Add codeSuggestionTriggerCharacters

Author: thecoolwinter

Sources/CodeEditSourceEditor/Controller/TextViewController+TextFormation.swift

@@ -24,6 +24,7 @@ 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.
@@ -120,4 +121,24 @@ 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.swift

@@ -85,6 +85,8 @@ public class TextViewController: NSViewController {
     /// The provided highlight provider.
     public var highlightProviders: [HighlightProviding]
 
+    public weak var completionDelegate: CodeSuggestionDelegate?
+
     // MARK: - Config Helpers
 
     /// The font to use in the `textView`

Sources/CodeEditSourceEditor/Filters/CodeSuggestionTriggerFilter.swift

@@ -0,0 +1,32 @@
+//
+//  CodeSuggestionTriggerFilter.swift
+//  CodeEditSourceEditor
+//
+//  Created by Khan Winter on 7/22/25.
+//
+
+import Foundation
+import TextFormation
+import TextStory
+
+struct CodeSuggestionTriggerFilter: Filter {
+    let triggerCharacters: Set<String>
+    let didTrigger: () -> Void
+
+    func processMutation(
+        _ mutation: TextMutation,
+        in interface: TextInterface,
+        with providers: WhitespaceProviders
+    ) -> FilterAction {
+        guard mutation.delta >= 0,
+              let lastChar = mutation.string.last else {
+            return .none
+        }
+
+        if triggerCharacters.contains(String(lastChar)) || lastChar.isNumber || lastChar.isLetter {
+            didTrigger()
+        }
+
+        return .none
+    }
+}

Sources/CodeEditSourceEditor/SourceEditorConfiguration/SourceEditorConfiguration+Peripherals.swift

@@ -28,20 +28,24 @@ extension SourceEditorConfiguration {
         /// non-standard quote character: `“ (0x201C)`.
         public var warningCharacters: Set<UInt16>
 
+        public var codeSuggestionTriggerCharacters: Set<String>
+
         public init(
             showGutter: Bool = true,
             showMinimap: Bool = true,
             showReformattingGuide: Bool = false,
             showFoldingRibbon: Bool = true,
             invisibleCharactersConfiguration: InvisibleCharactersConfiguration = .empty,
-            warningCharacters: Set<UInt16> = []
+            warningCharacters: Set<UInt16> = [],
+            codeSuggestionTriggerCharacters: Set<String> = []
         ) {
             self.showGutter = showGutter
             self.showMinimap = showMinimap
             self.showReformattingGuide = showReformattingGuide
             self.showFoldingRibbon = showFoldingRibbon
             self.invisibleCharactersConfiguration = invisibleCharactersConfiguration
             self.warningCharacters = warningCharacters
+            self.codeSuggestionTriggerCharacters = codeSuggestionTriggerCharacters
         }
 
         @MainActor
@@ -79,6 +83,10 @@ extension SourceEditorConfiguration {
                 controller.updateContentInsets()
                 controller.updateTextInsets()
             }
+
+            if oldConfig?.codeSuggestionTriggerCharacters != codeSuggestionTriggerCharacters {
+                controller.setUpTextFormation()
+            }
         }
     }
 }