Inset gallery content to safe area when editing attachment description

Packages/ComposeUI/Sources/ComposeUI/Views/Attachments/AttachmentWrapperGalleryContentViewController.swift

@@ -44,6 +44,10 @@ class AttachmentWrapperGalleryContentViewController: UIViewController, GalleryCo
         false
     }
     
+    var showBelowSafeArea: Bool {
+        false
+    }
+    
     init(draftAttachment: DraftAttachment, wrapped: any GalleryContentViewController) {
         self.draftAttachment = draftAttachment
         self.wrapped = wrapped
@@ -76,16 +80,6 @@ class AttachmentWrapperGalleryContentViewController: UIViewController, GalleryCo
         if !visible {
             editDescriptionViewController.textView?.resignFirstResponder()
         }
-        if #available(iOS 16.0, macCatalyst 17.0, *),
-           let wrapped = wrapped as? ImageGalleryContentViewController,
-           let interaction = wrapped.analysisInteraction {
-            if visible {
-                let bottom = editDescriptionViewController.view.bounds.height - editDescriptionViewController.view.keyboardLayoutGuide.layoutFrame.height
-                interaction.supplementaryInterfaceContentInsets = UIEdgeInsets(top: 0, left: 0, bottom: bottom, right: 0)
-            } else {
-                interaction.supplementaryInterfaceContentInsets = .zero
-            }
-        }
     }
     
     func galleryContentDidAppear() {
@@ -155,7 +149,9 @@ private class EditAttachmentDescriptionViewController: UIViewController {
         ])
 
         if let wrapped {
+            addChild(wrapped)
             stack.addArrangedSubview(wrapped.view)
+            wrapped.didMove(toParent: self)
         }
         
         textView = UITextView()

Packages/GalleryVC/Sources/GalleryVC/Content/ImageGalleryContentViewController.swift

@@ -25,7 +25,7 @@ open class ImageGalleryContentViewController: UIViewController, GalleryContentVi
     private static let analyzer = ImageAnalyzer()
     private var _analysisInteraction: AnyObject?
     @available(iOS 16.0, macCatalyst 17.0, *)
-    public var analysisInteraction: ImageAnalysisInteraction? { _analysisInteraction as? ImageAnalysisInteraction }
+    private var analysisInteraction: ImageAnalysisInteraction? { _analysisInteraction as? ImageAnalysisInteraction }
     
     public init(image: UIImage, caption: String?, gifController: GIFController?) {
         self.caption = caption

Packages/GalleryVC/Sources/GalleryVC/GalleryContentViewController.swift

@@ -18,6 +18,7 @@ public protocol GalleryContentViewController: UIViewController {
     var insetBottomControlsAccessoryViewControllerToSafeArea: Bool { get }
     var presentationAnimation: GalleryContentPresentationAnimation { get }
     var hideControlsOnZoom: Bool { get }
+    var showBelowSafeArea: Bool { get }
     
     func shouldHideControls() -> Bool
     func setControlsVisible(_ visible: Bool, animated: Bool, dueToUserInteraction: Bool)
@@ -47,6 +48,10 @@ public extension GalleryContentViewController {
         true
     }
     
+    var showBelowSafeArea: Bool {
+        true
+    }
+    
     func shouldHideControls() -> Bool {
         true
     }

Packages/GalleryVC/Sources/GalleryVC/GalleryItemViewController.swift

@@ -45,6 +45,7 @@ class GalleryItemViewController: UIViewController {
     private(set) var scrollAndZoomEnabled = true
     
     private var scrollViewSizeForLastZoomScaleUpdate: CGSize?
+    private var skipScrollViewZoomUpdate = false
     
     var showShareButton: Bool = true {
         didSet {
@@ -83,6 +84,7 @@ class GalleryItemViewController: UIViewController {
         // We calculate zoom/position ignoring the safe area, so content insets need to not incorporate it either.
         // Otherwise, content that fills the screen (extending into the safe area) may still end up scrollable
         // (this is readily observable with tall images on a landscape iPad).
+        // Even if the content is not being shown below the safe area, we still set this to make the calculations more consistent/straightforward.
         scrollView.contentInsetAdjustmentBehavior = .never
         
         view.addSubview(scrollView)
@@ -229,19 +231,16 @@ class GalleryItemViewController: UIViewController {
         NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillUpdate), name: UIResponder.keyboardWillHideNotification, object: nil)
         NotificationCenter.default.addObserver(self, selector: #selector(keyboardWillUpdate), name: UIResponder.keyboardWillChangeFrameNotification, object: nil)
         
-        if #available(iOS 17.0, *) {
-            view.keyboardLayoutGuide.usesBottomSafeArea = false
-        }
     }
     
     @objc private func keyboardWillUpdate() {
-        updateZoomScale(resetZoom: true)
+        updateScrollView(resetZoom: true)
     }
     
     override func viewSafeAreaInsetsDidChange() {
         super.viewSafeAreaInsetsDidChange()
         
-        updateZoomScale(resetZoom: false)
+        updateScrollView(resetZoom: false)
         // Ensure the transform is correct if the controls are hidden
         setControlsVisible(controlsVisible, animated: false, dueToUserInteraction: false)
         
@@ -255,7 +254,7 @@ class GalleryItemViewController: UIViewController {
         // This might also fix an issue on macOS (Designed for iPad) where the content isn't placed correctly. See #446
         if scrollViewSizeForLastZoomScaleUpdate != scrollView.bounds.size {
             scrollViewSizeForLastZoomScaleUpdate = scrollView.bounds.size
-            updateZoomScale(resetZoom: true)
+            updateScrollView(resetZoom: true)
         }
         centerContent()
         // Ensure the transform is correct if the controls are hidden and their size changed.
@@ -293,7 +292,7 @@ class GalleryItemViewController: UIViewController {
             contentViewLeadingConstraint!.isActive = true
             contentViewTopConstraint = content.view.topAnchor.constraint(equalTo: scrollView.topAnchor)
             contentViewTopConstraint!.isActive = true
-            updateZoomScale(resetZoom: true)
+            updateScrollView(resetZoom: true)
         } else {
             // If the content was previously added, deactivate the old constraints.
             contentViewLeadingConstraint?.isActive = false
@@ -332,6 +331,13 @@ class GalleryItemViewController: UIViewController {
             topControlsView.transform = CGAffineTransform(translationX: 0, y: visible ? 0 : -topControlsView.bounds.height)
             bottomControlsView.transform = CGAffineTransform(translationX: 0, y: visible ? 0 : bottomControlsView.bounds.height)
             content.setControlsVisible(visible, animated: animated, dueToUserInteraction: dueToUserInteraction)
+            
+            if !content.showBelowSafeArea {
+                skipScrollViewZoomUpdate = true
+                updateScrollView(resetZoom: abs(scrollView.zoomScale - scrollView.minimumZoomScale) < 0.01)
+                skipScrollViewZoomUpdate = false
+                scrollView.layoutIfNeeded()
+            }
         }
         if animated {
             let animator = UIViewPropertyAnimator(duration: 0.2, timingParameters: UISpringTimingParameters())
@@ -344,7 +350,7 @@ class GalleryItemViewController: UIViewController {
         setNeedsUpdateOfHomeIndicatorAutoHidden()
     }
     
-    func updateZoomScale(resetZoom: Bool) {
+    func updateScrollView(resetZoom: Bool) {
         scrollView.contentSize = content.contentSize
         
         guard scrollAndZoomEnabled else {
@@ -358,17 +364,7 @@ class GalleryItemViewController: UIViewController {
             return
         }
         
-        // Post-iOS 17, we can ask the keyboard layout guide to ignore the bottom safe area.
+        let heightScale = availableHeightForContent() / content.contentSize.height
-        // Pre, we have to do that ourselves.
-        let keyboardHeight: CGFloat
-        if #available(iOS 17.0, *) {
-            keyboardHeight = view.keyboardLayoutGuide.layoutFrame.height
-        } else {
-            let bottomSafeArea = view.bounds.height - view.safeAreaLayoutGuide.layoutFrame.maxY
-            let rawKeyboardHeight = view.keyboardLayoutGuide.layoutFrame.height
-            keyboardHeight = abs(rawKeyboardHeight - bottomSafeArea) < 1 ? 0 : rawKeyboardHeight
-        }
-        let heightScale = (view.bounds.height - keyboardHeight) / content.contentSize.height
         let widthScale = view.bounds.width / content.contentSize.width
         let minScale = min(widthScale, heightScale)
         let maxScale = minScale >= 1 ? minScale + 2 : 2
@@ -381,6 +377,20 @@ class GalleryItemViewController: UIViewController {
             scrollView.zoomScale = max(minScale, min(maxScale, scrollView.zoomScale))
         }
         
+        let bottomInset: CGFloat
+        let bottomIndicatorInset: CGFloat
+        if !content.showBelowSafeArea,
+           controlsVisible,
+           let bottomControlsView {
+            bottomInset = bottomControlsView.bounds.height + view.safeAreaInsets.top
+            bottomIndicatorInset = bottomControlsView.safeAreaLayoutGuide.layoutFrame.height
+        } else {
+            bottomInset = 0
+            bottomIndicatorInset = 0
+        }
+        scrollView.contentInset = UIEdgeInsets(top: 0, left: 0, bottom: bottomInset, right: 0)
+        scrollView.verticalScrollIndicatorInsets = UIEdgeInsets(top: 0, left: 0, bottom: bottomIndicatorInset, right: 0)
+        
         centerContent()
     }
     
@@ -389,15 +399,29 @@ class GalleryItemViewController: UIViewController {
             return
         }
         
+        let additionalYOffset = content.showBelowSafeArea ? 0 : view.safeAreaInsets.top
         // Note: use frame for the content.view, because that's in the coordinate space of the scroll view
         // which means it's already been scaled by the zoom factor.
-        let yOffset = max(0, (view.bounds.height - view.keyboardLayoutGuide.layoutFrame.height - content.view.frame.height) / 2)
+        let yOffset = max(0, (availableHeightForContent() - content.view.frame.height) / 2)
-        contentViewTopConstraint!.constant = yOffset
+        contentViewTopConstraint!.constant = yOffset + additionalYOffset
         
         let xOffset = max(0, (view.bounds.width - content.view.frame.width) / 2)
         contentViewLeadingConstraint!.constant = xOffset
     }
     
+    private func availableHeightForContent() -> CGFloat {
+        var availableHeight: CGFloat
+        if content.showBelowSafeArea {
+            availableHeight = view.bounds.height
+        } else {
+            availableHeight = view.safeAreaLayoutGuide.layoutFrame.height
+            if controlsVisible {
+                availableHeight -= bottomControlsView?.safeAreaLayoutGuide.layoutFrame.height ?? 0
+            }
+        }
+        return availableHeight
+    }
+    
     private func updateShareButton() {
         shareButton.isEnabled = !content.activityItemsForSharing.isEmpty
     }
@@ -580,14 +604,14 @@ extension GalleryItemViewController: GalleryContentViewControllerContainer {
     }
     
     func galleryContentChanged() {
-        updateZoomScale(resetZoom: true)
+        updateScrollView(resetZoom: true)
         updateShareButton()
         updateCaptionTextView()
     }
     
     func disableGalleryScrollAndZoom() {
         scrollAndZoomEnabled = false
-        updateZoomScale(resetZoom: true)
+        updateScrollView(resetZoom: true)
         scrollView.isScrollEnabled = false
         // Make sure the content is re-added with the correct constraints
         if content.parent == self {
@@ -610,6 +634,10 @@ extension GalleryItemViewController: UIScrollViewDelegate {
     }
     
     func scrollViewDidZoom(_ scrollView: UIScrollView) {
+        guard !skipScrollViewZoomUpdate else {
+            return
+        }
+
         if scrollView.zoomScale <= scrollView.minimumZoomScale {
             setControlsVisible(true, animated: true, dueToUserInteraction: true)
         } else {

Packages/GalleryVC/Sources/GalleryVC/GalleryPresentationAnimationController.swift

@@ -56,7 +56,7 @@ class GalleryPresentationAnimationController: NSObject, UIViewControllerAnimated
         
         container.layoutIfNeeded()
         // Make sure the zoom scale is updated before getting the content view frame, since it needs to take into account the correct transform.
-        itemViewController.updateZoomScale(resetZoom: true)
+        itemViewController.updateScrollView(resetZoom: true)
         
         let sourceFrameInContainer = container.convert(sourceView.bounds, from: sourceView)
         let destFrameInContainer = container.convert(itemViewController.content.view.bounds, from: itemViewController.content.view)