#LunarTUI

#Features

• Double-buffered terminal rendering with diff updates.
• Layout traits and built-in horizontal, vertical, grid, and flex layouts.
• Widgets including Label, Paragraph, Divider, Image, Container, Block, and ProgressBar.
• UTF-8 text rendering and basic text wrapping support.
• A terminal-agnostic event model that can be driven by any compatible event backend.

#Installation

moon add FrozenLemonTee/LunarTUI

import {
  "FrozenLemonTee/LunarTUI@0.1.0",
}

#Packages

• FrozenLemonTee/LunarTUI/src/base: core rendering types, layout/widget traits, and event protocol.
• FrozenLemonTee/LunarTUI/src/layouts: built-in layout implementations.
• FrozenLemonTee/LunarTUI/src/widgets: built-in widgets.
• FrozenLemonTee/LunarTUI/src/terminal: terminal drawing, buffering, cursor helpers, and native terminal output.

#Basic Rendering Example

let title = @widgets.Label::new(
  "Welcome to LunarTUI",
  left=2,
  top=1,
)
let progress = @widgets.ProgressBar::new(
  20,
  value=0.75,
  left=2,
  top=3,
  prefix="Loading:",
  suffix="complete",
)
let container = @widgets.Container::new(
  0,
  0,
  80,
  24,
  layout=@layouts.VLayout::new(),
  children=[title, progress],
)
let terminal = @terminal.Terminal::new(@base.Area::new(80, 24))
@terminal.Terminal::clear()
terminal.draw(container)
@terminal.Terminal::newline()

#Event Model

let key = @base.KeyEvent::new(
  @base.KeyState::Down,
  @base.KeyCode::Enter,
)
let event = @base.Event::key(key)

#Widget Event Protocol

pub(open) trait Widget {
  fn width(self : Self) -> Int
  fn height(self : Self) -> Int
  fn render(self : Self, frame : Frame) -> Unit
  fn handle_event(self : Self, event : Event) -> EventResult
}

1. Poll or receive a backend event from an external event source.
2. Convert it into @base.Event.
3. Route it to the focused widget or component tree.
4. Inspect the returned EventResult.
5. Redraw only when the result is Redraw.

• Ignored: the widget did not handle the event; parent or sibling routing may continue.
• Handled: the widget handled the event, but no immediate redraw is required.
• Redraw: the widget handled the event and the application should render again.

#Default Event Backend

let source = @lunartui.EventSource::new()
match source.poll_event(32) {
  Some(event) => {
    match widget.handle_event(event) {
      @base.EventResult::Redraw => terminal.draw(widget)
      @base.EventResult::Handled => ()
      @base.EventResult::Ignored => ()
    }
  }
  None => ()
}

#Demo

TerminalEvent -> LunarEvent -> LunarEvent/lunartui -> LunarTUI -> application redraw loop

#Development

moon check --target native
moon test --target native

#License