path: root/man/XpmRead.man

.\" Copyright (C) 1989-95 GROUPE BULL
.\"
.\" Permission is hereby granted, free of charge, to any person obtaining a copy
.\" of this software and associated documentation files (the "Software"), to
.\" deal in the Software without restriction, including without limitation the
.\" rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
.\" sell copies of the Software, and to permit persons to whom the Software is
.\" furnished to do so, subject to the following conditions:
.\"
.\" The above copyright notice and this permission notice shall be included in
.\" all copies or substantial portions of the Software.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
.\" IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
.\" FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
.\" GROUPE BULL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
.\" AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
.\" CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
.\"
.\" Except as contained in this notice, the name of GROUPE BULL shall not be
.\" used in advertising or otherwise to promote the sale, use or other dealings
.\" in this Software without prior written authorization from GROUPE BULL.
.\"
.hw XImage
.TH XpmRead __libmansuffix__ __xorgversion__ "libXpm functions"
.SH NAME
XpmRead \- read an XPM file

.SH SYNOPSIS
.nf
.HP
.BI "int XpmReadFileToImage(Display *" display ", char *" filename ,
.BI "XImage **" image_return ", XImage **" shapeimage_return ,
.BI "XpmAttributes *" attributes );
.HP
.BI "int XpmReadFileToPixmap(Display *" display ", Drawable " d ", char *" filename ,
.BI "Pixmap *" pixmap_return ", Pixmap *" shapemask_return ,
.BI "XpmAttributes *" attributes );
.HP
.BI "int XpmReadFileToXpmImage(char *" filename ", XpmImage *" image ,
.BI "XpmInfo *" info );
.HP
.BI "int XpmReadFileToBuffer(char *" filename ", char **" buffer_return );
.HP
.BI "int XpmReadFileToData(char *" filename ", char ***" data_return );
.fi

.SH ARGUMENTS
.IP   \fIdisplay\fP li
Specifies the connection to the X server.
.IP   \fIfilename\fP li
Specifies the file name to use.
.IP   \fIimage_return\fP li
Returns the image which is created.
.IP   \fIshapeimage_return\fP li
Returns the shape mask image which is created if the color None is used.
.IP   \fIattributes\fP li
Specifies the location of a structure to get and store information (or NULL).
.IP   \fIbuffer_return\fP li
Returns the buffer created.
.IP   \fIdata_return\fP li
Returns the data array created.
.IP   \fIimage\fP li
Specifies the image structure location.
.IP   \fIinfo\fP li
Specifies the location of a structure to store possible information (or NULL).

.SH DESCRIPTION
.SS XpmReadFileToImage
.PP
The
.BR XpmReadFileToImage ()
function reads in a file in the XPM format.
If the file cannot be opened it returns
.BR XpmOpenFailed .
If the file can be opened but does not contain valid XPM data, it returns
.BR XpmFileInvalid .
If insufficient working storage is allocated, it returns
.BR XpmNoMemory .
If the passed XpmAttributes structure pointer is not NULL,
.BR XpmReadFileToImage ()
looks for the following attributes:
XpmVisual, XpmColormap, XpmDepth, XpmColorSymbols, XpmExactColors, XpmCloseness,
XpmRGBCloseness, XpmAllocCloseColors, XpmReturnPixels, XpmReturnAllocPixels, XpmAllocColor,
XpmFreeColors, XpmColorClosure, XpmReturnExtensions, XpmReturnColorTable, XpmBitmapFormat,
sets the XpmSize, the XpmCharsPerPixel, and possibly the XpmHotspot attributes when returning.
As a backward compatibility feature,
.BR 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,
.BR XpmReadFileToImage ()
will change the valuemask to mention this and will try to continue.
So the caller should check on this before accessing this data.
.PP
Note: The valuemask of the passed XpmAttributes must be set to some valid value,
at least zero, otherwise unpredictable errors can occur.
.PP
.BR XpmReadFileToImage ()
allocates colors, as read from the file or possibly 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 allocating 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 colormap.
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.
.PP
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 exactColors attribute is set it then returns
.BR XpmColorError ,
otherwise it creates the images and returns
.BR XpmSuccess .
If no color is found, and no close color exists or is wanted,
and all visuals have been exhausted,
.B XpmColorFailed
is returned.
.PP
.BR XpmReadFileToImage ()
returns the created image to
.I image_return
if not NULL and possibly the created shapemask to
.I shapeimage_return
if not NULL and the color None is used.
If required it stores into the XpmAttributes 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
.BR XDestroyImage (__libmansuffix__),
the allocated colors using
.BR XFreeColors (__libmansuffix__)
or the application equivalent function
when the standard Xlib functions are not used,
and possibly the data returned into the XpmAttributes using
.BR XpmFreeAttributes (__libmansuffix__).
In addition, on systems which support such features
.BR XpmReadFileToImage ()
deals with compressed files by forking an uncompress or gzip process and
reading from the piped result. 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,
.BR 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
.BR XpmReadFileToImage (),
it reads from the standard input.

.SS XpmReadFileToPixmap
The
.BR XpmReadFileToPixmap ()
function creates X images using
.BR XpmReadFileToImage ()
and thus returns the same errors.
In addition on success it then creates the related pixmaps, using
.BR XPutImage (__libmansuffix__),
which are returned to
.I pixmap_return
and
.I shapemask_return
if not NULL, and finally destroys the created images using
.BR XDestroyImage (__libmansuffix__).
When finished the caller must free the pixmaps using
.BR XFreePixmap (__libmansuffix__),
the allocated colors using
.BR XFreeColors (__libmansuffix__)
or the application equivalent function when the standard Xlib functions
are not used, and possibly the data returned into the XpmAttributes using
.BR XpmFreeAttributes (__libmansuffix__).

.SS XpmReadFileToBuffer
.PP
.BR XpmReadFileToBuffer ()
allocates and fills a buffer from a file.
.BR XpmReadFileToBuffer ()
returns
.B XpmOpenFailed
if it cannot open the file, returns
.B XpmNoMemory
if insufficient working storage is allocated, and
.B XpmSuccess
otherwise. The allocated buffer returned by
.BR XpmReadFileToBuffer ()
should be freed with
.BR XpmFree (__libmansuffix__)
when done.
.PP
As a convenience, the
.BR XpmReadFileToBuffer ()
and
.BR XpmWriteFileFromBuffer (__libmansuffix__)
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
.BR XpmReadFileToBuffer (),
.BR XpmCreatePixmapFromBuffer (__libmansuffix__),
and
.BR XpmFree (__libmansuffix__)
instead of
.BR XpmReadFileToPixmap ().
On some systems this may lead to a performance improvement,
since the parsing will be performed in memory, but it uses more memory.

.SS XpmReadFileToData
.PP
.BR XpmReadFileToData ()
returns
.B XpmOpenFailed
if it cannot open the file,
.B XpmNoMemory
if insufficient working storage is allocated,
.B XpmFileInvalid
if this is not a valid XPM file, and
.B XpmSuccess
otherwise.
The allocated data returned by
.BR XpmReadFileToData ()
should be freed with
.BR XpmFree (__libmansuffix__)
when done.

.SS XpmReadFileToXpmImage
.PP
The
.BR XpmReadFileToXpmImage ()
function reads in a file in the XPM format.
If the file cannot be opened it returns
.BR XpmOpenFailed .
If the file can be opened but does not contain valid XPM data, it returns
.BR XpmFileInvalid .
If insufficient working storage is allocated, it returns
.BR XpmNoMemory .
On success it fills in the given XpmImage structure and returns
.BR XpmSuccess .

.SH "SEE ALSO"
.ad l
.nh
.BR XpmCreateBuffer (__libmansuffix__),
.BR XpmCreateData (__libmansuffix__),
.BR XpmCreateImage (__libmansuffix__),
.BR XpmCreatePixmap (__libmansuffix__),
.BR XpmCreateXpmImage (__libmansuffix__),
.BR XpmFreeAttributes (__libmansuffix__),
.BR XpmWrite (__libmansuffix__)