utility-screen/main.go

package main

import (
	"os"
	"time"

	"github.com/nsf/termbox-go"
)

// ScreenState keeps some app-wide variables
type ScreenState struct {
	updateFreq time.Duration
	autoUpdate bool
}

var state *ScreenState

func main() {
	state = new(ScreenState)
	var err error

	err = termbox.Init()
	if err != nil {
		panic(err)
	}
	defer termbox.Close()

	style := defaultStyle()
	termbox.SetOutputMode(termbox.Output256)

	state.updateFreq = 60
	state.autoUpdate = false

	mainLoop(style)
}

func readUserInput(e chan termbox.Event) {
	for {
		e <- termbox.PollEvent()
	}
}

func sendRefreshEvent(e chan termbox.Event) {
	for {
		time.Sleep(time.Second * state.updateFreq)
		if state.autoUpdate {
			e <- termbox.Event{Key: 'r'}
		}
	}
}

func mainLoop(style style) {
	state.updateFreq = time.Second * 60
	screens := defaultScreens()
	displayScreen := screens[mainScreenIndex]
	layoutAndDrawScreen(displayScreen, style)

	eventchan := make(chan termbox.Event)
	go readUserInput(eventchan)
	//go sendRefreshEvent(eventchan)

	for {
		// Read User Input
		event := <-eventchan // termbox.PollEvent()
		if event.Type == termbox.EventKey {
			if event.Key == termbox.KeyCtrlC {
				break
			}
			newScreenIndex := displayScreen.handleKeyPress(event)
			if newScreenIndex < len(screens) {
				displayScreen = screens[newScreenIndex]
				layoutAndDrawScreen(displayScreen, style)
			} else if newScreenIndex == exitScreenIndex {
				break
			}
		}
		if event.Type == termbox.EventResize || event.Type == termbox.EventNone {
			layoutAndDrawScreen(displayScreen, style)
		}
	}
}

// Screens Setup
const (
	mainScreenIndex = iota
	//aboutScreenIndex
	exitScreenIndex
)

func defaultScreens() []Screen {
	//var view_port ViewPort
	mainScreen := mainScreen{}
	//aboutScreen := aboutScreen{}
	screens := [...]Screen{
		&mainScreen,
		//	&aboutScreen,
	}
	return screens[:]
}

// WriteToLog Writes to the Log
func WriteToLog(d string) {
	f, err := os.OpenFile("system-status.log", os.O_CREATE|os.O_APPEND|os.O_WRONLY, 0664)
	if err != nil {
		panic(err)
	}
	f.WriteString(d)
	f.Close()
}