ansi_escape_codes 1.4.0

Yet another package for ANSI escape sequences. It differs from the others only in that it focuses on using constants rather than functions or methods.

ansi_escape_codes

This is yet another package of many for ANSI escape codes. It differs from the others only in that it focuses on using constants rather than functions or methods.

Since version 1.4.0, analysis has also been added.

Usage

const text =
    // 4-bit colors.
    '${ansi.fgBrightGreen}Lorem'
    ' ${ansi.fgGreen}ipsum'
    ' ${ansi.bgBrightBlack}${ansi.fgWhite}dolor${ansi.bgDefault}'
    ' ${ansi.bgBrightWhite}${ansi.fgBlack}sit${ansi.bgDefault}'
    // 8-bit colors.
    ' ${ansi.fg256HighRed}amet,'
    ' ${ansi.fg256Red}consectetur${ansi.fgDefault}'
    // 24-bit colors.
    ' ${ansi.bgRgbOpen}249;105;14${ansi.bgRgbClose}'
    '${ansi.fgRgbOpen}64;48;32${ansi.fgRgbClose}'
    'adipiscing'
    // Inverted colors.
    ' ${ansi.invert} elit,${ansi.notInverted}'
    '${ansi.fgDefault}${ansi.bgDefault}'
    // Italic.
    ' ${ansi.italic}sed${ansi.notItalic}'
    ' do'
    // Bold and faint.
    ' ${ansi.bold}eiusmod${ansi.notBoldNotFaint}'
    ' ${ansi.faint}tempor${ansi.notBoldNotFaint}'
    '${ansi.fgCyan}'
    ' incididunt'
    ' ${ansi.increasedIntensity}ut${ansi.normalIntensity}'
    ' ${ansi.decreasedIntensity}labore${ansi.normalIntensity}'
    '${ansi.fgDefault}'
    // Etc.
    ' ${ansi.underline}et${ansi.notUnderlined}'
    ' ${ansi.strike}dolore${ansi.notStriked}'
    ' ${ansi.hide}magna${ansi.notHidden}'
    ' ${ansi.blink}aliqua${ansi.notBlinking}.';

print(text);

Colors

4-bit colors

https://en.wikipedia.org/wiki/ANSI_escape_code#3-bit_and_4-bit

Foreground	Background
fgBlack	bgBlack
fgRed	bgRed
fgGreen	bgGreen
fgYellow	bgYellow
fgBlue	bgBlue
fgMagenta	bgMagenta
fgCyan	bgCyan
fgWhite	bgWhite
fgBrightBlack	bgBrightBlack
fgBrightRed	bgBrightRed
fgBrightGreen	bgBrightGreen
fgBrightYellow	bgBrightYellow
fgBrightBlue	bgBrightBlue
fgBrightMagenta	bgBrightMagenta
fgBrightCyan	bgBrightCyan
fgBrightWhite	bgBrightWhite

Example:

print('$fgBrightYellow$bgGreen Yellow text on green field $reset');

8-bit colors (256-color table)

https://en.wikipedia.org/wiki/ANSI_escape_code#8-bit

Templates for using a color from a 256-color table:

• Foreground:

  '${fg256Open}${colorIndex}${fg256Close}'
  

• Background:

  '${bg256Open}${colorIndex}${bg256Close}'
  

• Underline:

  '${underline256Open}${colorIndex}${underline256Close}'
  

Where colorIndex is the color index from the 256-color table. You can use predefined values from the following table:

Index	Name	Comment
0	black
1	red
2	green
3	yellow
4	blue
5	magenta
6	cyan
7	white
8	highBlack
9	highRed
10	highGreen
11	highYellow
12	highBlue
13	highMagenta
14	highCyan
15	highWhite
16-231	rgbNNN	N are numbers from 0 to 5 (6 × 6 × 6 cube (216 colors): 16 + 36 × r + 6 × g + b)
232-255	grayN	N is a number from 0 to 23 (grayscale from dark to light in 24 steps)

Example:

print('$fg256Open$highYellow$fg256Close$bg256Open$green$bg256Close Yellow text on green field $fgDefault');

You don't have to use templates and take the predefined values from the following table:

Index	Name	Comment
0	(fg/bg/underline)256Black
1	(fg/bg/underline)256Red
2	(fg/bg/underline)256Green
3	(fg/bg/underline)256Yellow
4	(fg/bg/underline)256Blue
5	(fg/bg/underline)256Magenta
6	(fg/bg/underline)256Cyan
7	(fg/bg/underline)256White
8	(fg/bg/underline)256HighBlack
9	(fg/bg/underline)256HighRed
10	(fg/bg/underline)256HighGreen
11	(fg/bg/underline)256HighYellow
12	(fg/bg/underline)256HighBlue
13	(fg/bg/underline)256HighMagenta
14	(fg/bg/underline)256HighCyan
15	(fg/bg/underline)256HighWhite
16..231	(fg/bg/underline)256RgbNNN	N are numbers from 0 to 5 (6 × 6 × 6 cube (216 colors): 16 + 36 × r + 6 × g + b)
232..255	(fg/bg/underline)256GrayN	N is a number from 0 to 23 (grayscale from dark to light in 24 steps)

Example:

print('$fg256HighYellow$bg256Green Yellow text on green field $reset');
print('$fg256Rgb550$bg256Rgb240 Yellow text on green field $reset');

You can use the following functions:

• to get color indexes:

  int rgb(int r, int g, int b);
  int gray(int level);
  

  Where r, g, b are values from 0 to 5. And where level is a value from 0 to 23.

  Example:

  print('$fg256Open${rgb(5, 5, 0)}$fg256Close$bg256Open${rgb(2, 4, 0)}$bg256Close Yellow text on green field $reset');
  print('$fg256Open${gray(16)}$fg256Close$bg256Open${gray(8)}$bg256Close Gray text on gray field $reset');
  

• to set the color:

  String fg256(int colorIndex);
  String bg256(int colorIndex);
  String underline256(int colorIndex);
  

  Example:

  print('${fg256(highYellow)}${bg256(green)} Yellow text on green field $reset');
  

24-bit colors (RGB)

https://en.wikipedia.org/wiki/ANSI_escape_code#24-bit

Templates for using a RGB color:

• Foreground:

  '${fgRgbOpen}${r};${g};${b}${fgRgbClose}'
  

• Background:

  '${bgRgbOpen}${r};${g};${b}${bgRgbClose}`'
  

• Underline:

  '${underlineRgbOpen}${r};${g};${b}${underlineRgbClose}'
  

Where r, g, b are values from 0 to 255.

You can use the following functions to dynamically generate a value:

String fgRgb(int r, int g, int b);
String bgRgb(int r, int g, int b);
String underlineRgb(int r, int g, int b);

Example:

print('${fgRgb(255, 255, 0)}${bgRgb(128, 192, 0)} Yellow text on green field $reset');

Reset color

You can reset the set color with fgDefault, bgDefault and underlineColorDefault. Or with reset, which will turn off all attributes.

Control sequences

Default constant	Template	Function	Description
cursorUp	${cursorUpOpen}[${n}]${cursorUpClose}	cursorUpN(n)	Moves the cursor up n (default 1) lines.
cursorDown	${cursorDownOpen}[${n}]${cursorDownClose}	cursorDownN(n)	Moves the cursor down n (default 1) lines.
cursorForward	${cursorForwardOpen}[${n}]${cursorForwardClose}	cursorForwardN(n)	Moves the cursor forward n (default 1) cells.
cursorBack	${cursorBackOpen}[${n}]${cursorBackClose}	cursorBackN(n)	Moves the cursor back n (default 1) cells.
cursorNextLine	${cursorNextLineOpen}[${n}]${cursorNextLineClose}	cursorNextLineN(n)	Moves cursor to beginning of the line n (default 1) lines down.
cursorPrevLine	${cursorPrevLineOpen}[${n}]${cursorPrevLineClose}	cursorPrevLineN(n)	Moves cursor to beginning of the line n (default 1) lines up.
cursorHPos	${cursorHPosOpen}[${n}]${cursorHPosClose}	cursorHPosN(n)	Moves the cursor to column n (default 1).
cursorPos	${cursorPosOpen}[${row};${col}]${cursorPosClose}	cursorPosTo(row, col)	Moves the cursor to row and col. The values are 1-based, and default to 1 (top left corner) if omitted.
cursorHVPos	${cursorHVPosOpen}[${row};${col}]${cursorHVPosClose}	cursorHVPosTo(row, col)	Same as cursorPos, but counts as a format effector function (like cr or lf) rather than an editor function (like cursorUp or cursorNextLine). This can lead to different handling in certain terminal modes.
clearScreen…	${clearScreenOpen}[${n}]${clearScreenClose}		Clears part of the screen. If n is 0 (or missing), clear from cursor to end of screen (clearScreenToEnd). If n is 1, clear from cursor to beginning of the screen (clearScreenToBegin). If n is 2, clear entire screen and moves cursor to upper left (clearScreen). If n is 3, clear entire screen and delete all lines saved in the scrollback buffer (clearScreenWithBuf).
eraseLine…	${eraseLineOpen}[${n}]${eraseLineClose}		Erases part of the line. If n is 0 (or missing), clear from cursor to the end of the line (eraseLineToEnd). If n is 1, clear from cursor to beginning of the line (eraseLineToBegin). If n is 2, clear entire line (eraseLine). Cursor position does not change.
scrollUp	${scrollUpOpen}[${n}]${scrollUpClose}	scrollUpN(n)	Scroll whole page up by n (default 1) lines. New lines are added at the bottom.
scrollDown	${scrollDownOpen}[${n}]${scrollDownClose}	scrollDownN(n)	Scroll whole page down by n (default 1) lines. New lines are added at the top.
hideCursor			Shows the cursor.
showCursor			Hides the cursor.
saveCursor			Saves the cursor position, encoding shift state and formatting attributes.
restoreCursor			Restores the cursor position, encoding shift state and formatting attributes from the previous saveCursor if any, otherwise resets these all to their defaults.

Analysis

You can find out if a string contains escape sequences by using the has method hasEscapeSequences and others.

With the removeEscapeSequences method and others, you can remove all escape sequences from a string, converting it to plain text.

Find all escape sequences in a string using the allEscapeSequences method and others.

Finally, you can convert the escape sequence into a readable form using the showEscapeSequences method:

const text =
    '${ansi.fgBrightGreen}Lorem ${ansi.fgGreen}ipsum...';
print(ansi.showEscapeSequences(text));

[CSI 92 SGR]Lorem [CSI 32 SGR]ipsum...

Escape sequences can also be recognized:

print(ansi.showEscapeSequences(text, recognizeSequences: true));

[fgBrightGreen]Lorem [fgGreen]ipsum...