Implemented state using ChangeNotifier.

Author: zinigor

lib/dart_comfy_frontend.dart

@@ -7,3 +7,5 @@ export 'src/workflow.dart' show Workflow;
 export 'src/workflow/node.dart' show WorkflowNode;
 export 'src/workflow/input.dart' show WorkflowInput;
 export 'src/workflow/output.dart' show WorkflowOutput;
+export 'src/workflow/model.dart' show WorkflowModel;
+export 'src/workflow/view.dart' show WorkflowView;

lib/src/workflow/model.dart

@@ -0,0 +1,83 @@
+import 'dart:convert';
+import 'dart:collection';
+import 'package:flutter/material.dart';
+import '../workflow.dart';
+import 'node.dart';
+
+class WorkflowModel extends ChangeNotifier {
+
+  Workflow? _workflow;
+
+  UnmodifiableListView<WorkflowNode> get nodes => UnmodifiableListView(_workflow?.nodes ?? []);
+
+  // void add(Item item) {
+  //   _items.add(item);
+  //   // This call tells the widgets that are listening to this model to rebuild.
+  //   notifyListeners();
+  // }
+  //
+  // /// Removes all items from the cart.
+  // void removeAll() {
+  //   _items.clear();
+  //   // This call tells the widgets that are listening to this model to rebuild.
+  //   notifyListeners();
+  // }
+
+  void loadExample() {
+    const documentJson = '''
+    {
+    "last_node_id": 1,
+    "last_link_id": 1,
+    "nodes": [
+    {
+  "id": 67,
+  "type": "Reroute",
+  "pos": [
+    351.7936096191406,
+    1119.392822265625
+  ],
+  "size": [
+    82,
+    26
+  ],
+  "flags": {},
+  "order": 95,
+  "mode": 4,
+  "inputs": [
+    {
+      "name": "",
+      "type": "*",
+      "link": 175
+    }
+  ],
+  "outputs": [
+    {
+      "name": "MODEL",
+      "type": "MODEL",
+      "links": [
+        257
+      ],
+      "slot_index": 0
+    }
+  ],
+  "properties": {
+    "showOutputText": true,
+    "horizontal": false
+  },
+  "color": "#223",
+  "bgcolor": "#335"
+}
+
+  ],
+    "links": [],
+    "groups": [],
+    "config": {},
+    "extra": {},
+    "version": 0.4
+  }
+''';
+
+    _workflow = Workflow.fromJSON(jsonDecode(documentJson));
+    notifyListeners();
+  }
+}

lib/src/workflow/view.dart

@@ -0,0 +1,24 @@
+import 'package:flutter/material.dart';
+import '../workflow/model.dart';
+
+class WorkflowView extends StatelessWidget {
+
+  final WorkflowModel workflow;
+
+  WorkflowView(this.workflow);
+
+  @override
+  Widget build(BuildContext context) {
+    return Column(
+      children: [
+        Stack(
+          children: workflow.nodes.map<Text>((item) => Text(item.type)).toList()
+        ),
+        TextButton(
+          onPressed: () => workflow.loadExample(),
+          child: Text('Load example'),
+        )
+      ]
+    );
+  }
+}

pubspec.yaml

@@ -8,6 +8,7 @@ environment:
 
 # Add regular dependencies here.
 dependencies:
+  provider: ^6.1.5
   # path: ^1.8.0
 
 dev_dependencies: