cup_edit/lib/filament_gesture_detector.dart

import 'dart:async';
import 'dart:io';

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

enum GestureType { RotateCamera, PanCamera, PanBackground }

class FilamentGestureDetector extends StatefulWidget {
  final Widget? child;
  final FilamentController controller;
  final bool showControlOverlay;
  final bool enableControls;

  const FilamentGestureDetector(
      {Key? key,
      required this.controller,
      this.child,
      this.showControlOverlay = false,
      this.enableControls = true})
      : super(key: key);

  @override
  State<StatefulWidget> createState() => _FilamentGestureDetectorState();
}

class _FilamentGestureDetectorState extends State<FilamentGestureDetector> {
  GestureType gestureType = GestureType.PanCamera;

  final _icons = {
    GestureType.PanBackground: Icons.image,
    GestureType.PanCamera: Icons.pan_tool,
    GestureType.RotateCamera: Icons.rotate_90_degrees_ccw
  };

  bool _rotating = false;
  bool _scaling = false;

  // to avoid duplicating code for pan/rotate (panStart, panUpdate, panEnd, rotateStart, rotateUpdate etc)
  // we have only a single function for start/update/end.
  // when the gesture type is changed, these properties are updated to point to the correct function.
  late Function(double x, double y) _functionStart;
  late Function(double x, double y) _functionUpdate;
  late Function() _functionEnd;

  double _lastScale = 0;

  @override
  void initState() {
    _setFunction();
    super.initState();
  }

  void _setFunction() {
    switch (gestureType) {
      case GestureType.RotateCamera:
        _functionStart = widget.controller.rotateStart;
        _functionUpdate = widget.controller.rotateUpdate;
        _functionEnd = widget.controller.rotateEnd;
        break;
      case GestureType.PanCamera:
        _functionStart = widget.controller.panStart;
        _functionUpdate = widget.controller.panUpdate;
        _functionEnd = widget.controller.panEnd;
        break;
      // TODO
      case GestureType.PanBackground:
        _functionStart = (x, y) async {};
        _functionUpdate = (x, y) async {};
        _functionEnd = () async {};
    }
  }

  @override
  void didUpdateWidget(FilamentGestureDetector oldWidget) {
    if (widget.showControlOverlay != oldWidget.showControlOverlay ||
        widget.enableControls != oldWidget.enableControls) {
      setState(() {});
    }

    super.didUpdateWidget(oldWidget);
  }

  Timer? _scrollTimer;

  @override
  Widget build(BuildContext context) {
    print(widget.enableControls);
    return Stack(children: [
      Positioned.fill(
          // pinch zoom on mobile
          // couldn't find any equivalent for pointerCount in Listener so we use two widgets:
          // - outer is a GestureDetector only for pinch zoom
          // - inner is a Listener for all other gestures (including scroll zoom on desktop)
          child: GestureDetector(
              onDoubleTap: () {
                _rotating = !_rotating;
                print("Set rotating to $_rotating");
              },
              onScaleStart: !widget.enableControls
                  ? null
                  : (d) async {
                      _scaling = true;
                      if (d.pointerCount == 2) {
                        widget.controller.zoomEnd();
                        widget.controller.zoomBegin();
                      }
                    },
              onScaleEnd: !widget.enableControls
                  ? null
                  : (d) async {
                      _scaling = false;
                      if (d.pointerCount == 2) {
                        _lastScale = 0;
                        widget.controller.zoomEnd();
                      }
                    },
              onScaleUpdate: !widget.enableControls
                  ? null
                  : (d) async {
                      if (d.pointerCount == 2) {
                        if (_lastScale != 0) {
                          widget.controller.zoomUpdate(Platform.isIOS
                              ? 1000 * (_lastScale - d.scale)
                              : 100 * (_lastScale - d.scale));
                        }
                      }
                      _lastScale = d.scale;
                    },
              child: Listener(
                  onPointerSignal: !widget.enableControls
                      ? null
                      : (pointerSignal) async {
                          // scroll-wheel zoom on desktop
                          if (pointerSignal is PointerScrollEvent) {
                            _scrollTimer?.cancel();
                            widget.controller.zoomBegin();
                            widget.controller.zoomUpdate(
                                pointerSignal.scrollDelta.dy > 0 ? 10 : -10);
                            _scrollTimer =
                                Timer(Duration(milliseconds: 100), () {
                              widget.controller.zoomEnd();
                              _scrollTimer = null;
                            });
                          }
                        },
                  onPointerPanZoomStart:
                      !widget.enableControls ? null : (pzs) {},
                  onPointerDown: !widget.enableControls
                      ? null
                      : (d) async {
                          if (d.buttons == kTertiaryButton || _rotating) {
                            widget.controller.rotateStart(
                                d.localPosition.dx, d.localPosition.dy);
                          } else {
                            _functionStart(
                                d.localPosition.dx, d.localPosition.dy);
                          }
                        },
                  onPointerMove: !widget.enableControls
                      ? null
                      : (d) async {
                          if (d.buttons == kTertiaryButton || _rotating) {
                            widget.controller.rotateUpdate(
                                d.localPosition.dx, d.localPosition.dy);
                          } else {
                            _functionUpdate(
                                d.localPosition.dx, d.localPosition.dy);
                          }
                        },
                  onPointerUp: !widget.enableControls
                      ? null
                      : (d) async {
                          if (d.buttons == kTertiaryButton || _rotating) {
                            widget.controller.rotateEnd();
                          } else {
                            _functionEnd();
                          }
                        },
                  child: widget.child))),
      widget.showControlOverlay
          ? Align(
              alignment: Alignment.bottomRight,
              child: GestureDetector(
                onTap: () {
                  setState(() {
                    var curIdx = GestureType.values.indexOf(gestureType);
                    var nextIdx = curIdx == GestureType.values.length - 1
                        ? 0
                        : curIdx + 1;
                    gestureType = GestureType.values[nextIdx];
                    _setFunction();
                  });
                },
                child: Container(
                    padding: const EdgeInsets.all(50),
                    child: Icon(_icons[gestureType], color: Colors.green)),
              ))
          : Container()
    ]);
  }
}