@c Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995, 1998, 1999, 2000, 2001,
@c 2002, 2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
@c See the file elisp.texi for copying conditions.
-@setfilename ../info/display
+@setfilename ../../info/display
@node Display, System Interface, Processes, Top
@chapter Emacs Display
text property changes, overlay property changes are not recorded in
the buffer's undo list.
+ Since more than one overlay can specify a property value for the
+same character, Emacs lets you specify a priority value of each
+overlay. You should not make assumptions about which overlay will
+prevail when there is a conflict and they have the same priority.
+
These functions read and set the properties of an overlay:
@defun overlay-get overlay prop
@item priority
@kindex priority @r{(overlay property)}
This property's value (which should be a nonnegative integer number)
-determines the priority of the overlay. The priority matters when two
-or more overlays cover the same character and both specify the same
-property; the one whose @code{priority} value is larger takes priority
-over the other. For the @code{face} property, the higher priority
-value does not completely replace the other; instead, its face
-attributes override the face attributes of the lower priority
-@code{face} property.
+determines the priority of the overlay. No priority, or @code{nil},
+means zero.
+
+The priority matters when two or more overlays cover the same
+character and both specify the same property; the one whose
+@code{priority} value is larger overrides the other. For the
+@code{face} property, the higher priority overlay's value does not
+completely override the other value; instead, its face attributes
+override the face attributes of the lower priority @code{face}
+property.
Currently, all overlays take priority over text properties. Please
avoid using negative priority values, as we have not yet decided just
The overlay-arrow string is displayed in any given buffer if the value
of @code{overlay-arrow-position} in that buffer points into that
-buffer. Thus, it works to can display multiple overlay arrow strings
+buffer. Thus, it is possible to display multiple overlay arrow strings
by creating buffer-local bindings of @code{overlay-arrow-position}.
However, it is usually cleaner to use
@code{overlay-arrow-variable-list} to achieve this result.
@code{display-images-p} to determine if images can in principle be
displayed (@pxref{Display Feature Testing}).
+@menu
+* Image Formats:: Supported image formats.
+* Image Descriptors:: How to specify an image for use in @code{:display}.
+* XBM Images:: Special features for XBM format.
+* XPM Images:: Special features for XPM format.
+* GIF Images:: Special features for GIF format.
+* PostScript Images:: Special features for PostScript format.
+* Other Image Types:: Various other formats are supported.
+* Defining Images:: Convenient ways to define an image for later use.
+* Showing Images:: Convenient ways to display an image once it is defined.
+* Image Cache:: Internal mechanisms of image display.
+@end menu
+
+@node Image Formats
+@subsection Image Formats
+@cindex image formats
+@cindex image types
+
Emacs can display a number of different image formats; some of them
are supported only if particular support libraries are installed on
your machine. In some environments, Emacs can load image
libraries @code{libXpm} version 3.4k and @code{libz}), GIF (requiring
@code{libungif} 4.1.0), PostScript, PBM, JPEG (requiring the
@code{libjpeg} library version v6a), TIFF (requiring @code{libtiff}
-v3.4), and PNG (requiring @code{libpng} 1.0.2).
+v3.4), PNG (requiring @code{libpng} 1.0.2), and SVG (requiring
+@code{librsvg} 2.0.0).
You specify one of these formats with an image type symbol. The image
type symbols are @code{xbm}, @code{xpm}, @code{gif}, @code{postscript},
-@code{pbm}, @code{jpeg}, @code{tiff}, and @code{png}.
+@code{pbm}, @code{jpeg}, @code{tiff}, @code{png}, and @code{svg}.
@defvar image-types
This variable contains a list of those image type symbols that are
@code{t} if the dynamic library could be loaded, @code{nil} otherwise.
@end defun
-@menu
-* Image Descriptors:: How to specify an image for use in @code{:display}.
-* XBM Images:: Special features for XBM format.
-* XPM Images:: Special features for XPM format.
-* GIF Images:: Special features for GIF format.
-* PostScript Images:: Special features for PostScript format.
-* Other Image Types:: Various other formats are supported.
-* Defining Images:: Convenient ways to define an image for later use.
-* Showing Images:: Convenient ways to display an image once it is defined.
-* Image Cache:: Internal mechanisms of image display.
-@end menu
-
@node Image Descriptors
@subsection Image Descriptors
@cindex image descriptor
For PNG images, specify image type @code{png}.
+ For SVG images, specify image type @code{svg}.
+
@node Defining Images
@subsection Defining Images