widget/material: add hovered to RadioButton

Signed-off-by: Egon Elbre <egonelbre@gmail.com>

widget/enum.go

@@ -10,7 +10,8 @@ import (
 )
 
 type Enum struct {
-	Value string
+	Value   string
+	Hovered string
 
 	changed bool
 
@@ -56,6 +57,12 @@ func (e *Enum) Layout(gtx layout.Context, key string) layout.Dimensions {
 				}
 			}
 		}
+		if e.Hovered == key {
+			e.Hovered = ""
+		}
+		if clk.Hovered() {
+			e.Hovered = key
+		}
 		clk.Add(gtx.Ops)
 	}
 

widget/material/radiobutton.go

@@ -36,7 +36,7 @@ func RadioButton(th *Theme, group *widget.Enum, key, label string) RadioButtonSt
 
 // Layout updates enum and displays the radio button.
 func (r RadioButtonStyle) Layout(gtx layout.Context) layout.Dimensions {
-	dims := r.layout(gtx, r.Group.Value == r.Key, false)
+	dims := r.layout(gtx, r.Group.Value == r.Key, r.Group.Hovered == r.Key)
 	gtx.Constraints.Min = dims.Size
 	r.Group.Layout(gtx, r.Key)
 	return dims