Merge pull request #30 from DutchCodingCompany/feature/pagination_state_view

Setup PaginationStateView for handling all the pagination states

Author: NRijnberg

lib/pagination/pagination_state_view.dart

@@ -0,0 +1,62 @@
+import 'package:dcc_toolkit/dcc_toolkit.dart';
+import 'package:flutter/material.dart';
+
+/// A widget that displays a different widget based on the state of the pagination
+///
+/// [state] is the state of the pagination
+/// [loadingWidget] is the widget to display when [state] is [PaginationState.isLoading]
+/// [emptyWidget] is the widget to display when [state] is [PaginationState.items] is empty
+/// [errorWidget] is the widget to display when [state] is [PaginationState.hasError]
+/// [builder] is the builder for the actual success view (usually [PaginatedScrollView])
+/// [onRefresh] is the refresh callback for [RefreshIndicator]
+class PaginationStateView<T> extends StatelessWidget {
+  /// Constructor
+  const PaginationStateView({
+    required this.state,
+    required this.loadingWidget,
+    required this.emptyWidget,
+    required this.errorWidget,
+    required this.builder,
+    this.onRefresh,
+    super.key,
+  });
+
+  /// The state of the pagination
+  final PaginationState<T> state;
+
+  /// Custom widget for [PaginationState.isLoading]
+  final Widget loadingWidget;
+
+  /// Custom widget for [PaginationState.items] is empty
+  final Widget emptyWidget;
+
+  /// Custom widget for [PaginationState.hasError]
+  final Widget errorWidget;
+
+  /// Builder for the actual success view (usually [PaginatedScrollView])
+  final WidgetBuilder builder;
+
+  /// Optional: refresh callback for [RefreshIndicator]
+  final RefreshCallback? onRefresh;
+
+  @override
+  Widget build(BuildContext context) {
+    // If there is a refresh callback and the state is not loading, enable the refresh indicator
+    return onRefresh != null && !state.isLoading
+        ? RefreshIndicator(
+          onRefresh: onRefresh!,
+          child: switch (state) {
+            PaginationState(isLoading: true) => loadingWidget,
+            PaginationState(hasError: true) => errorWidget,
+            PaginationState(items: const []) => emptyWidget,
+            PaginationState() => builder(context),
+          },
+        )
+        : switch (state) {
+          PaginationState(isLoading: true) => loadingWidget,
+          PaginationState(hasError: true) => errorWidget,
+          PaginationState(items: const []) => emptyWidget,
+          PaginationState() => builder(context),
+        };
+  }
+}