Moved code related to ANSI escape codes to new file called ansi.py

6 files changed, 154 insertions, 159 deletions

diff --git a/cmd2/ansi.py b/cmd2/ansi.py
new file mode 100644
index 00000000..889f1cb3
--- /dev/null
+++ b/cmd2/ansi.py
@@ -0,0 +1,118 @@
+# coding=utf-8
+"""Support for ANSI escape codes which are used for things like applying style to text"""
+import re
+from typing import Any
+
+import colorama
+from colorama import Fore, Back, Style
+from wcwidth import wcswidth
+
+# Regular expression to match ANSI escape codes
+ANSI_ESCAPE_RE = re.compile(r'\x1b[^m]*m')
+
+# Foreground color presets
+FG_COLORS = {
+    'black': Fore.BLACK,
+    'red': Fore.RED,
+    'green': Fore.GREEN,
+    'yellow': Fore.YELLOW,
+    'blue': Fore.BLUE,
+    'magenta': Fore.MAGENTA,
+    'cyan': Fore.CYAN,
+    'white': Fore.WHITE,
+    'gray': Fore.LIGHTBLACK_EX,
+    'lightred': Fore.LIGHTRED_EX,
+    'lightblue': Fore.LIGHTBLUE_EX,
+    'lightgreen': Fore.LIGHTGREEN_EX,
+    'lightyellow': Fore.LIGHTYELLOW_EX,
+    'lightmagenta': Fore.LIGHTMAGENTA_EX,
+    'lightcyan': Fore.LIGHTCYAN_EX,
+    'lightwhite': Fore.LIGHTWHITE_EX,
+    'reset': Fore.RESET,
+}
+
+# Background color presets
+BG_COLORS = {
+    'black': Back.BLACK,
+    'red': Back.RED,
+    'green': Back.GREEN,
+    'yellow': Back.YELLOW,
+    'blue': Back.BLUE,
+    'magenta': Back.MAGENTA,
+    'cyan': Back.CYAN,
+    'white': Back.WHITE,
+    'gray': Back.LIGHTBLACK_EX,
+    'lightred': Back.LIGHTRED_EX,
+    'lightblue': Back.LIGHTBLUE_EX,
+    'lightgreen': Back.LIGHTGREEN_EX,
+    'lightyellow': Back.LIGHTYELLOW_EX,
+    'lightmagenta': Back.LIGHTMAGENTA_EX,
+    'lightcyan': Back.LIGHTCYAN_EX,
+    'lightwhite': Back.LIGHTWHITE_EX,
+    'reset': Back.RESET,
+}
+
+
+def strip_ansi(text: str) -> str:
+    """Strip ANSI escape codes from a string.
+
+    :param text: string which may contain ANSI escape codes
+    :return: the same string with any ANSI escape codes removed
+    """
+    return ANSI_ESCAPE_RE.sub('', text)
+
+
+def ansi_safe_wcswidth(text: str) -> int:
+    """
+    Wraps wcswidth to make it compatible with colored strings
+
+    :param text: the string being measured
+    """
+    # Strip ANSI escape codes since they cause wcswidth to return -1
+    return wcswidth(strip_ansi(text))
+
+
+def style(text: Any, *, fg: str = '', bg: str = '', bold: bool = False, underline: bool = False) -> str:
+    """
+    Applies styles to text
+
+    :param text: Any object compatible with str.format()
+    :param fg: foreground color. Accepts color names like 'red' or 'blue'
+    :param bg: background color. Accepts color names like 'red' or 'blue'
+    :param bold: apply the bold style if True. Defaults to False.
+    :param underline: apply the underline style if True. Defaults to False.
+    """
+    values = []
+    text = "{}".format(text)
+
+    # Add styles
+    if fg:
+        try:
+            values.append(FG_COLORS[fg.lower()])
+        except KeyError:
+            raise ValueError('Color {} does not exist.'.format(fg))
+    if bg:
+        try:
+            values.append(BG_COLORS[bg.lower()])
+        except KeyError:
+            raise ValueError('Color {} does not exist.'.format(bg))
+    if bold:
+        values.append(Style.BRIGHT)
+    if underline:
+        underline_enable = colorama.ansi.code_to_chars(4)
+        values.append(underline_enable)
+
+    values.append(text)
+
+    # Remove styles
+    if fg:
+        values.append(FG_COLORS['reset'])
+    if bg:
+        values.append(BG_COLORS['reset'])
+    if bold:
+        values.append(Style.NORMAL)
+    if underline:
+        underline_disable = colorama.ansi.code_to_chars(24)
+        values.append(underline_disable)
+
+    return "".join(values)
diff --git a/cmd2/argparse_completer.py b/cmd2/argparse_completer.py
index 6b3f5298..c3f73552 100644
--- a/cmd2/argparse_completer.py
+++ b/cmd2/argparse_completer.py
@@ -68,8 +68,8 @@ from typing import List, Dict, Tuple, Callable, Union
 
 from colorama import Fore
 
+from .ansi import ansi_safe_wcswidth
 from .rl_utils import rl_force_redisplay
-from .utils import ansi_safe_wcswidth
 
 # attribute that can optionally added to an argparse argument (called an Action) to
 # define the completion choices for the argument. You may provide a Collection or a Function.
diff --git a/cmd2/cmd2.py b/cmd2/cmd2.py
index 75cee55d..20e26e15 100644
--- a/cmd2/cmd2.py
+++ b/cmd2/cmd2.py
@@ -45,6 +45,7 @@ from typing import Any, Callable, Dict, List, Mapping, Optional, Tuple, Type, Un
 import colorama
 from colorama import Fore
 
+from . import ansi
 from . import constants
 from . import plugin
 from . import utils
@@ -374,7 +375,7 @@ class Cmd(cmd.Cmd):
         self.quit_on_sigint = False  # Quit the loop on interrupt instead of just resetting prompt
 
         # Attributes which ARE dynamically settable at runtime
-        self.colors = constants.COLORS_TERMINAL
+        self.colors = constants.ANSI_TERMINAL
         self.continuation_prompt = '> '
         self.debug = False
         self.echo = False
@@ -559,7 +560,7 @@ class Cmd(cmd.Cmd):
 
         :return: prompt stripped of any ANSI escape codes
         """
-        return utils.strip_ansi(self.prompt)
+        return ansi.strip_ansi(self.prompt)
 
     @property
     def aliases(self) -> Dict[str, str]:
@@ -579,12 +580,11 @@ class Cmd(cmd.Cmd):
     def _decolorized_write(self, fileobj: IO, msg: str) -> None:
         """Write a string to a fileobject, stripping ANSI escape sequences if necessary
 
-        Honor the current colors setting, which requires us to check whether the
-        fileobject is a tty.
+        Honor the current colors setting, which requires us to check whether the fileobject is a tty.
         """
-        if self.colors.lower() == constants.COLORS_NEVER.lower() or \
-                (self.colors.lower() == constants.COLORS_TERMINAL.lower() and not fileobj.isatty()):
-            msg = utils.strip_ansi(msg)
+        if self.colors.lower() == constants.ANSI_NEVER.lower() or \
+                (self.colors.lower() == constants.ANSI_TERMINAL.lower() and not fileobj.isatty()):
+            msg = ansi.strip_ansi(msg)
         fileobj.write(msg)
 
     def poutput(self, msg: Any, *, end: str = '\n') -> None:
@@ -617,7 +617,7 @@ class Cmd(cmd.Cmd):
                           the message text already has the desired style. Defaults to True.
         """
         if add_color:
-            final_msg = utils.style(msg, fg='lightred')
+            final_msg = ansi.style(msg, fg='lightred')
         else:
             final_msg = "{}".format(msg)
         self._decolorized_write(sys.stderr, final_msg + end)
@@ -640,11 +640,11 @@ class Cmd(cmd.Cmd):
             final_msg = "{}".format(msg)
 
         if add_color:
-            final_msg = utils.style(final_msg, fg='lightred')
+            final_msg = ansi.style(final_msg, fg='lightred')
 
         if not self.debug:
             warning = "\nTo enable full traceback, run the following command:  'set debug true'"
-            final_msg += utils.style(warning, fg="lightyellow")
+            final_msg += ansi.style(warning, fg="lightyellow")
 
         # Set add_color to False since style has already been applied
         self.perror(final_msg, end=end, add_color=False)
@@ -692,8 +692,8 @@ class Cmd(cmd.Cmd):
                 # Don't attempt to use a pager that can block if redirecting or running a script (either text or Python)
                 # Also only attempt to use a pager if actually running in a real fully functional terminal
                 if functional_terminal and not self._redirecting and not self._in_py and not self._script_dir:
-                    if self.colors.lower() == constants.COLORS_NEVER.lower():
-                        msg_str = utils.strip_ansi(msg_str)
+                    if self.colors.lower() == constants.ANSI_NEVER.lower():
+                        msg_str = ansi.strip_ansi(msg_str)
 
                     pager = self.pager
                     if chop:
@@ -1278,7 +1278,7 @@ class Cmd(cmd.Cmd):
                 longest_match_length = 0
 
                 for cur_match in matches_to_display:
-                    cur_length = utils.ansi_safe_wcswidth(cur_match)
+                    cur_length = ansi.ansi_safe_wcswidth(cur_match)
                     if cur_length > longest_match_length:
                         longest_match_length = cur_length
             else:
@@ -2750,7 +2750,7 @@ class Cmd(cmd.Cmd):
                 widest = 0
                 # measure the commands
                 for command in cmds:
-                    width = utils.ansi_safe_wcswidth(command)
+                    width = ansi.ansi_safe_wcswidth(command)
                     if width > widest:
                         widest = width
                 # add a 4-space pad
@@ -3247,7 +3247,7 @@ class Cmd(cmd.Cmd):
             if args.__statement__.command == "pyscript":
                 warning = ("pyscript has been renamed and will be removed in the next release, "
                            "please use run_pyscript instead\n")
-                self.perror(utils.style(warning, fg="lightyellow"))
+                self.perror(ansi.style(warning, fg="lightyellow"))
 
         return py_return
 
@@ -3556,7 +3556,7 @@ class Cmd(cmd.Cmd):
         # Check if all commands ran
         if commands_run < len(history):
             warning = "Command {} triggered a stop and ended transcript generation early".format(commands_run)
-            self.perror(utils.style(warning, fg="lightyellow"))
+            self.perror(ansi.style(warning, fg="lightyellow"))
 
         # finally, we can write the transcript out to the file
         try:
@@ -3676,7 +3676,7 @@ class Cmd(cmd.Cmd):
             if args.__statement__.command == "load":
                 warning = ("load has been renamed and will be removed in the next release, "
                            "please use run_script instead\n")
-                self.perror(utils.style(warning, fg="lightyellow"))
+                self.perror(ansi.style(warning, fg="lightyellow"))
 
     # load has been deprecated
     do_load = do_run_script
@@ -3703,7 +3703,7 @@ class Cmd(cmd.Cmd):
         if args.__statement__.command == "_relative_load":
             warning = ("_relative_load has been renamed and will be removed in the next release, "
                        "please use _relative_run_script instead\n")
-            self.perror(utils.style(warning, fg="lightyellow"))
+            self.perror(ansi.style(warning, fg="lightyellow"))
 
         file_path = args.file_path
         # NOTE: Relative path is an absolute path, it is just relative to the current script directory
@@ -3724,7 +3724,6 @@ class Cmd(cmd.Cmd):
         import time
         import unittest
         import cmd2
-        from colorama import Style
         from .transcript import Cmd2TestCase
 
         class TestMyAppCase(Cmd2TestCase):
@@ -3740,12 +3739,12 @@ class Cmd(cmd.Cmd):
         verinfo = ".".join(map(str, sys.version_info[:3]))
         num_transcripts = len(transcripts_expanded)
         plural = '' if len(transcripts_expanded) == 1 else 's'
-        self.poutput(Style.BRIGHT + utils.center_text('cmd2 transcript test', pad='=') + Style.NORMAL)
+        self.poutput(ansi.style(utils.center_text('cmd2 transcript test', pad='='), bold=True))
         self.poutput('platform {} -- Python {}, cmd2-{}, readline-{}'.format(sys.platform, verinfo, cmd2.__version__,
                                                                              rl_type))
         self.poutput('cwd: {}'.format(os.getcwd()))
         self.poutput('cmd2 app: {}'.format(sys.argv[0]))
-        self.poutput(Style.BRIGHT + 'collected {} transcript{}'.format(num_transcripts, plural) + Style.NORMAL)
+        self.poutput(ansi.style('collected {} transcript{}'.format(num_transcripts, plural), bold=True))
 
         self.__class__.testfiles = transcripts_expanded
         sys.argv = [sys.argv[0]]  # the --test argument upsets unittest.main()
@@ -3758,8 +3757,8 @@ class Cmd(cmd.Cmd):
         if test_results.wasSuccessful():
             self._decolorized_write(sys.stderr, stream.read())
             finish_msg = '{0} transcript{1} passed in {2:.3f} seconds'.format(num_transcripts, plural, execution_time)
-            finish_msg = utils.style(utils.center_text(finish_msg, pad='='), fg="green")
-            self.poutput(Style.BRIGHT + finish_msg + Style.NORMAL)
+            finish_msg = ansi.style(utils.center_text(finish_msg, pad='='), fg="green", bold=True)
+            self.poutput(finish_msg)
         else:
             # Strip off the initial traceback which isn't particularly useful for end users
             error_str = stream.read()
@@ -3827,14 +3826,14 @@ class Cmd(cmd.Cmd):
                 # That will be included in the input lines calculations since that is where the cursor is.
                 num_prompt_terminal_lines = 0
                 for line in prompt_lines[:-1]:
-                    line_width = utils.ansi_safe_wcswidth(line)
+                    line_width = ansi.ansi_safe_wcswidth(line)
                     num_prompt_terminal_lines += int(line_width / terminal_size.columns) + 1
 
                 # Now calculate how many terminal lines are take up by the input
                 last_prompt_line = prompt_lines[-1]
-                last_prompt_line_width = utils.ansi_safe_wcswidth(last_prompt_line)
+                last_prompt_line_width = ansi.ansi_safe_wcswidth(last_prompt_line)
 
-                input_width = last_prompt_line_width + utils.ansi_safe_wcswidth(readline.get_line_buffer())
+                input_width = last_prompt_line_width + ansi.ansi_safe_wcswidth(readline.get_line_buffer())
 
                 num_input_terminal_lines = int(input_width / terminal_size.columns) + 1
 
diff --git a/cmd2/constants.py b/cmd2/constants.py
index f0cdf816..ac8822c0 100644
--- a/cmd2/constants.py
+++ b/cmd2/constants.py
@@ -2,11 +2,6 @@
 # coding=utf-8
 """Constants and definitions"""
 
-import re
-
-import colorama
-from colorama import Fore, Back
-
 # Used for command parsing, output redirection, tab completion and word
 # breaks. Do not change.
 QUOTES = ['"', "'"]
@@ -18,66 +13,11 @@ REDIRECTION_TOKENS = [REDIRECTION_PIPE, REDIRECTION_OUTPUT, REDIRECTION_APPEND]
 COMMENT_CHAR = '#'
 MULTILINE_TERMINATOR = ';'
 
-# Regular expression to match ANSI escape codes
-ANSI_ESCAPE_RE = re.compile(r'\x1b[^m]*m')
-
 LINE_FEED = '\n'
 
-# Values for colors setting
-COLORS_NEVER = 'Never'
-COLORS_TERMINAL = 'Terminal'
-COLORS_ALWAYS = 'Always'
-
-
-# Foreground color presets.
-FG_COLORS = {
-    'black': Fore.BLACK,
-    'red': Fore.RED,
-    'green': Fore.GREEN,
-    'yellow': Fore.YELLOW,
-    'blue': Fore.BLUE,
-    'magenta': Fore.MAGENTA,
-    'cyan': Fore.CYAN,
-    'white': Fore.WHITE,
-    'gray': Fore.LIGHTBLACK_EX,
-    'lightred': Fore.LIGHTRED_EX,
-    'lightblue': Fore.LIGHTBLUE_EX,
-    'lightgreen': Fore.LIGHTGREEN_EX,
-    'lightyellow': Fore.LIGHTYELLOW_EX,
-    'lightmagenta': Fore.LIGHTMAGENTA_EX,
-    'lightcyan': Fore.LIGHTCYAN_EX,
-    'lightwhite': Fore.LIGHTWHITE_EX,
-    'reset': Fore.RESET,
-}
-
-# Background color presets.
-BG_COLORS = {
-    'black': Back.BLACK,
-    'red': Back.RED,
-    'green': Back.GREEN,
-    'yellow': Back.YELLOW,
-    'blue': Back.BLUE,
-    'magenta': Back.MAGENTA,
-    'cyan': Back.CYAN,
-    'white': Back.WHITE,
-    'gray': Back.LIGHTBLACK_EX,
-    'lightred': Back.LIGHTRED_EX,
-    'lightblue': Back.LIGHTBLUE_EX,
-    'lightgreen': Back.LIGHTGREEN_EX,
-    'lightyellow': Back.LIGHTYELLOW_EX,
-    'lightmagenta': Back.LIGHTMAGENTA_EX,
-    'lightcyan': Back.LIGHTCYAN_EX,
-    'lightwhite': Back.LIGHTWHITE_EX,
-    'reset': Back.RESET,
-}
-
-
-# Underline style built upon Colorama class
-class UnderlineStyle(colorama.ansi.AnsiCodes):
-    ENABLE = 4
-    DISABLE = 24
-
-
-Underline = UnderlineStyle()
-
 DEFAULT_SHORTCUTS = {'?': 'help', '!': 'shell', '@': 'run_script', '@@': '_relative_run_script'}
+
+# Values for cmd2 setting that determines when to allow ANSI escape codes
+ANSI_NEVER = 'Never'
+ANSI_TERMINAL = 'Terminal'
+ANSI_ALWAYS = 'Always'
diff --git a/cmd2/transcript.py b/cmd2/transcript.py
index 316592ce..25a79310 100644
--- a/cmd2/transcript.py
+++ b/cmd2/transcript.py
@@ -13,7 +13,7 @@ import re
 import unittest
 from typing import Tuple
 
-from . import utils
+from . import ansi, utils
 
 
 class Cmd2TestCase(unittest.TestCase):
@@ -56,13 +56,13 @@ class Cmd2TestCase(unittest.TestCase):
     def _test_transcript(self, fname: str, transcript):
         line_num = 0
         finished = False
-        line = utils.strip_ansi(next(transcript))
+        line = ansi.strip_ansi(next(transcript))
         line_num += 1
         while not finished:
             # Scroll forward to where actual commands begin
             while not line.startswith(self.cmdapp.visible_prompt):
                 try:
-                    line = utils.strip_ansi(next(transcript))
+                    line = ansi.strip_ansi(next(transcript))
                 except StopIteration:
                     finished = True
                     break
@@ -89,7 +89,7 @@ class Cmd2TestCase(unittest.TestCase):
             result = self.cmdapp.stdout.read()
             stop_msg = 'Command indicated application should quit, but more commands in transcript'
             # Read the expected result from transcript
-            if utils.strip_ansi(line).startswith(self.cmdapp.visible_prompt):
+            if ansi.strip_ansi(line).startswith(self.cmdapp.visible_prompt):
                 message = '\nFile {}, line {}\nCommand was:\n{}\nExpected: (nothing)\nGot:\n{}\n'.format(
                           fname, line_num, command, result)
                 self.assertTrue(not (result.strip()), message)
@@ -97,7 +97,7 @@ class Cmd2TestCase(unittest.TestCase):
                 self.assertFalse(stop, stop_msg)
                 continue
             expected = []
-            while not utils.strip_ansi(line).startswith(self.cmdapp.visible_prompt):
+            while not ansi.strip_ansi(line).startswith(self.cmdapp.visible_prompt):
                 expected.append(line)
                 try:
                     line = next(transcript)
diff --git a/cmd2/utils.py b/cmd2/utils.py
index a5b7f43f..812fa227 100644
--- a/cmd2/utils.py
+++ b/cmd2/utils.py
@@ -12,71 +12,9 @@ import threading
 import unicodedata
 from typing import Any, Iterable, List, Optional, TextIO, Union
 
-from colorama import Style
-from wcwidth import wcswidth
-
 from . import constants
 
 
-def strip_ansi(text: str) -> str:
-    """Strip ANSI escape codes from a string.
-
-    :param text: string which may contain ANSI escape codes
-    :return: the same string with any ANSI escape codes removed
-    """
-    return constants.ANSI_ESCAPE_RE.sub('', text)
-
-
-def ansi_safe_wcswidth(text: str) -> int:
-    """
-    Wraps wcswidth to make it compatible with colored strings
-
-    :param text: the string being measured
-    """
-    # Strip ANSI escape codes since they cause wcswidth to return -1
-    return wcswidth(strip_ansi(text))
-
-
-def style(text: Any, *, fg: str = '', bg: str = '', bold: bool = False, underline: bool = False) -> str:
-    """
-    Applies style to text
-
-    :param text: Any object compatible with str.format()
-    :param fg: foreground color. Accepts color names like 'red' or 'blue'
-    :param bg: background color. Accepts color names like 'red' or 'blue'
-    :param bold: apply the bold style if True. Defaults to False.
-    :param underline: apply the underline style if True. Defaults to False.
-    """
-    values = []
-    text = "{}".format(text)
-    if fg:
-        try:
-            values.append(constants.FG_COLORS[fg.lower()])
-        except KeyError:
-            raise ValueError('Color {} does not exist.'.format(fg))
-    if bg:
-        try:
-            values.append(constants.BG_COLORS[bg.lower()])
-        except KeyError:
-            raise ValueError('Color {} does not exist.'.format(bg))
-    if bold:
-        values.append(Style.BRIGHT)
-    if underline:
-        values.append(constants.Underline.ENABLE)
-
-    values.append(text)
-    if fg:
-        values.append(constants.FG_COLORS['reset'])
-    if bg:
-        values.append(constants.BG_COLORS['reset'])
-    if bold:
-        values.append(Style.NORMAL)
-    if underline:
-        values.append(constants.Underline.DISABLE)
-
-    return "".join(values)
-
-
 def is_quoted(arg: str) -> bool:
     """
     Checks if a string is quoted