--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libervia/frontends/tools/css_color.py	Fri Jun 02 14:12:38 2023 +0200
@@ -0,0 +1,245 @@
+#!/usr/bin/env python3
+
+
+# CSS color parsing
+# Copyright (C) 2009-2021 Jérome-Poisson
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero 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 Affero General Public License for more details.
+
+# You should have received a copy of the GNU Affero General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from libervia.backend.core.log import getLogger
+
+log = getLogger(__name__)
+
+
+CSS_COLORS = {
+    "black": "000000",
+    "silver": "c0c0c0",
+    "gray": "808080",
+    "white": "ffffff",
+    "maroon": "800000",
+    "red": "ff0000",
+    "purple": "800080",
+    "fuchsia": "ff00ff",
+    "green": "008000",
+    "lime": "00ff00",
+    "olive": "808000",
+    "yellow": "ffff00",
+    "navy": "000080",
+    "blue": "0000ff",
+    "teal": "008080",
+    "aqua": "00ffff",
+    "orange": "ffa500",
+    "aliceblue": "f0f8ff",
+    "antiquewhite": "faebd7",
+    "aquamarine": "7fffd4",
+    "azure": "f0ffff",
+    "beige": "f5f5dc",
+    "bisque": "ffe4c4",
+    "blanchedalmond": "ffebcd",
+    "blueviolet": "8a2be2",
+    "brown": "a52a2a",
+    "burlywood": "deb887",
+    "cadetblue": "5f9ea0",
+    "chartreuse": "7fff00",
+    "chocolate": "d2691e",
+    "coral": "ff7f50",
+    "cornflowerblue": "6495ed",
+    "cornsilk": "fff8dc",
+    "crimson": "dc143c",
+    "darkblue": "00008b",
+    "darkcyan": "008b8b",
+    "darkgoldenrod": "b8860b",
+    "darkgray": "a9a9a9",
+    "darkgreen": "006400",
+    "darkgrey": "a9a9a9",
+    "darkkhaki": "bdb76b",
+    "darkmagenta": "8b008b",
+    "darkolivegreen": "556b2f",
+    "darkorange": "ff8c00",
+    "darkorchid": "9932cc",
+    "darkred": "8b0000",
+    "darksalmon": "e9967a",
+    "darkseagreen": "8fbc8f",
+    "darkslateblue": "483d8b",
+    "darkslategray": "2f4f4f",
+    "darkslategrey": "2f4f4f",
+    "darkturquoise": "00ced1",
+    "darkviolet": "9400d3",
+    "deeppink": "ff1493",
+    "deepskyblue": "00bfff",
+    "dimgray": "696969",
+    "dimgrey": "696969",
+    "dodgerblue": "1e90ff",
+    "firebrick": "b22222",
+    "floralwhite": "fffaf0",
+    "forestgreen": "228b22",
+    "gainsboro": "dcdcdc",
+    "ghostwhite": "f8f8ff",
+    "gold": "ffd700",
+    "goldenrod": "daa520",
+    "greenyellow": "adff2f",
+    "grey": "808080",
+    "honeydew": "f0fff0",
+    "hotpink": "ff69b4",
+    "indianred": "cd5c5c",
+    "indigo": "4b0082",
+    "ivory": "fffff0",
+    "khaki": "f0e68c",
+    "lavender": "e6e6fa",
+    "lavenderblush": "fff0f5",
+    "lawngreen": "7cfc00",
+    "lemonchiffon": "fffacd",
+    "lightblue": "add8e6",
+    "lightcoral": "f08080",
+    "lightcyan": "e0ffff",
+    "lightgoldenrodyellow": "fafad2",
+    "lightgray": "d3d3d3",
+    "lightgreen": "90ee90",
+    "lightgrey": "d3d3d3",
+    "lightpink": "ffb6c1",
+    "lightsalmon": "ffa07a",
+    "lightseagreen": "20b2aa",
+    "lightskyblue": "87cefa",
+    "lightslategray": "778899",
+    "lightslategrey": "778899",
+    "lightsteelblue": "b0c4de",
+    "lightyellow": "ffffe0",
+    "limegreen": "32cd32",
+    "linen": "faf0e6",
+    "mediumaquamarine": "66cdaa",
+    "mediumblue": "0000cd",
+    "mediumorchid": "ba55d3",
+    "mediumpurple": "9370db",
+    "mediumseagreen": "3cb371",
+    "mediumslateblue": "7b68ee",
+    "mediumspringgreen": "00fa9a",
+    "mediumturquoise": "48d1cc",
+    "mediumvioletred": "c71585",
+    "midnightblue": "191970",
+    "mintcream": "f5fffa",
+    "mistyrose": "ffe4e1",
+    "moccasin": "ffe4b5",
+    "navajowhite": "ffdead",
+    "oldlace": "fdf5e6",
+    "olivedrab": "6b8e23",
+    "orangered": "ff4500",
+    "orchid": "da70d6",
+    "palegoldenrod": "eee8aa",
+    "palegreen": "98fb98",
+    "paleturquoise": "afeeee",
+    "palevioletred": "db7093",
+    "papayawhip": "ffefd5",
+    "peachpuff": "ffdab9",
+    "peru": "cd853f",
+    "pink": "ffc0cb",
+    "plum": "dda0dd",
+    "powderblue": "b0e0e6",
+    "rosybrown": "bc8f8f",
+    "royalblue": "4169e1",
+    "saddlebrown": "8b4513",
+    "salmon": "fa8072",
+    "sandybrown": "f4a460",
+    "seagreen": "2e8b57",
+    "seashell": "fff5ee",
+    "sienna": "a0522d",
+    "skyblue": "87ceeb",
+    "slateblue": "6a5acd",
+    "slategray": "708090",
+    "slategrey": "708090",
+    "snow": "fffafa",
+    "springgreen": "00ff7f",
+    "steelblue": "4682b4",
+    "tan": "d2b48c",
+    "thistle": "d8bfd8",
+    "tomato": "ff6347",
+    "turquoise": "40e0d0",
+    "violet": "ee82ee",
+    "wheat": "f5deb3",
+    "whitesmoke": "f5f5f5",
+    "yellowgreen": "9acd32",
+    "rebeccapurple": "663399",
+}
+DEFAULT = "000000"
+
+
+def parse(raw_value, as_string=True):
+    """parse CSS color value and return normalised value
+
+    @param raw_value(unicode): CSS value
+    @param as_string(bool): if True return a string,
+        else return a tuple of int
+    @return (unicode, tuple): normalised value
+        if as_string is True, value is 3 or 4 hex words (e.g. u"ff00aabb")
+        else value is a 3 or 4 tuple of int (e.g.: (255, 0, 170, 187)).
+        If present, the 4th value is the alpha channel
+        If value can't be parsed, a warning message is logged, and DEFAULT is returned
+    """
+    raw_value = raw_value.strip().lower()
+    if raw_value.startswith("#"):
+        # we have a hexadecimal value
+        str_value = raw_value[1:]
+        if len(raw_value) in (3, 4):
+            str_value = "".join([2 * v for v in str_value])
+    elif raw_value.startswith("rgb"):
+        left_p = raw_value.find("(")
+        right_p = raw_value.find(")")
+        rgb_values = [v.strip() for v in raw_value[left_p + 1 : right_p].split(",")]
+        expected_len = 4 if raw_value.startswith("rgba") else 3
+        if len(rgb_values) != expected_len:
+            log.warning("incorrect value: {}".format(raw_value))
+            str_value = DEFAULT
+        else:
+            int_values = []
+            for rgb_v in rgb_values:
+                p_idx = rgb_v.find("%")
+                if p_idx == -1:
+                    # base 10 value
+                    try:
+                        int_v = int(rgb_v)
+                        if int_v > 255:
+                            raise ValueError("value exceed 255")
+                        int_values.append(int_v)
+                    except ValueError:
+                        log.warning("invalid int: {}".format(rgb_v))
+                        int_values.append(0)
+                else:
+                    # percentage
+                    try:
+                        int_v = int(int(rgb_v[:p_idx]) / 100.0 * 255)
+                        if int_v > 255:
+                            raise ValueError("value exceed 255")
+                        int_values.append(int_v)
+                    except ValueError:
+                        log.warning("invalid percent value: {}".format(rgb_v))
+                        int_values.append(0)
+            str_value = "".join(["{:02x}".format(v) for v in int_values])
+    elif raw_value.startswith("hsl"):
+        log.warning("hue-saturation-lightness not handled yet")  # TODO
+        str_value = DEFAULT
+    else:
+        try:
+            str_value = CSS_COLORS[raw_value]
+        except KeyError:
+            log.warning("unrecognised format: {}".format(raw_value))
+            str_value = DEFAULT
+
+    if as_string:
+        return str_value
+    else:
+        return tuple(
+            [
+                int(str_value[i] + str_value[i + 1], 16)
+                for i in range(0, len(str_value), 2)
+            ]
+        )