Initial commit

lib/components/loading.dart

@@ -0,0 +1,106 @@
+import 'package:fluent_ui/fluent_ui.dart';
+import 'package:pixes/foundation/app.dart';
+import 'package:pixes/network/res.dart';
+
+abstract class LoadingState<T extends StatefulWidget, S extends Object> extends State<T>{
+  bool isLoading = true;
+
+  S? data;
+
+  String? error;
+
+  Future<Res<S>> loadData();
+
+  Widget buildContent(BuildContext context, S data);
+
+  @override
+  Widget build(BuildContext context) {
+    if(isLoading){
+      loadData().then((value) {
+        if(value.success) {
+          setState(() {
+            isLoading = false;
+            data = value.data;
+          });
+        } else {
+          setState(() {
+            isLoading = false;
+            error = value.errorMessage!;
+          });
+        }
+      });
+      return const Center(
+        child: ProgressRing(),
+      );
+    } else if (error != null){
+      return Center(
+        child: Text(error!),
+      );
+    } else {
+      return buildContent(context, data!);
+    }
+  }
+}
+
+abstract class MultiPageLoadingState<T extends StatefulWidget, S extends Object> extends State<T>{
+  bool _isFirstLoading = true;
+
+  bool _isLoading = false;
+
+  List<S>? _data;
+
+  String? _error;
+
+  int _page = 1;
+
+  Future<Res<List<S>>> loadData(int page);
+
+  Widget buildContent(BuildContext context, final List<S> data);
+
+  bool get isLoading => _isLoading || _isFirstLoading;
+
+  void nextPage() {
+    if(_isLoading) return;
+    _isLoading = true;
+    loadData(_page).then((value) {
+      _isLoading = false;
+      if(value.success) {
+        _page++;
+        setState(() {
+          _data!.addAll(value.data);
+        });
+      } else {
+        context.showToast(message: "Network Error");
+      }
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    if(_isFirstLoading){
+      loadData(_page).then((value) {
+        if(value.success) {
+          _page++;
+          setState(() {
+            _isFirstLoading = false;
+            _data = value.data;
+          });
+        } else {
+          setState(() {
+            _isFirstLoading = false;
+            _error = value.errorMessage!;
+          });
+        }
+      });
+      return const Center(
+        child: ProgressRing(),
+      );
+    } else if (_error != null){
+      return Center(
+        child: Text(_error!),
+      );
+    } else {
+      return buildContent(context, _data!);
+    }
+  }
+}