Introduce a Color class

This color class abstracts away all the possible representations of a
color in various UIs. These are color objects:

Color(9)              # red
Color('red')          # red
Color(196)            # red
Color('NEUTRAL')      # neutral (resets attributes)
Color()               # no effect

The configuration stores Color objects now, code that requires colors
doesn't have to worry about integer representations of colors.

One semantic change: when an empty color is passed as a priority color,
it will resort to an empty color instead of the neutral color. In
practice this should have the same visual effect. Test case
test_priority_color4 is adapted for this.

This commit is the result after an initial refactoring of the color code
(squashed its history into this one). @mruwek also contributed to this
refactoring, thanks for the help and the ideas to get to this point.

test/test_config.py

@@ -122,23 +122,19 @@ class ConfigTest(TopydoTest):
 
     def test_config20(self):
         """ No project color value. """
-        self.assertEqual(config("test/data/ConfigTest5.conf").project_color(),
-                         config().defaults["colorscheme"]["project_color"])
+        self.assertEqual(config("test/data/ConfigTest5.conf").project_color().color, 1)
 
     def test_config21(self):
         """ No context color value. """
-        self.assertEqual(config("test/data/ConfigTest5.conf").context_color(),
-                         config().defaults["colorscheme"]["context_color"])
+        self.assertEqual(config("test/data/ConfigTest5.conf").context_color().color, 5)
 
     def test_config22(self):
         """ No metadata color value. """
-        self.assertEqual(config("test/data/ConfigTest5.conf").metadata_color(),
-                         config().defaults["colorscheme"]["metadata_color"])
+        self.assertEqual(config("test/data/ConfigTest5.conf").metadata_color().color, 2)
 
     def test_config23(self):
         """ No link color value. """
-        self.assertEqual(config("test/data/ConfigTest5.conf").link_color(),
-                         config().defaults["colorscheme"]["link_color"])
+        self.assertEqual(config("test/data/ConfigTest5.conf").link_color().color, 6)
 
 if __name__ == '__main__':
     unittest.main()

test/test_list_format.py

@@ -679,7 +679,7 @@ C -
         self.assertEqual(self.output, result)
 
     @mock.patch('topydo.lib.ListFormat.get_terminal_size')
-    def test_list_format44(self, mock_terminal_size):
+    def test_list_format45(self, mock_terminal_size):
         """ Colorblocks should not affect truncating or right_alignment. """
         self.maxDiff = None
         mock_terminal_size.return_value = self.terminal_size(100, 25)

topydo/lib/Color.py

+# Topydo - A todo.txt client written in Python.
+# Copyright (C) 2016 Bram Schoenmakers <me@bramschoenmakers.nl>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+""" This module provides a class that represents a color. """
+
+
+class Color:
+    color_names_dict = {
+        'black': 0,
+        'red': 1,
+        'green': 2,
+        'yellow': 3,
+        'blue': 4,
+        'magenta': 5,
+        'cyan': 6,
+        'gray': 7,
+        'darkgray': 8,
+        'light-red': 9,
+        'light-green': 10,
+        'light-yellow': 11,
+        'light-blue': 12,
+        'light-magenta': 13,
+        'light-cyan': 14,
+        'white': 15,
+    }
+
+    def __init__(self, p_value=None):
+        """ p_value is user input, be it a word color or an xterm code """
+        self._value = None
+        self.color = p_value
+
+    @property
+    def color(self):
+        return self._value
+
+    @color.setter
+    def color(self, p_value):
+        try:
+            if not p_value:
+                self._value = None
+            elif p_value in Color.color_names_dict:
+                self._value = Color.color_names_dict[p_value]
+            else:
+                self._value = int(p_value)
+
+                # values not in the 256 range are normalized to be neutral
+                if not 0 <= self._value < 256:
+                    raise ValueError
+        except ValueError:
+            # garbage was entered, make it neutral, so at least some
+            # highlighting may take place
+            self._value = -1
+
+    def is_neutral(self):
+        """
+        A neutral color is the default color on the shell, setting this color
+        will reset all other attributes (background, foreground, decoration).
+        """
+        return self._value == -1
+
+    def is_valid(self):
+        """
+        Whether the color is a valid color.
+        """
+        return self._value is not None
+
+    def as_ansi(self, p_decoration='normal', p_background=False):
+        if not self.is_valid():
+            return ''
+        elif self.is_neutral():
+            return '\033[0m'
+
+        is_low_color = 0 <= self._value < 8
+        is_high_color = 8 <= self._value < 16
+        is_256 = 16 <= self._value < 255
+
+        decoration_dict = {
+            'normal': '0',
+            'bold': '1',
+            'faint': '2',
+            'italic': '3',
+            'underline': '4',
+        }
+        decoration = decoration_dict[p_decoration]
+
+        base = 40 if p_background else 30
+        if is_high_color:
+            color = '1;{}'.format(base + self._value - 8)
+        elif is_256:
+            color = '{};5;{}'.format(base + 8, self._value)
+        elif is_low_color:
+            color = str(base + self._value)
+        else:
+            color = ''
+
+        return '\033[{};{}m'.format(
+            decoration,
+            color
+        )
+

topydo/lib/Colors.py

-# Topydo - A todo.txt client written in Python.
-# Copyright (C) 2014 - 2015 Bram Schoenmakers <me@bramschoenmakers.nl>
-#
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-""" This module serves for managing output colors. """
-
-from topydo.lib.Config import config
-
-NEUTRAL_COLOR = '\033[0m'
-
-def int_to_ansi(p_int, p_decorator='normal', p_safe=True, p_background=''):
-    """
-    Returns ansi code for color based on xterm color id (0-255) and
-    decoration, where decoration can be one of: normal, bold, faint,
-    italic, or underline. When p_safe is True, resulting ansi code is
-    constructed in most compatible way, but with support for only base 16
-    colors.
-    """
-    decoration_dict = {
-            'normal': '0',
-            'bold': '1',
-            'faint': '2',
-            'italic': '3',
-            'underline': '4'
-    }
-
-    decoration = decoration_dict[p_decorator]
-
-    try:
-        if p_safe:
-            if p_background:
-                p_background = ';4{}'.format(p_background)
-
-            if 8 > int(p_int) >= 0:
-                return '\033[{};3{}{}m'.format(decoration, str(p_int), p_background)
-            elif 16 > int(p_int):
-                p_int = int(p_int) - 8
-                return '\033[{};1;3{}{}m'.format(decoration, str(p_int), p_background)
-
-        if 256 > int(p_int) >= 0:
-            if p_background:
-                p_background = ';48;5;{}'.format(str(p_int))
-
-            return '\033[{};38;5;{}{}m'.format(decoration, str(p_int), p_background)
-        else:
-            return NEUTRAL_COLOR
-    except ValueError:
-        return None
-
-def _name_to_int(p_color_name):
-    """ Returns xterm color id from color name. """
-    color_names_dict = {
-            'black': 0,
-            'red': 1,
-            'green': 2,
-            'yellow': 3,
-            'blue': 4,
-            'magenta': 5,
-            'cyan': 6,
-            'gray': 7,
-            'darkgray': 8,
-            'light-red': 9,
-            'light-green': 10,
-            'light-yellow': 11,
-            'light-blue': 12,
-            'light-magenta': 13,
-            'light-cyan': 14,
-            'white': 15,
-    }
-
-    try:
-        return color_names_dict[p_color_name]
-    except KeyError:
-        return 404
-
-def _name_to_ansi(p_color_name, p_decorator):
-    """ Returns ansi color code from color name. """
-    number = _name_to_int(p_color_name)
-
-    return int_to_ansi(number, p_decorator)
-
-def _get_ansi(p_color, p_decorator):
-    """ Returns ansi color code from color name or xterm color id. """
-    if p_color == '':
-        ansi = ''
-    else:
-        ansi = int_to_ansi(p_color, p_decorator, False)
-
-        if not ansi:
-            ansi = _name_to_ansi(p_color, p_decorator)
-
-    return ansi
-
-def _get_priority_colors():
-    pri_ansi_colors = dict()
-    pri_colors = config().priority_colors()
-
-    for pri in pri_colors:
-        color = _get_ansi(pri_colors[pri], 'normal')
-
-        if color == '':
-            color = NEUTRAL_COLOR
-
-        pri_ansi_colors[pri] = color
-
-    return pri_ansi_colors
-
-
-class Colors(object):
-    def __init__(self):
-        self.priority_colors = _get_priority_colors()
-        self.project_color = config().project_color()
-        self.context_color = config().context_color()
-        self.metadata_color = config().metadata_color()
-        self.link_color = config().link_color()
-
-    def get_project_color(self):
-        return _get_ansi(self.project_color, 'bold')
-
-    def get_context_color(self):
-        return _get_ansi(self.context_color, 'bold')
-
-    def get_metadata_color(self):
-        return _get_ansi(self.metadata_color, 'bold')
-
-    def get_link_color(self):
-        return _get_ansi(self.link_color, 'underline')
-
-    def get_priority_color(self, p_priority):
-        try:
-            priority_color = self.priority_colors[p_priority]
-        except KeyError:
-            priority_color = NEUTRAL_COLOR
-
-        return priority_color

topydo/lib/Config.py

@@ -18,6 +18,8 @@ import configparser
 import os
 import shlex
 
+from topydo.lib.Color import Color
+
 def home_config_path(p_filename):
     return os.path.join(os.path.expanduser('~'), p_filename)
 
@@ -237,53 +239,53 @@ class _Config:
         return [] if hidden_tags == '' else [tag.strip() for tag in
                                              hidden_tags.split(',')]
 
-    def priority_colors(self):
+    def priority_color(self, p_priority):
         """
         Returns a dict with priorities as keys and color numbers as value.
         """
-        pri_colors_str = self.cp.get('colorscheme', 'priority_colors')
-
         def _str_to_dict(p_string):
             pri_colors_dict = dict()
             for pri_color in p_string.split(','):
                 pri, color = pri_color.split(':')
-                pri_colors_dict[pri] = color
+                pri_colors_dict[pri] = Color(color)
 
             return pri_colors_dict
 
         try:
+            pri_colors_str = self.cp.get('colorscheme', 'priority_colors')
+
             if pri_colors_str == '':
-                pri_colors_dict = {'A': '', 'B': '', 'C': ''}
+                pri_colors_dict = _str_to_dict('A:-1,B:-1,C:-1')
             else:
                 pri_colors_dict = _str_to_dict(pri_colors_str)
         except ValueError:
             pri_colors_dict = _str_to_dict(self.defaults['colorscheme']['priority_colors'])
 
-        return pri_colors_dict
+        return pri_colors_dict[p_priority] if p_priority in pri_colors_dict else Color('NEUTRAL')
 
     def project_color(self):
         try:
-            return self.cp.get('colorscheme', 'project_color')
+            return Color(self.cp.getint('colorscheme', 'project_color'))
         except ValueError:
-            return int(self.defaults['colorscheme']['project_color'])
+            return Color(self.cp.get('colorscheme', 'project_color'))
 
     def context_color(self):
         try:
-            return self.cp.get('colorscheme', 'context_color')
+            return Color(self.cp.getint('colorscheme', 'context_color'))
         except ValueError:
-            return int(self.defaults['colorscheme']['context_color'])
+            return Color(self.cp.get('colorscheme', 'context_color'))
 
     def metadata_color(self):
         try:
-            return self.cp.get('colorscheme', 'metadata_color')
+            return Color(self.cp.getint('colorscheme', 'metadata_color'))
         except ValueError:
-            return int(self.defaults['colorscheme']['metadata_color'])
+            return Color(self.cp.get('colorscheme', 'metadata_color'))
 
     def link_color(self):
         try:
-            return self.cp.get('colorscheme', 'link_color')
+            return Color(self.cp.getint('colorscheme', 'link_color'))
         except ValueError:
-            return int(self.defaults['colorscheme']['link_color'])
+            return Color(self.cp.get('colorscheme', 'link_color'))
 
     def auto_creation_date(self):
         try:

topydo/lib/ListFormat.py

@@ -20,7 +20,7 @@ import arrow
 import re
 
 from topydo.lib.Config import config
-from topydo.lib.Colorblock import color_block
+from topydo.lib.ProgressColor import progress_color
 from topydo.lib.Utils import get_terminal_size, escape_ansi
 
 MAIN_PATTERN = (r'^({{(?P<before>.+?)}})?'
@@ -129,6 +129,12 @@ def _right_align(p_str):
 
     return p_str
 
+def color_block(p_todo, p_256_color):
+    return '{} {}'.format(
+        progress_color(p_todo, p_256_color).as_ansi(p_background=True),
+        config().priority_color(p_todo.priority()).as_ansi(),
+    )
+
 class ListFormatParser(object):
     """ Parser of format string. """
     def __init__(self, p_todolist, p_format=None):
@@ -195,9 +201,9 @@ class ListFormatParser(object):
             # relative completion date
             'X': lambda t: 'x ' + humanize_date(t.completion_date()) if t.is_completed() else '',
 
-            'z': lambda t: color_block(t) if config().colors() else ' ',
+            'z': lambda t: color_block(t, p_256_color=False) if config().colors() else ' ',
 
-            'Z': lambda t: color_block(t, p_safe=False) if config().colors() else ' ',
+            'Z': lambda t: color_block(t, p_256_color=True) if config().colors() else ' ',
         }
         self.format_list = self._preprocess_format()
 

topydo/lib/Colorblock.py → topydo/lib/ProgressColor.py

 # Topydo - A todo.txt client written in Python.
-# Copyright (C) 2014 - 2015 Bram Schoenmakers <me@bramschoenmakers.nl>
+# Copyright (C) 2016 Bram Schoenmakers <me@bramschoenmakers.nl>
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
@@ -16,22 +16,22 @@
 
 import re
 
-from topydo.lib.Colors import int_to_ansi, Colors
+from topydo.lib.Color import Color
 from topydo.lib.Recurrence import relative_date_to_date
 
-COLOR16_RANGE = [
-    10,  # light green
-    2,   # green
-    3,   # yellow
-    1,   # red
-]
+def progress_color(p_todo, p_256color=False):
+    color16_range = [
+        10,  # light green
+        2,   # green
+        3,   # yellow
+        1,   # red
+    ]
 
-# https://upload.wikimedia.org/wikipedia/en/1/15/Xterm_256color_chart.svg
-# a gradient from green to yellow to red
-COLOR256_RANGE = \
-    [22, 28, 34, 40, 46, 82, 118, 154, 190, 226, 220, 214, 208, 202, 196]
+    # https://upload.wikimedia.org/wikipedia/en/1/15/Xterm_256color_chart.svg
+    # a gradient from green to yellow to red
+    color256_range = \
+        [22, 28, 34, 40, 46, 82, 118, 154, 190, 226, 220, 214, 208, 202, 196]
 
-def progress_color_code(p_todo, p_safe=True):
     def get_length():
         """
         Returns the length of the p_todo item in days, based on the recurrence
@@ -76,26 +76,15 @@ def progress_color_code(p_todo, p_safe=True):
         else:
             return 0
 
-    def progress_to_color():
-        color_range = COLOR16_RANGE if p_safe else COLOR256_RANGE
-        progress = get_progress()
-
-        # TODO: remove linear scale to exponential scale
-        if progress > 1:
-            # overdue, return the last color
-            return color_range[-1]
-        else:
-            # not overdue, calculate position over color range excl. due date
-            # color
-            pos = round(progress * (len(color_range) - 2))
-            return color_range[pos]
-
-    return progress_to_color()
-
-def color_block(p_todo, p_safe=True):
-    color_code = progress_color_code(p_todo, p_safe)
-    ansi_code = int_to_ansi(color_code, p_safe=p_safe, p_background=color_code)
-    priority_color = Colors().get_priority_color(p_todo.priority())
-
-    return '{} {}'.format(ansi_code, priority_color)
-
+    color_range = color256_range if p_256color else color16_range
+    progress = get_progress()
+
+    # TODO: remove linear scale to exponential scale
+    if progress > 1:
+        # overdue, return the last color
+        return Color(color_range[-1])
+    else:
+        # not overdue, calculate position over color range excl. due date
+        # color
+        pos = round(progress * (len(color_range) - 2))
+        return Color(color_range[pos])

topydo/lib/prettyprinters/Colors.py

@@ -18,7 +18,7 @@
 
 import re
 
-from topydo.lib.Colors import NEUTRAL_COLOR, Colors
+from topydo.lib.Color import Color
 from topydo.lib.Config import config
 from topydo.lib.PrettyPrinterFilter import PrettyPrinterFilter
 
@@ -33,35 +33,35 @@ class PrettyPrinterColorFilter(PrettyPrinterFilter):
     def filter(self, p_todo_str, p_todo):
         """ Applies the colors. """
         if config().colors():
-            colorscheme = Colors()
-            priority_color = colorscheme.get_priority_color(p_todo.priority())
-            project_color = colorscheme.get_project_color()
-            context_color = colorscheme.get_context_color()
-            metadata_color = colorscheme.get_metadata_color()
-            link_color = colorscheme.get_link_color()
+            priority_color = config().priority_color(p_todo.priority())
+            project_color = config().project_color()
+            context_color = config().context_color()
+            metadata_color = config().metadata_color()
+            link_color = config().link_color()
+            neutral_color = Color('NEUTRAL')
 
             # color projects / contexts
             p_todo_str = re.sub(
                 r'\B(\+|@)(\S*\w)',
                 lambda m: (
-                    context_color if m.group(0)[0] == "@"
-                    else project_color) + m.group(0) + priority_color,
+                    context_color.as_ansi() if m.group(0)[0] == "@"
+                    else project_color.as_ansi()) + m.group(0) + priority_color.as_ansi(),
                 p_todo_str)
 
             # tags
             p_todo_str = re.sub(r'\b\S+:[^/\s]\S*\b',
-                                metadata_color + r'\g<0>' + priority_color,
+                                metadata_color.as_ansi() + r'\g<0>' + priority_color.as_ansi(),
                                 p_todo_str)
 
             # add link_color to any valid URL specified outside of the tag.
             p_todo_str = re.sub(r'(^|\s)(\w+:){1}(//\S+)',
-                                r'\1' + link_color + r'\2\3' + priority_color,
+                                r'\1' + link_color.as_ansi() + r'\2\3' + priority_color.as_ansi(),
                                 p_todo_str)
 
-            p_todo_str += NEUTRAL_COLOR
+            p_todo_str += neutral_color.as_ansi()
 
             # color by priority
-            p_todo_str = priority_color + p_todo_str
+            p_todo_str = priority_color.as_ansi() + p_todo_str
 
         return p_todo_str
 

topydo/ui/Colors.py

-# Topydo - A todo.txt client written in Python.
-# Copyright (C) 2015 Bram Schoenmakers <me@bramschoenmakers.nl>
-#
-# This program is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-""" Provides color support suitable for urwid. """
-
-COLOR_MAP = {
-    'black': 'black',
-    'red': 'dark red',
-    'green': 'dark green',
-    'yellow': 'brown',
-    'blue': 'dark blue',
-    'magenta': 'dark magenta',
-    'cyan': 'dark cyan',
-    'gray': 'light gray',
-    'darkgray': 'dark gray',
-    'light-red': 'light red',
-    'light-green': 'light green',
-    'light-yellow': 'yellow',
-    'light-blue': 'light blue',
-    'light-magenta': 'light magenta',
-    'light-cyan': 'light cyan',
-    'white': 'white',
-}
-
-# Add 256 urwid-like colors
-for i in range(256):
-    COLOR_MAP[str(i)] = 'h' + str(i)

topydo/ui/TodoWidget.py

@@ -16,7 +16,6 @@
 
 from topydo.lib.Config import config
 from topydo.lib.ListFormat import ListFormatParser
-from topydo.ui.Colors import COLOR_MAP
 
 import urwid
 
@@ -30,16 +29,21 @@ def _markup(p_todo, p_focus):
     item.
     """
 
-    priority_colors = config().priority_colors()
-
-    try:
-        # retrieve the assigned value in the config file
-        fg_color = priority_colors[p_todo.priority()]
-
-        # convert to a color that urwid understands
-        fg_color = COLOR_MAP[fg_color]
-    except KeyError:
-        fg_color = 'black' if p_focus else 'default'
+    def to_urwid_color(p_color):
+        """
+        Given a Color object, transform it to a color that urwid understands.
+        """
+        if not p_color.is_valid():
+            return 'black'
+        elif p_color.is_neutral():
+            return 'default'
+        else:
+            return 'h{}'.format(p_color.color)
+
+    # retrieve the assigned value in the config file
+    fg_color = config().priority_color(p_todo.priority())
+    fg_color = 'black' if p_focus and fg_color.is_neutral() else to_urwid_color(
+        fg_color)
 
     bg_color = 'light gray' if p_focus else 'default'