add standalone gesture detector widget

2022-12-05 17:56:24 +08:00
parent 4bb11d44c3
commit 4b277e1b4c
1 changed files with 132 additions and 0 deletions
--- a/lib/filament_gesture_detector.dart
+++ b/lib/filament_gesture_detector.dart
@@ -0,0 +1,132 @@
+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 showControls;
+
+  const FilamentGestureDetector({
+    Key? key,
+    required this.controller,
+    this.child,
+    this.showControls = false,
+  }) : 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
+  };
+
+  // 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 Future Function(double x, double y) _functionStart;
+  late Future Function(double x, double y) _functionUpdate;
+  late Future 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(Widget oldWidget) {
+    if (widget.showControls !=
+        (oldWidget as FilamentGestureDetector).showControls) {
+      setState(() {});
+    }
+
+    super.didUpdateWidget(oldWidget);
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Stack(children: [
+      Positioned.fill(
+          child: GestureDetector(
+              behavior: HitTestBehavior.opaque,
+              onScaleStart: (d) async {
+                if (d.pointerCount == 2) {
+                  await widget.controller.zoomEnd();
+                  await widget.controller.zoomBegin();
+                } else {
+                  await _functionStart(d.focalPoint.dx, d.focalPoint.dy);
+                }
+              },
+              onScaleEnd: (d) async {
+                if (d.pointerCount == 2) {
+                  _lastScale = 0;
+                  await widget.controller.zoomEnd();
+                } else {
+                  await _functionEnd();
+                }
+              },
+              onScaleUpdate: (d) async {
+                if (d.pointerCount == 2) {
+                  if (_lastScale != 0) {
+                    await widget.controller
+                        .zoomUpdate(100 * (_lastScale - d.scale));
+                  }
+                } else {
+                  await _functionUpdate(d.focalPoint.dx, d.focalPoint.dy);
+                }
+                _lastScale = d.scale;
+              },
+              child: widget.child)),
+      widget.showControls
+          ? 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()
+    ]);
+  }
+}