xref: /openbmc/u-boot/tools/patman/terminal.py (revision 7f6a6db6) 
1# Copyright (c) 2011 The Chromium OS Authors.
2#
3# SPDX-License-Identifier:	GPL-2.0+
4#
5
6"""Terminal utilities
7
8This module handles terminal interaction including ANSI color codes.
9"""
10
11import os
12import sys
13
14# Selection of when we want our output to be colored
15COLOR_IF_TERMINAL, COLOR_ALWAYS, COLOR_NEVER = range(3)
16
17class Color(object):
18  """Conditionally wraps text in ANSI color escape sequences."""
19  BLACK, RED, GREEN, YELLOW, BLUE, MAGENTA, CYAN, WHITE = range(8)
20  BOLD = -1
21  BRIGHT_START = '\033[1;%dm'
22  NORMAL_START = '\033[22;%dm'
23  BOLD_START = '\033[1m'
24  RESET = '\033[0m'
25
26  def __init__(self, colored=COLOR_IF_TERMINAL):
27    """Create a new Color object, optionally disabling color output.
28
29    Args:
30      enabled: True if color output should be enabled. If False then this
31        class will not add color codes at all.
32    """
33    self._enabled = (colored == COLOR_ALWAYS or
34        (colored == COLOR_IF_TERMINAL and os.isatty(sys.stdout.fileno())))
35
36  def Start(self, color, bright=True):
37    """Returns a start color code.
38
39    Args:
40      color: Color to use, .e.g BLACK, RED, etc.
41
42    Returns:
43      If color is enabled, returns an ANSI sequence to start the given color,
44      otherwise returns empty string
45    """
46    if self._enabled:
47        base = self.BRIGHT_START if bright else self.NORMAL_START
48        return base % (color + 30)
49    return ''
50
51  def Stop(self):
52    """Retruns a stop color code.
53
54    Returns:
55      If color is enabled, returns an ANSI color reset sequence, otherwise
56      returns empty string
57    """
58    if self._enabled:
59        return self.RESET
60    return ''
61
62  def Color(self, color, text, bright=True):
63    """Returns text with conditionally added color escape sequences.
64
65    Keyword arguments:
66      color: Text color -- one of the color constants defined in this class.
67      text: The text to color.
68
69    Returns:
70      If self._enabled is False, returns the original text. If it's True,
71      returns text with color escape sequences based on the value of color.
72    """
73    if not self._enabled:
74        return text
75    if color == self.BOLD:
76        start = self.BOLD_START
77    else:
78        base = self.BRIGHT_START if bright else self.NORMAL_START
79        start = base % (color + 30)
80    return start + text + self.RESET
81