Minor improvements based on feedback at PR#231

Author: DzmitrySalauyeuAnadea

lib/src/code_field/actions/tab.dart

@@ -0,0 +1,21 @@
+import 'package:flutter/material.dart';
+
+import '../code_controller.dart';
+
+class TabKeyIntent extends Intent {
+  const TabKeyIntent();
+}
+
+class TabKeyAction extends Action<TabKeyIntent> {
+  final CodeController controller;
+
+  TabKeyAction({
+    required this.controller,
+  });
+
+  @override
+  Object? invoke(TabKeyIntent intent) {
+    controller.onTabKeyAction();
+    return null;
+  }
+}

lib/src/code_field/code_controller.dart

@@ -11,15 +11,16 @@ import 'package:meta/meta.dart';
 import '../../flutter_code_editor.dart';
 import '../autocomplete/autocompleter.dart';
 import '../code/code_edit_result.dart';
-import '../code_modifiers/insertion.dart';
 import '../code/key_event.dart';
+import '../code_modifiers/insertion.dart';
 import '../history/code_history_controller.dart';
 import '../history/code_history_record.dart';
 import '../search/controller.dart';
 import '../search/result.dart';
 import '../search/search_navigation_controller.dart';
 import '../search/settings_controller.dart';
 import '../single_line_comments/parser/single_line_comments.dart';
+import '../util/string_util.dart';
 import '../wip/autocomplete/popup_controller.dart';
 import 'actions/comment_uncomment.dart';
 import 'actions/copy.dart';
@@ -29,6 +30,7 @@ import 'actions/indent.dart';
 import 'actions/outdent.dart';
 import 'actions/redo.dart';
 import 'actions/search.dart';
+import 'actions/tab.dart';
 import 'actions/undo.dart';
 import 'search_result_highlighted_builder.dart';
 import 'span_builder.dart';
@@ -51,6 +53,7 @@ class CodeController extends TextEditingController {
   /// Calls [AbstractAnalyzer.analyze] after change with 500ms debounce.
   AbstractAnalyzer get analyzer => _analyzer;
   AbstractAnalyzer _analyzer;
+
   set analyzer(AbstractAnalyzer analyzer) {
     if (_analyzer == analyzer) {
       return;
@@ -108,6 +111,7 @@ class CodeController extends TextEditingController {
 
   SearchSettingsController get _searchSettingsController =>
       searchController.settingsController;
+
   SearchNavigationController get _searchNavigationController =>
       searchController.navigationController;
 
@@ -131,19 +135,20 @@ class CodeController extends TextEditingController {
     SearchIntent: SearchAction(controller: this),
     DismissIntent: CustomDismissAction(controller: this),
     EnterKeyIntent: EnterKeyAction(controller: this),
+    TabKeyIntent: TabKeyAction(controller: this),
   };
 
   static const defaultCodeModifiers = [
-      IndentModifier(),
-      CloseBlockModifier(),
-      TabModifier(),
-      InsertionCodeModifier.backticks,
-      InsertionCodeModifier.braces,
-      InsertionCodeModifier.brackets,
-      InsertionCodeModifier.doubleQuotes,
-      InsertionCodeModifier.parentheses,
-      InsertionCodeModifier.singleQuotes,
-    ];
+    IndentModifier(),
+    CloseBlockModifier(),
+    TabModifier(),
+    InsertionCodeModifier.backticks,
+    InsertionCodeModifier.braces,
+    InsertionCodeModifier.brackets,
+    InsertionCodeModifier.doubleQuotes,
+    InsertionCodeModifier.parentheses,
+    InsertionCodeModifier.singleQuotes,
+  ];
 
   CodeController({
     String? text,
@@ -356,30 +361,60 @@ class CodeController extends TextEditingController {
     insertStr('\n');
   }
 
+  void onTabKeyAction() {
+    if (popupController.shouldShow) {
+      insertSelectedWord();
+      return;
+    }
+
+    insertStr(' ' * params.tabSpaces);
+  }
+
   /// Inserts the word selected from the list of completions
   void insertSelectedWord() {
     final previousSelection = selection;
     final selectedWord = popupController.getSelectedWord();
     final startPosition = value.wordAtCursorStart;
+    final currentWord = value.wordAtCursor;
 
-    if (startPosition != null) {
-      final replacedText = text.replaceRange(
-        startPosition,
-        selection.baseOffset,
-        selectedWord,
-      );
+    if (startPosition == null || currentWord == null) {
+      popupController.hide();
+      return;
+    }
 
-      final adjustedSelection = previousSelection.copyWith(
-        baseOffset: startPosition + selectedWord.length,
-        extentOffset: startPosition + selectedWord.length,
-      );
+    final endReplacingPosition = startPosition + currentWord.length;
+    final endSelectionPosition = startPosition + selectedWord.length;
 
-      value = TextEditingValue(
-        text: replacedText,
-        selection: adjustedSelection,
-      );
+    var additionalSpaceIfEnd = '';
+    var offsetIfEndsWithSpace = 1;
+    if (text.length < endReplacingPosition + 1) {
+      additionalSpaceIfEnd = ' ';
+    } else {
+      final charAfterText = text[endReplacingPosition];
+      if (charAfterText != ' ' &&
+          !StringUtil.isDigit(charAfterText) &&
+          !StringUtil.isLetterEng(charAfterText)) {
+        // ex. case ';' or other finalizer, or symbol
+        offsetIfEndsWithSpace = 0;
+      }
     }
 
+    final replacedText = text.replaceRange(
+      startPosition,
+      endReplacingPosition,
+      '$selectedWord$additionalSpaceIfEnd',
+    );
+
+    final adjustedSelection = previousSelection.copyWith(
+      baseOffset: endSelectionPosition + offsetIfEndsWithSpace,
+      extentOffset: endSelectionPosition + offsetIfEndsWithSpace,
+    );
+
+    value = TextEditingValue(
+      text: replacedText,
+      selection: adjustedSelection,
+    );
+
     popupController.hide();
   }
 

lib/src/code_field/code_field.dart

@@ -15,6 +15,7 @@ import 'actions/enter_key.dart';
 import 'actions/indent.dart';
 import 'actions/outdent.dart';
 import 'actions/search.dart';
+import 'actions/tab.dart';
 import 'code_controller.dart';
 import 'default_styles.dart';
 import 'js_workarounds/js_workarounds.dart';
@@ -110,6 +111,11 @@ final _shortcuts = <ShortcutActivator, Intent>{
   LogicalKeySet(
     LogicalKeyboardKey.enter,
   ): const EnterKeyIntent(),
+
+  // TabKey
+  LogicalKeySet(
+    LogicalKeyboardKey.tab,
+  ): const TabKeyIntent(),
 };
 
 class CodeField extends StatefulWidget {

lib/src/code_modifiers/close_block_code_modifier.dart

@@ -5,7 +5,7 @@ import 'package:flutter/widgets.dart';
 import '../code_field/editor_params.dart';
 import 'code_modifier.dart';
 
-/// [CloseBlockModifier] is an implementation of [CodeModifier] 
+/// [CloseBlockModifier] is an implementation of [CodeModifier]
 /// that remove spaces before the closing bracket, if required.
 class CloseBlockModifier extends CodeModifier {
   const CloseBlockModifier() : super('}');

lib/src/code_modifiers/code_modifier.dart

@@ -7,7 +7,7 @@ abstract class CodeModifier {
 
   const CodeModifier(this.char);
 
-  // Helper to insert [str] in [text] between [start] and [end]
+  /// Helper to insert [str] in [text] between [start] and [end]
   TextEditingValue replace(String text, int start, int end, String str) {
     final len = str.length;
     return TextEditingValue(

lib/src/util/string_util.dart

@@ -0,0 +1,14 @@
+class StringUtil {
+  static bool isDigit(String char) {
+    if (char.isEmpty || char.length > 1) return false;
+    final codeUnit = char.codeUnitAt(0);
+    return codeUnit >= 48 && codeUnit <= 57; // Unicode range for '0' to '9'
+  }
+
+  static bool isLetterEng(String char) {
+    if (char.isEmpty || char.length > 1) return false;
+    final codeUnit = char.codeUnitAt(0);
+    return (codeUnit >= 65 && codeUnit <= 90) || // A-Z
+        (codeUnit >= 97 && codeUnit <= 122); // a-z
+  }
+}

lib/src/wip/autocomplete/popup.dart

@@ -45,9 +45,9 @@ class Popup extends StatefulWidget {
 
 class PopupState extends State<Popup> {
   final pageStorageBucket = PageStorageBucket();
+
   @override
   void initState() {
-    widget.controller.reset();
     widget.controller.addListener(rebuild);
     super.initState();
   }
@@ -69,6 +69,13 @@ class PopupState extends State<Popup> {
             (widget.editorOffset?.dx ?? 0) -
             100;
 
+    // Fixes assertion error when ISC isn't attached but _attach method
+    // of ISC instance are being called
+    ItemScrollController? isc;
+    if (widget.controller.itemScrollController.isAttached) {
+      isc = widget.controller.itemScrollController;
+    }
+
     return PageStorage(
       bucket: pageStorageBucket,
       child: Positioned(
@@ -98,7 +105,7 @@ class PopupState extends State<Popup> {
             child: ScrollablePositionedList.builder(
               shrinkWrap: true,
               physics: const ClampingScrollPhysics(),
-              itemScrollController: widget.controller.itemScrollController,
+              itemScrollController: isc,
               itemPositionsListener: widget.controller.itemPositionsListener,
               itemCount: widget.controller.suggestions.length,
               itemBuilder: (context, index) {

lib/src/wip/autocomplete/popup_controller.dart

@@ -7,7 +7,7 @@ class PopupController extends ChangeNotifier {
   bool shouldShow = false;
   bool enabled = true;
 
-  ItemScrollController itemScrollController = ItemScrollController();
+  final ItemScrollController itemScrollController = ItemScrollController();
   final ItemPositionsListener itemPositionsListener =
       ItemPositionsListener.create();
 
@@ -23,12 +23,8 @@ class PopupController extends ChangeNotifier {
 
   int get selectedIndex => _selectedIndex;
 
-  void reset() {
-    itemScrollController = ItemScrollController();
-  }
-
   void show(List<String> suggestions) {
-    if (enabled == false) {
+    if (!enabled) {
       return;
     }