Flutter 手势系列教程---Listener

const Listener({
    Key key,
    this.onPointerDown,
    this.onPointerMove,
    // We have to ignore the lint rule here in order to use deprecated
    // parameters and keep backward compatibility.
    // TODO(tongmu): After it goes stable, remove these 3 parameters from Listener
    // and Listener should no longer need an intermediate class _PointerListener.
    // https://github.com/flutter/flutter/issues/36085
    @Deprecated(
      'Use MouseRegion.onEnter instead. See MouseRegion.opaque for behavioral difference. '
      'This feature was deprecated after v1.10.14.'
    )
    this.onPointerEnter,
    @Deprecated(
      'Use MouseRegion.onExit instead. See MouseRegion.opaque for behavioral difference. '
      'This feature was deprecated after v1.10.14.'
    )
    this.onPointerExit,
    @Deprecated(
      'Use MouseRegion.onHover instead. See MouseRegion.opaque for behavioral difference. '
      'This feature was deprecated after v1.10.14.'
    )
    this.onPointerHover,
    this.onPointerUp,
    this.onPointerCancel,
    this.onPointerSignal,
    this.behavior = HitTestBehavior.deferToChild,
    Widget child,
  }) : assert(behavior != null),
       _child = child,
       super(key: key);

import 'package:flutter/material.dart';


class ListenerExample extends StatefulWidget {
  @override
  _ListenerExampleState createState() => _ListenerExampleState();
}

class _ListenerExampleState extends State<ListenerExample> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text("Listener"),
      ),
      body: Center(
        child: Stack(
          children: [
            Listener(
              onPointerDown: (event) {
                print("onPointerDown----$event");
              },
              onPointerMove: (event) {
                print("onPointerMove----$event");
              },
              onPointerUp: (event) {
                print("onPointerUp----$event");
              },
              // onPointerSignal: (event) {
              //   print("onPointerSignal----$event");
              // },
              // onPointerCancel: (event) {
              //   print("onPointerCancel----$event");
              // },
              // onPointerEnter: (event) {
              //   print("onPointerEnter----$event");
              // },
              // onPointerExit: (event) {
              //   print("onPointerExit----$event");
              // },
              // onPointerHover: (event) {
              //   print("onPointerHover----$event");
              // },
              child: Container(
                color: Colors.pink,
                child: Text("Jimi",
                  style: TextStyle(
                    color: Colors.white,
                    fontSize: 30
                  ),
                ),
              ),
            ),
            Positioned(
              child: Listener(
                onPointerDown: (event) {
                  print("red---- $event");
                },
                child: Container(
                  width: 100,
                  height: 100,
                  color: Colors.red,
                  child: Text("Jimi"),
                ),
              ),
            )
          ],
        ),
      ),
    );
  }
}

flutter: onPointerDown----PointerDownEvent#128be(position: Offset(204.5, 403.5))
flutter: onPointerUp----PointerUpEvent#a9558(position: Offset(204.5, 403.5))
flutter: red---- PointerDownEvent#8ffdf(position: Offset(140.5, 317.0))

const PointerEvent({
  this.embedderId = 0,
  this.timeStamp = Duration.zero,
  this.pointer = 0,
  this.kind = PointerDeviceKind.touch,
  this.device = 0,
  this.position = Offset.zero,
  Offset? localPosition,
  this.delta = Offset.zero,
  Offset? localDelta,
  this.buttons = 0,
  this.down = false,
  this.obscured = false,
  this.pressure = 1.0,
  this.pressureMin = 1.0,
  this.pressureMax = 1.0,
  this.distance = 0.0,
  this.distanceMax = 0.0,
  this.size = 0.0,
  this.radiusMajor = 0.0,
  this.radiusMinor = 0.0,
  this.radiusMin = 0.0,
  this.radiusMax = 0.0,
  this.orientation = 0.0,
  this.tilt = 0.0,
  this.platformData = 0,
  this.synthesized = false,
  this.transform,
  this.original,
}) : localPosition = localPosition ?? position,
     localDelta = localDelta ?? delta;

import 'package:flutter/material.dart';


class ListenerSimpleExample extends StatefulWidget {
  @override
  _ListenerSimpleExampleState createState() => _ListenerSimpleExampleState();
}

class _ListenerSimpleExampleState extends State<ListenerSimpleExample> with AutomaticKeepAliveClientMixin {

  @override
  bool get wantKeepAlive => true;

  @override
  Widget build(BuildContext context) {
    super.build(context);
    return Scaffold(
      appBar: AppBar(
        title: Text("Listener"),
      ),
      body: Center(
        child: Stack(
          children: [
            Listener(
              child: ConstrainedBox(
                  constraints: BoxConstraints.tight(Size(400, 200)),
                  child: Container(
                    color: Colors.greenAccent,
                  )
              ),
              onPointerDown: (event) => print("绿色盒子被点击了"),
            ),
            Listener(
              child: ConstrainedBox(
                constraints: BoxConstraints.tight(Size(400, 200)),
                child: Center(child: Text("点击文字", style: TextStyle(
                  color: Colors.white,
                  fontSize: 30
                ),)),
              ),
              onPointerDown: (event) => print("文字点击事件回调"),
              behavior: HitTestBehavior.deferToChild,
              // behavior: HitTestBehavior.opaque,
              // behavior: HitTestBehavior.translucent,
            )
          ],
        ),
      ),
    );
  }
}

flutter: 绿色盒子被点击了
flutter: 文字点击事件回调

flutter: 文字点击事件回调
flutter: 文字点击事件回调

flutter: 文字点击事件回调
flutter: 绿色盒子被点击了
flutter: 文字点击事件回调