feat: add widgets for padding and opacity (#21)

packages/fleet/README.md

@@ -123,9 +123,9 @@ All we did was replace `ColoredBox` with [`AColoredBox`][acoloredbox] and use
 [`setStateWithAnimation`][setstatewithanimation] instead of `setState`.
 
 The `AColoredBox` widget is a drop-in replacement for `ColoredBox` that supports
-**state-based animation**. Any widget you want to animate through Fleet needs to
-support state-based animation. These widgets don't have any special parameters
-related to animation and can be just as well used without animation.
+animating with Fleet. Widgets that support animating with Fleet don't have any
+special parameters related to animation and can be used without animation, just
+as well.
 
 Fleet provides drop-in replacements for a number of generally useful Flutter
 framework widgets (all with the prefix `A`). Any widget can be made to support
@@ -157,7 +157,11 @@ for animating with Fleet:
 - AAlign
 - AColoredBox
 - AContainer
+- AOpacity
+- APadding
 - ASizedBox
+- ASliverOpacity
+- ASliverPadding
 
 ---
 

packages/fleet/lib/fleet.dart

@@ -1,5 +1,13 @@
 export 'src/animatable_flutter_widgets.dart'
-    show AAlign, AColoredBox, AContainer, ASizedBox;
+    show
+        AAlign,
+        AColoredBox,
+        AContainer,
+        AOpacity,
+        APadding,
+        ASizedBox,
+        ASliverOpacity,
+        ASliverPadding;
 export 'src/animatable_widget.dart'
     show
         AnimatableAlignmentGeometry,

packages/fleet/lib/src/animatable_flutter_widgets.dart

@@ -228,6 +228,86 @@ class _AContainerState extends AnimatableState<AContainer> {
   }
 }
 
+/// Animatable version of [Opacity].
+///
+/// {@category Animatable Flutter widget}
+class AOpacity extends StatefulWidget {
+  /// Creates an animatable version of [Opacity].
+  const AOpacity({
+    super.key,
+    required this.opacity,
+    this.alwaysIncludeSemantics = false,
+    this.child,
+  });
+
+  /// See [Opacity.opacity].
+  final double opacity;
+
+  /// See [Opacity.alwaysIncludeSemantics].
+  final bool alwaysIncludeSemantics;
+
+  /// See [ProxyWidget.child].
+  final Widget? child;
+
+  @override
+  State<AOpacity> createState() => _AOpacityState();
+}
+
+class _AOpacityState extends AnimatableState<AOpacity> {
+  late final _opacity = AnimatableDouble(widget.opacity, state: this);
+
+  @override
+  void updateAnimatableParameters() {
+    _opacity.value = widget.opacity;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Opacity(
+      opacity: _opacity.animatedValue,
+      alwaysIncludeSemantics: widget.alwaysIncludeSemantics,
+      child: widget.child,
+    );
+  }
+}
+
+/// Animatable version of [Padding].
+///
+/// {@category Animatable Flutter widget}
+class APadding extends StatefulWidget {
+  /// Creates an animatable version of [Padding].
+  const APadding({super.key, required this.padding, this.child});
+
+  /// See [Padding.padding].
+  final EdgeInsetsGeometry padding;
+
+  /// See [ProxyWidget.child].
+  final Widget? child;
+
+  @override
+  State<APadding> createState() => _APaddingState();
+}
+
+class _APaddingState extends AnimatableState<APadding> {
+  late final _padding = AnimatableEdgeInsetsGeometry(
+    widget.padding,
+    state: this,
+  );
+
+  @override
+  void updateAnimatableParameters() {
+    _padding.value = widget.padding;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Padding(
+      padding: _padding.animatedValue,
+      child: widget.child,
+    );
+  }
+}
+
 /// Animatable version of [SizedBox].
 ///
 /// {@category Animatable Flutter widget}
@@ -282,3 +362,83 @@ class _ASizedBoxState extends AnimatableState<ASizedBox> {
     );
   }
 }
+
+/// Animatable version of [SliverOpacity].
+///
+/// {@category Animatable Flutter widget}
+class ASliverOpacity extends StatefulWidget {
+  /// Creates an animatable version of [SliverOpacity].
+  const ASliverOpacity({
+    super.key,
+    required this.opacity,
+    this.alwaysIncludeSemantics = false,
+    this.sliver,
+  });
+
+  /// See [SliverOpacity.opacity].
+  final double opacity;
+
+  /// See [SliverOpacity.alwaysIncludeSemantics].
+  final bool alwaysIncludeSemantics;
+
+  /// See [ProxyWidget.child].
+  final Widget? sliver;
+
+  @override
+  State<ASliverOpacity> createState() => _ASliverOpacityState();
+}
+
+class _ASliverOpacityState extends AnimatableState<ASliverOpacity> {
+  late final _opacity = AnimatableDouble(widget.opacity, state: this);
+
+  @override
+  void updateAnimatableParameters() {
+    _opacity.value = widget.opacity;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return SliverOpacity(
+      opacity: _opacity.animatedValue,
+      alwaysIncludeSemantics: widget.alwaysIncludeSemantics,
+      sliver: widget.sliver,
+    );
+  }
+}
+
+/// Animatable version of [SliverPadding].
+///
+/// {@category Animatable Flutter widget}
+class ASliverPadding extends StatefulWidget {
+  /// Creates an animatable version of [SliverPadding].
+  const ASliverPadding({super.key, required this.padding, this.sliver});
+
+  /// See [SliverPadding.padding].
+  final EdgeInsetsGeometry padding;
+
+  /// See [ProxyWidget.child].
+  final Widget? sliver;
+
+  @override
+  State<ASliverPadding> createState() => _ASliverPaddingState();
+}
+
+class _ASliverPaddingState extends AnimatableState<ASliverPadding> {
+  late final _padding = AnimatableEdgeInsetsGeometry(
+    widget.padding,
+    state: this,
+  );
+
+  @override
+  void updateAnimatableParameters() {
+    _padding.value = widget.padding;
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return SliverPadding(
+      padding: _padding.animatedValue,
+      sliver: widget.sliver,
+    );
+  }
+}

packages/fleet/lib/src/animate.dart

@@ -165,7 +165,11 @@ extension SetStateWithAnimationExtension on State {
 /// - [AAlign]
 /// - [AColoredBox]
 /// - [AContainer]
+/// - [AOpacity]
+/// - [APadding]
 /// - [ASizedBox]
+/// - [ASliverOpacity]
+/// - [ASliverPadding]
 ///
 /// {@endtemplate}
 ///

packages/fleet/pubspec.yaml

@@ -1,7 +1,7 @@
 name: fleet
 description:
   An animation Framework for Flutter. It is state-based, declarative,
-  extensible, composable and aims to be user-friendly.
+  extensible, composable and easy to use.
 version: 0.1.1
 issue_tracker: https://github.com/blaugold/fleet/issues
 homepage: https://github.com/blaugold/fleet/tree/main/packages/fleet