Add EffectList

Author: gskinner

CHANGELOG.md

@@ -6,8 +6,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [4.3.0] - 2023-09-21
 ### Added
-- `AlignEffect`
+- `AlignEffect` - animated alignment
 - `transformHitTests` on `ScaleEffect` and `RotateEffect`
+- `EffectList` - build lists of effects with the chained API
 
 ### Changed
 - fix to properly support `FollowPathEffect.rotate`

README.md

@@ -8,7 +8,7 @@ Flutter Animate
 A performant library that makes it simple to add almost any kind of animated 
 effect in Flutter.
 
-1. Pre-built effects, like fade, scale, slide, align, flip, blur, shake,
+1. Pre-built effects like fade, scale, slide, align, flip, blur, shake,
    shimmer, shadows, crossfades, follow path, and color effects (saturation,
    color, and tint)
 2. Easy custom effects and simplified animated builders

lib/flutter_animate.dart

@@ -1,5 +1,6 @@
 export 'src/animate.dart';
 export 'src/animate_list.dart';
+export 'src/effect_list.dart';
 export 'src/flutter_animate.dart';
 export 'src/adapters/adapters.dart';
 export 'src/effects/effects.dart';

lib/src/effect_list.dart

@@ -0,0 +1,37 @@
+import 'dart:collection';
+import '../flutter_animate.dart';
+
+/// Simple helper class to build a list of effects via the chained api.
+/// Example:
+///
+/// ```
+/// List<Effect> myEffects = EffectList().fadeIn().scale();
+/// // ...
+/// Animate(effects: myEffects, child: foo);
+/// ```
+class EffectList extends ListBase<Effect> with AnimateManager<EffectList> {
+  final List<Effect> _effects = [];
+
+  @override
+  EffectList addEffect(Effect effect) {
+    _effects.add(effect);
+    return this;
+  }
+
+  // concrete implementations required when extending ListBase:
+  @override
+  set length(int length) {
+    _effects.length = length;
+  }
+
+  @override
+  int get length => _effects.length;
+
+  @override
+  Effect operator [](int index) => _effects[index];
+
+  @override
+  void operator []=(int index, Effect value) {
+    _effects[index] = value;
+  }
+}