Highlight focused view

Signal/src/ViewControllers/ConversationView/ConversationViewController.m

@@ -1982,7 +1982,8 @@ typedef enum : NSUInteger {
 
 - (void)conversationCellDidLongpressText:(ConversationViewCell *)cell viewItem:(ConversationViewItem *)viewItem
 {
-    MessageActionsViewController *messageActionsViewController = [MessageActionsViewController new];
+    MessageActionsViewController *messageActionsViewController =
+        [[MessageActionsViewController alloc] initWithFocusedView:cell];
     [[OWSWindowManager sharedManager] presentMessageActions:messageActionsViewController];
 }
 

SignalMessaging/ViewControllers/MessageActionsViewController.swift

@@ -10,14 +10,45 @@ class MessageActionsViewController: UIViewController {
     @objc
     weak var delegate: MessageActionsDelegate?
 
+    let focusedView: UIView
+
+    @objc
+    required init(focusedView: UIView) {
+        self.focusedView = focusedView
+
+        super.init(nibName: nil, bundle: nil)
+    }
+
+    required init?(coder aDecoder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+
     override func loadView() {
         self.view = UIView()
-        view.backgroundColor = .purple
+        view.backgroundColor = UIColor.black.withAlphaComponent(0.4)
+
+        highlightFocusedView()
 
         let tapGesture = UITapGestureRecognizer(target: self, action: #selector(didTapBackground))
         self.view.addGestureRecognizer(tapGesture)
     }
 
+    private func highlightFocusedView() {
+        guard let snapshotView = self.focusedView.snapshotView(afterScreenUpdates: false) else {
+            owsFail("\(self.logTag) in \(#function) snapshotView was unexpectedly nil")
+            return
+        }
+        view.addSubview(snapshotView)
+
+        guard let focusedViewSuperview = focusedView.superview else {
+            owsFail("\(self.logTag) in \(#function) focusedViewSuperview was unexpectedly nil")
+            return
+        }
+
+        let convertedFrame = view.convert(focusedView.frame, from: focusedViewSuperview)
+        snapshotView.frame = convertedFrame
+    }
+
     @objc
     func didTapBackground() {
         self.delegate?.dismissMessageActions(self)