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Command: XpmRead | Section: 3 | Source: OpenBSD | File: XpmRead.3
XpmRead(3) libXpm functions XpmRead(3)
NAME
XpmRead - read an XPM file
SYNOPSIS
int XpmReadFileToImage(Display *display, char *filename,
XImage **image_return, XImage **shapeimage_return,
XpmAttributes *attributes);
int XpmReadFileToPixmap(Display *display, Drawable d, char *filename,
Pixmap *pixmap_return, Pixmap *shapemask_return,
XpmAttributes *attributes);
int XpmReadFileToXpmImage(char *filename, XpmImage *image,
XpmInfo *info);
int XpmReadFileToBuffer(char *filename, char **buffer_return);
int XpmReadFileToData(char *filename, char ***data_return);
ARGUMENTS
display
Specifies the connection to the X server.
filename
Specifies the file name to use.
image_return
Returns the image which is created.
shapeimage_return
Returns the shape mask image which is created if the color None
is used.
attributes
Specifies the location of a structure to get and store informa-
tion (or NULL).
buffer_return
Returns the buffer created.
data_return
Returns the data array created.
image Specifies the image structure location.
info Specifies the location of a structure to store possible informa-
tion (or NULL).
DESCRIPTION
XpmReadFileToImage
The XpmReadFileToImage() function reads in a file in the XPM format.
If the file cannot be opened it returns XpmOpenFailed. If the file can
be opened but does not contain valid XPM data, it returns XpmFileIn-
valid. If insufficient working storage is allocated, it returns Xpm-
NoMemory. If the passed XpmAttributes structure pointer is not NULL,
XpmReadFileToImage() looks for the following attributes: XpmVisual,
XpmColormap, XpmDepth, XpmColorSymbols, XpmExactColors, XpmCloseness,
XpmRGBCloseness, XpmAllocCloseColors, XpmReturnPixels, XpmReturnAl-
locPixels, XpmAllocColor, XpmFreeColors, XpmColorClosure, XpmReturnEx-
tensions, XpmReturnColorTable, XpmBitmapFormat, sets the XpmSize, the
XpmCharsPerPixel, and possibly the XpmHotspot attributes when return-
ing. As a backward compatibility feature, XpmReadFileToImage() also
looks for the XpmReturnInfos attributes. As specified in the table
(page 12), if the data related to the attributes XpmReturnExtensions,
XpmReturnColorTable, and XpmReturnInfos cannot be returned as requested
because of insufficient memory storage, XpmReadFileToImage() will
change the valuemask to mention this and will try to continue. So the
caller should check on this before accessing this data.
Note: The valuemask of the passed XpmAttributes must be set to some
valid value, at least zero, otherwise unpredictable errors can occur.
XpmReadFileToImage() allocates colors, as read from the file or possi-
bly overridden as specified in the XpmColorSymbols attributes. The
colors are allocated using the color settings for the visual specified
by the XpmColorKey attribute, which has the value XPM_MONO, XPM_GRAY4,
XPM_GRAY, or XPM_COLOR. If the XpmColorKey attribute is not set it is
determined by examining the type of visual. If no default value exists
for the specified visual, it first looks for other defaults nearer to
the monochrome visual type and secondly nearer to the color visual
type. If the color which is found is not valid (cannot be parsed), it
looks for another default one according to the same algorithm. If al-
locating a color fails, and the closeness attribute is set, it tries to
find a color already in the colormap that is closest to the desired
color, and uses that. If the alloc_close_colors attribute is set to
False, the found close color is not allocated but it is used anyway.
This is especially useful for applications which use a private colormap
containing read/write cells and have complete control over the col-
ormap. On the other hand, since in such a case there is no guarantee
that the color pixel will not change any time, this should be avoided
when using the default colormap. If no color can be found that is
within closeness of the Red, Green, and Blue components of the desired
color, it reverts to trying other default values as explained above.
For finer control over the closeness requirements of a particular icon,
the red_closeness, green_closeness, and blue_closeness attributes may
be used instead of the more general closeness attribute.
The RGB components are integers within the range 0 (black) to 65535
(white). A closeness of less than 10000, for example, will cause only
quite close colors to be matched, while a closeness of more than 50000
will allow quite dissimilar colors to match. Specifying a closeness of
more than 65535 will allow any color to match, thus forcing the icon to
be drawn in color no matter how bad the colormap is. The value 40000
seems to be about right for many situations requiring reasonable but
not perfect matches. With this setting the color must only be within
the same general area of the RGB cube as the desired color. If the ex-
actColors attribute is set it then returns XpmColorError, otherwise it
creates the images and returns XpmSuccess. If no color is found, and
no close color exists or is wanted, and all visuals have been ex-
hausted, XpmColorFailed is returned.
XpmReadFileToImage() returns the created image to image_return if not
NULL and possibly the created shapemask to shapeimage_return if not
NULL and the color None is used. If required it stores into the XpmAt-
tributes structure the list of the used pixels. When the image depth
is one, the image format is either as specified by the bitmap_format
attribute if set or ZPixmap. When the depth is different from one the
image format is always ZPixmap. When finished the caller must free the
images using XDestroyImage(3), the allocated colors using XFreeCol-
ors(3) or the application equivalent function when the standard Xlib
functions are not used, and possibly the data returned into the XpmAt-
tributes using XpmFreeAttributes(3). In addition, on systems which
support such features XpmReadFileToImage() deals with compressed files
by forking an uncompress or gzip process and reading from the piped re-
sult. It assumes that the specified file is compressed if the given
file name ends by .Z or .gz. In case the file name does not end so,
XpmReadFileToImage() looks for the given file name assuming it is not a
compressed file. And if instead of a file name NULL is passed to Xpm-
ReadFileToImage(), it reads from the standard input.
XpmReadFileToPixmap
The XpmReadFileToPixmap() function creates X images using XpmReadFile-
ToImage() and thus returns the same errors. In addition on success it
then creates the related pixmaps, using XPutImage(3), which are re-
turned to pixmap_return and shapemask_return if not NULL, and finally
destroys the created images using XDestroyImage(3). When finished the
caller must free the pixmaps using XFreePixmap(3), the allocated colors
using XFreeColors(3) or the application equivalent function when the
standard Xlib functions are not used, and possibly the data returned
into the XpmAttributes using XpmFreeAttributes(3).
XpmReadFileToBuffer
XpmReadFileToBuffer() allocates and fills a buffer from a file. Xpm-
ReadFileToBuffer() returns XpmOpenFailed if it cannot open the file,
returns XpmNoMemory if insufficient working storage is allocated, and
XpmSuccess otherwise. The allocated buffer returned by XpmReadFileTo-
Buffer() should be freed with XpmFree(3) when done.
As a convenience, the XpmReadFileToBuffer() and XpmWriteFileFrom-
Buffer(3) are provided to copy a file to a buffer and to write a file
from a buffer. Thus for instance one may decide to use XpmReadFileTo-
Buffer(), XpmCreatePixmapFromBuffer(3), and XpmFree(3) instead of Xpm-
ReadFileToPixmap(). On some systems this may lead to a performance im-
provement, since the parsing will be performed in memory, but it uses
more memory.
XpmReadFileToData
XpmReadFileToData() returns XpmOpenFailed if it cannot open the file,
XpmNoMemory if insufficient working storage is allocated, XpmFileIn-
valid if this is not a valid XPM file, and XpmSuccess otherwise. The
allocated data returned by XpmReadFileToData() should be freed with
XpmFree(3) when done.
XpmReadFileToXpmImage
The XpmReadFileToXpmImage() function reads in a file in the XPM format.
If the file cannot be opened it returns XpmOpenFailed. If the file can
be opened but does not contain valid XPM data, it returns XpmFileIn-
valid. If insufficient working storage is allocated, it returns Xpm-
NoMemory. On success it fills in the given XpmImage structure and re-
turns XpmSuccess.
SEE ALSO
XpmCreateBuffer(3), XpmCreateData(3), XpmCreateImage(3),
XpmCreatePixmap(3), XpmCreateXpmImage(3), XpmFreeAttributes(3),
XpmWrite(3)
X Version 11 libXpm 3.5.16 XpmRead(3)