Pan Gesture Recogniser that differentiates between device types

device_kind_pan_gesture_detector.dart

import 'package:flutter/gestures.dart';
import 'package:flutter/material.dart';

// pan gesture detector that only responds to specific device kinds
// e.g. only responds to mouse drags but ignores trackpad drags
class DeviceKindPanGestureDetector extends StatefulWidget {
  const DeviceKindPanGestureDetector({
    required this.child,
    required this.onStart,
    required this.onUpdate,
    required this.onEnd,
    required this.supportedDevices,
    this.behavior,
    this.isActive = true,
    this.singlePointer = false,
    super.key,
  });

  final Widget child;
  final void Function(DragStartDetails details) onStart;
  final void Function(DragUpdateDetails details) onUpdate;
  final void Function(DragEndDetails? details) onEnd;
  final Set<PointerDeviceKind> supportedDevices;
  final HitTestBehavior? behavior;
  final bool isActive;
  final bool singlePointer;

  @override
  State<DeviceKindPanGestureDetector> createState() =>
      _DeviceKindPanGestureDetectorState();
}

class _DeviceKindPanGestureDetectorState
    extends State<DeviceKindPanGestureDetector> {
  @override
  void didUpdateWidget(DeviceKindPanGestureDetector oldWidget) {
    super.didUpdateWidget(oldWidget);
    setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    return RawGestureDetector(
      behavior: widget.behavior,
      gestures: <Type, GestureRecognizerFactory>{
        PanGestureRecognizer:
            GestureRecognizerFactoryWithHandlers<PanGestureRecognizer>(
          () => PanGestureRecognizer(
            supportedDevices: widget.supportedDevices,
          ),
          (PanGestureRecognizer instance) {
            instance
              ..onStart = widget.isActive ? widget.onStart : null
              ..onUpdate = widget.isActive ? widget.onUpdate : null
              ..onEnd = widget.isActive ? widget.onEnd : null
              ..onCancel = widget.isActive ? () => widget.onEnd(null) : null;
          },
        ),
      },
    );
  }
}

// Pan recognizer with click support
class ClickExample extends StatelessWidget {
  const ClickExample({
    super.key,
  });

  @override
  Widget build(BuildContext context) {
    return DeviceKindPanGestureDetector(
      onStart: (start) {
        //   start drawing
      },
      onEnd: (end) {
        //   stop drawing
      },
      onUpdate: (update) {
        //   update drawing
      },
      supportedDevices: const {
        PointerDeviceKind.touch,
        PointerDeviceKind.mouse,
      },
      child: Container(),
    );
  }
}