TermTextBuf/com.gitlab.alfredjijo.ttb.terminal/Buffer

Buffer

class Buffer(var width: Int, var height: Int, val maxScrollback: Int)

The core data structure representing the terminal emulator's text buffer. It manages the 2D grid of character cells, scrollback history, and cursor position.

Constructors

Buffer

constructor(width: Int, height: Int, maxScrollback: Int)

Properties

currentStyle

var currentStyle: CharacterStyle

The active style attributes applied to any new characters written or inserted.

cursorColumn

var cursorColumn: Int

The current 0-indexed column position of the cursor.

cursorRow

var cursorRow: Int

The current 0-indexed row position of the cursor on the visible screen.

height

var height: Int

The number of rows in the terminal screen.

maxScrollback

val maxScrollback: Int

The maximum number of lines preserved in history when scrolling.

width

var width: Int

The number of columns in the terminal screen.

Functions

clearAll

fun clearAll()

Clears the visible screen AND the scrollback history.

clearScreen

fun clearScreen()

Clears all visible text on the screen and resets the cursor to (0,0).

fillLine

fun fillLine(row: Int, char: Char = ' ')

Overwrites an entire row with a specific character and the current style.

getCharAt

fun getCharAt(col: Int, row: Int): Char

Retrieves the character at a specific coordinate (negative row queries history).

getEntireContentAsString

fun getEntireContentAsString(): String

Retrieves the scrollback history and the visible screen as a single multi-line string.

getLine

fun getLine(row: Int): Line

Retrieves a specific Line object from the visible screen for rendering.

getLineAsString

fun getLineAsString(row: Int): String

Retrieves a specific line as a raw string (negative row queries history).

getScreenAsString

fun getScreenAsString(): String

Retrieves the entire visible screen concatenated as a multi-line string.

getStyleAt

fun getStyleAt(col: Int, row: Int): CharacterStyle

Retrieves the style attributes at a specific coordinate (negative row queries history).

insert

fun insert(text: String)

Inserts text at the current cursor position. Existing characters on the line are shifted to the right. Characters pushed past the screen width are discarded.

insertEmptyLineAtBottom

fun insertEmptyLineAtBottom()

Inserts an empty line at the bottom of the screen, pushing everything up and saving the top line to scrollback history.

moveCursor

fun moveCursor(dCol: Int, dRow: Int)

Moves the cursor relative to its current position, clamping to boundaries.

fun print(text: String)

Writes a sequence of characters to the buffer.

resize

fun resize(newWidth: Int, newHeight: Int)

Dynamically resizes the terminal grid and reflows the text. Text that was soft-wrapped will unwrap if the width increases. Text will soft-wrap if the width decreases.

setCursorPosition

fun setCursorPosition(col: Int, row: Int)

write

fun write(char: Char)

Writes a single character to the buffer at the current cursor position, overwriting existing text and advancing the cursor.