Views/Player/HingeLayoutObserver.swift

@@ -18,6 +18,28 @@ struct HingeLayoutObserver: ViewModifier {
     /// tabletop layout on simulators without a hinge control.
     static let forceTabletop = ProcessInfo.processInfo.environment["YATTEE_FORCE_TABLETOP"] == "1"
 
+    /// Last reported tabletop state, outliving the player sheet: re-presenting
+    /// the player seeds from it so the layout doesn't animate in from the
+    /// unfolded state.
+    @MainActor static var lastKnownTabletop = false
+
+    /// The first report after appearing corrects the seed without animation.
+    @State private var hasReceivedReport = false
+
+    private func apply(_ tabletop: Bool) {
+        Self.lastKnownTabletop = tabletop
+        let animated = hasReceivedReport
+        hasReceivedReport = true
+        guard tabletop != isTabletop else { return }
+        if animated {
+            withAnimation(.easeInOut(duration: 0.3)) { isTabletop = tabletop }
+        } else {
+            var transaction = Transaction()
+            transaction.disablesAnimations = true
+            withTransaction(transaction) { isTabletop = tabletop }
+        }
+    }
+
     func body(content: Content) -> some View {
         if Self.forceTabletop {
             // The override stands in for a half-open hinge, which only exists
@@ -29,10 +51,7 @@ struct HingeLayoutObserver: ViewModifier {
                 // Mirror the real hinge state: no programmatic rotation (and no
                 // orientation lock) while the hinge is open.
                 OrientationManager.shared.canRotateProgrammatically = !isInterior
-                guard isInterior != isTabletop else { return }
-                withAnimation(.easeInOut(duration: 0.3)) {
-                    isTabletop = isInterior
-                }
+                apply(isInterior)
             }
         } else if #available(iOS 27.1, *) {
             content.onHingeChange { _, context in
@@ -43,11 +62,9 @@ struct HingeLayoutObserver: ViewModifier {
                     // programmatic rotation, so the player must not offer it.
                     OrientationManager.shared.canRotateProgrammatically = status == .closed
                 }
-                let tabletop = context.hinge?.status == .partiallyOpen
-                guard tabletop != isTabletop else { return }
-                withAnimation(.easeInOut(duration: 0.3)) {
-                    isTabletop = tabletop
-                }
+                // nil when leaving the hierarchy: keep the last state then
+                guard let status = context.hinge?.status else { return }
+                apply(status == .partiallyOpen)
             }
         } else {
             content