fix unchecked dispose issues (#298)

Author: quaaantumdev

lib/src/code_field/code_controller.dart

@@ -125,6 +125,8 @@ class CodeController extends TextEditingController {
   @visibleForTesting
   TextSpan? lastTextSpan;
 
+  bool _disposed = false;
+
   late final actions = <Type, Action<Intent>>{
     CommentUncommentIntent: CommentUncommentAction(controller: this),
     CopySelectionTextIntent: CopyAction(controller: this),
@@ -233,6 +235,10 @@ class CodeController extends TextEditingController {
       return;
     }
 
+    if (_disposed) {
+      return;
+    }
+
     analysisResult = result;
     _lastAnalyzedText = codeSentToAnalysis.text;
     notifyListeners();
@@ -971,6 +977,7 @@ class CodeController extends TextEditingController {
 
   @override
   void dispose() {
+    _disposed = true;
     _debounce?.cancel();
     historyController.dispose();
     searchController.dispose();

lib/src/code_field/code_field.dart

@@ -266,6 +266,9 @@ class _CodeFieldState extends State<CodeField> {
     disableSpellCheckIfWeb();
 
     WidgetsBinding.instance.addPostFrameCallback((_) {
+      if(!mounted){
+        return;
+      }
       final double width = _codeFieldKey.currentContext!.size!.width;
       final double height = _codeFieldKey.currentContext!.size!.height;
       windowSize = Size(width, height);
@@ -317,6 +320,9 @@ class _CodeFieldState extends State<CodeField> {
   void rebuild() {
     setState(() {
       WidgetsBinding.instance.addPostFrameCallback((_) {
+        if(!mounted){
+          return;
+        }
         // For some reason _codeFieldKey.currentContext is null in tests
         // so check first.
         final context = _codeFieldKey.currentContext;