1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
|
from django.core.exceptions import FieldDoesNotExist, ImproperlyConfigured
from django.db.models import CharField, signals
from django.db.models.fields.files import ImageField
from colorfield.utils import get_image_file_background_color
from colorfield.validators import (
color_hex_validator,
color_hexa_validator,
color_rgb_validator,
color_rgba_validator,
)
from colorfield.widgets import ColorWidget
VALIDATORS_PER_FORMAT = {
"hex": color_hex_validator,
"hexa": color_hexa_validator,
"rgb": color_rgb_validator,
"rgba": color_rgba_validator,
}
DEFAULT_PER_FORMAT = {
"hex": "#FFFFFF",
"hexa": "#FFFFFFFF",
"rgb": "rgb(255, 255, 255)",
"rgba": "rgba(255, 255, 255, 1)",
}
class ColorField(CharField):
default_validators = []
def __init__(self, *args, **kwargs):
# works like Django choices, but does not restrict input to the given choices
self.samples = kwargs.pop("samples", None)
self.format = kwargs.pop("format", "hex").lower()
if self.format not in ["hex", "hexa", "rgb", "rgba"]:
raise ValueError(f"Unsupported color format: {self.format}")
self.default_validators = [VALIDATORS_PER_FORMAT[self.format]]
self.image_field = kwargs.pop("image_field", None)
if self.image_field:
kwargs.setdefault("blank", True)
kwargs.setdefault("max_length", 25)
if kwargs.get("null"):
kwargs.setdefault("blank", True)
kwargs.setdefault("default", None)
elif kwargs.get("blank"):
kwargs.setdefault("default", "")
else:
kwargs.setdefault("default", DEFAULT_PER_FORMAT[self.format])
super().__init__(*args, **kwargs)
if self.choices and self.samples:
raise ImproperlyConfigured(
"Invalid options: 'choices' and 'samples' are mutually exclusive, "
"you can set only one of the two for a ColorField instance."
)
def formfield(self, **kwargs):
palette = []
if self.choices:
choices = self.get_choices(include_blank=False)
palette = [choice[0] for choice in choices]
elif self.samples:
palette = [choice[0] for choice in self.samples]
kwargs["widget"] = ColorWidget(
attrs={
"default": self.get_default(),
"format": self.format,
"palette": palette,
# # TODO: in case choices is defined,
# # this will be used to hide the widget color spectrum
# 'palette_choices_only': bool(self.choices),
}
)
return super().formfield(**kwargs)
def contribute_to_class(self, cls, name, **kwargs):
super().contribute_to_class(cls, name, **kwargs)
if cls._meta.abstract:
return
if self.image_field:
signals.post_save.connect(self._update_from_image_field, sender=cls)
def deconstruct(self):
name, path, args, kwargs = super().deconstruct()
kwargs["samples"] = self.samples
kwargs["image_field"] = self.image_field
return name, path, args, kwargs
def _get_image_field_color(self, instance):
color = ""
image_file = getattr(instance, self.image_field)
if image_file:
with image_file.open() as _:
color = get_image_file_background_color(image_file, self.format)
return color
def _update_from_image_field(self, instance, created, *args, **kwargs):
if not instance or not instance.pk or not self.image_field:
return
# check if the field is a valid ImageField
try:
field_cls = instance._meta.get_field(self.image_field)
if not isinstance(field_cls, ImageField):
raise ImproperlyConfigured(
"Invalid 'image_field' field type, "
"expected an instance of 'models.ImageField'."
)
except FieldDoesNotExist as error:
raise ImproperlyConfigured(
"Invalid 'image_field' field name, "
f"{self.image_field!r} field not found."
) from error
# update value from picking color from image field
color = self._get_image_field_color(instance)
color_field_name = self.attname
color_field_value = getattr(instance, color_field_name, None)
if color_field_value != color and color:
color_field_value = color or self.default
# update in-memory value
setattr(instance, color_field_name, color_field_value)
# update stored value
manager = instance.__class__.objects
manager.filter(pk=instance.pk).update(
**{color_field_name: color_field_value}
)
|
