Fix layout issues in timeline poll cells (PSB-125)

Fixes: #5326 Signed-off-by: Johannes Marbach <johannesm@element.io>
element-hq · Jul 5, 2022 · 62033f0 · 62033f0
1 parent 67249ac
commit 62033f0
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Showing 3 changed files with 95 additions and 1 deletion.
diff --git a/Riot/Modules/Common/SwiftUI/VectorHostingController.swift b/Riot/Modules/Common/SwiftUI/VectorHostingController.swift
@@ -27,6 +27,16 @@ class VectorHostingController: UIHostingController<AnyView> {
 
     var isNavigationBarHidden: Bool = false
     var hidesBackTitleWhenPushed: Bool = false
+
+    var forceZeroSafeAreaInsets: Bool {
+        get {
+            self.view.forceZeroSafeAreaInsets
+        }
+        set {
+            self.view.forceZeroSafeAreaInsets = newValue
+        }
+    }
+
     private var theme: Theme
 
     // MARK: Public
@@ -43,6 +53,7 @@ class VectorHostingController: UIHostingController<AnyView> {
     init<Content>(rootView: Content) where Content: View {
         self.theme = ThemeService.shared().theme
         super.init(rootView: AnyView(rootView.vectorContent()))
+        self.view.swizzleSafeAreaMethodsIfNeeded()
     }
 
     required init?(coder aDecoder: NSCoder) {
@@ -103,3 +114,83 @@ class VectorHostingController: UIHostingController<AnyView> {
         }
     }
 }
+
+// Hack for forcing zero safe area insets on hosting views. This problem occurs when the hosting view is embedded
+// in a table view. See https://stackoverflow.com/questions/61552497 for further info.
+
+private var hasSwizzledSafeAreaMethods = false
+private var forceZeroSafeAreaInsetsKey: Void?
+
+private extension UIView {
+
+    var forceZeroSafeAreaInsets: Bool {
+        get {
+            return objc_getAssociatedObject(self, &forceZeroSafeAreaInsetsKey) as? Bool == true
+        }
+        set {
+            objc_setAssociatedObject(self, &forceZeroSafeAreaInsetsKey, newValue, .OBJC_ASSOCIATION_RETAIN)
+        }
+    }
+
+    @objc private var _safeAreaInsets: UIEdgeInsets {
+        return forceZeroSafeAreaInsets ? .zero : self._safeAreaInsets
+    }
+
+    @objc private var _safeAreaLayoutGuide: UILayoutGuide? {
+        return forceZeroSafeAreaInsets ? nil : self._safeAreaLayoutGuide
+    }
+
+    func swizzleSafeAreaMethodsIfNeeded() {
+        guard !hasSwizzledSafeAreaMethods else {
+            return
+        }
+        hasSwizzledSafeAreaMethods = true
+
+        guard let getSafeAreaInsets = class_getInstanceMethod(classForCoder.self, #selector(getter: UIView.safeAreaInsets)) else {
+            return
+        }
+
+        guard let _getSafeAreaInsets = class_getInstanceMethod(classForCoder.self, #selector(getter: UIView._safeAreaInsets)) else {
+            return
+        }
+
+        let getSafeAreaInsetsImplementation = method_getImplementation(getSafeAreaInsets)
+        let _getSafeAreaInsetsImplementation = method_getImplementation(_getSafeAreaInsets)
+
+        class_replaceMethod(
+            classForCoder,
+            #selector(getter: UIView.safeAreaInsets),
+            _getSafeAreaInsetsImplementation,
+            method_getTypeEncoding(getSafeAreaInsets))
+
+        class_replaceMethod(
+            classForCoder,
+            #selector(getter: UIView._safeAreaInsets),
+            getSafeAreaInsetsImplementation,
+            method_getTypeEncoding(_getSafeAreaInsets))
+
+        guard let getSafeAreaLayoutGuide = class_getInstanceMethod(classForCoder.self, #selector(getter: UIView.safeAreaLayoutGuide)) else {
+            return
+        }
+
+        guard let _getSafeAreaLayoutGuide = class_getInstanceMethod(classForCoder.self, #selector(getter: UIView._safeAreaLayoutGuide)) else {
+            return
+        }
+
+        let getSafeAreaLayoutGuideImplementation = method_getImplementation(getSafeAreaLayoutGuide)
+        let _getSafeAreaLayoutGuideImplementation = method_getImplementation(_getSafeAreaLayoutGuide)
+
+        class_replaceMethod(
+            classForCoder,
+            #selector(getter: UIView.safeAreaLayoutGuide),
+            _getSafeAreaLayoutGuideImplementation,
+            method_getTypeEncoding(getSafeAreaLayoutGuide))
+
+        class_replaceMethod(
+            classForCoder,
+            #selector(getter: UIView._safeAreaLayoutGuide),
+            getSafeAreaLayoutGuideImplementation,
+            method_getTypeEncoding(_getSafeAreaLayoutGuide))
+    }
+
+}
diff --git a/RiotSwiftUI/Modules/Room/TimelinePoll/Coordinator/TimelinePollCoordinator.swift b/RiotSwiftUI/Modules/Room/TimelinePoll/Coordinator/TimelinePollCoordinator.swift
@@ -86,7 +86,9 @@ final class TimelinePollCoordinator: Coordinator, Presentable, PollAggregatorDel
     }
 
     func toPresentable() -> UIViewController {
-        return VectorHostingController(rootView: TimelinePollView(viewModel: viewModel.context))
+        let controller = VectorHostingController(rootView: TimelinePollView(viewModel: viewModel.context))
+        controller.forceZeroSafeAreaInsets = true
+        return controller
     }
 
     func canEndPoll() -> Bool {

diff --git a/changelog.d/5326.bugfix b/changelog.d/5326.bugfix
@@ -0,0 +1 @@
+Fix layout issues in timeline poll cells (PSB-125)