termbox-go: github.com/nsf/termbox-go Index | Files | Directories

package termbox

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

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


Package Files

api.go api_common.go syscalls_linux.go termbox.go termbox_common.go terminfo.go terminfo_builtin.go


var (
    IsInit bool = false

To know if termbox has been initialized or not

func CellBuffer

func CellBuffer() []Cell

Returns a slice into the termbox's back buffer. You can get its dimensions using 'Size' function. The slice remains valid as long as no 'Clear' or 'Flush' function calls were made after call to this function.

func Clear

func Clear(fg, bg Attribute) error

Clears the internal back buffer.

func Close

func Close()

Finalizes termbox library, should be called after successful initialization when termbox's functionality isn't required anymore.

func Flush

func Flush() error

Synchronizes the internal back buffer with the terminal.

func HideCursor

func HideCursor()

The shortcut for SetCursor(-1, -1).

func Init

func Init() error

Initializes termbox library. This function should be called before any other functions. After successful initialization, the library must be finalized using 'Close' function.

Example usage:

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

func Interrupt

func Interrupt()

Interrupt an in-progress call to PollEvent by causing it to return EventInterrupt. Note that this function will block until the PollEvent function has successfully been interrupted.

func SetCell

func SetCell(x, y int, ch rune, fg, bg Attribute)

Changes cell's parameters in the internal back buffer at the specified position.

func SetCursor

func SetCursor(x, y int)

Sets the position of the cursor. See also HideCursor().

func Size

func Size() (width int, height int)

Returns the size of the internal back buffer (which is mostly the same as terminal's window size in characters). But it doesn't always match the size of the terminal window, after the terminal size has changed, the internal back buffer will get in sync only after Clear or Flush function calls.

func Sync

func Sync() error

Sync comes handy when something causes desync between termbox's understanding of a terminal buffer and the reality. Such as a third party process. Sync forces a complete resync between the termbox and a terminal, it may not be visually pretty though.

type Attribute

type Attribute uint16
const (
    ColorDefault Attribute = iota

Cell colors, you can combine a color with multiple attributes using bitwise OR ('|').

const (
    AttrBold Attribute = 1 << (iota + 9)

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.

It's worth mentioning that some platforms don't support certain attibutes. For example windows console doesn't support AttrUnderline. And on some terminals applying AttrBold to background may result in blinking text. Use them with caution and test your code on various terminals.

type Cell

type Cell struct {
    Ch  rune
    Fg  Attribute
    Bg  Attribute

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 Event

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
    N      int       // number of bytes written when getting a raw event

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.

func ParseEvent

func ParseEvent(data []byte) Event

After getting a raw event from PollRawEvent function call, you can parse it again into an ordinary one using termbox logic. That is parse an event as termbox would do it. Returned event in addition to usual Event struct fields sets N field to the amount of bytes used within 'data' slice. If the length of 'data' slice is zero or event cannot be parsed for some other reason, the function will return a special event type: EventNone.

IMPORTANT: EventNone may contain a non-zero N, which means you should skip these bytes, because termbox cannot recognize them.

NOTE: This API is experimental and may change in future.

func PollEvent

func PollEvent() Event

Wait for an event and return it. This is a blocking function call.

func PollRawEvent

func PollRawEvent(data []byte) Event

Wait for an event and return it. This is a blocking function call. Instead of EventKey and EventMouse it returns EventRaw events. Raw event is written into `data` slice and Event's N field is set to the amount of bytes written. The minimum required length of the 'data' slice is 1. This requirement may vary on different platforms.

NOTE: This API is experimental and may change in future.

type EventType

type EventType uint8
const (
    EventKey EventType = iota

Event type. See Event.Type field.

type InputMode

type InputMode int
const (
    InputEsc InputMode = 1 << iota
    InputCurrent InputMode = 0

Input mode. See SetInputMode function.

func SetInputMode

func SetInputMode(mode InputMode) InputMode

Sets termbox input mode. Termbox has two input modes:

1. Esc input mode. When ESC sequence is in the buffer and it doesn't match any known sequence. ESC means KeyEsc. This is the default input mode.

2. Alt input mode. When ESC sequence is in the buffer and it doesn't match any known sequence. ESC enables ModAlt modifier for the next keyboard event.

Both input modes can be OR'ed with Mouse mode. Setting Mouse mode bit up will enable mouse button click events.

If 'mode' is InputCurrent, returns the current input mode. See also Input* constants.

type Key

type Key uint16
const (
    KeyF1 Key = 0xFFFF - iota


Key constants, see Event.Key field.

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

type Modifier

type Modifier uint8
const (
    ModAlt Modifier = 0x01

Alt modifier constant, see Event.Mod field and SetInputMode function.

type OutputMode

type OutputMode int
const (
    OutputCurrent OutputMode = iota

Output mode. See SetOutputMode function.

func SetOutputMode

func SetOutputMode(mode OutputMode) OutputMode

Sets the termbox output mode. Termbox has four output options:

1. OutputNormal => [1..8]

This mode provides 8 different colors:
    black, red, green, yellow, blue, magenta, cyan, white
Shortcut: ColorBlack, ColorRed, ...
Attributes: AttrBold, AttrUnderline, AttrReverse

Example usage:
    SetCell(x, y, '@', ColorBlack | AttrBold, ColorRed);

2. Output256 => [1..256]

In this mode you can leverage the 256 terminal mode:
0x01 - 0x08: the 8 colors as in OutputNormal
0x09 - 0x10: Color* | AttrBold
0x11 - 0xe8: 216 different colors
0xe9 - 0x1ff: 24 different shades of grey

Example usage:
    SetCell(x, y, '@', 184, 240);
    SetCell(x, y, '@', 0xb8, 0xf0);

3. Output216 => [1..216]

This mode supports the 3rd range of the 256 mode only.
But you dont need to provide an offset.

4. OutputGrayscale => [1..26]

This mode supports the 4th range of the 256 mode
and black and white colors from 3th range of the 256 mode
But you dont need to provide an offset.

In all modes, 0x00 represents the default color.

`go run _demos/output.go` to see its impact on your terminal.

If 'mode' is OutputCurrent, it returns the current output mode.

Note that this may return a different OutputMode than the one requested, as the requested mode may not be available on the target platform.



Package termbox imports 16 packages (graph) and is imported by 248 packages. Updated 2015-11-24. Refresh now. Tools for package owners.