Feature/text analysis ocr improvements

lib/ui/views/ocr/ocr_view.dart

@@ -63,9 +63,15 @@ class _Body extends StackedHookView<OcrViewModel> {
                           image: viewModel.image!,
                           onImageProcessed: viewModel.handleImageProcessed,
                           onImageError: viewModel.handleImageError,
-                          onTextSelected: (text) {
-                            controller.text = controller.text + text;
-                            viewModel.handleTextSelected();
+                          onTextBlockSelected: (textBlock) {
+                            if (controller.text.isEmpty) {
+                              controller.text = textBlock.text;
+                            } else {
+                              controller.text =
+                                  "${controller.text}\n${textBlock.text}";
+                            }
+                            viewModel.appendToHistory(
+                                controller.text, textBlock);
                           },
                           locked: false,
                           singleSelection: false,
@@ -144,30 +150,42 @@ class _SelectedText extends ViewModelWidget<OcrViewModel> {
                   ),
                   maxLength: 1000,
                   inputFormatters: [LengthLimitingTextInputFormatter(1000)],
+                  onChanged: viewModel.appendToHistory,
                 ),
               ),
             ),
           ),
-          AnimatedCrossFade(
-            crossFadeState: controller.text.isEmpty
-                ? CrossFadeState.showFirst
-                : CrossFadeState.showSecond,
-            duration: const Duration(milliseconds: 200),
-            firstChild: SizedBox.shrink(),
-            secondChild: Container(
-              padding: EdgeInsets.only(
-                bottom: MediaQuery.of(context).padding.bottom,
-              ),
-              width: double.infinity,
-              color: Colors.deepPurple,
-              child: TextButton.icon(
-                icon: const Icon(Icons.text_snippet, color: Colors.white),
-                label: const Text(
-                  'Analyze',
-                  style: TextStyle(color: Colors.white),
+          Container(
+            padding: EdgeInsets.only(
+              bottom: MediaQuery.of(context).padding.bottom,
+            ),
+            width: double.infinity,
+            color: Colors.deepPurple,
+            child: Row(
+              mainAxisAlignment: MainAxisAlignment.spaceEvenly,
+              children: [
+                IconButton(
+                  onPressed: viewModel.canUndo
+                      ? () => controller.text = viewModel.undo()
+                      : null,
+                  icon: const Icon(Icons.undo, color: Colors.white),
+                  splashColor: Colors.transparent,
                 ),
-                onPressed: () => viewModel.analyzeText(controller.text),
-              ),
+                IconButton(
+                  onPressed: viewModel.canRedo
+                      ? () => controller.text = viewModel.redo()
+                      : null,
+                  icon: const Icon(Icons.redo, color: Colors.white),
+                  splashColor: Colors.transparent,
+                ),
+                TextButton(
+                  child: const Text(
+                    'Analyze',
+                    style: TextStyle(color: Colors.white),
+                  ),
+                  onPressed: () => viewModel.analyzeText(controller.text),
+                ),
+              ],
             ),
           ),
         ],

lib/ui/views/ocr/ocr_viewmodel.dart

@@ -1,5 +1,6 @@
 import 'package:image_picker/image_picker.dart';
 import 'package:sagase/app/app.locator.dart';
+import 'package:sagase/datamodels/recognized_text_block.dart';
 import 'package:stacked/stacked.dart';
 import 'package:stacked_services/stacked_services.dart';
 
@@ -15,6 +16,11 @@ class OcrViewModel extends BaseViewModel {
   XFile? _image;
   XFile? get image => _image;
 
+  late List<(String, RecognizedTextBlock?)> _history;
+  late int _historyIndex;
+  bool get canUndo => _historyIndex >= 0;
+  bool get canRedo => _historyIndex < _history.length - 1;
+
   OcrViewModel(bool cameraStart) {
     if (cameraStart) {
       openCamera();
@@ -32,6 +38,8 @@ class OcrViewModel extends BaseViewModel {
   }
 
   Future<void> _processImage(ImageSource imageSource) async {
+    _history = [];
+    _historyIndex = -1;
     _image = null;
     _state = OcrState.waiting;
     rebuildUi();
@@ -69,15 +77,49 @@ class OcrViewModel extends BaseViewModel {
     rebuildUi();
   }
 
-  void handleTextSelected() {
-    rebuildUi();
-  }
-
   void analyzeText(String text) {
     if (text.isEmpty) return;
 
     _navigationService.back(result: text);
   }
+
+  void appendToHistory(String text, [RecognizedTextBlock? block]) {
+    _historyIndex++;
+
+    if (_historyIndex != _history.length) {
+      _history = _history.sublist(0, _historyIndex);
+    }
+
+    _history.add((text, block));
+
+    rebuildUi();
+  }
+
+  String undo() {
+    if (!canUndo) return '';
+
+    _history[_historyIndex].$2?.selected = false;
+
+    _historyIndex--;
+    rebuildUi();
+
+    if (_historyIndex == -1) {
+      return '';
+    } else {
+      return _history[_historyIndex].$1;
+    }
+  }
+
+  String redo() {
+    if (!canRedo) return '';
+
+    _historyIndex++;
+    _history[_historyIndex].$2?.selected = true;
+
+    rebuildUi();
+
+    return _history[_historyIndex].$1;
+  }
 }
 
 enum OcrState {

lib/ui/widgets/ocr_image.dart

@@ -17,7 +17,8 @@ class OcrImage extends StatefulWidget {
   final XFile image;
   final void Function(int)? onImageProcessed;
   final void Function() onImageError;
-  final void Function(String) onTextSelected;
+  final void Function(String)? onTextSelected;
+  final void Function(RecognizedTextBlock)? onTextBlockSelected;
   final bool locked;
   final bool singleSelection;
 
@@ -27,7 +28,8 @@ class OcrImage extends StatefulWidget {
     this.onImageProcessed,
     required this.onImageError,
     required this.locked,
-    required this.onTextSelected,
+    this.onTextSelected,
+    this.onTextBlockSelected,
     required this.singleSelection,
   });
 
@@ -108,7 +110,8 @@ class _OcrImageState extends State<OcrImage> {
   void handleSelect(RecognizedTextBlock textBlock) {
     setState(() {
       if (!textBlock.selected) {
-        widget.onTextSelected(textBlock.text);
+        widget.onTextSelected?.call(textBlock.text);
+        widget.onTextBlockSelected?.call(textBlock);
       }
 
       if (widget.singleSelection) {