Centralize Suggestion Updates

Author: thecoolwinter

Example/CodeEditSourceEditorExample/CodeEditSourceEditorExample.xcodeproj/project.xcworkspace/xcshareddata/swiftpm/Package.resolved

@@ -0,0 +1,70 @@
+//
+//  SuggestionTriggerCharacterModel.swift
+//  CodeEditSourceEditor
+//
+//  Created by Khan Winter on 8/25/25.
+//
+
+import AppKit
+import CodeEditTextView
+import TextStory
+
+/// Triggers the suggestion window when trigger characters are typed.
+/// Designed to be called in the ``TextViewDelegate``'s didReplaceCharacters method.
+///
+/// Was originally a `TextFilter` model, however those are called before text is changed and cursors are updated.
+/// The suggestion model expects up-to-date cursor positions as well as complete text contents. This being
+/// essentially a textview delegate ensures both of those promises are upheld.
+final class SuggestionTriggerCharacterModel {
+    weak var controller: TextViewController?
+    private var lastPosition: NSRange?
+
+    var triggerCharacters: Set<String>? {
+        controller?.configuration.peripherals.codeSuggestionTriggerCharacters
+    }
+
+    func textView(_ textView: TextView, didReplaceContentsIn range: NSRange, with string: String) {
+        guard let controller, let completionDelegate = controller.completionDelegate, let triggerCharacters else {
+            return
+        }
+
+        let mutation = TextMutation(
+            string: string,
+            range: range,
+            limit: textView.textStorage.length
+        )
+        guard mutation.delta >= 0,
+              let lastChar = mutation.string.last else {
+            lastPosition = nil
+            return
+        }
+
+        guard triggerCharacters.contains(String(lastChar)) || lastChar.isNumber || lastChar.isLetter else {
+            lastPosition = nil
+            return
+        }
+
+        let range = NSRange(location: mutation.postApplyRange.max, length: 0)
+        lastPosition = range
+        SuggestionController.shared.cursorsUpdated(
+            textView: controller,
+            delegate: completionDelegate,
+            position: CursorPosition(range: range),
+            presentIfNot: true
+        )
+    }
+
+    func selectionUpdated(_ position: CursorPosition) {
+        guard let controller, let completionDelegate = controller.completionDelegate else {
+            return
+        }
+
+        if lastPosition != position.range {
+            SuggestionController.shared.cursorsUpdated(
+                textView: controller,
+                delegate: completionDelegate,
+                position: position
+            )
+        }
+    }
+}

Sources/CodeEditSourceEditor/CodeSuggestion/Model/SuggestionTriggerCharacterModel.swift

@@ -16,6 +16,7 @@ final class SuggestionViewModel: ObservableObject {
 
     weak var delegate: CodeSuggestionDelegate?
 
+    private var cursorPosition: CursorPosition?
     private var syntaxHighlightedCache: [Int: NSAttributedString] = [:]
 
     func showCompletions(

Sources/CodeEditSourceEditor/CodeSuggestion/Model/SuggestionViewModel.swift

@@ -82,8 +82,8 @@ extension TextViewController {
         }
         isPostingCursorNotification = false
 
-        if let completionDelegate = completionDelegate, let position = cursorPositions.first {
-            SuggestionController.shared.cursorsUpdated(textView: self, delegate: completionDelegate, position: position)
+        if let position = cursorPositions.first {
+            suggestionTriggerModel.selectionUpdated(position)
         }
     }
 

Sources/CodeEditSourceEditor/Controller/TextViewController+Cursor.swift

@@ -24,7 +24,6 @@ extension TextViewController {
         setUpNewlineTabFilters(indentOption: configuration.behavior.indentOption)
         setUpDeletePairFilters(pairs: BracketPairs.allValues)
         setUpDeleteWhitespaceFilter(indentOption: configuration.behavior.indentOption)
-        setUpSuggestionsFilter()
     }
 
     /// Returns a `TextualIndenter` based on available language configuration.
@@ -121,24 +120,4 @@ extension TextViewController {
 
         return true
     }
-
-    func setUpSuggestionsFilter() {
-        textFilters.append(
-            CodeSuggestionTriggerFilter(
-                triggerCharacters: configuration.peripherals.codeSuggestionTriggerCharacters,
-                didTrigger: { [weak self] in
-                    guard let self else { return }
-                    if let completionDelegate = self.completionDelegate,
-                       let position = self.cursorPositions.first {
-                        SuggestionController.shared.cursorsUpdated(
-                            textView: self,
-                            delegate: completionDelegate,
-                            position: position,
-                            presentIfNot: true
-                        )
-                    }
-                }
-            )
-        )
-    }
 }

Sources/CodeEditSourceEditor/Controller/TextViewController+TextFormation.swift

@@ -27,6 +27,8 @@ extension TextViewController: TextViewDelegate {
                 coordinator.textViewDidChangeText(controller: self)
             }
         }
+
+        suggestionTriggerModel.textView(textView, didReplaceContentsIn: range, with: string)
     }
 
     public func textView(_ textView: TextView, shouldReplaceContentsIn range: NSRange, with string: String) -> Bool {

Sources/CodeEditSourceEditor/Controller/TextViewController+TextViewDelegate.swift

@@ -51,6 +51,8 @@ public class TextViewController: NSViewController {
     /// A default `NSParagraphStyle` with a set `lineHeight`
     lazy var paragraphStyle: NSMutableParagraphStyle = generateParagraphStyle()
 
+    var suggestionTriggerModel = SuggestionTriggerCharacterModel()
+
     // MARK: - Public Variables
 
     /// Passthrough value for the `textView`s string
@@ -224,6 +226,8 @@ public class TextViewController: NSViewController {
 
         super.init(nibName: nil, bundle: nil)
 
+        suggestionTriggerModel.controller = self
+
         if let idx = highlightProviders.firstIndex(where: { $0 is TreeSitterClient }),
            let client = highlightProviders[idx] as? TreeSitterClient {
             self.treeSitterClient = client