def __init__(self, mode=None, size=None, color=None, source=None):
"""
``mode`` must be one of the constants in the ``MODES`` set,
``size`` is a sequence of two integers (width and height of the new image);
``color`` is a sequence of integers, one for each
component of the image, used to initialize all the pixels to the
same value;
``source`` can be a sequence of integers of the appropriate size and format
that is copied as-is in the buffer of the new image or an existing image;
in Python 2.x ``source`` can also be an instance of ``str`` and is interpreted
as a sequence of bytes.
``color`` and ``source`` are mutually exclusive and if
they are both omitted the image is initialized to transparent
black (all the bytes in the buffer have value 16 in the ``YV12``
mode, 255 in the ``CMYK*`` modes and 0 for everything else).
If ``source`` is present and is an image, ``mode`` and/or ``size``
can be omitted; if they are specified and are different from the
source mode and/or size, the source image is converted.
"""
self._mode = None
self._size = None
self._buffer = None
self.info = {}
if mode is not None:
if mode not in MODES:
raise ValueError("{} is not a valid mode.".format(mode))
self._mode = mode
if size is not None:
try:
self._size = ImageSize(*size)
except:
raise ValueError("size must be an iterable returning 2 " "elements, not {}".format(size))
if source:
# TODO: deal with source having a value
if color:
warnings.warn("color is disregarded when source is not None.")
if isinstance(source, ImageMixin):
if size:
if size != source.size:
# deal with resizing
pass
else:
pass
else:
self._size = source.size
if mode is None:
self._mode = source.mode
else:
# deal with converting color
pass
else:
# source had better be an iterable that we can stuff
# into a buffer
# python2 supports a byte string
if util.py27 and isinstance(source, str):
pass
elif size and mode:
assert self.size.width % self.mode.x_divisor == 0
assert self.size.height % self.mode.y_divisor == 0
if color and len(color) != self.components:
raise ValueError(
"color must be an iterable with {} values, "
"one for each component in {}.".format(self.components, self.mode)
)
# initialize buffer to the correct size and color
_buffer = util.initialize_buffer(mode, size, color)
# TODO: externalize this structure building stuff
line_struct = type(
"LineBuffer",
(Line,),
{
"_fields_": [("pixels", mode.pixel_cls * self.size.width)],
"image_cls": self.__class__,
"mode": self.mode,
},
)
image_struct = type("ImageBuffer", (_Image,), {"_fields_": [("lines", line_struct * self.size.height)]})
self._image_data = image_struct.from_buffer(_buffer)
self._buffer = memoryview(_buffer)
else:
raise ValueError(
"You must minimally specify a source from "
"which to build the image or a mode and size "
"with which to initialize the buffer."
)
def setUpClass(cls):
cls.pixels = {}
for mode in MODES:
buffer = util.initialize_buffer(mode, (1, 1))
cls.pixels[mode] = mode.pixel_cls.from_buffer(buffer)