blob: 5c9e3eea20cf967a4f92477ac46789985b97ddbd [file] [log] [blame]
# SPDX-License-Identifier: GPL-2.0+
# Copyright (c) 2011 The Chromium OS Authors.
#
"""Terminal utilities
This module handles terminal interaction including ANSI color codes.
"""
from __future__ import print_function
import os
import re
import shutil
import sys
# Selection of when we want our output to be colored
COLOR_IF_TERMINAL, COLOR_ALWAYS, COLOR_NEVER = range(3)
# Initially, we are set up to print to the terminal
print_test_mode = False
print_test_list = []
# The length of the last line printed without a newline
last_print_len = None
# credit:
# stackoverflow.com/questions/14693701/how-can-i-remove-the-ansi-escape-sequences-from-a-string-in-python
ansi_escape = re.compile(r'\x1b(?:[@-Z\\-_]|\[[0-?]*[ -/]*[@-~])')
class PrintLine:
"""A line of text output
Members:
text: Text line that was printed
newline: True to output a newline after the text
colour: Text colour to use
"""
def __init__(self, text, newline, colour):
self.text = text
self.newline = newline
self.colour = colour
def __str__(self):
return 'newline=%s, colour=%s, text=%s' % (self.newline, self.colour,
self.text)
def CalcAsciiLen(text):
"""Calculate the length of a string, ignoring any ANSI sequences
When displayed on a terminal, ANSI sequences don't take any space, so we
need to ignore them when calculating the length of a string.
Args:
text: Text to check
Returns:
Length of text, after skipping ANSI sequences
>>> col = Color(COLOR_ALWAYS)
>>> text = col.Color(Color.RED, 'abc')
>>> len(text)
14
>>> CalcAsciiLen(text)
3
>>>
>>> text += 'def'
>>> CalcAsciiLen(text)
6
>>> text += col.Color(Color.RED, 'abc')
>>> CalcAsciiLen(text)
9
"""
result = ansi_escape.sub('', text)
return len(result)
def TrimAsciiLen(text, size):
"""Trim a string containing ANSI sequences to the given ASCII length
The string is trimmed with ANSI sequences being ignored for the length
calculation.
>>> col = Color(COLOR_ALWAYS)
>>> text = col.Color(Color.RED, 'abc')
>>> len(text)
14
>>> CalcAsciiLen(TrimAsciiLen(text, 4))
3
>>> CalcAsciiLen(TrimAsciiLen(text, 2))
2
>>> text += 'def'
>>> CalcAsciiLen(TrimAsciiLen(text, 4))
4
>>> text += col.Color(Color.RED, 'ghi')
>>> CalcAsciiLen(TrimAsciiLen(text, 7))
7
"""
if CalcAsciiLen(text) < size:
return text
pos = 0
out = ''
left = size
# Work through each ANSI sequence in turn
for m in ansi_escape.finditer(text):
# Find the text before the sequence and add it to our string, making
# sure it doesn't overflow
before = text[pos:m.start()]
toadd = before[:left]
out += toadd
# Figure out how much non-ANSI space we have left
left -= len(toadd)
# Add the ANSI sequence and move to the position immediately after it
out += m.group()
pos = m.start() + len(m.group())
# Deal with text after the last ANSI sequence
after = text[pos:]
toadd = after[:left]
out += toadd
return out
def Print(text='', newline=True, colour=None, limit_to_line=False):
"""Handle a line of output to the terminal.
In test mode this is recorded in a list. Otherwise it is output to the
terminal.
Args:
text: Text to print
newline: True to add a new line at the end of the text
colour: Colour to use for the text
"""
global last_print_len
if print_test_mode:
print_test_list.append(PrintLine(text, newline, colour))
else:
if colour:
col = Color()
text = col.Color(colour, text)
if newline:
print(text)
last_print_len = None
else:
if limit_to_line:
cols = shutil.get_terminal_size().columns
text = TrimAsciiLen(text, cols)
print(text, end='', flush=True)
last_print_len = CalcAsciiLen(text)
def PrintClear():
"""Clear a previously line that was printed with no newline"""
global last_print_len
if last_print_len:
print('\r%s\r' % (' '* last_print_len), end='', flush=True)
last_print_len = None
def SetPrintTestMode():
"""Go into test mode, where all printing is recorded"""
global print_test_mode
print_test_mode = True
def GetPrintTestLines():
"""Get a list of all lines output through Print()
Returns:
A list of PrintLine objects
"""
global print_test_list
ret = print_test_list
print_test_list = []
return ret
def EchoPrintTestLines():
"""Print out the text lines collected"""
for line in print_test_list:
if line.colour:
col = Color()
print(col.Color(line.colour, line.text), end='')
else:
print(line.text, end='')
if line.newline:
print()
class Color(object):
"""Conditionally wraps text in ANSI color escape sequences."""
BLACK, RED, GREEN, YELLOW, BLUE, MAGENTA, CYAN, WHITE = range(8)
BOLD = -1
BRIGHT_START = '\033[1;%dm'
NORMAL_START = '\033[22;%dm'
BOLD_START = '\033[1m'
RESET = '\033[0m'
def __init__(self, colored=COLOR_IF_TERMINAL):
"""Create a new Color object, optionally disabling color output.
Args:
enabled: True if color output should be enabled. If False then this
class will not add color codes at all.
"""
try:
self._enabled = (colored == COLOR_ALWAYS or
(colored == COLOR_IF_TERMINAL and
os.isatty(sys.stdout.fileno())))
except:
self._enabled = False
def Start(self, color, bright=True):
"""Returns a start color code.
Args:
color: Color to use, .e.g BLACK, RED, etc.
Returns:
If color is enabled, returns an ANSI sequence to start the given
color, otherwise returns empty string
"""
if self._enabled:
base = self.BRIGHT_START if bright else self.NORMAL_START
return base % (color + 30)
return ''
def Stop(self):
"""Returns a stop color code.
Returns:
If color is enabled, returns an ANSI color reset sequence,
otherwise returns empty string
"""
if self._enabled:
return self.RESET
return ''
def Color(self, color, text, bright=True):
"""Returns text with conditionally added color escape sequences.
Keyword arguments:
color: Text color -- one of the color constants defined in this
class.
text: The text to color.
Returns:
If self._enabled is False, returns the original text. If it's True,
returns text with color escape sequences based on the value of
color.
"""
if not self._enabled:
return text
if color == self.BOLD:
start = self.BOLD_START
else:
base = self.BRIGHT_START if bright else self.NORMAL_START
start = base % (color + 30)
return start + text + self.RESET