From 8c4ef3caa6a53c49bd90e57fd7257d3327041e23 Mon Sep 17 00:00:00 2001
From: Shadowfacts <me@shadowfacts.net>
Date: Sat, 24 Oct 2020 11:19:35 -0400
Subject: [PATCH] Fix system autocomplete not working in Compose post body and
 CW

---
 .../Compose/ComposeContentWarningTextField.swift     |  4 ++++
 Tusker/Screens/Compose/MainComposeTextView.swift     | 12 ++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/Tusker/Screens/Compose/ComposeContentWarningTextField.swift b/Tusker/Screens/Compose/ComposeContentWarningTextField.swift
index 33f8b2b2..70059cee 100644
--- a/Tusker/Screens/Compose/ComposeContentWarningTextField.swift
+++ b/Tusker/Screens/Compose/ComposeContentWarningTextField.swift
@@ -58,6 +58,10 @@ struct ComposeContentWarningTextField: UIViewRepresentable {
         }
         
         func textFieldDidChangeSelection(_ textField: UITextField) {
+            // Update text binding before potentially triggering SwiftUI view update.
+            // See comment in MainComposeTextView.Coordinator.textViewDidChangeSelection
+            text.wrappedValue = textField.text ?? ""
+            
             updateAutocompleteState(textField: textField)
         }
         
diff --git a/Tusker/Screens/Compose/MainComposeTextView.swift b/Tusker/Screens/Compose/MainComposeTextView.swift
index d2b87e5d..2ac83120 100644
--- a/Tusker/Screens/Compose/MainComposeTextView.swift
+++ b/Tusker/Screens/Compose/MainComposeTextView.swift
@@ -144,6 +144,7 @@ struct MainComposeWrappedTextView: UIViewRepresentable {
     
     func updateUIView(_ uiView: UITextView, context: Context) {
         uiView.text = text
+        
         if let visibilityButton = visibilityButton {
             visibilityButton.image = UIImage(systemName: visibility.imageName)
             updateVisibilityMenu(visibilityButton)
@@ -227,6 +228,17 @@ struct MainComposeWrappedTextView: UIViewRepresentable {
         }
         
         func textViewDidChangeSelection(_ textView: UITextView) {
+            // Update the value of the text binding.
+            // Sometimes, when the user accepts an autocomplete suggestion from the system keyboard, the system
+            // calls didChangeSelection before textDidChange, resulting in a loop where the updating the Tusker autocomplete
+            // state in didChangeSection (via updateAutocompleteState) triggers a new SwiftUI view update,
+            // but when that SwiftUI update is handled, the model still has the old text (from prior to accepting the autocomplete
+            // suggestion), meaning the UITextView's text gets set back to whatever it was prior to the system autocomplete.
+            // To work around that, we also update the text binding in didChangeSelection, to ensure that, if the autocomplete state
+            // does change and trigger a SwiftUI update, the binding will have the correct text that was produced by the system
+            // autocompletion.
+            text.wrappedValue = textView.text ?? ""
+            
             updateAutocompleteState()
         }