Add programmatically-controlled screen example

Author: gonuit

example/lib/main.dart

@@ -1,4 +1,5 @@
 import 'package:example/screens/presentation_screen.dart';
+import 'package:example/screens/programmatically_controlled_indicator_screen.dart';
 import 'package:example/widgets/web_frame.dart';
 import 'package:flutter/material.dart';
 
@@ -30,6 +31,8 @@ class MyApp extends StatelessWidget {
         '/presentation': (context) => PresentationScreen(),
         '/check-mark': (context) => CheckMarkIndicatorScreen(),
         '/warp': (context) => WarpIndicatorScreen(),
+        '/programmatically-controlled': (context) =>
+            ProgrammaticallyControlled(),
       },
     );
   }
@@ -132,6 +135,18 @@ class MainScreen extends StatelessWidget {
                 arguments: simpleIndicator,
               ),
             ),
+            const SizedBox(height: 15),
+            ElevatedButton(
+              child: Container(
+                height: 50,
+                alignment: Alignment.center,
+                child: Text("Programmatically-controlled warp"),
+              ),
+              onPressed: () => Navigator.pushNamed(
+                context,
+                '/programmatically-controlled',
+              ),
+            ),
           ],
         ),
       ),

example/lib/screens/programmatically_controlled_indicator_screen.dart

@@ -0,0 +1,85 @@
+import 'dart:math';
+
+import 'package:custom_refresh_indicator/custom_refresh_indicator.dart';
+import 'package:example/indicators/warp_indicator.dart';
+import 'package:example/widgets/example_list.dart';
+import 'package:flutter/material.dart';
+
+class ProgrammaticallyControlled extends StatefulWidget {
+  const ProgrammaticallyControlled({Key? key}) : super(key: key);
+
+  @override
+  State<ProgrammaticallyControlled> createState() =>
+      _ProgrammaticallyControlledState();
+}
+
+class _ProgrammaticallyControlledState
+    extends State<ProgrammaticallyControlled> {
+  final key = GlobalKey<CustomRefreshIndicatorState>();
+
+  final controller = IndicatorController(refreshEnabled: false);
+
+  bool _startedManually = false;
+
+  int _itemsCount = 4;
+  Future<void> onRefresh() async {
+    await Future.delayed(Duration(seconds: 2));
+    setState(() {
+      _itemsCount = Random().nextInt(4) + 1;
+    });
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(
+        title: Text("Programmatically-controlled"),
+        actions: [
+          AnimatedBuilder(
+            animation: controller,
+            builder: (context, _) {
+              return Row(
+                children: [
+                  IconButton(
+                    onPressed: controller.isIdle
+                        ? () {
+                            key.currentState!.show(
+                              draggingCurve: Curves.easeOutBack,
+                            );
+                            _startedManually = true;
+                          }
+                        : null,
+                    icon: const Icon(Icons.play_arrow),
+                  ),
+                  IconButton(
+                    onPressed: controller.isIdle
+                        ? () => key.currentState!.refresh(
+                              draggingCurve: Curves.easeOutBack,
+                            )
+                        : null,
+                    icon: const Icon(Icons.refresh),
+                  ),
+                  IconButton(
+                    onPressed: controller.isLoading && _startedManually
+                        ? () {
+                            key.currentState!.hide();
+                            _startedManually = false;
+                          }
+                        : null,
+                    icon: const Icon(Icons.stop),
+                  ),
+                ],
+              );
+            },
+          ),
+        ],
+      ),
+      body: WarpIndicator(
+        controller: controller,
+        indicatorKey: key,
+        onRefresh: onRefresh,
+        child: ExampleList(itemCount: _itemsCount),
+      ),
+    );
+  }
+}

example/lib/widgets/example_list.dart

@@ -3,8 +3,13 @@ import 'package:flutter/material.dart';
 import 'example_app_bar.dart';
 
 class ExampleList extends StatelessWidget {
+  final int itemCount;
+
   final Color backgroundColor;
-  const ExampleList([this.backgroundColor = appBackgroundColor]);
+  const ExampleList({
+    this.backgroundColor = appBackgroundColor,
+    this.itemCount = 4,
+  });
   @override
   Widget build(BuildContext context) {
     return DecoratedBox(
@@ -21,7 +26,7 @@ class ExampleList extends StatelessWidget {
           parent: ClampingScrollPhysics(),
         ),
         itemBuilder: (BuildContext context, int index) => const Element(),
-        itemCount: 4,
+        itemCount: itemCount,
         separatorBuilder: (BuildContext context, int index) => const Divider(
           height: 0,
           color: Color(0xFFe2d6ce),