create StylePhaseAnimator

packages/mix/lib/src/experiemental/style_phase_animator.dart

@@ -0,0 +1,110 @@
+import 'dart:async';
+
+import 'package:flutter/widgets.dart';
+
+import '../core/factory/style_mix.dart';
+import '../core/styled_widget.dart';
+import '../core/variant.dart';
+
+class PhaseAnimationData {
+  final Duration duration;
+  final Curve curve;
+  final Duration delay;
+
+  const PhaseAnimationData({
+    this.duration = const Duration(milliseconds: 200),
+    this.curve = Curves.easeInOut,
+    this.delay = Duration.zero,
+  });
+}
+
+class StylePhaseAnimator extends StatefulWidget {
+  const StylePhaseAnimator({
+    super.key,
+    this.repeat = true,
+    required this.initialStyle,
+    required this.phases,
+    required this.animation,
+    required this.child,
+  });
+
+  final bool repeat;
+  final Style initialStyle;
+  final Map<Variant, Style> phases;
+  final PhaseAnimationData Function(Variant phase) animation;
+  final Widget child;
+
+  @override
+  State<StylePhaseAnimator> createState() => _StylePhaseAnimatorState();
+}
+
+class _StylePhaseAnimatorState extends State<StylePhaseAnimator>
+    with TickerProviderStateMixin {
+  static const _initialVariant = Variant('phase.animator.initial');
+
+  Style get _definitiveStyle => widget.initialStyle.addAll(
+        widget.phases.entries.map((e) => e.key(e.value())),
+      );
+  List<Variant> get _variants => [_initialVariant, ...widget.phases.keys];
+
+  int _currentIndex = 0;
+  Variant get _currentVariant => _variants[_currentIndex];
+  Timer? _timer;
+
+  late final AnimationController _controller = AnimationController(
+    duration: widget.animation(_variants[_currentIndex]).duration,
+    vsync: this,
+  );
+
+  @override
+  void initState() {
+    super.initState();
+    _controller.forward();
+    _controller.addStatusListener(animationListener);
+  }
+
+  void _next() {
+    final int nextIndex;
+    if (widget.repeat) {
+      nextIndex = (_currentIndex + 1) % _variants.length;
+    } else {
+      nextIndex = (_currentIndex + 1).clamp(0, _variants.length - 1);
+    }
+
+    setState(() {
+      _currentIndex = nextIndex;
+    });
+  }
+
+  @override
+  void dispose() {
+    _timer?.cancel();
+    _timer = null;
+    _controller.dispose();
+    super.dispose();
+  }
+
+  void animationListener(status) {
+    if (status == AnimationStatus.completed) {
+      _timer = Timer(widget.animation(_variants[_currentIndex]).delay, () {
+        _next();
+        _controller.duration =
+            widget.animation(_variants[_currentIndex]).duration;
+        _controller.forward(from: 0);
+      });
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return SpecBuilder(
+      style: _definitiveStyle.applyVariant(_currentVariant).animate(
+            duration: widget.animation(_currentVariant).duration,
+            curve: widget.animation(_currentVariant).curve,
+          ),
+      builder: (context) {
+        return widget.child;
+      },
+    );
+  }
+}