Widgets refresh via goroutine

All widgets now refresh their own data using their own internal go
routine. This allows them to set their own update schedule (where
RefreshInterval is the time in seconds between refreshes).

The app uses a goroutine to redraw itself once a second.

weather/widget.go

@@ -10,16 +10,19 @@ import (
 )
 
 type Widget struct {
-	RefreshedAt time.Time
-	View        *tview.TextView
+	RefreshedAt     time.Time
+	RefreshInterval int
+	View            *tview.TextView
 }
 
 func NewWidget() *Widget {
 	widget := Widget{
-		RefreshedAt: time.Now(),
+		RefreshedAt:     time.Now(),
+		RefreshInterval: 600,
 	}
 
 	widget.addView()
+	go widget.refresher()
 
 	return &widget
 }
@@ -118,6 +121,21 @@ func icon(data *owm.CurrentWeatherData) string {
 	return icon
 }
 
+func (widget *Widget) refresher() {
+	tick := time.NewTicker(time.Duration(widget.RefreshInterval) * time.Second)
+	quit := make(chan struct{})
+
+	for {
+		select {
+		case <-tick.C:
+			widget.Refresh()
+		case <-quit:
+			tick.Stop()
+			return
+		}
+	}
+}
+
 func (widget *Widget) refreshedAt() string {
 	return widget.RefreshedAt.Format("15:04:05")
 }