mirror of
https://github.com/ae-utbm/sith3.git
synced 2024-09-20 09:58:05 +00:00
126 lines
4.2 KiB
Python
126 lines
4.2 KiB
Python
from pathlib import Path
|
|
|
|
from django.core.exceptions import FieldError
|
|
from django.db import models
|
|
from django.db.models.fields.files import ImageFieldFile
|
|
from PIL import Image
|
|
|
|
from core.utils import resize_image_explicit
|
|
|
|
|
|
class ResizedImageFieldFile(ImageFieldFile):
|
|
def get_resized_dimensions(self, image: Image.Image) -> tuple[int, int]:
|
|
"""Get the dimensions of the resized image.
|
|
|
|
If the width and height are given, they are used.
|
|
If only one is given, the other is calculated to keep the same ratio.
|
|
|
|
Returns:
|
|
Tuple of width and height
|
|
"""
|
|
width = self.field.width
|
|
height = self.field.height
|
|
if width is not None and height is not None:
|
|
return self.field.width, self.field.height
|
|
if width is None:
|
|
width = int(image.width * height / image.height)
|
|
elif height is None:
|
|
height = int(image.height * width / image.width)
|
|
return width, height
|
|
|
|
def get_name(self) -> str:
|
|
"""Get the name of the resized image.
|
|
|
|
If the field has a force_format attribute,
|
|
the extension of the file will be changed to match it.
|
|
Otherwise, the name is left unchanged.
|
|
|
|
Raises:
|
|
ValueError: If the image format is unknown
|
|
"""
|
|
if not self.field.force_format:
|
|
return self.name
|
|
formats = {val: key for key, val in Image.registered_extensions().items()}
|
|
new_format = self.field.force_format
|
|
if new_format in formats:
|
|
extension = formats[new_format]
|
|
else:
|
|
raise ValueError(f"Unknown format {new_format}")
|
|
return str(Path(self.file.name).with_suffix(extension))
|
|
|
|
def save(self, name, content, save=True): # noqa FBT002
|
|
content.file.seek(0)
|
|
img = Image.open(content.file)
|
|
width, height = self.get_resized_dimensions(img)
|
|
img_format = self.field.force_format or img.format
|
|
new_content = resize_image_explicit(img, (width, height), img_format)
|
|
name = self.get_name()
|
|
return super().save(name, new_content, save)
|
|
|
|
|
|
class ResizedImageField(models.ImageField):
|
|
"""A field that automatically resizes images to a given size.
|
|
|
|
This field is useful for profile pictures or product icons, for example.
|
|
|
|
The final size of the image is determined by the width and height parameters :
|
|
|
|
- If both are given, the image will be resized
|
|
to fit in a rectangle of width x height
|
|
- If only one is given, the other will be calculated to keep the same ratio
|
|
|
|
If the force_format parameter is given, the image will be converted to this format.
|
|
|
|
Examples:
|
|
To resize an image with a height of 100px, without changing the ratio,
|
|
and a format of WEBP :
|
|
|
|
```python
|
|
class Product(models.Model):
|
|
icon = ResizedImageField(height=100, force_format="WEBP")
|
|
```
|
|
|
|
To explicitly resize an image to 100x100px (but possibly change the ratio) :
|
|
|
|
```python
|
|
class Product(models.Model):
|
|
icon = ResizedImageField(width=100, height=100)
|
|
```
|
|
|
|
Raises:
|
|
FieldError: If neither width nor height is given
|
|
|
|
Args:
|
|
width: If given, the width of the resized image
|
|
height: If given, the height of the resized image
|
|
force_format: If given, the image will be converted to this format
|
|
"""
|
|
|
|
attr_class = ResizedImageFieldFile
|
|
|
|
def __init__(
|
|
self,
|
|
width: int | None = None,
|
|
height: int | None = None,
|
|
force_format: str | None = None,
|
|
**kwargs,
|
|
):
|
|
if width is None and height is None:
|
|
raise FieldError(
|
|
f"{self.__class__.__name__} requires "
|
|
"width, height or both, but got neither"
|
|
)
|
|
self.width = width
|
|
self.height = height
|
|
self.force_format = force_format
|
|
super().__init__(**kwargs)
|
|
|
|
def deconstruct(self):
|
|
name, path, args, kwargs = super().deconstruct()
|
|
if self.width is not None:
|
|
kwargs["width"] = self.width
|
|
if self.height is not None:
|
|
kwargs["height"] = self.height
|
|
kwargs["force_format"] = self.force_format
|
|
return name, path, args, kwargs
|