Major refactor of ANSI terminal formatting and control logic.

cliutils/ansiterm.nim

@@ -0,0 +1,112 @@
+import std/[nre, sequtils]
+
+const CSI = "\x1b["
+const RESET_FORMATTING* = "\x1b[0m"
+const ANSI_ESCAPE_CODE_ENDINGS*: seq[char] = toSeq('A'..'Z') & toSeq('a'..'z')
+let FORMATTING_REGEX* = re("\x1b\\[([0-9;]*)([a-zA-Z])")
+
+type
+  CursorType* = enum
+    ctBlockBlink = 1, ctBlock, ctUnderlineBlink, ctUnderline, ctBarBlink, ctBar
+
+  EraseMode* = enum
+    emToEnd, emToStart, emAll
+
+  TerminalColors* = enum
+    cBlack, cRed, cGreen, cYellow, cBlue, cMagenta, cCyan, cWhite
+
+
+proc stripFormatting*(text: string): string =
+  text.replace(FORMATTING_REGEX, "")
+
+proc stripAnsi*(text: string): string = stripFormatting(text)
+
+func ansiAwareSubstring*(s: string, start, length: int): string =
+  result = ""
+  var curAnsiEscCode = ""
+  var i = 0
+  var visibleLen = 0
+
+  while i < len(s) and visibleLen < length:
+
+    if len(s) > i + len(CSI) and
+      # We need to notice ANSI escape codes...
+       s[i..<i + len(CSI)] == CSI:
+      var j = i + len(CSI)
+      while j < s.len and s[j] notin ANSI_ESCAPE_CODE_ENDINGS: j += 1
+
+      # and remember it if we're before the start of the substring
+      if i < start: curAnsiEscCode = s[i..j]
+
+      # or add it without increasing our substring length
+      else: result.add(s[i..j])
+
+      # either way we want to pick up after it
+      i = j
+
+    else:
+      result.add(s[i])
+      visibleLen += 1
+
+    i += 1
+
+  result = curAnsiEscCode & result
+
+func color*(text: string, fg = cWhite, bg = cBlack): string =
+  return CSI & $int(fg) & ";" & $(int(bg) + 40) & "m" & text & RESET_FORMATTING
+
+
+func color*(text: string, fg: TerminalColors): string =
+  return CSI & $int(fg) & "m" & text & RESET_FORMATTING
+
+
+func color*(text: string, bg: TerminalColors): string =
+  return CSI & $(int(bg) + 40) & "m" & text & RESET_FORMATTING
+
+
+func invert*(text: string): string = return CSI & "7m" & text & RESET_FORMATTING
+func striketrough*(text: string): string = return CSI & "9m" & text & RESET_FORMATTING
+
+
+func eraseDisplay*(mode = emToEnd): string = return CSI & $int(mode) & "J"
+func eraseLine*(mode = emToEnd): string = return CSI & $int(mode) & "K"
+
+
+func blinkSlow*(text: string): string = return CSI & "5m" & text & RESET_FORMATTING
+func blinkFast*(text: string): string = return CSI & "6m" & text & RESET_FORMATTING
+
+
+func cursorUp*(n: int = 1): string = return CSI & $int(n) & "A"
+func cursorDown*(n: int = 1): string = return CSI & $int(n) & "B"
+func cursorForward*(n: int = 1): string = return CSI & $int(n) & "C"
+func cursorBackward*(n: int = 1): string = return CSI & $int(n) & "D"
+func cursorNextLine*(n: int = 1): string = return CSI & $int(n) & "E"
+func cursorPrevLine*(n: int = 1): string = return CSI & $int(n) & "F"
+func cursorHorizontalAbsolute*(col: int): string = return CSI & $int(col) & "G"
+
+
+func cursorPosition*(row, col: int): string =
+  return CSI & $int(row) & ";" & $int(col) & "H"
+
+
+proc cursorType*(ct: CursorType): string = return CSI & $int(ct) & " q"
+func saveCursorPosition*(): string = return CSI & "s"
+func restoreCursorPosition*(): string = return CSI & "u"
+
+
+func scrollUp*(n: int = 1): string = return CSI & $int(n) & "S"
+func scrollDown*(n: int = 1): string = return CSI & $int(n) & "T"
+
+
+proc write*(f: File, x, y: int, text: string) =
+  f.write(cursorPosition(y, x) & text)
+
+
+proc write*(x, y: int, text: string) =
+  stdout.write(cursorPosition(y, x) & text)
+
+
+proc setCursorType*(ct: CursorType) = stdout.write(cursorType(ct))
+proc setCursorPosition*(x, y: int) = stdout.write(cursorPosition(y, x))
+proc hideCursor*() = stdout.write(CSI & "?25l")
+proc showCursor*() = stdout.write(CSI & "?25l")