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lib/widgets/animated_nav_icon.dart

@@ -0,0 +1,62 @@
+import 'package:flutter/material.dart';
+
+/// Ícone de navegação que dá um pequeno "pulo" (scale bounce) sempre que
+/// passa a ficar selecionado, para reforçar o feedback de toque na
+/// bottom navigation bar.
+class AnimatedNavIcon extends StatefulWidget {
+  const AnimatedNavIcon({
+    super.key,
+    required this.icon,
+    required this.selected,
+  });
+
+  final IconData icon;
+  final bool selected;
+
+  @override
+  State<AnimatedNavIcon> createState() => _AnimatedNavIconState();
+}
+
+class _AnimatedNavIconState extends State<AnimatedNavIcon>
+    with SingleTickerProviderStateMixin {
+  late final AnimationController _controller = AnimationController(
+    vsync: this,
+    duration: const Duration(milliseconds: 320),
+  );
+  late final Animation<double> _bounce = TweenSequence<double>([
+    TweenSequenceItem(
+      tween: Tween(begin: 1.0, end: 1.35).chain(
+        CurveTween(curve: Curves.easeOut),
+      ),
+      weight: 40,
+    ),
+    TweenSequenceItem(
+      tween: Tween(begin: 1.35, end: 1.0).chain(
+        CurveTween(curve: Curves.easeOutBack),
+      ),
+      weight: 60,
+    ),
+  ]).animate(_controller);
+
+  @override
+  void didUpdateWidget(covariant AnimatedNavIcon oldWidget) {
+    super.didUpdateWidget(oldWidget);
+    if (widget.selected && !oldWidget.selected) {
+      _controller.forward(from: 0);
+    }
+  }
+
+  @override
+  void dispose() {
+    _controller.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return ScaleTransition(
+      scale: _bounce,
+      child: Icon(widget.icon),
+    );
+  }
+}