import 'package:flutter/material.dart'; import 'package:lightmeter/res/dimens.dart'; class CenteredSlider extends StatefulWidget { final Icon? icon; final double value; final double min; final double max; final ValueChanged onChanged; final bool isVertical; const CenteredSlider({ this.icon, required this.value, required this.min, required this.max, required this.onChanged, this.isVertical = false, super.key, }); @override State createState() => _CenteredSliderState(); } class _CenteredSliderState extends State { double relativeValue = 0.0; @override void initState() { super.initState(); relativeValue = (widget.value - widget.min) / (widget.max - widget.min); } @override void didUpdateWidget(CenteredSlider oldWidget) { super.didUpdateWidget(oldWidget); relativeValue = (widget.value - widget.min) / (widget.max - widget.min); } @override Widget build(BuildContext context) { return SizedBox( height: widget.isVertical ? double.maxFinite : Dimens.cameraSliderHandleSize, width: !widget.isVertical ? double.maxFinite : Dimens.cameraSliderHandleSize, child: LayoutBuilder( builder: (context, constraints) { final biggestSize = widget.isVertical ? constraints.maxHeight : constraints.maxWidth; final handleDistance = biggestSize - Dimens.cameraSliderHandleSize; return RotatedBox( quarterTurns: widget.isVertical ? -1 : 0, child: GestureDetector( behavior: HitTestBehavior.translucent, onTapUp: (details) => _updateHandlePosition( details.localPosition.dx, handleDistance, ), onHorizontalDragUpdate: (details) => _updateHandlePosition( details.localPosition.dx, handleDistance, ), child: SizedBox( height: Dimens.cameraSliderHandleSize, width: biggestSize, child: _Slider( handleDistance: handleDistance, handleSize: Dimens.cameraSliderHandleSize, trackThickness: Dimens.cameraSliderTrackHeight, value: relativeValue, icon: RotatedBox( quarterTurns: widget.isVertical ? 1 : 0, child: widget.icon, ), ), ), ), ); }, ), ); } void _updateHandlePosition(double offset, double handleDistance) { if (offset <= Dimens.cameraSliderHandleSize / 2) { relativeValue = 0; } else if (offset >= handleDistance + Dimens.cameraSliderHandleSize / 2) { relativeValue = 1; } else { relativeValue = (offset - Dimens.cameraSliderHandleSize / 2) / handleDistance; } setState(() {}); widget.onChanged(relativeValue * (widget.max - widget.min) + widget.min); } } class _Slider extends StatelessWidget { final double handleSize; final double trackThickness; final double handleDistance; final double value; final Widget icon; const _Slider({ required this.handleSize, required this.trackThickness, required this.handleDistance, required this.value, required this.icon, }); @override Widget build(BuildContext context) { return Stack( alignment: Alignment.center, children: [ Positioned( height: trackThickness, /// add thickness to maintain radius overlap with handle width: handleDistance + trackThickness, child: ClipRRect( borderRadius: BorderRadius.circular(trackThickness / 2), child: ColoredBox(color: Theme.of(context).colorScheme.surfaceVariant), ), ), AnimatedPositioned.fromRect( duration: Dimens.durationM, rect: Rect.fromCenter( center: Offset( handleSize / 2 + handleDistance * value, handleSize / 2, ), width: handleSize, height: handleSize, ), child: _Handle( color: Theme.of(context).colorScheme.primary, size: handleSize, child: IconTheme( data: Theme.of(context).iconTheme.copyWith( color: Theme.of(context).colorScheme.onPrimary, size: Dimens.cameraSliderHandleIconSize, ), child: icon, ), ), ), ], ); } } class _Handle extends StatelessWidget { final Color color; final double size; final Widget? child; const _Handle({ required this.color, required this.size, this.child, }); @override Widget build(BuildContext context) { return ClipRRect( borderRadius: BorderRadius.circular(size / 2), child: SizedBox( height: size, width: size, child: ColoredBox( color: color, child: child, ), ), ); } }