From 58c6d508ecea6bb32105b52ff97f2706cb0d0e3a Mon Sep 17 00:00:00 2001
From: Shadowfacts <me@shadowfacts.net>
Date: Mon, 12 Oct 2020 19:39:50 -0400
Subject: [PATCH] Prevent caret from changing position on auto complete

---
 Tusker/Screens/Compose/ComposeContentWarningTextField.swift | 6 ++++++
 Tusker/Screens/Compose/MainComposeTextView.swift            | 5 +++++
 2 files changed, 11 insertions(+)

diff --git a/Tusker/Screens/Compose/ComposeContentWarningTextField.swift b/Tusker/Screens/Compose/ComposeContentWarningTextField.swift
index 6148e3e3ad..72cf26aa12 100644
--- a/Tusker/Screens/Compose/ComposeContentWarningTextField.swift
+++ b/Tusker/Screens/Compose/ComposeContentWarningTextField.swift
@@ -70,11 +70,17 @@ struct ComposeContentWarningTextField: UIViewRepresentable {
                 return
             }
             
+            let distanceToEnd = textField.offset(from: selectedRange.start, to: textField.endOfDocument)
+            
             let selectedRangeStartUTF16 = textField.offset(from: textField.beginningOfDocument, to: selectedRange.start)
             let characterBeforeCursorIndex = text.utf16.index(text.startIndex, offsetBy: selectedRangeStartUTF16)
             
             textField.text!.replaceSubrange(lastWordStartIndex..<characterBeforeCursorIndex, with: string)
             didChange(textField)
+            
+            // keep the cursor at the same position in the text, immediately after what was inserted
+            let newCursorPosition = textField.position(from: textField.endOfDocument, offset: -distanceToEnd)!
+            textField.selectedTextRange = textField.textRange(from: newCursorPosition, to: newCursorPosition)
         }
         
         private func updateAutocompleteState(textField: UITextField) {
diff --git a/Tusker/Screens/Compose/MainComposeTextView.swift b/Tusker/Screens/Compose/MainComposeTextView.swift
index a893455f83..a499680dc6 100644
--- a/Tusker/Screens/Compose/MainComposeTextView.swift
+++ b/Tusker/Screens/Compose/MainComposeTextView.swift
@@ -239,10 +239,15 @@ struct MainComposeWrappedTextView: UIViewRepresentable {
                 return
             }
             
+            let distanceToEnd = text.utf16.count - textView.selectedRange.upperBound
+            
             let characterBeforeCursorIndex = text.utf16.index(text.startIndex, offsetBy: textView.selectedRange.upperBound)
             
             textView.text.replaceSubrange(lastWordStartIndex..<characterBeforeCursorIndex, with: string)
             self.textViewDidChange(textView)
+            
+            // keep the cursor at the same position in the text, immediately after what was inserted
+            textView.selectedRange = NSRange(location: textView.text.utf16.count - distanceToEnd, length: 0)
         }
         
         private func updateAutocompleteState() {