Termbox-Go using

.SimpleUse.go

package main

import (
	"github.com/nsf/termbox-go"
	"log"
)

func draw(ch rune) {
	w, h := termbox.Size()
	bg := termbox.ColorBlack
	fg := termbox.ColorWhite

	termbox.Clear(fg, bg)

	for x := 0; x < w; x++ {
		for y := 0; y < h; y++ {
			termbox.SetCell(x, y, ch, fg, bg)
		}
	}

	termbox.Flush()
}

func main() {
	err := termbox.Init()
	if err != nil {
		log.Println(err.Error())
	}
	defer termbox.Close()

	termbox.SetInputMode(termbox.InputEsc | termbox.InputMouse)

loop:
	for {
		switch ev := termbox.PollEvent(); ev.Type {
		case termbox.EventKey:
			if ev.Key == termbox.KeyCtrlQ {
				break loop
			} else {
				draw(ev.Ch)
			}
		}
	}

	log.Println("Good Bye!")
}

1. KeyEvent.go

// termbox is a library for creating cross-platform text-based interfaces
package termbox

// public API, common OS agnostic part

type (
	InputMode int
	EventType uint8
	Modifier  uint8
	Key       uint16
	Attribute uint16
)

// This type represents a termbox event. The 'Mod', 'Key' and 'Ch' fields are
// valid if 'Type' is EventKey. The 'Width' and 'Height' fields are valid if
// 'Type' is EventResize. The 'Err' field is valid if 'Type' is EventError.
type Event struct {
	Type   EventType // one of Event* constants
	Mod    Modifier  // one of Mod* constants or 0
	Key    Key       // one of Key* constants, invalid if 'Ch' is not 0
	Ch     rune      // a unicode character
	Width  int       // width of the screen
	Height int       // height of the screen
	Err    error     // error in case if input failed
	MouseX int       // x coord of mouse
	MouseY int       // y coord of mouse
}

// A cell, single conceptual entity on the screen. The screen is basically a 2d
// array of cells. 'Ch' is a unicode character, 'Fg' and 'Bg' are foreground
// and background attributes respectively.
type Cell struct {
	Ch rune
	Fg Attribute
	Bg Attribute
}

// Key constants, see Event.Key field.
const (
	KeyF1 Key = 0xFFFF - iota
	KeyF2
	KeyF3
	KeyF4
	KeyF5
	KeyF6
	KeyF7
	KeyF8
	KeyF9
	KeyF10
	KeyF11
	KeyF12
	KeyInsert
	KeyDelete
	KeyHome
	KeyEnd
	KeyPgup
	KeyPgdn
	KeyArrowUp
	KeyArrowDown
	KeyArrowLeft
	KeyArrowRight
	key_min // see terminfo
	MouseLeft
	MouseMiddle
	MouseRight
)

const (
	KeyCtrlTilde      Key = 0x00
	KeyCtrl2          Key = 0x00
	KeyCtrlSpace      Key = 0x00
	KeyCtrlA          Key = 0x01
	KeyCtrlB          Key = 0x02
	KeyCtrlC          Key = 0x03
	KeyCtrlD          Key = 0x04
	KeyCtrlE          Key = 0x05
	KeyCtrlF          Key = 0x06
	KeyCtrlG          Key = 0x07
	KeyBackspace      Key = 0x08
	KeyCtrlH          Key = 0x08
	KeyTab            Key = 0x09
	KeyCtrlI          Key = 0x09
	KeyCtrlJ          Key = 0x0A
	KeyCtrlK          Key = 0x0B
	KeyCtrlL          Key = 0x0C
	KeyEnter          Key = 0x0D
	KeyCtrlM          Key = 0x0D
	KeyCtrlN          Key = 0x0E
	KeyCtrlO          Key = 0x0F
	KeyCtrlP          Key = 0x10
	KeyCtrlQ          Key = 0x11
	KeyCtrlR          Key = 0x12
	KeyCtrlS          Key = 0x13
	KeyCtrlT          Key = 0x14
	KeyCtrlU          Key = 0x15
	KeyCtrlV          Key = 0x16
	KeyCtrlW          Key = 0x17
	KeyCtrlX          Key = 0x18
	KeyCtrlY          Key = 0x19
	KeyCtrlZ          Key = 0x1A
	KeyEsc            Key = 0x1B
	KeyCtrlLsqBracket Key = 0x1B
	KeyCtrl3          Key = 0x1B
	KeyCtrl4          Key = 0x1C
	KeyCtrlBackslash  Key = 0x1C
	KeyCtrl5          Key = 0x1D
	KeyCtrlRsqBracket Key = 0x1D
	KeyCtrl6          Key = 0x1E
	KeyCtrl7          Key = 0x1F
	KeyCtrlSlash      Key = 0x1F
	KeyCtrlUnderscore Key = 0x1F
	KeySpace          Key = 0x20
	KeyBackspace2     Key = 0x7F
	KeyCtrl8          Key = 0x7F
)

// Alt modifier constant, see Event.Mod field and SetInputMode function.
const (
	ModAlt Modifier = 0x01
)

// Cell attributes, it is possible to use multiple attributes by combining them
// using bitwise OR ('|'). Although, colors cannot be combined. But you can
// combine attributes and a single color.
const (
	ColorDefault Attribute = iota
	ColorBlack
	ColorRed
	ColorGreen
	ColorYellow
	ColorBlue
	ColorMagenta
	ColorCyan
	ColorWhite
)

const (
	AttrBold Attribute = 1 << (iota + 4)
	AttrUnderline
	AttrReverse
)

// Input mode. See SetInputMode function.
const (
	InputEsc InputMode = 1 << iota
	InputAlt
	InputMouse
	InputCurrent InputMode = 0
)

// Event type. See Event.Type field.
const (
	EventKey EventType = iota
	EventResize
	EventMouse
	EventError
)