add HoverSample

Samples/UIWidgetsSamples_2019_4/Assets/MaterialSample/HoverSample.cs

+using Unity.UIWidgets.engine2;
+using Unity.UIWidgets.foundation;
+using Unity.UIWidgets.painting;
+using Unity.UIWidgets.widgets;
+using TextStyle = Unity.UIWidgets.painting.TextStyle;
+using ui_ = Unity.UIWidgets.widgets.ui_;
+using uiwidgets;
+using Unity.UIWidgets.gestures;
+using Unity.UIWidgets.material;
+using Color = Unity.UIWidgets.ui.Color;
+
+namespace UIWidgetsSample
+{
+  /**
+   *
+   * STILL NOT WORKING, THERE SHOULD BE A BUG. FIX IT !!!!
+   * 
+   */
+  public class HoverSample : UIWidgetsPanel
+  {
+    protected void OnEnable()
+    {
+      base.OnEnable();
+    }
+
+    protected override void main()
+    {
+      ui_.runApp(new MyApp());
+    }
+
+    class MyApp : StatelessWidget
+    {
+      public override Widget build(BuildContext context)
+      {
+        return new MaterialApp(
+          debugShowCheckedModeBanner: false,
+          title: "Flutter Demo",
+          home: new Scaffold(
+            appBar: new AppBar(title: new Text("good")),
+            body: new Center(
+              child: new MyStatefulWidget()
+            )
+          )
+        );
+      }
+    }
+
+    class MyStatefulWidget : StatefulWidget
+    {
+      public MyStatefulWidget(Key key = null) : base(key: key)
+      {
+      }
+
+      public override State createState() => new _MyStatefulWidgetState();
+    }
+
+    class _MyStatefulWidgetState : State<MyStatefulWidget>
+    {
+      Color textColor = Colors.blue;
+      int _enterCounter = 0;
+      int _exitCounter = 0;
+      float x = 0.0f;
+      float y = 0.0f;
+
+      void _incrementEnter(PointerEvent details)
+      {
+        UnityEngine.Debug.Log("enter");
+        setState(() => { _enterCounter++; });
+      }
+
+      void _incrementExit(PointerEvent details)
+      {
+        setState(() =>
+        {
+          textColor = Colors.blue;
+          _exitCounter++;
+        });
+      }
+
+      void _updateLocation(PointerEvent details)
+      {
+        setState(() =>
+        {
+          textColor = Colors.red;
+          x = details.position.dx;
+          y = details.position.dy;
+        });
+      }
+
+
+      public override Widget build(BuildContext context)
+      {
+        return new MouseRegion(
+          onEnter: _incrementEnter,
+          onHover: _updateLocation,
+          onExit: _incrementExit,
+          child: new FlatButton(
+            color: Colors.white,
+            textColor: Colors.teal[700], //when hovered text color change
+            shape: new RoundedRectangleBorder(
+              borderRadius: BorderRadius.circular(5),
+              side: new BorderSide(
+                color: Colors.teal[700]
+              )
+            ),
+            onPressed: () => { },
+            child: new Text("Log in", style: new TextStyle(color: textColor))
+          )
+        );
+      }
+    }
+  }
+}