Typeclass for elements that support customizable borders

L is the universal layout element type - a type-erased wrapper for the DSL.

This allows mixing different element types in layouts while providing a common interface. Uses existential quantification to store any Element type inside L.

Constructors: * L a - Wraps any Element (Text, Box, Table, etc.) * UL [L] - Special case for unordered lists (allows nesting) * AutoCenter L - Smart centering that adapts to layout context width * LBox, LStatusCard, LTable - Specialized constructors for bordered elements

Example usage: layout [text "title", box "content" [...], center (text "footer")] All different types unified as L, so they can be composed together.

Tree structure for hierarchical data

Center element within specified width

Create horizontal row with no spacing between elements (for gradients, etc.)

Add underline with custom character

Add colored underline with custom character and color

Example usage: underlineColored "=" ColorRed $ text "Error Section" underlineColored "~" ColorGreen $ text Success underlineColored "─" ColorBrightCyan $ text Info

Align text to the left within specified width

Align text to the right within specified width

Align text to the center within specified width

Justify text (spread words evenly to fill width)

Wrap text to multiple lines with specified width

Create table with headers and rows

Create section with title and content

Create section with custom glyph

Create section with custom glyph and flanking chars

Create key-value pairs

Create tree structure

Create leaf tree node (no children)

Create branch tree node with children

Create margin with custom prefix

Example usage: margin "[error]" [text "Something went wrong"] margin "[info]" [text "FYI: Check the logs"]

Horizontal rule with default character and width

Horizontal rule with custom character

Horizontal rule with custom character and width

Vertical rule with default character and height

Vertical rule with custom character

Vertical rule with custom character and height

Add padding around element

Create horizontal bar chart

Create an animated spinner

Example usage: spinner Loading 5 SpinnerDots -- Shows the 5th frame of dots spinner spinner Processing 0 SpinnerLine -- Shows first frame with label

Increment the frame number each render to animate: layout [spinner Working (tickCount mod 10) SpinnerDots]

Spinner style with animation frames

Create a sparkline from a list of values

A data series for line plots: points, label, color

Create a braille line plot

A slice of a pie chart: value, label, color

Create a braille pie chart

A bar item: value, label, color

Create a vertical bar chart

A group of stacked bars: segments and group label

Create a stacked vertical bar chart

Heatmap data: grid of values, row labels, column labels

Create a heatmap with default cell width (6)

Create a heatmap with custom cell width

Apply a border style to elements that support borders

Elements that support borders: box, statusCard, table Other elements are returned unchanged

Example usage: withBorder BorderDouble $ table [Name] [[text Alice]]

Apply a color to an element

Example usage: withColor ColorBrightYellow $ box Warning [text "Check logs"]

Apply a style to an element Example usage: withStyle StyleBold $ text "Important!"

The core application structure - Elm Architecture style

Build interactive TUI apps by defining: * Initial state and startup commands * How to update state based on messages * What events to subscribe to * How to render state to UI

Example: @ data CounterMsg = Inc | Dec

counterApp :: LayoutzApp Int CounterMsg counterApp = LayoutzApp { appInit = (0, CmdNone) , appUpdate = \msg count -> case msg of Inc -> (count + 1, CmdNone) Dec -> (count - 1, CmdNone) , appSubscriptions = \_ -> subKeyPress $ \key -> case key of KeyChar + -> Just Inc KeyChar - -> Just Dec _ -> Nothing , appView = \count -> layout [text $ "Count: " <> show count] } @

Keyboard input representation

Commands - side effects the runtime will execute after each update

Create a command from an IO action (fire and forget)

Create a command that produces a message after IO completes

Create a command that fires a message after a delay

Execute a command and return any resulting message

Subscriptions - event sources your app listens to

Options for running a LayoutzApp. Use defaultAppOptions and override the fields you care about:

runAppWith defaultAppOptions { optAlignment = AppAlignCenter } myApp

Sensible defaults: left-aligned.

App-level alignment within the terminal window

Run an interactive TUI application with default options.

This function: * Sets up raw terminal mode (no echo, no buffering) * Clears screen and hides cursor * Enters event loop that: - Listens to subscribed events (keyboard, ticks, etc.) - Dispatches messages to update function - Updates state and re-renders * Restores terminal on exit (ESC, Ctrl+C, or Ctrl+D)

Press ESC, Ctrl+C, or Ctrl+D to quit the application.

Run an interactive TUI application with custom options.

runAppWith defaultAppOptions { optAlignment = AppAlignCenter } myApp

Subscribe to keyboard events

Subscribe to periodic ticks with custom interval (milliseconds)

Combine multiple subscriptions