etui/backend

Types

Backend

pub type Backend(state) {
  Backend(
    init: fn() -> Result(state, Error),
    render: fn(state, List(RenderOp)) -> Result(state, Error),
    poll: fn(state, Int) -> Result(#(InputEvent, state), Error),
    next_size: fn(state) -> Result(#(TerminalSize, state), Error),
    cleanup: fn(state) -> Nil,
  )
}

Constructors

Backend(
  init: fn() -> Result(state, Error),
  render: fn(state, List(RenderOp)) -> Result(state, Error),
  poll: fn(state, Int) -> Result(#(InputEvent, state), Error),
  next_size: fn(state) -> Result(#(TerminalSize, state), Error),
  cleanup: fn(state) -> Nil,
)

Error

</>

pub type Error {
  TerminalUnsupported(reason: String)
  IOError(reason: String)
  Interrupted
}

Constructors

```
TerminalUnsupported(reason: String)
```
```
IOError(reason: String)
```
```
Interrupted
```

InputEvent

</>

pub type InputEvent {
  KeyPress(key: String)
  Resize(width: Int, height: Int)
  Tick
  MousePress(x: Int, y: Int, button: MouseButton)
  MouseRelease(x: Int, y: Int, button: MouseButton)
  MouseScroll(x: Int, y: Int, up: Bool)
}

Constructors

```
KeyPress(key: String)
```
```
Resize(width: Int, height: Int)
```
```
Tick
```
```
MousePress(x: Int, y: Int, button: MouseButton)
```
Mouse button pressed. x/y are 0-based terminal cell coordinates.

MouseRelease(x: Int, y: Int, button: MouseButton)

Mouse button released.

```
MouseScroll(x: Int, y: Int, up: Bool)
```
Mouse wheel scrolled. up: True = scroll up, False = scroll down.

MouseButton

</>

Mouse button identifier.

pub type MouseButton {
  MouseLeft
  MouseMiddle
  MouseRight
}

Constructors

```
MouseLeft
```
```
MouseMiddle
```
```
MouseRight
```

RenderOp

</>

Terminal backend abstraction. Two implementations: Erlang + JS/Node.

pub type RenderOp {
  MoveCursor(x: Int, y: Int)
  Write(String)
  ClearScreen
  EnterAltScreen
  ExitAltScreen
  EnableMouse
  DisableMouse
}

Constructors

```
MoveCursor(x: Int, y: Int)
```
```
Write(String)
```
```
ClearScreen
```
```
EnterAltScreen
```
```
ExitAltScreen
```
```
EnableMouse
```
Enable SGR mouse tracking (button + scroll events, pixel-precise coords).
```
DisableMouse
```
Disable all mouse tracking.

TerminalSize

</>

pub type TerminalSize {
  TerminalSize(width: Int, height: Int)
}

Constructors

```
TerminalSize(width: Int, height: Int)
```

Values

cleanup

</>

pub fn cleanup(backend: Backend(state), state: state) -> Nil

clear_and_home

</>

pub fn clear_and_home() -> List(RenderOp)

init

</>

pub fn init(backend: Backend(state)) -> Result(state, Error)

next_size

</>

pub fn next_size(
  backend: Backend(state),
  state: state,
) -> Result(#(TerminalSize, state), Error)

poll

</>

pub fn poll(
  backend: Backend(state),
  state: state,
  timeout_ms: Int,
) -> Result(#(InputEvent, state), Error)

render

</>

pub fn render(
  backend: Backend(state),
  state: state,
  ops: List(RenderOp),
) -> Result(state, Error)