home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
SGI Freeware 1999 August
/
SGI Freeware 1999 August.iso
/
dist
/
fw_xemacs.idb
/
usr
/
freeware
/
lib
/
xemacs-20.4
/
info
/
lispref.info-34.z
/
lispref.info-34
Encoding:
Amiga
Atari
Commodore
DOS
FM Towns/JPY
Macintosh
Macintosh JP
Macintosh to JP
NeXTSTEP
RISC OS/Acorn
Shift JIS
UTF-8
Wrap
GNU Info File
|
1998-05-21
|
49.6 KB
|
1,151 lines
This is Info file ../../info/lispref.info, produced by Makeinfo version
1.68 from the input file lispref.texi.
Edition History:
GNU Emacs Lisp Reference Manual Second Edition (v2.01), May 1993 GNU
Emacs Lisp Reference Manual Further Revised (v2.02), August 1993 Lucid
Emacs Lisp Reference Manual (for 19.10) First Edition, March 1994
XEmacs Lisp Programmer's Manual (for 19.12) Second Edition, April 1995
GNU Emacs Lisp Reference Manual v2.4, June 1995 XEmacs Lisp
Programmer's Manual (for 19.13) Third Edition, July 1995 XEmacs Lisp
Reference Manual (for 19.14 and 20.0) v3.1, March 1996 XEmacs Lisp
Reference Manual (for 19.15 and 20.1, 20.2) v3.2, April, May 1997
Copyright (C) 1990, 1991, 1992, 1993, 1994, 1995 Free Software
Foundation, Inc. Copyright (C) 1994, 1995 Sun Microsystems, Inc.
Copyright (C) 1995, 1996 Ben Wing.
Permission is granted to make and distribute verbatim copies of this
manual provided the copyright notice and this permission notice are
preserved on all copies.
Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided that the
entire resulting derived work is distributed under the terms of a
permission notice identical to this one.
Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that this permission notice may be stated in a
translation approved by the Foundation.
Permission is granted to copy and distribute modified versions of
this manual under the conditions for verbatim copying, provided also
that the section entitled "GNU General Public License" is included
exactly as in the original, and provided that the entire resulting
derived work is distributed under the terms of a permission notice
identical to this one.
Permission is granted to copy and distribute translations of this
manual into another language, under the above conditions for modified
versions, except that the section entitled "GNU General Public License"
may be included in a translation approved by the Free Software
Foundation instead of in the original English.
File: lispref.info, Node: Fonts, Next: Colors, Prev: Faces, Up: Faces and Window-System Objects
Fonts
=====
This section describes how to work with font specifier and font
instance objects, which encapsulate fonts in the window system.
* Menu:
* Font Specifiers:: Specifying how a font will appear.
* Font Instances:: What a font specifier gets instanced as.
* Font Instance Names:: The name of a font instance.
* Font Instance Size:: The size of a font instance.
* Font Instance Characteristics:: Display characteristics of font instances.
* Font Convenience Functions:: Convenience functions that automatically
instance and retrieve the properties
of a font specifier.
File: lispref.info, Node: Font Specifiers, Next: Font Instances, Up: Fonts
Font Specifiers
---------------
- Function: font-specifier-p OBJECT
This predicate returns `t' if OBJECT is a font specifier, and
`nil' otherwise.
File: lispref.info, Node: Font Instances, Next: Font Instance Names, Prev: Font Specifiers, Up: Fonts
Font Instances
--------------
- Function: font-instance-p OBJECT
This predicate returns `t' if OBJECT is a font instance, and `nil'
otherwise.
- Function: make-font-instance NAME &optional DEVICE NOERROR
This function creates a new font-instance object of the specified
name. DEVICE specifies the device this object applies to and
defaults to the selected device. An error is signalled if the
font is unknown or cannot be allocated; however, if NOERROR is
non-`nil', `nil' is simply returned in this case.
The returned object is a normal, first-class lisp object. The way
you "deallocate" the font is the way you deallocate any other lisp
object: you drop all pointers to it and allow it to be garbage
collected. When these objects are GCed, the underlying X data is
deallocated as well.
File: lispref.info, Node: Font Instance Names, Next: Font Instance Size, Prev: Font Instances, Up: Fonts
Font Instance Names
-------------------
- Function: list-fonts PATTERN &optional DEVICE
This function returns a list of font names matching the given
pattern. DEVICE specifies which device to search for names, and
defaults to the currently selected device.
- Function: font-instance-name FONT-INSTANCE
This function returns the name used to allocate FONT-INSTANCE.
- Function: font-instance-truename FONT-INSTANCE
This function returns the canonical name of the given font
instance. Font names are patterns which may match any number of
fonts, of which the first found is used. This returns an
unambiguous name for that font (but not necessarily its only
unambiguous name).
File: lispref.info, Node: Font Instance Size, Next: Font Instance Characteristics, Prev: Font Instance Names, Up: Fonts
Font Instance Size
------------------
- Function: x-font-size FONT
This function returns the nominal size of the given font. This is
done by parsing its name, so it's likely to lose. X fonts can be
specified (by the user) in either pixels or 10ths of points, and
this returns the first one it finds, so you have to decide which
units the returned value is measured in yourself ...
- Function: x-find-larger-font FONT &optional DEVICE
This function loads a new, slightly larger version of the given
font (or font name). Returns the font if it succeeds, `nil'
otherwise. If scalable fonts are available, this returns a font
which is 1 point larger. Otherwise, it returns the next larger
version of this font that is defined.
- Function: x-find-smaller-font FONT &optional DEVICE
This function loads a new, slightly smaller version of the given
font (or font name). Returns the font if it succeeds, `nil'
otherwise. If scalable fonts are available, this returns a font
which is 1 point smaller. Otherwise, it returns the next smaller
version of this font that is defined.
File: lispref.info, Node: Font Instance Characteristics, Next: Font Convenience Functions, Prev: Font Instance Size, Up: Fonts
Font Instance Characteristics
-----------------------------
- Function: font-instance-properties FONT
This function returns the properties (an alist or `nil') of
FONT-INSTANCE.
- Function: x-make-font-bold FONT &optional DEVICE
Given an X font specification, this attempts to make a "bold" font.
If it fails, it returns `nil'.
- Function: x-make-font-unbold FONT &optional DEVICE
Given an X font specification, this attempts to make a non-bold
font. If it fails, it returns `nil'.
- Function: x-make-font-italic FONT &optional DEVICE
Given an X font specification, this attempts to make an "italic"
font. If it fails, it returns `nil'.
- Function: x-make-font-unitalic FONT &optional DEVICE
Given an X font specification, this attempts to make a non-italic
font. If it fails, it returns `nil'.
- Function: x-make-font-bold-italic FONT &optional DEVICE
Given an X font specification, this attempts to make a
"bold-italic" font. If it fails, it returns `nil'.
File: lispref.info, Node: Font Convenience Functions, Prev: Font Instance Characteristics, Up: Fonts
Font Convenience Functions
--------------------------
- Function: font-name FONT &optional DOMAIN
This function returns the name of the FONT in the specified
DOMAIN, if any. FONT should be a font specifier object and DOMAIN
is normally a window and defaults to the selected window if
omitted. This is equivalent to using `specifier-instance' and
applying `font-instance-name' to the result.
- Function: font-truename FONT &optional DOMAIN
This function returns the truename of the FONT in the specified
DOMAIN, if any. FONT should be a font specifier object and DOMAIN
is normally a window and defaults to the selected window if
omitted. This is equivalent to using `specifier-instance' and
applying `font-instance-truename' to the result.
- Function: font-properties FONT &optional DOMAIN
This function returns the properties of the FONT in the specified
DOMAIN, if any. FONT should be a font specifier object and DOMAIN
is normally a window and defaults to the selected window if
omitted. This is equivalent to using `specifier-instance' and
applying `font-instance-properties' to the result.
File: lispref.info, Node: Colors, Prev: Fonts, Up: Faces and Window-System Objects
Colors
======
* Menu:
* Color Specifiers:: Specifying how a color will appear.
* Color Instances:: What a color specifier gets instanced as.
* Color Instance Properties:: Properties of color instances.
* Color Convenience Functions:: Convenience functions that automatically
instance and retrieve the properties
of a color specifier.
File: lispref.info, Node: Color Specifiers, Next: Color Instances, Up: Colors
Color Specifiers
----------------
- Function: color-specifier-p OBJECT
This function returns non-`nil' if OBJECT is a color specifier.
File: lispref.info, Node: Color Instances, Next: Color Instance Properties, Prev: Color Specifiers, Up: Colors
Color Instances
---------------
A "color-instance object" is an object describing the way a color
specifier is instanced in a particular domain. Functions such as
`face-background-instance' return a color-instance object. For example,
(face-background-instance 'default (next-window))
=> #<color-instance moccasin 47=(FFFF,E4E4,B5B5) 0x678d>
The color-instance object returned describes the way the background
color of the `default' face is displayed in the next window after the
selected one.
- Function: color-instance-p OBJECT
This function returns non-`nil' if OBJECT is a color-instance.
File: lispref.info, Node: Color Instance Properties, Next: Color Convenience Functions, Prev: Color Instances, Up: Colors
Color Instance Properties
-------------------------
- Function: color-instance-name COLOR-INSTANCE
This function returns the name used to allocate COLOR-INSTANCE.
- Function: color-instance-rgb-components COLOR-INSTANCE
This function returns a three element list containing the red,
green, and blue color components of COLOR-INSTANCE.
(color-instance-rgb-components
(face-background-instance 'default (next-window)))
=> (65535 58596 46517)
File: lispref.info, Node: Color Convenience Functions, Prev: Color Instance Properties, Up: Colors
Color Convenience Functions
---------------------------
- Function: color-name COLOR &optional DOMAIN
This function returns the name of the COLOR in the specified
DOMAIN, if any. COLOR should be a color specifier object and
DOMAIN is normally a window and defaults to the selected window if
omitted. This is equivalent to using `specifier-instance' and
applying `color-instance-name' to the result.
- Function: color-rgb-components COLOR &optional DOMAIN
This function returns the RGB components of the COLOR in the
specified DOMAIN, if any. COLOR should be a color specifier
object and DOMAIN is normally a window and defaults to the
selected window if omitted. This is equivalent to using
`specifier-instance' and applying `color-instance-rgb-components'
to the result.
(color-rgb-components (face-background 'default (next-window)))
=> (65535 58596 46517)
File: lispref.info, Node: Glyphs, Next: Annotations, Prev: Faces and Window-System Objects, Up: Top
Glyphs
******
A "glyph" is an object that is used for pixmaps and images of all
sorts, as well as for things that "act" like pixmaps, such as
non-textual strings ("annotations") displayed in a buffer or in the
margins. It is used in begin-glyphs and end-glyphs attached to extents,
marginal and textual annotations, overlay arrows (`overlay-arrow-*'
variables), toolbar buttons, mouse pointers, frame icons, truncation and
continuation markers, and the like. (Basically, any place there is an
image or something that acts like an image, there will be a glyph object
representing it.)
The actual image that is displayed (as opposed to its position or
clipping) is defined by an "image specifier" object contained within
the glyph. The separation between an image specifier object and a
glyph object is made because the glyph includes other properties than
just the actual image: e.g. the face it is displayed in (for text
images), the alignment of the image (when it is in a buffer), etc.
- Function: glyphp OBJECT
This function returns `t' if OBJECT is a glyph.
* Menu:
* Glyph Functions:: Functions for working with glyphs.
* Images:: Graphical images displayed in a frame.
* Glyph Types:: Each glyph has a particular type.
* Mouse Pointer:: Controlling the mouse pointer.
* Redisplay Glyphs:: Glyphs controlling various redisplay functions.
* Subwindows:: Inserting an externally-controlled subwindow
into a buffer.
File: lispref.info, Node: Glyph Functions, Next: Images, Up: Glyphs
Glyph Functions
===============
* Menu:
* Creating Glyphs:: Creating new glyphs.
* Glyph Properties:: Accessing and modifying a glyph's properties.
* Glyph Convenience Functions::
Convenience functions for accessing particular
properties of a glyph.
* Glyph Dimensions:: Determining the height, width, etc. of a glyph.
File: lispref.info, Node: Creating Glyphs, Next: Glyph Properties, Up: Glyph Functions
Creating Glyphs
---------------
- Function: make-glyph &optional SPEC-LIST TYPE
This function creates a new glyph object of type TYPE.
SPEC-LIST is used to initialize the glyph's image. It is
typically an image instantiator (a string or a vector; *Note Image
Specifiers::), but can also be a list of such instantiators (each
one in turn is tried until an image is successfully produced), a
cons of a locale (frame, buffer, etc.) and an instantiator, a list
of such conses, or any other form accepted by
`canonicalize-spec-list'. *Note Specifiers:: for more information
about specifiers.
TYPE specifies the type of the glyph, which specifies in which
contexts the glyph can be used, and controls the allowable image
types into which the glyph's image can be instantiated. TYPE
should be one of `buffer' (used for glyphs in an extent, the
modeline, the toolbar, or elsewhere in a buffer), `pointer' (used
for the mouse-pointer), or `icon' (used for a frame's icon), and
defaults to `buffer'. *Note Glyph Types::.
- Function: make-glyph-internal &optional TYPE
This function creates a new, uninitialized glyph of type TYPE.
- Function: make-pointer-glyph &optional SPEC-LIST
This function is equivalent to calling `make-glyph' with a TYPE of
`pointer'.
- Function: make-icon-glyph &optional SPEC-LIST
This function is equivalent to calling `make-glyph' with a TYPE of
`icon'.
File: lispref.info, Node: Glyph Properties, Next: Glyph Convenience Functions, Prev: Creating Glyphs, Up: Glyph Functions
Glyph Properties
----------------
Each glyph has a list of properties, which control all of the
aspects of the glyph's appearance. The following symbols have
predefined meanings:
`image'
The image used to display the glyph.
`baseline'
Percent above baseline that glyph is to be displayed. Only for
glyphs displayed inside of a buffer.
`contrib-p'
Whether the glyph contributes to the height of the line it's on.
Only for glyphs displayed inside of a buffer.
`face'
Face of this glyph (*not* a specifier).
- Function: set-glyph-property GLYPH PROPERTY VALUE &optional LOCALE
TAG-SET HOW-TO-ADD
This function changes a property of a GLYPH.
For built-in properties, the actual value of the property is a
specifier and you cannot change this; but you can change the
specifications within the specifier, and that is what this
function will do. For user-defined properties, you can use this
function to either change the actual value of the property or, if
this value is a specifier, change the specifications within it.
If PROPERTY is a built-in property, the specifications to be added
to this property can be supplied in many different ways:
* If VALUE is a simple instantiator (e.g. a string naming a
pixmap filename) or a list of instantiators, then the
instantiator(s) will be added as a specification of the
property for the given LOCALE (which defaults to `global' if
omitted).
* If VALUE is a list of specifications (each of which is a cons
of a locale and a list of instantiators), then LOCALE must be
`nil' (it does not make sense to explicitly specify a locale
in this case), and specifications will be added as given.
* If VALUE is a specifier (as would be returned by
`glyph-property' if no LOCALE argument is given), then some
or all of the specifications in the specifier will be added
to the property. In this case, the function is really
equivalent to `copy-specifier' and LOCALE has the same
semantics (if it is a particular locale, the specification
for the locale will be copied; if a locale type,
specifications for all locales of that type will be copied;
if `nil' or `all', then all specifications will be copied).
HOW-TO-ADD should be either `nil' or one of the symbols `prepend',
`append', `remove-tag-set-prepend', `remove-tag-set-append',
`remove-locale', `remove-locale-type', or `remove-all'. See
`copy-specifier' and `add-spec-to-specifier' for a description of
what each of these means. Most of the time, you do not need to
worry about this argument; the default behavior usually is fine.
In general, it is OK to pass an instance object (e.g. as returned
by `glyph-property-instance') as an instantiator in place of an
actual instantiator. In such a case, the instantiator used to
create that instance object will be used (for example, if you set
a font-instance object as the value of the `font' property, then
the font name used to create that object will be used instead).
If some cases, however, doing this conversion does not make sense,
and this will be noted in the documentation for particular types
of instance objects.
If PROPERTY is not a built-in property, then this function will
simply set its value if LOCALE is `nil'. However, if LOCALE is
given, then this function will attempt to add VALUE as the
instantiator for the given LOCALE, using `add-spec-to-specifier'.
If the value of the property is not a specifier, it will
automatically be converted into a `generic' specifier.
- Function: glyph-property GLYPH PROPERTY &optional LOCALE
This function returns GLYPH's value of the given PROPERTY.
If LOCALE is omitted, the GLYPH's actual value for PROPERTY will
be returned. For built-in properties, this will be a specifier
object of a type appropriate to the property (e.g. a font or color
specifier). For other properties, this could be anything.
If LOCALE is supplied, then instead of returning the actual value,
the specification(s) for the given locale or locale type will be
returned. This will only work if the actual value of PROPERTY is
a specifier (this will always be the case for built-in properties,
but may or may not apply to user-defined properties). If the
actual value of PROPERTY is not a specifier, this value will
simply be returned regardless of LOCALE.
The return value will be a list of instantiators (e.g. vectors
specifying pixmap data), or a list of specifications, each of
which is a cons of a locale and a list of instantiators.
Specifically, if LOCALE is a particular locale (a buffer, window,
frame, device, or `global'), a list of instantiators for that
locale will be returned. Otherwise, if LOCALE is a locale type
(one of the symbols `buffer', `window', `frame', or `device'), the
specifications for all locales of that type will be returned.
Finally, if LOCALE is `all', the specifications for all locales of
all types will be returned.
The specifications in a specifier determine what the value of
PROPERTY will be in a particular "domain" or set of circumstances,
which is typically a particular Emacs window along with the buffer
it contains and the frame and device it lies within. The value is
derived from the instantiator associated with the most specific
locale (in the order buffer, window, frame, device, and `global')
that matches the domain in question. In other words, given a
domain (i.e. an Emacs window, usually), the specifier for PROPERTY
will first be searched for a specification whose locale is the
buffer contained within that window; then for a specification
whose locale is the window itself; then for a specification whose
locale is the frame that the window is contained within; etc. The
first instantiator that is valid for the domain (usually this
means that the instantiator is recognized by the device [i.e. the
X server or TTY device] that the domain is on). The function
`glyph-property-instance' actually does all this, and is used to
determine how to display the glyph.
- Function: glyph-property-instance GLYPH PROPERTY &optional DOMAIN
DEFAULT NO-FALLBACK
This function returns the instance of GLYPH's PROPERTY in the
specified DOMAIN.
Under most circumstances, DOMAIN will be a particular window, and
the returned instance describes how the specified property
actually is displayed for that window and the particular buffer in
it. Note that this may not be the same as how the property
appears when the buffer is displayed in a different window or
frame, or how the property appears in the same window if you
switch to another buffer in that window; and in those cases, the
returned instance would be different.
The returned instance is an image-instance object, and you can
query it using the appropriate image instance functions. For
example, you could use `image-instance-depth' to find out the
depth (number of color planes) of a pixmap displayed in a
particular window. The results might be different from the
results you would get for another window (perhaps the user
specified a different image for the frame that window is on; or
perhaps the same image was specified but the window is on a
different X server, and that X server has different color
capabilities from this one).
DOMAIN defaults to the selected window if omitted.
DOMAIN can be a frame or device, instead of a window. The value
returned for such a domain is used in special circumstances when a
more specific domain does not apply; for example, a frame value
might be used for coloring a toolbar, which is conceptually
attached to a frame rather than a particular window. The value is
also useful in determining what the value would be for a
particular window within the frame or device, if it is not
overridden by a more specific specification.
If PROPERTY does not name a built-in property, its value will
simply be returned unless it is a specifier object, in which case
it will be instanced using `specifier-instance'.
Optional arguments DEFAULT and NO-FALLBACK are the same as in
`specifier-instance'. *Note Specifiers::.
- Function: remove-glyph-property GLYPH PROPERTY &optional LOCALE
TAG-SET EXACT-P
This function removes a property from a glyph. For built-in
properties, this is analogous to `remove-specifier'. *Note
remove-specifier-p: Specifiers, for the meaning of the LOCALE,
TAG-SET, and EXACT-P arguments.
File: lispref.info, Node: Glyph Convenience Functions, Next: Glyph Dimensions, Prev: Glyph Properties, Up: Glyph Functions
Glyph Convenience Functions
---------------------------
The following functions are provided for working with specific
properties of a glyph. Note that these are exactly like calling the
general functions described above and passing in the appropriate value
for PROPERTY.
Remember that if you want to determine the "value" of a specific
glyph property, you probably want to use the `*-instance' functions.
For example, to determine whether a glyph contributes to its line
height, use `glyph-contrib-p-instance', not `glyph-contrib-p'. (The
latter will return a boolean specifier or a list of specifications, and
you probably aren't concerned with these.)
- Function: glyph-image GLYPH &optional LOCALE
This function is equivalent to calling `glyph-property' with a
property of `image'. The return value will be an image specifier
if LOCALE is `nil' or omitted; otherwise, it will be a
specification or list of specifications.
- Function: set-glyph-image GLYPH SPEC &optional LOCALE TAG-SET
HOW-TO-ADD
This function is equivalent to calling `set-glyph-property' with a
property of `image'.
- Function: glyph-image-instance GLYPH &optional DOMAIN DEFAULT
NO-FALLBACK
This function returns the instance of GLYPH's image in the given
DOMAIN, and is equivalent to calling `glyph-property-instance'
with a property of `image'. The return value will be an image
instance.
Normally DOMAIN will be a window or `nil' (meaning the selected
window), and an instance object describing how the image appears
in that particular window and buffer will be returned.
- Function: glyph-contrib-p GLYPH &optional LOCALE
This function is equivalent to calling `glyph-property' with a
property of `contrib-p'. The return value will be a boolean
specifier if LOCALE is `nil' or omitted; otherwise, it will be a
specification or list of specifications.
- Function: set-glyph-contrib-p GLYPH SPEC &optional LOCALE TAG-SET
HOW-TO-ADD
This function is equivalent to calling `set-glyph-property' with a
property of `contrib-p'.
- Function: glyph-contrib-p-instance GLYPH &optional DOMAIN DEFAULT
NO-FALLBACK
This function returns whether the glyph contributes to its line
height in the given DOMAIN, and is equivalent to calling
`glyph-property-instance' with a property of `contrib-p'. The
return value will be either `nil' or `t'. (Normally DOMAIN will be
a window or `nil', meaning the selected window.)
- Function: glyph-baseline GLYPH &optional LOCALE
This function is equivalent to calling `glyph-property' with a
property of `baseline'. The return value will be a specifier if
LOCALE is `nil' or omitted; otherwise, it will be a specification
or list of specifications.
- Function: set-glyph-baseline GLYPH SPEC &optional LOCALE TAG-SET
HOW-TO-ADD
This function is equivalent to calling `set-glyph-property' with a
property of `baseline'.
- Function: glyph-baseline-instance GLYPH &optional DOMAIN DEFAULT
NO-FALLBACK
This function returns the instance of GLYPH's baseline value in
the given DOMAIN, and is equivalent to calling
`glyph-property-instance' with a property of `baseline'. The
return value will be an integer or `nil'.
Normally DOMAIN will be a window or `nil' (meaning the selected
window), and an instance object describing the baseline value
appears in that particular window and buffer will be returned.
- Function: glyph-face GLYPH
This function returns the face of GLYPH. (Remember, this is not a
specifier, but a simple property.)
- Function: set-glyph-face GLYPH FACE
This function changes the face of GLYPH to FACE.
File: lispref.info, Node: Glyph Dimensions, Prev: Glyph Convenience Functions, Up: Glyph Functions
Glyph Dimensions
----------------
- Function: glyph-width GLYPH &optional WINDOW
This function returns the width of GLYPH on WINDOW. This may not
be exact as it does not take into account all of the context that
redisplay will.
- Function: glyph-ascent GLYPH &optional WINDOW
This function returns the ascent value of GLYPH on WINDOW. This
may not be exact as it does not take into account all of the
context that redisplay will.
- Function: glyph-descent GLYPH &optional WINDOW
This function returns the descent value of GLYPH on WINDOW. This
may not be exact as it does not take into account all of the
context that redisplay will.
- Function: glyph-height GLYPH &optional WINDOW
This function returns the height of GLYPH on WINDOW. (This is
equivalent to the sum of the ascent and descent values.) This may
not be exact as it does not take into account all of the context
that redisplay will.
File: lispref.info, Node: Images, Next: Glyph Types, Prev: Glyph Functions, Up: Glyphs
Images
======
* Menu:
* Image Specifiers:: Specifying how an image will appear.
* Image Instantiator Conversion::
Conversion is applied to image instantiators
at the time they are added to an
image specifier or at the time they
are passed to `make-image-instance'.
* Image Instances:: What an image specifier gets instanced as.
File: lispref.info, Node: Image Specifiers, Next: Image Instantiator Conversion, Up: Images
Image Specifiers
----------------
An image specifier is used to describe the actual image of a glyph.
It works like other specifiers (*note Specifiers::.), in that it
contains a number of specifications describing how the image should
appear in a variety of circumstances. These specifications are called
"image instantiators". When XEmacs wants to display the image, it
instantiates the image into an "image instance". Image instances are
their own primitive object type (similar to font instances and color
instances), describing how the image appears in a particular domain.
(On the other hand, image instantiators, which are just descriptions of
how the image should appear, are represented using strings or vectors.)
- Function: image-specifier-p OBJECT
This function returns non-`nil' if OBJECT is an image specifier.
Usually, an image specifier results from calling `glyph-image' on
a glyph.
- Function: make-image-specifier SPEC-LIST
This function creates a new image specifier object and initializes
it according to SPEC-LIST. It is unlikely that you will ever want
to do this, but this function is provided for completeness and for
experimentation purposes. *Note Specifiers::.
Image instantiators come in many formats: `xbm', `xpm', `gif',
`jpeg', etc. This describes the format of the data describing the
image. The resulting image instances also come in many types -
`mono-pixmap', `color-pixmap', `text', `pointer', etc. This refers to
the behavior of the image and the sorts of places it can appear. (For
example, a color-pixmap image has fixed colors specified for it, while
a mono-pixmap image comes in two unspecified shades "foreground" and
"background" that are determined from the face of the glyph or
surrounding text; a text image appears as a string of text and has an
unspecified foreground, background, and font; a pointer image behaves
like a mono-pixmap image but can only be used as a mouse pointer
[mono-pixmap images cannot be used as mouse pointers]; etc.) It is
important to keep the distinction between image instantiator format and
image instance type in mind. Typically, a given image instantiator
format can result in many different image instance types (for example,
`xpm' can be instanced as `color-pixmap', `mono-pixmap', or `pointer';
whereas `cursor-font' can be instanced only as `pointer'), and a
particular image instance type can be generated by many different image
instantiator formats (e.g. `color-pixmap' can be generated by `xpm',
`gif', `jpeg', etc.).
*Note Image Instances:: for a more detailed discussion of image
instance types.
An image instantiator should be a string or a vector of the form
`[FORMAT :KEYWORD VALUE ...]'
i.e. a format symbol followed by zero or more alternating
keyword-value pairs. The "format" field should be a symbol, one of
`nothing'
(Don't display anything; no keywords are valid for this. Can only
be instanced as `nothing'.)
`string'
(Display this image as a text string. Can only be instanced as
`text', although support for instancing as `mono-pixmap' should be
added.)
`formatted-string'
(Display this image as a text string with replaceable fields,
similar to a modeline format string; not currently implemented.)
`xbm'
(An X bitmap; only if X support was compiled into this XEmacs.
Can be instanced as `mono-pixmap', `color-pixmap', or `pointer'.)
`xpm'
(An XPM pixmap; only if XPM support was compiled into this XEmacs.
Can be instanced as `color-pixmap', `mono-pixmap', or `pointer'.
XPM is an add-on library for X that was designed to rectify the
shortcomings of the XBM format. Most implementations of X include
the XPM library as a standard part. If your vendor does not, it
is highly recommended that you download it and install it. You
can get it from the standard XEmacs FTP site, among other places.)
`xface'
(An X-Face bitmap, used to encode people's faces in e-mail
messages; only if X-Face support was compiled into this XEmacs.
Can be instanced as `mono-pixmap', `color-pixmap', or `pointer'.)
`gif'
(A GIF87 or GIF89 image; only if GIF support was compiled into this
XEmacs. Can be instanced as `color-pixmap'. Note that XEmacs
includes GIF decoding functions as a standard part of it, so if
you have X support, you will normally have GIF support, unless you
explicitly disable it at configure time.)
`jpeg'
(A JPEG-format image; only if JPEG support was compiled into this
XEmacs. Can be instanced as `color-pixmap'. If you have the JPEG
libraries present on your system when XEmacs is built, XEmacs will
automatically detect this and use them, unless you explicitly
disable it at configure time.)
`png'
(A PNG/GIF24 image; only if PNG support was compiled into this
XEmacs. Can be instanced as `color-pixmap'.)
`tiff'
(A TIFF-format image; only if TIFF support was compiled into this
XEmacs. Not currently implemented.)
`cursor-font'
(One of the standard cursor-font names, such as `watch' or
`right_ptr' under X. Under X, this is, more specifically, any of
the standard cursor names from appendix B of the Xlib manual [also
known as the file `<X11/cursorfont.h>'] minus the `XC_' prefix. On
other window systems, the valid names will be specific to the type
of window system. Can only be instanced as `pointer'.)
`font'
(A glyph from a font; i.e. the name of a font, and glyph index
into it of the form `FONT fontname index [[mask-font] mask-index]'.
Only if X support was compiled into this XEmacs. Currently can
only be instanced as `pointer', although this should probably be
fixed.)
`subwindow'
(An embedded X window; not currently implemented.)
`autodetect'
(XEmacs tries to guess what format the data is in. If X support
exists, the data string will be checked to see if it names a
filename. If so, and this filename contains XBM or XPM data, the
appropriate sort of pixmap or pointer will be created. [This
includes picking up any specified hotspot or associated mask
file.] Otherwise, if `pointer' is one of the allowable
image-instance types and the string names a valid cursor-font
name, the image will be created as a pointer. Otherwise, the
image will be displayed as text. If no X support exists, the
image will always be displayed as text.)
The valid keywords are:
`:data'
(Inline data. For most formats above, this should be a string.
For XBM images, this should be a list of three elements: width,
height, and a string of bit data. This keyword is not valid for
instantiator format `nothing'.)
`:file'
(Data is contained in a file. The value is the name of this file.
If both `:data' and `:file' are specified, the image is created
from what is specified in `:data' and the string in `:file'
becomes the value of the `image-instance-file-name' function when
applied to the resulting image-instance. This keyword is not
valid for instantiator formats `nothing', `string',
`formatted-string', `cursor-font', `font', and `autodetect'.)
`:foreground'
`:background'
(For `xbm', `xface', `cursor-font', and `font'. These keywords
allow you to explicitly specify foreground and background colors.
The argument should be anything acceptable to
`make-color-instance'. This will cause what would be a
`mono-pixmap' to instead be colorized as a two-color color-pixmap,
and specifies the foreground and/or background colors for a pointer
instead of black and white.)
`:mask-data'
(For `xbm' and `xface'. This specifies a mask to be used with the
bitmap. The format is a list of width, height, and bits, like for
`:data'.)
`:mask-file'
(For `xbm' and `xface'. This specifies a file containing the mask
data. If neither a mask file nor inline mask data is given for an
XBM image, and the XBM image comes from a file, XEmacs will look
for a mask file with the same name as the image file but with
`Mask' or `msk' appended. For example, if you specify the XBM file
`left_ptr' [usually located in `/usr/include/X11/bitmaps'], the
associated mask file `left_ptrmsk' will automatically be picked
up.)
`:hotspot-x'
`:hotspot-y'
(For `xbm' and `xface'. These keywords specify a hotspot if the
image is instantiated as a `pointer'. Note that if the XBM image
file specifies a hotspot, it will automatically be picked up if no
explicit hotspot is given.)
`:color-symbols'
(Only for `xpm'. This specifies an alist that maps strings that
specify symbolic color names to the actual color to be used for
that symbolic color (in the form of a string or a color-specifier
object). If this is not specified, the contents of
`xpm-color-symbols' are used to generate the alist.)
If instead of a vector, the instantiator is a string, it will be
converted into a vector by looking it up according to the specs in the
`console-type-image-conversion-list' for the console type of the domain
(usually a window; sometimes a frame or device) over which the image is
being instantiated.
If the instantiator specifies data from a file, the data will be
read in at the time that the instantiator is added to the image
specifier (which may be well before the image is actually displayed),
and the instantiator will be converted into one of the inline-data
forms, with the filename retained using a `:file' keyword. This
implies that the file must exist when the instantiator is added to the
image, but does not need to exist at any other time (e.g. it may safely
be a temporary file).
- Function: valid-image-instantiator-format-p FORMAT
This function returns non-`nil' if FORMAT is a valid image
instantiator format. Note that the return value for many formats
listed above depends on whether XEmacs was compiled with support
for that format.
- Function: image-instantiator-format-list
This function return a list of valid image-instantiator formats.
- Variable: xpm-color-symbols
This variable holds definitions of logical color-names used when
reading XPM files. Elements of this list should be of the form
`(COLOR-NAME FORM-TO-EVALUATE)'. The COLOR-NAME should be a
string, which is the name of the color to define; the
FORM-TO-EVALUATE should evaluate to a color specifier object, or a
string to be passed to `make-color-instance' (*note Colors::.). If
a loaded XPM file references a symbolic color called COLOR-NAME,
it will display as the computed color instead.
The default value of this variable defines the logical color names
`"foreground"' and `"background"' to be the colors of the
`default' face.
- Variable: x-bitmap-file-path
A list of the directories in which X bitmap files may be found.
If nil, this is initialized from the `"*bitmapFilePath"' resource.
This is used by the `make-image-instance' function (however, note
that if the environment variable `XBMLANGPATH' is set, it is
consulted first).
File: lispref.info, Node: Image Instantiator Conversion, Next: Image Instances, Prev: Image Specifiers, Up: Images
Image Instantiator Conversion
-----------------------------
- Function: set-console-type-image-conversion-list CONSOLE-TYPE LIST
This function sets the image-conversion-list for consoles of the
given CONSOLE-TYPE. The image-conversion-list specifies how image
instantiators that are strings should be interpreted. Each
element of the list should be a list of two elements (a regular
expression string and a vector) or a list of three elements (the
preceding two plus an integer index into the vector). The string
is converted to the vector associated with the first matching
regular expression. If a vector index is specified, the string
itself is substituted into that position in the vector.
Note: The conversion above is applied when the image instantiator
is added to an image specifier, not when the specifier is actually
instantiated. Therefore, changing the image-conversion-list only
affects newly-added instantiators. Existing instantiators in
glyphs and image specifiers will not be affected.
- Function: console-type-image-conversion-list CONSOLE-TYPE
This function returns the image-conversion-list for consoles of
the given CONSOLE-TYPE.
File: lispref.info, Node: Image Instances, Prev: Image Instantiator Conversion, Up: Images
Image Instances
---------------
Image-instance objects encapsulate the way a particular image
(pixmap, etc.) is displayed on a particular device.
In most circumstances, you do not need to directly create image
instances; use a glyph instead. However, it may occasionally be useful
to explicitly create image instances, if you want more control over the
instantiation process.
- Function: image-instance-p OBJECT
This function returns non-`nil' if OBJECT is an image instance.
* Menu:
* Image Instance Types:: Each image instances has a particular type.
* Image Instance Functions:: Functions for working with image instances.
File: lispref.info, Node: Image Instance Types, Next: Image Instance Functions, Up: Image Instances
Image Instance Types
....................
Image instances come in a number of different types. The type of an
image instance specifies the nature of the image: Whether it is a text
string, a mono pixmap, a color pixmap, etc.
The valid image instance types are
`nothing'
Nothing is displayed.
`text'
Displayed as text. The foreground and background colors and the
font of the text are specified independent of the pixmap.
Typically these attributes will come from the face of the
surrounding text, unless a face is specified for the glyph in
which the image appears.
`mono-pixmap'
Displayed as a mono pixmap (a pixmap with only two colors where the
foreground and background can be specified independent of the
pixmap; typically the pixmap assumes the foreground and background
colors of the text around it, unless a face is specified for the
glyph in which the image appears).
`color-pixmap'
Displayed as a color pixmap.
`pointer'
Used as the mouse pointer for a window.
`subwindow'
A child window that is treated as an image. This allows (e.g.)
another program to be responsible for drawing into the window.
Not currently implemented.
- Function: valid-image-instance-type-p TYPE
This function returns non-`nil' if TYPE is a valid image instance
type.
- Function: image-instance-type-list
This function returns a list of the valid image instance types.
- Function: image-instance-type IMAGE-INSTANCE
This function returns the type of the given image instance. The
return value will be one of `nothing', `text', `mono-pixmap',
`color-pixmap', `pointer', or `subwindow'.
- Function: text-image-instance-p OBJECT
This function returns non-`nil' if OBJECT is an image instance of
type `text'.
- Function: mono-pixmap-image-instance-p OBJECT
This function returns non-`nil' if OBJECT is an image instance of
type `mono-pixmap'.
- Function: color-pixmap-image-instance-p OBJECT
This function returns non-`nil' if OBJECT is an image instance of
type `color-pixmap'.
- Function: pointer-image-instance-p OBJECT
This function returns non-`nil' if OBJECT is an image instance of
type `pointer'.
- Function: subwindow-image-instance-p OBJECT
This function returns non-`nil' if OBJECT is an image instance of
type `subwindow'.
- Function: nothing-image-instance-p OBJECT
This function returns non-`nil' if OBJECT is an image instance of
type `nothing'.
File: lispref.info, Node: Image Instance Functions, Prev: Image Instance Types, Up: Image Instances
Image Instance Functions
........................
- Function: make-image-instance DATA &optional DEVICE DEST-TYPES
NO-ERROR
This function creates a new image-instance object.
DATA is an image instantiator, which describes the image (*note
Image Specifiers::.).
DEST-TYPES should be a list of allowed image instance types that
can be generated. The DEST-TYPES list is unordered. If multiple
destination types are possible for a given instantiator, the "most
natural" type for the instantiator's format is chosen. (For XBM,
the most natural types are `mono-pixmap', followed by
`color-pixmap', followed by `pointer'. For the other normal image
formats, the most natural types are `color-pixmap', followed by
`mono-pixmap', followed by `pointer'. For the string and
formatted-string formats, the most natural types are `text',
followed by `mono-pixmap' (not currently implemented), followed by
`color-pixmap' (not currently implemented). The other formats can
only be instantiated as one type. (If you want to control more
specifically the order of the types into which an image is
instantiated, just call `make-image-instance' repeatedly until it
succeeds, passing less and less preferred destination types each
time.
If DEST-TYPES is omitted, all possible types are allowed.
NO-ERROR controls what happens when the image cannot be generated.
If NIL, an error message is generated. If T, no messages are
generated and this function returns NIL. If anything else, a
warning message is generated and this function returns NIL.
- Function: colorize-image-instance IMAGE-INSTANCE FOREGROUND
BACKGROUND
This function makes the image instance be displayed in the given
colors. Image instances come in two varieties: bitmaps, which are
1 bit deep which are rendered in the prevailing foreground and
background colors; and pixmaps, which are of arbitrary depth
(including 1) and which have the colors explicitly specified.
This function converts a bitmap to a pixmap. If the image
instance was a pixmap already, nothing is done (and `nil' is
returned). Otherwise `t' is returned.
- Function: image-instance-name IMAGE-INSTANCE
This function returns the name of the given image instance.
- Function: image-instance-string IMAGE-INSTANCE
This function returns the string of the given image instance.
This will only be non-`nil' for text image instances.
- Function: image-instance-file-name IMAGE-INSTANCE
This function returns the file name from which IMAGE-INSTANCE was
read, if known.
- Function: image-instance-mask-file-name IMAGE-INSTANCE
This function returns the file name from which IMAGE-INSTANCE's
mask was read, if known.
- Function: image-instance-depth IMAGE-INSTANCE
This function returns the depth of the image instance. This is 0
for a mono pixmap, or a positive integer for a color pixmap.
- Function: image-instance-height IMAGE-INSTANCE
This function returns the height of the image instance, in pixels.
- Function: image-instance-width IMAGE-INSTANCE
This function returns the width of the image instance, in pixels.
- Function: image-instance-hotspot-x IMAGE-INSTANCE
This function returns the X coordinate of the image instance's
hotspot, if known. This is a point relative to the origin of the
pixmap. When an image is used as a mouse pointer, the hotspot is
the point on the image that sits over the location that the
pointer points to. This is, for example, the tip of the arrow or
the center of the crosshairs.
This will always be `nil' for a non-pointer image instance.
- Function: image-instance-hotspot-y IMAGE-INSTANCE
This function returns the Y coordinate of the image instance's
hotspot, if known.
- Function: image-instance-foreground IMAGE-INSTANCE
This function returns the foreground color of IMAGE-INSTANCE, if
applicable. This will be a color instance or `nil'. (It will only
be non-`nil' for colorized mono pixmaps and for pointers.)
- Function: image-instance-background IMAGE-INSTANCE
This function returns the background color of IMAGE-INSTANCE, if
applicable. This will be a color instance or `nil'. (It will only
be non-`nil' for colorized mono pixmaps and for pointers.)