Crate text_terminal

A text-mode terminal emulator.

This provides basic support for various standards of control codes and escape sequences:

• ANSI
• VT100
• xterm

This terminal emulator also supports Unicode characters; see the unicode-segmentation crate. This support stems from our usage of Rust Strings, which must be valid UTF-8.

The text terminal emulator has several main responsibilities:

• Managing the scrollback buffer, a string of characters that should be printed to the screen.
• Determining which parts of that buffer should be displayed and using the window manager to do so.
• Handling the command line user input.
• Displaying the cursor at the right position
• Handling events delivered from the window manager.

Resources

• https://www.gnu.org/software/screen/manual/screen.html#Control-Sequences
• https://man7.org/linux/man-pages/man4/console_codes.4.html
• https://vt100.net/docs/vt510-rm/chapter4.html
• https://en.wikipedia.org/wiki/ANSI_escape_code

Structs

• AsciiControlCodes
  The set of ASCII values that are non-printable characters and require special handling by a terminal emulator.
• BackgroundColor
  A wrapper type around Color that is used in crate::AnsiStyleCodes to set the background color (behind displayed text).
• Column
  A column index or number of columns in the x-dimension of the screen viewport.
• ForegroundColor
  A wrapper type around Color that is used in crate::AnsiStyleCodes to set the foreground color (for displayed text).
• FormatFlags
  The flags that describe the formatting of a given text character.
• Line
  An entire unbroken line of characters (Units) that has been written to a terminal.
• LineIndex
  An index of a Line in the scrollback buffer.
• ModeSwitch
  The set of “frequently-supported” commands to switch terminal modes.
• Row
  A row index or number of rows in the y-dimension of the screen viewport.
• ScreenPoint
  A 2D position value that represents a point on the screen, in which (0, 0) represents the top-left corner. Thus, a valid ScreenPoint must fit be the bounds of the current ScreenSize.
• ScreenSize
  The size of a terminal screen, expressed as the number of columns (x dimension) by the number of rows (y dimension).
• ScrollbackBuffer
  The scrollback buffer is stored as a row-major vector of Lines.
• ScrollbackBufferPoint
  A 2D position value that represents a point in the scrollback buffer, in which (0, 0) represents the Unit at the first column of the first line.
• StatusReportCommands
• Style
  The style of text, including formatting and color choice, for the character(s) displayed in a Unit.
• StyleDiff
  A representation of the difference between two Styles.
• TerminalMode
  The set of options that determine terminal behavior.
• TextTerminal
  A text-based terminal that supports the ANSI, xterm, VT100, and other standards.
• TtyBackend
  A terminal backend that is simply a character device TTY endpoint (a full terminal emulator) on the other side, which only allows writing a stream of bytes to it.
• UnderlinedColor
  A wrapper type around Color that is used in crate::AnsiStyleCodes to set the color of the underline for underlined text.
• Unit
  A Unit is a single character block displayed in the terminal.
• UnitIndex
  An index of a Unit in a Line in the scrollback buffer.

Enums

• AnsiStyleCodes
  The set of all possible ANSI escape codes for setting text style.
• CarriageReturnSendsLineFeed
  Whether a Carriage Return subsequently issues a Line Feed (newline / new line).
• Character
  The character stored in each Unit of the terminal screen.
• Color
  The set of colors that can be displayed by a terminal emulator.
• CursorStyle
• DisplayAction
  A pending action to display content from the terminal’s scrollback buffer on the screen.
• InsertMode
  Whether text characters printed to the terminal will be inserted before other characters or will replace/overwrite existing characters.
• LineFeedSendsCarriageReturn
  Whether a Line Feed (newline / new line) subsequently issues a Carriage Return.
• ScrollAction
  A pending action to scroll the screen up or down by a number of rows.
• ScrollPosition
  The position (“viewport”) that the terminal is currently scrolled to.
• ShowCursor
  Whether the screen cursor is visible.
• Wrap
  Whether or not to wrap cursor movement or text display to the previous/next line or row.

Traits

• TerminalBackend