com.unity.uiwidgets/Tests/Editor/MouseHover.cs

using System.Collections.Generic;
using Unity.UIWidgets.foundation;
using Unity.UIWidgets.painting;
using Unity.UIWidgets.rendering;
using Unity.UIWidgets.widgets;
using Color = Unity.UIWidgets.ui.Color;

namespace UIWidgets.Tests
{
    public class MouseHoverWidget:StatefulWidget
    {
        public MouseHoverWidget(Key key) : base(key)
        {
        }

        public override State createState()
        {
            return new _MouseHoverWidgetState();
        }
    }

    class _MouseHoverWidgetState:State<MouseHoverWidget>
    {

        public static Widget createRow(bool canHover = true, bool nest = false)
        {
            Widget result = new Container(width: 200, height: 60, color: Color.fromARGB(255, 255, 0, 255));
            if (canHover)
            {
                result = new HoverTrackWidget(null,
                    result);
            }

            if (nest)
            {
                result = new Container(child:result, padding: EdgeInsets.all(40), color: Color.fromARGB(255, 255, 0, 0));
                result = new HoverTrackWidget(null,
                    result);
            }

            return result;
        }
        
        public override Widget build(BuildContext context)
        {//1 131231
            return new Container(
                alignment: Alignment.center, color: Color.fromARGB(255, 0, 255, 0),
                child: new Column(
                    mainAxisAlignment:MainAxisAlignment.spaceAround,
                    children: new List<Widget>
                    {
                        createRow(),
                        createRow(false),
                        createRow(),
                        createRow(true, true),
                    }));
        }
    }

    public class HoverTrackWidget : StatefulWidget
    {
        public readonly Widget child;
        public HoverTrackWidget(Key key, Widget child) : base(key)
        {
            this.child = child;
        }

        public override State createState()
        {
            return new _HoverTrackWidgetState();
        }
    }

    class _HoverTrackWidgetState : State<HoverTrackWidget>
    {
        private bool hover;
        public override Widget build(BuildContext context)
        {
            return new Listener(child:
                new Container(
                    forgroundDecoration: hover ? new BoxDecoration(color: Color.fromARGB(80, 255, 255, 255)) : null,
                    child: widget.child
                ),
                onPointerEnter: (evt) => {
                    if (mounted)
                    {
                        setState(() => { hover = true; });
                    } },
                onPointerLeave: (evt) =>
                {
                    if (mounted)
                    {
                        setState(() => { hover = false; });
                    }
                }
            );
        }
    }
    
}