2875 |
@code{display} property, this feature is available starting in Emacs 21. |
@code{display} property, this feature is available starting in Emacs 21. |
2876 |
|
|
2877 |
Emacs can display a number of different image formats; some of them |
Emacs can display a number of different image formats; some of them |
2878 |
are supported only if particular support libraries are installed on your |
are supported only if particular support libraries are installed on |
2879 |
machine. The supported image formats include XBM, XPM (needing the |
your machine. In some environments, Emacs allows loading image |
2880 |
|
libraries on demand; if so, the variable @code{image-library-alist} |
2881 |
|
can be used to modify the set of known names for these dynamic |
2882 |
|
libraries (though it is not posible to add new image formats). |
2883 |
|
|
2884 |
|
The supported image formats include XBM, XPM (needing the |
2885 |
libraries @code{libXpm} version 3.4k and @code{libz}), GIF (needing |
libraries @code{libXpm} version 3.4k and @code{libz}), GIF (needing |
2886 |
@code{libungif} 4.1.0), Postscript, PBM, JPEG (needing the |
@code{libungif} 4.1.0), Postscript, PBM, JPEG (needing the |
2887 |
@code{libjpeg} library version v6a), TIFF (needing @code{libtiff} v3.4), |
@code{libjpeg} library version v6a), TIFF (needing @code{libtiff} v3.4), |
2892 |
@code{pbm}, @code{jpeg}, @code{tiff}, and @code{png}. |
@code{pbm}, @code{jpeg}, @code{tiff}, and @code{png}. |
2893 |
|
|
2894 |
@defvar image-types |
@defvar image-types |
2895 |
|
@vindex image-types |
2896 |
This variable contains a list of those image type symbols that are |
This variable contains a list of those image type symbols that are |
2897 |
supported in the current configuration. |
potentially supported in the current configuration. |
2898 |
|
@emph{Potentially} here means that Emacs knows about the image types, |
2899 |
|
not necessarily that they can be loaded (they could depend on |
2900 |
|
unavailable dynamic libraries, for example). |
2901 |
|
|
2902 |
|
To know which image types are really available, use |
2903 |
|
@code{image-type-available-p}. |
2904 |
|
@end defvar |
2905 |
|
|
2906 |
|
@defvar image-library-alist |
2907 |
|
@vindex image-library-alist |
2908 |
|
This in an alist of image types vs external libraries needed to |
2909 |
|
display them. |
2910 |
|
|
2911 |
|
Each element is a list @code{(@var{IMAGE-TYPE} @var{LIBRARY}...)}, |
2912 |
|
where the car is a supported image format from @code{image-types}, and |
2913 |
|
the rest are strings giving alternate filenames for the corresponding |
2914 |
|
external libraries to load. |
2915 |
|
|
2916 |
|
They are tried in the order they appear on the list; if none of them |
2917 |
|
can be loaded, the running session of Emacs won't support the image |
2918 |
|
type. No entries are needed for @code{pbm} and @code{xbm} images; |
2919 |
|
they're always supported. |
2920 |
|
|
2921 |
|
This variable is ignored if the image libraries are statically linked |
2922 |
|
into Emacs. |
2923 |
@end defvar |
@end defvar |
2924 |
|
|
2925 |
|
@defun image-type-available-p type |
2926 |
|
@findex image-type-available-p |
2927 |
|
|
2928 |
|
This function returns non-nil if image type TYPE is available, i.e., |
2929 |
|
if images of this type can be loaded and displayed in Emacs. TYPE |
2930 |
|
should be one of the types contained in @code{image-types}. |
2931 |
|
|
2932 |
|
For image types whose support libraries are statically linked, this |
2933 |
|
function always returns @code{t}; for other image types, it returns |
2934 |
|
@code{t} if the dynamic library could be loaded, @code{nil} otherwise. |
2935 |
|
@end defun |
2936 |
|
|
2937 |
@menu |
@menu |
2938 |
* Image Descriptors:: How to specify an image for use in @code{:display}. |
* Image Descriptors:: How to specify an image for use in @code{:display}. |
2939 |
* XBM Images:: Special features for XBM format. |
* XBM Images:: Special features for XBM format. |