Added ui for single mode

main.go

@@ -34,10 +34,16 @@ func main() {
 		data.Services = append(data.Services, service)
 	}
 
-	var ui UI = &TermUI{}
+	var ui UI
+	if len(data.Services) > 1 {
+		ui = &TermUI{}
+	} else {
+		ui = &TermUISingle{}
+	}
 	if *dummy {
 		ui = &DummyUI{}
 	}
+
 	if err := ui.Init(*data); err != nil {
 		log.Fatal(err)
 	}

ui_single.go

@@ -0,0 +1,106 @@
+package main
+
+import (
+	"fmt"
+
+	"github.com/divan/termui"
+)
+
+// TermUISingle is a termUI implementation of UI interface.
+type TermUISingle struct {
+	Title      *termui.Par
+	Status     *termui.Par
+	Sparklines map[VarName]*termui.Sparkline
+	Sparkline  *termui.Sparklines
+}
+
+// Init creates widgets, sets sizes and labels.
+func (t *TermUISingle) Init(data UIData) error {
+	err := termui.Init()
+	if err != nil {
+		return err
+	}
+
+	t.Sparklines = make(map[VarName]*termui.Sparkline)
+
+	termui.UseTheme("helloworld")
+
+	t.Title = func() *termui.Par {
+		p := termui.NewPar("")
+		p.Height = 3
+		p.TextFgColor = termui.ColorWhite
+		p.Border.Label = "Services Monitor"
+		p.Border.FgColor = termui.ColorCyan
+		return p
+	}()
+	t.Status = func() *termui.Par {
+		p := termui.NewPar("")
+		p.Height = 3
+		p.TextFgColor = termui.ColorWhite
+		p.Border.Label = "Status"
+		p.Border.FgColor = termui.ColorCyan
+		return p
+	}()
+
+	for _, name := range data.Vars {
+		_, ok := t.Sparklines[name]
+		if !ok {
+			spl := termui.NewSparkline()
+			spl.Height = 1
+			spl.TitleColor = colorByKind(name.Kind())
+			spl.LineColor = colorByKind(name.Kind())
+			spl.Title = name.Long()
+			t.Sparklines[name] = &spl
+		}
+	}
+
+	t.Sparkline = func() *termui.Sparklines {
+		var spls []termui.Sparkline
+		for _, sp := range t.Sparklines {
+			spls = append(spls, *sp)
+		}
+		s := termui.NewSparklines(spls...)
+		s.Height = 2*len(spls) + 2
+		s.HasBorder = true
+		s.Border.Label = fmt.Sprintf("Monitoring")
+		return s
+	}()
+
+	termui.Body.AddRows(
+		termui.NewRow(
+			termui.NewCol(6, 0, t.Title),
+			termui.NewCol(6, 0, t.Status)),
+		termui.NewRow(termui.NewCol(12, 0, t.Sparkline)),
+	)
+
+	termui.Body.Align()
+
+	return nil
+}
+
+// Update updates UI widgets from UIData.
+func (t *TermUISingle) Update(data UIData) {
+	// single mode assumes we have one service only to monitor
+	service := data.Services[0]
+
+	t.Title.Text = fmt.Sprintf("monitoring %s, press q to quit", service.Name)
+	t.Status.Text = fmt.Sprintf("Last update: %v", data.LastTimestamp.Format("15:04:05 02/Jan/06"))
+
+	// Sparklines
+	for i, name := range data.Vars {
+		spl := &t.Sparkline.Lines[i]
+		spl.Title = fmt.Sprintf("%s: %v", name.Long(), service.Value(name))
+		spl.TitleColor = colorByKind(name.Kind())
+		spl.LineColor = colorByKind(name.Kind())
+		spl.Data = service.Values(name)
+	}
+
+	termui.Body.Width = termui.TermWidth()
+	termui.Body.Align()
+	termui.Render(termui.Body)
+}
+
+// Close shuts down UI module.
+func (t *TermUISingle) Close() {
+	termui.Close()
+}