add IconToggle

lib/flutter_icons.dart

@@ -14,3 +14,4 @@ export 'zocial.dart';
 export 'foundation.dart';
 export 'font_awesome_5.dart';
 export 'flutter_icon_data.dart' show IconWeight;
+export 'icon_toggle.dart';

lib/icon_toggle.dart

@@ -0,0 +1,143 @@
+///
+///
+/// 自定义的bool选择组件
+///
+///
+import 'package:flutter/material.dart';
+import 'dart:math' as math;
+
+Widget _defaultTransitionBuilder(Widget child, Animation<double> animation) =>
+    ScaleTransition(
+      scale: animation,
+      child: child,
+    );
+
+class IconToggle extends StatefulWidget {
+  IconToggle({
+    this.uncheckedIconData = Icons.radio_button_unchecked,
+    this.checkedIconData = Icons.radio_button_checked,
+    this.activeColor = Colors.blue,
+    this.inactiveColor = Colors.grey,
+    this.value = false,
+    this.onChanged,
+    this.transitionBuilder = _defaultTransitionBuilder,
+    this.duration = const Duration(milliseconds: 100),
+    this.reverseDuration,
+  });
+  final IconData checkedIconData;
+  final IconData uncheckedIconData;
+  final Color activeColor;
+  final Color inactiveColor;
+  final bool value;
+  final ValueChanged<bool> onChanged;
+  final AnimatedSwitcherTransitionBuilder transitionBuilder;
+  final Duration duration;
+  final Duration reverseDuration;
+  @override
+  _IconToggleState createState() => _IconToggleState();
+}
+
+class _IconToggleState extends State<IconToggle>
+    with SingleTickerProviderStateMixin {
+  AnimationController _controller;
+  Animation<double> _position;
+
+  @override
+  void initState() {
+    super.initState();
+    _controller = AnimationController(
+        vsync: this,
+        duration: Duration(milliseconds: 100),
+        reverseDuration: Duration(milliseconds: 50));
+    _position = CurvedAnimation(parent: _controller, curve: Curves.linear);
+    _position.addStatusListener((status) {
+      if (status == AnimationStatus.dismissed && widget.onChanged != null) {
+        widget.onChanged(!widget.value);
+      }
+    });
+  }
+
+  @override
+  void dispose() {
+    _controller?.dispose();
+    super.dispose();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return GestureDetector(
+      onTapDown: (event) {
+        _controller?.forward();
+      },
+      onTapUp: (event) {
+        _controller?.reverse();
+      },
+      child: _IconToggleable<double>(
+        listenable: _position,
+        activeColor: widget.activeColor,
+        inactiveColor: widget.inactiveColor,
+        child: AnimatedSwitcher(
+          duration: widget.duration,
+          reverseDuration: widget.reverseDuration,
+          transitionBuilder: widget.transitionBuilder,
+          child: Icon(
+            widget.value ? widget.checkedIconData : widget.uncheckedIconData,
+            color: widget.value ? widget.activeColor : widget.inactiveColor,
+            size: 22,
+            key: ValueKey<bool>(widget.value),
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+class _IconToggleable<T> extends AnimatedWidget {
+  _IconToggleable({
+    Animation<T> listenable,
+    this.activeColor,
+    this.inactiveColor,
+    this.child,
+  }) : super(listenable: listenable);
+  final Color activeColor;
+  final Color inactiveColor;
+  final Widget child;
+  @override
+  Widget build(BuildContext context) {
+    return CustomPaint(
+      painter: _IconPainter(
+        position: listenable,
+        activeColor: activeColor,
+        inactiveColor: inactiveColor,
+      ),
+      child: child,
+    );
+  }
+}
+
+class _IconPainter extends CustomPainter {
+  _IconPainter({
+    @required this.position,
+    this.activeColor,
+    this.inactiveColor,
+  });
+  final Animation<double> position;
+  final Color activeColor;
+  final Color inactiveColor;
+
+  double get _value => position != null ? position.value : 0;
+
+  @override
+  void paint(Canvas canvas, Size size) {
+    final Paint paint = Paint()
+      ..color = Color.lerp(inactiveColor, activeColor, _value)
+          .withOpacity(math.min(_value, 0.1))
+      ..style = PaintingStyle.fill
+      ..strokeWidth = 2.0;
+    canvas.drawCircle(
+        Offset(size.width / 2, size.height / 2), 20 * _value, paint);
+  }
+
+  @override
+  bool shouldRepaint(CustomPainter oldDelegate) => true;
+}