First pass at improved colorizing

- colors setting now allows Always, Terminal, Never values
- poutput() and perror() honor these new settings

1 files changed, 143 insertions, 0 deletions

diff --git a/examples/colors.py b/examples/colors.py
new file mode 100755
index 00000000..59e108b6
--- /dev/null
+++ b/examples/colors.py
@@ -0,0 +1,143 @@
+#!/usr/bin/env python
+# coding=utf-8
+"""
+A sample application for cmd2. Demonstrating colorized output.
+
+Experiment with the command line options on the `speak` command to see how
+different output colors ca
+
+The colors setting has three possible values:
+
+Never
+    poutput() and pfeedback() strip all ANSI escape sequences
+    which instruct the terminal to colorize output
+
+Terminal
+    (the default value) poutput() and pfeedback() do not strip any ANSI escape
+    sequences when the output is a terminal, but if the output is a pipe or a
+    file the escape sequences are stripped. If you want colorized output you
+    must add ANSI escape sequences, preferably using some python color library
+    like `plumbum.colors`, `colorama`, `blessings`, or `termcolor`.
+
+Always
+    poutput() and pfeedback() never strip ANSI escape sequences, regardless of
+    the output destination
+
+
+"""
+
+import random
+import argparse
+
+import cmd2
+from colorama import Fore, Back
+
+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,
+}
+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,
+}
+
+class CmdLineApp(cmd2.Cmd):
+    """Example cmd2 application demonstrating colorized output."""
+
+    # Setting this true makes it run a shell command if a cmd2/cmd command doesn't exist
+    # default_to_shell = True
+    MUMBLES = ['like', '...', 'um', 'er', 'hmmm', 'ahh']
+    MUMBLE_FIRST = ['so', 'like', 'well']
+    MUMBLE_LAST = ['right?']
+
+    def __init__(self):
+        self.multiline_commands = ['orate']
+        self.maxrepeats = 3
+
+        # Add stuff to settable and shortcuts before calling base class initializer
+        self.settable['maxrepeats'] = 'max repetitions for speak command'
+        self.shortcuts.update({'&': 'speak'})
+
+        # Set use_ipython to True to enable the "ipy" command which embeds and interactive IPython shell
+        super().__init__(use_ipython=False)
+
+    speak_parser = argparse.ArgumentParser()
+    speak_parser.add_argument('-p', '--piglatin', action='store_true', help='atinLay')
+    speak_parser.add_argument('-s', '--shout', action='store_true', help='N00B EMULATION MODE')
+    speak_parser.add_argument('-r', '--repeat', type=int, help='output [n] times')
+    speak_parser.add_argument('-f', '--fg', help='foreground color to apply to output')
+    speak_parser.add_argument('-b', '--bg', help='background color to apply to output')
+    speak_parser.add_argument('words', nargs='+', help='words to say')
+
+    @cmd2.with_argparser(speak_parser)
+    def do_speak(self, args):
+        """Repeats what you tell me to."""
+        words = []
+        for word in args.words:
+            if args.piglatin:
+                word = '%s%say' % (word[1:], word[0])
+            if args.shout:
+                word = word.upper()
+            words.append(word)
+
+        repetitions = args.repeat or 1
+
+        color_on = ''
+        if args.fg and args.fg in FG_COLORS:
+            color_on += FG_COLORS[args.fg]
+        if args.bg and args.bg in BG_COLORS:
+            color_on += BG_COLORS[args.bg]
+        color_off = Fore.RESET + Back.RESET
+
+        for i in range(min(repetitions, self.maxrepeats)):
+            # .poutput handles newlines, and accommodates output redirection too
+            self.poutput(color_on + ' '.join(words) + color_off)
+
+    do_say = do_speak  # now "say" is a synonym for "speak"
+    do_orate = do_speak  # another synonym, but this one takes multi-line input
+
+    mumble_parser = argparse.ArgumentParser()
+    mumble_parser.add_argument('-r', '--repeat', type=int, help='how many times to repeat')
+    mumble_parser.add_argument('-f', '--fg', help='foreground color to apply to output')
+    mumble_parser.add_argument('-b', '--bg', help='background color to apply to output')
+    mumble_parser.add_argument('words', nargs='+', help='words to say')
+
+    @cmd2.with_argparser(mumble_parser)
+    def do_mumble(self, args):
+        """Mumbles what you tell me to."""
+        color_on = ''
+        if args.fg and args.fg in FG_COLORS:
+            color_on += FG_COLORS[args.fg]
+        if args.bg and args.bg in BG_COLORS:
+            color_on += BG_COLORS[args.bg]
+        color_off = Fore.RESET + Back.RESET
+
+        repetitions = args.repeat or 1
+        for i in range(min(repetitions, self.maxrepeats)):
+            output = []
+            if random.random() < .33:
+                output.append(random.choice(self.MUMBLE_FIRST))
+            for word in args.words:
+                if random.random() < .40:
+                    output.append(random.choice(self.MUMBLES))
+                output.append(word)
+            if random.random() < .25:
+                output.append(random.choice(self.MUMBLE_LAST))
+            self.poutput(color_on + ' '.join(output) + color_off)
+
+
+if __name__ == '__main__':
+    c = CmdLineApp()
+    c.cmdloop()