From 37eca71e776fb4a23c047475fa27c3e750d02869 Mon Sep 17 00:00:00 2001
From: Igor Solomennikov <igor@signal.org>
Date: Tue, 8 Aug 2023 09:35:13 -0700
Subject: [PATCH] Fix tall images overlapping safe area.

---
 .../MediaItemViewController.swift             | 33 ++++++++++---------
 1 file changed, 18 insertions(+), 15 deletions(-)

diff --git a/Signal/src/ViewControllers/MediaGallery/MediaItemViewController.swift b/Signal/src/ViewControllers/MediaGallery/MediaItemViewController.swift
index 76158eac66..3d41ead816 100644
--- a/Signal/src/ViewControllers/MediaGallery/MediaItemViewController.swift
+++ b/Signal/src/ViewControllers/MediaGallery/MediaItemViewController.swift
@@ -4,6 +4,7 @@
 //
 
 import CoreMedia
+import SignalMessaging
 import SignalServiceKit
 import SignalUI
 import YYImage
@@ -40,7 +41,7 @@ class MediaItemViewController: OWSViewController, VideoPlaybackStatusProvider {
 
     // MARK: - Layout
 
-    private var lastKnownScrollViewWidth: CGFloat = 0
+    private var lastKnownScrollViewSafeAreaSize: CGSize = .zero
     private lazy var scrollView: UIScrollView = {
         let scrollView = UIScrollView(frame: view.bounds)
         scrollView.delegate = self
@@ -89,7 +90,7 @@ class MediaItemViewController: OWSViewController, VideoPlaybackStatusProvider {
             mediaSize = .zero
         }
 
-        let scrollViewSize = scrollView.bounds.size
+        let scrollViewSize = scrollView.safeAreaLayoutGuide.layoutFrame.size
 
         guard mediaSize.isNonEmpty && scrollViewSize.isNonEmpty else {
             // Invalid content or view state.
@@ -108,8 +109,8 @@ class MediaItemViewController: OWSViewController, VideoPlaybackStatusProvider {
 
         // Center the media view in the scroll view.
         let mediaViewSize = mediaView.frame.size
-        let yOffset = max(0, (scrollViewSize.height - mediaViewSize.height) / 2)
-        let xOffset = max(0, (scrollViewSize.width - mediaViewSize.width) / 2)
+        let yOffset = max(0, (scrollView.bounds.height - mediaViewSize.height) / 2)
+        let xOffset = max(0, (scrollView.bounds.width - mediaViewSize.width) / 2)
         mediaViewTopConstraint?.constant = yOffset
         mediaViewBottomConstraint?.constant = yOffset
         mediaViewLeadingConstraint?.constant = xOffset
@@ -131,6 +132,17 @@ class MediaItemViewController: OWSViewController, VideoPlaybackStatusProvider {
         }
     }
 
+    private func resetScrollViewZoomIfNecessary() {
+        // In iOS multi-tasking, the size of root view (and hence the scroll view)
+        // is set later, after viewWillAppear, etc.  Therefore we need to reset the
+        // zoomScale to the default whenever the scrollView width changes.
+        let currentScrollViewSize = scrollView.safeAreaLayoutGuide.layoutFrame.size
+        if !(currentScrollViewSize - lastKnownScrollViewSafeAreaSize).asPoint.fuzzyEquals(.zero, tolerance: 0.001) {
+            scrollView.zoomScale = scrollView.minimumZoomScale
+        }
+        lastKnownScrollViewSafeAreaSize = currentScrollViewSize
+    }
+
     func zoomOut(animated: Bool) {
         guard scrollView.zoomScale != scrollView.minimumZoomScale else { return }
         scrollView.setZoomScale(scrollView.minimumZoomScale, animated: animated)
@@ -311,17 +323,8 @@ class MediaItemViewController: OWSViewController, VideoPlaybackStatusProvider {
         super.viewDidLayoutSubviews()
 
         updateZoomScaleAndConstraints()
-
-        // In iOS multi-tasking, the size of root view (and hence the scroll view)
-        // is set later, after viewWillAppear, etc.  Therefore we need to reset the
-        // zoomScale to the default whenever the scrollView width changes.
-        let tolerance: CGFloat = 0.001
-        let currentScrollViewWidth = scrollView.frame.width
-        if abs(lastKnownScrollViewWidth - currentScrollViewWidth) > tolerance {
-            scrollView.zoomScale = scrollView.minimumZoomScale
-        }
-        lastKnownScrollViewWidth = currentScrollViewWidth
-    }
+        resetScrollViewZoomIfNecessary()
+   }
 
     // MARK: - Helpers