Fully document PIL.ImageWin

This commit is contained in:
Stephen Johnson 2013-10-13 22:19:12 -07:00
parent 4b4f090258
commit 7030e50b36
4 changed files with 108 additions and 69 deletions

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@ -20,44 +20,49 @@
import warnings
from PIL import Image
##
# The <b>ImageWin</b> module contains support to create and display
# images under Windows 95/98, NT, 2000 and later.
class HDC:
"""
Wraps a HDC integer. The resulting object can be passed to the
:py:meth:`~PIL.ImageWin.Dib.draw` and :py:meth:`~PIL.ImageWin.Dib.expose`
methods.
"""
def __init__(self, dc):
self.dc = dc
def __int__(self):
return self.dc
class HWND:
"""
Wraps a HWND integer. The resulting object can be passed to the
:py:meth:`~PIL.ImageWin.Dib.draw` and :py:meth:`~PIL.ImageWin.Dib.expose`
methods, instead of a DC.
"""
def __init__(self, wnd):
self.wnd = wnd
def __int__(self):
return self.wnd
##
# Create a Windows bitmap with the given mode and size. The mode can
# be one of "1", "L", "P", or "RGB".
#
# If the display requires a palette, this constructor creates a
# suitable palette and associates it with the image. For an "L" image,
# 128 greylevels are allocated. For an "RGB" image, a 6x6x6 colour
# cube is used, together with 20 greylevels.
#
# To make sure that palettes work properly under Windows, you must
# call the <b>palette</b> method upon certain events from Windows.
class Dib:
"""
A Windows bitmap with the given mode and size. The mode can be one of "1",
"L", "P", or "RGB".
##
# Create Windows bitmap.
#
# @param image Either a PIL image, or a mode string. If a
# mode string is used, a size must also be given. The
# mode can be one of "1", "L", "P", or "RGB".
# @param size If the first argument is a mode string, this
# defines the size of the image.
If the display requires a palette, this constructor creates a suitable
palette and associates it with the image. For an "L" image, 128 greylevels
are allocated. For an "RGB" image, a 6x6x6 colour cube is used, together
with 20 greylevels.
To make sure that palettes work properly under Windows, you must call the
**palette** method upon certain events from Windows.
:param image: Either a PIL image, or a mode string. If a mode string is
used, a size must also be given. The mode can be one of "1",
"L", "P", or "RGB".
:param size: If the first argument is a mode string, this
defines the size of the image.
"""
def __init__(self, image, size=None):
if hasattr(image, "mode") and hasattr(image, "size"):
@ -74,15 +79,15 @@ class Dib:
if image:
self.paste(image)
##
# Copy the bitmap contents to a device context.
#
# @param handle Device context (HDC), cast to a Python integer,
# or a HDC or HWND instance. In PythonWin, you can use the
# <b>GetHandleAttrib</b> method of the <b>CDC</b> class to get
# a suitable handle.
def expose(self, handle):
"""
Copy the bitmap contents to a device context.
:param handle: Device context (HDC), cast to a Python integer, or a HDC
or HWND instance. In PythonWin, you can use the
:py:meth:`CDC.GetHandleAttrib` to get a suitable handle.
"""
if isinstance(handle, HWND):
dc = self.image.getdc(handle)
try:
@ -94,6 +99,15 @@ class Dib:
return result
def draw(self, handle, dst, src=None):
"""
Same as expose, but allows you to specify where to draw the image, and
what part of it to draw.
The destination and source areas are given as 4-tuple rectangles. If
the source is omitted, the entire image is copied. If the source and
the destination have different sizes, the image is resized as
necessary.
"""
if not src:
src = (0,0) + self.size
if isinstance(handle, HWND):
@ -106,22 +120,22 @@ class Dib:
result = self.image.draw(handle, dst, src)
return result
##
# Installs the palette associated with the image in the
# given device context.
# <p>
# This method should be called upon <b>QUERYNEWPALETTE</b>
# and <b>PALETTECHANGED</b> events from Windows. If this
# method returns a non-zero value, one or more display
# palette entries were changed, and the image should be
# redrawn.
#
# @param handle Device context (HDC), cast to a Python integer,
# or an HDC or HWND instance.
# @return A true value if one or more entries were changed
# (this indicates that the image should be redrawn).
def query_palette(self, handle):
"""
Installs the palette associated with the image in the given device
context.
This method should be called upon **QUERYNEWPALETTE** and
**PALETTECHANGED** events from Windows. If this method returns a
non-zero value, one or more display palette entries were changed, and
the image should be redrawn.
:param handle: Device context (HDC), cast to a Python integer, or an
HDC or HWND instance.
:return: A true value if one or more entries were changed (this
indicates that the image should be redrawn).
"""
if isinstance(handle, HWND):
handle = self.image.getdc(handle)
try:
@ -132,17 +146,18 @@ class Dib:
result = self.image.query_palette(handle)
return result
##
# Paste a PIL image into the bitmap image.
#
# @param im A PIL image. The size must match the target region.
# If the mode does not match, the image is converted to the
# mode of the bitmap image.
# @param box A 4-tuple defining the left, upper, right, and
# lower pixel coordinate. If None is given instead of a
# tuple, all of the image is assumed.
def paste(self, im, box=None):
"""
Paste a PIL image into the bitmap image.
:param im: A PIL image. The size must match the target region.
If the mode does not match, the image is converted to the
mode of the bitmap image.
:param box: A 4-tuple defining the left, upper, right, and
lower pixel coordinate. If None is given instead of a
tuple, all of the image is assumed.
"""
im.load()
if self.mode != im.mode:
im = im.convert(self.mode)
@ -151,21 +166,23 @@ class Dib:
else:
self.image.paste(im.im)
##
# Load display memory contents from byte data.
#
# @param buffer A buffer containing display data (usually
# data returned from <b>tobytes</b>)
def frombytes(self, buffer):
"""
Load display memory contents from byte data.
:param buffer: A buffer containing display data (usually
data returned from <b>tobytes</b>)
"""
return self.image.frombytes(buffer)
##
# Copy display memory contents to bytes object.
#
# @return A bytes object containing display data.
def tobytes(self):
"""
Copy display memory contents to bytes object.
:return: A bytes object containing display data.
"""
return self.image.tobytes()
##

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@ -102,14 +102,6 @@ can be found here.
:undoc-members:
:show-inheritance:
:mod:`ImageWin` Module
----------------------
.. automodule:: PIL.ImageWin
:members:
:undoc-members:
:show-inheritance:
:mod:`JpegPresets` Module
-------------------------

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@ -0,0 +1,29 @@
.. py:module:: PIL.ImageWin
.. py:currentmodule:: PIL.ImageWin
:py:mod:`ImageWin` Module (Windows-only)
========================================
The :py:mod:`ImageWin` module contains support to create and display images on
Windows.
ImageWin can be used with PythonWin and other user interface toolkits that
provide access to Windows device contexts or window handles. For example,
Tkinter makes the window handle available via the winfo_id method:
.. code-block:: python
from PIL import ImageWin
dib = ImageWin.Dib(...)
hwnd = ImageWin.HWND(widget.winfo_id())
dib.draw(hwnd, xy)
.. autoclass:: PIL.ImageWin.Dib
:members:
.. autoclass:: PIL.ImageWin.HDC
.. autoclass:: PIL.ImageWin.HWND

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@ -21,4 +21,5 @@ Reference
ImageSequence
ImageStat
ImageTk
ImageWin
../PIL