73 lines
1.8 KiB
Dart
73 lines
1.8 KiB
Dart
import 'package:flutter/material.dart';
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class TypingDots extends StatefulWidget {
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const TypingDots({super.key, this.size = 6, this.color, this.spacing = 4});
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final double size;
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final double spacing;
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final Color? color;
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@override
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State<TypingDots> createState() => _TypingDotsState();
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}
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class _TypingDotsState extends State<TypingDots>
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with SingleTickerProviderStateMixin {
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late final AnimationController _controller;
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@override
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void initState() {
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super.initState();
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_controller = AnimationController(
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vsync: this,
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duration: const Duration(milliseconds: 1200),
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)..repeat();
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}
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@override
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void dispose() {
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_controller.dispose();
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super.dispose();
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}
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double _opacity(double t, double offset) {
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final phase = (t + offset) % 1.0;
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final distance = (phase - 0.5).abs();
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final ramp = 1.0 - (distance / 0.5);
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return 0.3 + 0.7 * ramp.clamp(0.0, 1.0);
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}
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@override
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Widget build(BuildContext context) {
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final color =
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widget.color ?? Theme.of(context).colorScheme.onSurfaceVariant;
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return AnimatedBuilder(
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animation: _controller,
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builder: (context, child) {
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final t = _controller.value;
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return Row(
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mainAxisSize: MainAxisSize.min,
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children: [
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_dot(color, _opacity(t, 0.0)),
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SizedBox(width: widget.spacing),
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_dot(color, _opacity(t, 0.2)),
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SizedBox(width: widget.spacing),
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_dot(color, _opacity(t, 0.4)),
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],
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);
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},
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);
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}
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Widget _dot(Color color, double opacity) {
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return Opacity(
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opacity: opacity,
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child: Container(
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width: widget.size,
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height: widget.size,
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decoration: BoxDecoration(color: color, shape: BoxShape.circle),
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),
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);
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}
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}
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