Smooth out orientation change animations

Sources/Popover+Lifecycle.swift

@@ -130,7 +130,7 @@ public extension Popover {
 
             withTransaction(transaction) {
                 /// Temporarily use the same size for a smooth animation.
-                newPopover.setSize(oldContext.size)
+                newPopover.updateFrame(with: oldContext.size)
 
                 /// Replace the old popover with the new popover.
                 model.popovers[oldPopoverIndex] = newPopover

Sources/Popover.swift

@@ -477,16 +477,16 @@ public extension Popover {
         }
     }
 
-    /// Set the popover's size from SwiftUI. Also update the frame.
-    func setSize(_ size: CGSize?) {
+    /// Updates the popover's frame using its size.
+    func updateFrame(with size: CGSize?) {
+        let frame = calculateFrame(from: size)
         context.size = size
-        let frame = getFrame(from: size)
         context.staticFrame = frame
         context.frame = frame
     }
 
-    /// Calculate the popover's frame based on it's size and position.
-    func getFrame(from size: CGSize?) -> CGRect {
+    /// Calculate the popover's frame based on its size and position.
+    func calculateFrame(from size: CGSize?) -> CGRect {
         guard let window = context.presentedPopoverContainer?.window else { return .zero }
 
         switch attributes.position {

Sources/PopoverContainerView.swift

@@ -64,17 +64,16 @@ struct PopoverContainerView: View {
                 )
 
                 /// Read the popover's size in the view.
-                .sizeReader { size in
-                    print("size: \(size).. \(popover.context.transaction)")
+                .sizeReader(transaction: popover.context.transaction) { size in
                     if let transaction = popover.context.transaction {
                         /// When `popover.context.size` is nil, the popover was just presented.
                         if popover.context.size == nil {
-                            popover.setSize(size)
+                            popover.updateFrame(with: size)
                             popoverModel.refresh(with: transaction)
                         } else {
                             /// Otherwise, the popover is *replacing* a previous popover, so animate it.
                             withTransaction(transaction) {
-                                popover.setSize(size)
+                                popover.updateFrame(with: size)
                                 popoverModel.refresh(with: transaction)
                             }
                         }

Sources/PopoverModel.swift

@@ -83,32 +83,19 @@ class PopoverModel: ObservableObject {
      This is called when the device rotates or has a bounds change.
      */
     func updateFrames() {
-        var popoversToUpdate = [Popover]()
-
+        /**
+         First, update all popovers anyway.
+
+         For some reason, relative positioning + `.center` doesn't need the rotation animation to complete before having a size change.
+         */
         for popover in popovers {
-            popover.setSize(popover.context.size)
-
-            if
-                case let .relative(popoverAnchors) = popover.attributes.position,
-                popoverAnchors == [.center]
-            {
-                /// For some reason, relative positioning + `.center` doesn't need the rotation animation to complete before having a size change.
-                popover.setSize(popover.context.size)
-                update()
-            } else {
-                popoversToUpdate.append(popover)
-            }
+            popover.updateFrame(with: popover.context.size)
         }
+        update()
 
-        /// Other popovers need to wait until the rotation has completed before updating.
+        /// Some other popovers need to wait until the rotation has completed before updating.
         DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
-            for popover in popoversToUpdate {
-                popover.setSize(popover.context.size)
-            }
-
-            withAnimation {
-                self.update()
-            }
+            self.refresh(with: Transaction(animation: .default))
         }
     }
 

Sources/PopoverTemplates.swift

@@ -568,7 +568,7 @@ public struct PopoverTemplates {
                         model.active = nil
                     }
             )
-            .onDataChange(of: model.selected) { _, _ in
+            .onValueChange(of: model.selected) { _, _ in
                 if
                     let selected = model.selected,
                     selected == menuID.id

Sources/PopoverUtilities.swift

@@ -42,8 +42,12 @@ public extension View {
         )
     }
 
-    /// Read a view's size. From https://stackoverflow.com/a/66822461/14351818
-    func sizeReader(size: @escaping (CGSize) -> Void) -> some View {
+    /**
+     Read a view's size. The closure is called whenever the size itself changes, or the transaction changes (in the event of a screen rotation.)
+
+     From https://stackoverflow.com/a/66822461/14351818
+     */
+    func sizeReader(transaction: Transaction?, size: @escaping (CGSize) -> Void) -> some View {
         return background(
             GeometryReader { geometry in
                 Color.clear
@@ -53,12 +57,24 @@ public extension View {
                             size(newValue)
                         }
                     }
+                    .onValueChange(of: transaction) { _, _ in
+                        DispatchQueue.main.async {
+                            size(geometry.size)
+                        }
+                    }
             }
             .hidden()
         )
     }
 }
 
+extension Transaction: Equatable {
+    public static func == (lhs: Transaction, rhs: Transaction) -> Bool {
+        lhs.animation == rhs.animation
+    }
+}
+
+
 struct ContentFrameReaderPreferenceKey: PreferenceKey {
     static var defaultValue: CGRect { return CGRect() }
     static func reduce(value: inout CGRect, nextValue: () -> CGRect) { value = nextValue() }
@@ -193,7 +209,7 @@ struct ChangeObserver<Content: View, Value: Equatable>: View {
 
 public extension View {
     /// Detect changes in bindings (fallback of `.onChange` for iOS 13+).
-    func onDataChange<Value: Equatable>(
+    func onValueChange<Value: Equatable>(
         of value: Value,
         perform action: @escaping (_ oldValue: Value, _ newValue: Value) -> Void
     ) -> some View {

Sources/SwiftUI/Modifiers.swift

@@ -70,7 +70,7 @@ struct PopoverModifier: ViewModifier {
                 }
 
                 /// Detect a state change in `$present`.
-                .onDataChange(of: present) { _, newValue in
+                .onValueChange(of: present) { _, newValue in
 
                     /// `newValue` is true, so present the popover.
                     if newValue {
@@ -179,7 +179,7 @@ struct MultiPopoverModifier: ViewModifier {
                 }
 
                 /// `$selection` was changed, determine if the popover should be presented, animated, or dismissed.
-                .onDataChange(of: selection) { oldSelection, newSelection in
+                .onValueChange(of: selection) { oldSelection, newSelection in
                     let model = window.popoverModel
 
                     /// Save the frame in `selectionFrameTags` to provide `excludedFrames`.