-This is ../info/lispref.info, produced by makeinfo version 4.0 from
+This is ../info/lispref.info, produced by makeinfo version 4.0b from
lispref/lispref.texi.
INFO-DIR-SECTION XEmacs Editor
Foundation instead of in the original English.
\1f
+File: lispref.info, Node: Specifiers In-Depth, Next: Specifier Instancing, Prev: Introduction to Specifiers, Up: Specifiers
+
+In-Depth Overview of a Specifier
+================================
+
+ A specifier object encapsulates a set of "specifications", each of
+which says what its value should be if a particular condition applies.
+For example, one specification might be "The value should be
+darkseagreen2 on X devices" another might be "The value should be blue
+in the *Help* buffer". In specifier terminology, these conditions are
+called "locales" and the values are called "instantiators". Given a
+specifier, a logical question is "What is its value in a particular
+situation?" This involves looking through the specifications to see
+which ones apply to this particular situation, and perhaps preferring
+one over another if more than one applies. In specifier terminology, a
+"particular situation" is called a "domain", and determining its value
+in a particular domain is called "instancing". Most of the time, a
+domain is identified by a particular window. For example, if the
+redisplay engine is drawing text in the default face in a particular
+window, it retrieves the specifier for the foreground color of the
+default face and "instances" it in the domain given by that window; in
+other words, it asks the specifier, "What is your value in this
+window?".
+
+ More specifically, a specifier contains a set of "specifications",
+each of which associates a "locale" (a window object, a buffer object,
+a frame object, a device object, or the symbol `global') with an
+"inst-list", which is a list of one or more "inst-pairs". (For each
+possible locale, there can be at most one specification containing that
+locale.) Each inst-pair is a cons of a "tag set" (an unordered list of
+zero or more symbols, or "tags") and an "instantiator" (the allowed
+form of this varies depending on the type of specifier). In a given
+specification, there may be more than one inst-pair with the same tag
+set; this is unlike for locales.
+
+ The tag set is used to restrict the sorts of devices over which the
+instantiator is valid and to uniquely identify instantiators added by a
+particular application, so that different applications can work on the
+same specifier and not interfere with each other. Each tag can have a
+"predicate" associated with it, which is a function of one argument (a
+device) that specifies whether the tag matches that particular device.
+(If a tag does not have a predicate, it matches all devices.) All tags
+in a tag set must match a device for the associated inst-pair to be
+instantiable over that device. (A null tag set is perfectly valid.)
+
+ The valid device types (normally `x', `tty', and `stream') and
+device classes (normally `color', `grayscale', and `mono') can always
+be used as tags, and match devices of the associated type or class
+(*note Consoles and Devices::). User-defined tags may be defined, with
+an optional predicate specified. An application can create its own
+tag, use it to mark all its instantiators, and be fairly confident that
+it will not interfere with other applications that modify the same
+specifier--Functions that add a specification to a specifier usually
+only overwrite existing inst-pairs with the same tag set as was given,
+and a particular tag or tag set can be specified when removing
+instantiators.
+
+ When a specifier is instanced in a domain, both the locale and the
+tag set can be viewed as specifying necessary conditions that must
+apply in that domain for an instantiator to be considered as a possible
+result of the instancing. More specific locales always override more
+general locales (thus, there is no particular ordering of the
+specifications in a specifier); however, the tag sets are simply
+considered in the order that the inst-pairs occur in the
+specification's inst-list.
+
+ Note also that the actual object that results from the instancing
+(called an "instance object") may not be the same as the instantiator
+from which it was derived. For some specifier types (such as integer
+specifiers and boolean specifiers), the instantiator will be returned
+directly as the instance object. For other types, however, this is not
+the case. For example, for font specifiers, the instantiator is a
+font-description string and the instance object is a font-instance
+object, which describes how the font is displayed on a particular
+device. A font-instance object encapsulates such things as the actual
+font name used to display the font on that device (a font-description
+string under X is usually a wildcard specification that may resolve to
+different font names, with possibly different foundries, widths, etc.,
+on different devices), the extra properties of that font on that
+device, etc. Furthermore, this conversion (called "instantiation")
+might fail--a font or color might not exist on a particular device, for
+example.
+
+\1f
+File: lispref.info, Node: Specifier Instancing, Next: Specifier Types, Prev: Specifiers In-Depth, Up: Specifiers
+
+How a Specifier Is Instanced
+============================
+
+ Instancing of a specifier in a particular window domain proceeds as
+follows:
+
+ * First, XEmacs searches for a specification whose locale is the
+ same as the window. If that fails, the search is repeated,
+ looking for a locale that is the same as the window's buffer. If
+ that fails, the search is repeated using the window's frame, then
+ using the device that frame is on. Finally, the specification
+ whose locale is the symbol `global' (if there is such a
+ specification) is considered.
+
+ * The inst-pairs contained in the specification that was found are
+ considered in their order in the inst-list, looking for one whose
+ tag set matches the device that is derived from the window domain.
+ (The tag set is an unordered list of zero or more tag symbols.
+ For all tags that have predicates associated with them, the
+ predicate must match the device.)
+
+ * If a matching tag set is found, the corresponding instantiator is
+ passed to the specifier's instantiation method, which is specific
+ to the type of the specifier. If it succeeds, the resulting
+ instance object is returned as the result of the instancing and
+ the instancing is done. Otherwise, the operation continues,
+ looking for another matching inst-pair in the current
+ specification.
+
+ * When there are no more inst-pairs to be considered in the current
+ specification, the search starts over, looking for another
+ specification as in the first step above.
+
+ * If all specifications are exhausted and no instance object can be
+ derived, the instancing fails. (Actually, this is not completely
+ true. Some specifier objects for built-in properties have a
+ "fallback" value, which is either an inst-list or another
+ specifier object, that is consulted if the instancing is about to
+ fail. If it is an inst-list, the searching proceeds using the
+ inst-pairs in that list. If it is a specifier, the entire
+ instancing starts over using that specifier instead of the given
+ one. Fallback values are set by the C code and cannot be
+ modified, except perhaps indirectly, using any Lisp functions.
+ The purpose of them is to supply some values to make sure that
+ instancing of built-in properties can't fail and to implement some
+ basic specifier inheritance, such as the fact that faces inherit
+ their properties from the `default' face.)
+
+ It is also possible to instance a specifier over a frame domain or
+device domain instead of over a window domain. The C code, for example,
+instances the `top-toolbar-height' variable over a frame domain in
+order to determine the height of a frame's top toolbar. Instancing over
+a frame or device is similar to instancing over a window except that
+specifications for locales that cannot be derived from the domain are
+ignored. Specifically, instancing over a frame looks first for frame
+locales, then device locales, then the `global' locale. Instancing
+over a device domain looks only for device locales and the `global'
+locale.
+
+\1f
+File: lispref.info, Node: Specifier Types, Next: Adding Specifications, Prev: Specifier Instancing, Up: Specifiers
+
+Specifier Types
+===============
+
+ There are various different types of specifiers. The type of a
+specifier controls what sorts of instantiators are valid, how an
+instantiator is instantiated, etc. Here is a list of built-in specifier
+types:
+
+`boolean'
+ The valid instantiators are the symbols `t' and `nil'. Instance
+ objects are the same as instantiators so no special instantiation
+ function is needed.
+
+`integer'
+ The valid instantiators are integers. Instance objects are the
+ same as instantiators so no special instantiation function is
+ needed. `modeline-shadow-thickness' is an example of an integer
+ specifier (negative thicknesses indicate that the shadow is drawn
+ recessed instead of raised).
+
+`natnum'
+ The valid instantiators are natnums (non-negative integers).
+ Instance objects are the same as instantiators so no special
+ instantiation function is needed. Natnum specifiers are used for
+ dimension variables such as `top-toolbar-height'.
+
+`generic'
+ All Lisp objects are valid instantiators. Instance objects are
+ the same as instantiators so no special instantiation function is
+ needed.
+
+`font'
+ The valid instantiators are strings describing fonts or vectors
+ indicating inheritance from the font of some face. Instance
+ objects are font-instance objects, which are specific to a
+ particular device. The instantiation method for font specifiers
+ can fail, unlike for integer, natnum, boolean, and generic
+ specifiers.
+
+`color'
+ The valid instantiators are strings describing colors or vectors
+ indicating inheritance from the foreground or background of some
+ face. Instance objects are color-instance objects, which are
+ specific to a particular device. The instantiation method for
+ color specifiers can fail, as for font specifiers.
+
+`image'
+ Images are perhaps the most complicated type of built-in
+ specifier. The valid instantiators are strings (a filename,
+ inline data for a pixmap, or text to be displayed in a text glyph)
+ or vectors describing inline data of various sorts or indicating
+ inheritance from the background-pixmap property of some face.
+ Instance objects are either strings (for text images),
+ image-instance objects (for pixmap images), or subwindow objects
+ (for subwindow images). The instantiation method for image
+ specifiers can fail, as for font and color specifiers.
+
+`face-boolean'
+ The valid instantiators are the symbols `t' and `nil' and vectors
+ indicating inheritance from a boolean property of some face.
+ Specifiers of this sort are used for all of the built-in boolean
+ properties of faces. Instance objects are either the symbol `t'
+ or the symbol `nil'.
+
+`toolbar'
+ The valid instantiators are toolbar descriptors, which are lists
+ of toolbar-button descriptors (each of which is a vector of two or
+ four elements). *Note Toolbar::, for more information.
+
+ Color and font instance objects can also be used in turn as
+instantiators for a new color or font instance object. Since these
+instance objects are device-specific, the instantiator can be used
+directly as the new instance object, but only if they are of the same
+device. If the devices differ, the base color or font of the
+instantiating object is effectively used instead as the instantiator.
+
+ *Note Faces and Window-System Objects::, for more information on
+fonts, colors, and face-boolean specifiers. *Note Glyphs::, for more
+information about image specifiers. *Note Toolbar::, for more
+information on toolbar specifiers.
+
+ - Function: specifier-type specifier
+ This function returns the type of SPECIFIER. The returned value
+ will be a symbol: one of `integer', `boolean', etc., as listed in
+ the above table.
+
+ Functions are also provided to query whether an object is a
+particular kind of specifier:
+
+ - Function: boolean-specifier-p object
+ This function returns non-`nil' if OBJECT is a boolean specifier.
+
+ - Function: integer-specifier-p object
+ This function returns non-`nil' if OBJECT is an integer specifier.
+
+ - Function: natnum-specifier-p object
+ This function returns non-`nil' if OBJECT is a natnum specifier.
+
+ - Function: generic-specifier-p object
+ This function returns non-`nil' if OBJECT is a generic specifier.
+
+ - Function: face-boolean-specifier-p object
+ This function returns non-`nil' if OBJECT is a face-boolean
+ specifier.
+
+ - Function: toolbar-specifier-p object
+ This function returns non-`nil' if OBJECT is a toolbar specifier.
+
+ - Function: font-specifier-p object
+ This function returns non-`nil' if OBJECT is a font specifier.
+
+ - Function: color-specifier-p object
+ This function returns non-`nil' if OBJECT is a color specifier.
+
+ - Function: image-specifier-p object
+ This function returns non-`nil' if OBJECT is an image specifier.
+
+\1f
+File: lispref.info, Node: Adding Specifications, Next: Retrieving Specifications, Prev: Specifier Types, Up: Specifiers
+
+Adding specifications to a Specifier
+====================================
+
+ - Function: add-spec-to-specifier specifier instantiator &optional
+ locale tag-set how-to-add
+ This function adds a specification to SPECIFIER. The
+ specification maps from LOCALE (which should be a window, buffer,
+ frame, device, or the symbol `global', and defaults to `global')
+ to INSTANTIATOR, whose allowed values depend on the type of the
+ specifier. Optional argument TAG-SET limits the instantiator to
+ apply only to the specified tag set, which should be a list of
+ tags all of which must match the device being instantiated over
+ (tags are a device type, a device class, or tags defined with
+ `define-specifier-tag'). Specifying a single symbol for TAG-SET
+ is equivalent to specifying a one-element list containing that
+ symbol. Optional argument HOW-TO-ADD specifies what to do if
+ there are already specifications in the specifier. It should be
+ one of
+
+ `prepend'
+ Put at the beginning of the current list of instantiators for
+ LOCALE.
+
+ `append'
+ Add to the end of the current list of instantiators for
+ LOCALE.
+
+ `remove-tag-set-prepend'
+ This is the default. Remove any existing instantiators whose
+ tag set is the same as TAG-SET; then put the new instantiator
+ at the beginning of the current list.
+
+ `remove-tag-set-append'
+ Remove any existing instantiators whose tag set is the same as
+ TAG-SET; then put the new instantiator at the end of the
+ current list.
+
+ `remove-locale'
+ Remove all previous instantiators for this locale before
+ adding the new spec.
+
+ `remove-locale-type'
+ Remove all specifications for all locales of the same type as
+ LOCALE (this includes LOCALE itself) before adding the new
+ spec.
+
+ `remove-all'
+ Remove all specifications from the specifier before adding
+ the new spec.
+
+ `remove-tag-set-prepend' is the default.
+
+ You can retrieve the specifications for a particular locale or
+ locale type with the function `specifier-spec-list' or
+ `specifier-specs'.
+
+ - Function: add-spec-list-to-specifier specifier spec-list &optional
+ how-to-add
+ This function adds a "spec-list" (a list of specifications) to
+ SPECIFIER. The format of a spec-list is
+
+ `((LOCALE (TAG-SET . INSTANTIATOR) ...) ...)'
+
+ where
+
+ * LOCALE := a window, a buffer, a frame, a device, or `global'
+
+ * TAG-SET := an unordered list of zero or more TAGS, each of
+ which is a symbol
+
+ * TAG := a device class (*note Consoles and Devices::), a
+ device type, or a tag defined with `define-specifier-tag'
+
+ * INSTANTIATOR := format determined by the type of specifier
+
+ The pair `(TAG-SET . INSTANTIATOR)' is called an "inst-pair". A
+ list of inst-pairs is called an "inst-list". The pair `(LOCALE .
+ INST-LIST)' is called a "specification". A spec-list, then, can
+ be viewed as a list of specifications.
+
+ HOW-TO-ADD specifies how to combine the new specifications with
+ the existing ones, and has the same semantics as for
+ `add-spec-to-specifier'.
+
+ In many circumstances, the higher-level function `set-specifier' is
+ more convenient and should be used instead.
+
+ - Special Form: let-specifier specifier-list &rest body
+ This special form temporarily adds specifications to specifiers,
+ evaluates forms in BODY and restores the specifiers to their
+ previous states. The specifiers and their temporary
+ specifications are listed in SPECIFIER-LIST.
+
+ The format of SPECIFIER-LIST is
+
+ ((SPECIFIER VALUE &optional LOCALE TAG-SET HOW-TO-ADD) ...)
+
+ SPECIFIER is the specifier to be temporarily modified. VALUE is
+ the instantiator to be temporarily added to specifier in LOCALE.
+ LOCALE, TAG-SET and HOW-TO-ADD have the same meaning as in
+ `add-spec-to-specifier'.
+
+ This special form is implemented as a macro; the code resulting
+ from macro expansion will add specifications to specifiers using
+ `add-spec-to-specifier'. After forms in BODY are evaluated, the
+ temporary specifications are removed and old specifier spec-lists
+ are restored.
+
+ LOCALE, TAG-SET and HOW-TO-ADD may be omitted, and default to
+ `nil'. The value of the last form in BODY is returned.
+
+ NOTE: If you want the specifier's instance to change in all
+ circumstances, use `(selected-window)' as the LOCALE. If LOCALE
+ is `nil' or omitted, it defaults to `global'.
+
+ The following example removes the 3D modeline effect in the
+ currently selected window for the duration of a second:
+
+ (let-specifier ((modeline-shadow-thickness 0 (selected-window)))
+ (sit-for 1))
+
+ - Function: set-specifier specifier value &optional locale tag-set
+ how-to-add
+ This function adds some specifications to SPECIFIER. VALUE can be
+ a single instantiator or tagged instantiator (added as a global
+ specification), a list of tagged and/or untagged instantiators
+ (added as a global specification), a cons of a locale and
+ instantiator or locale and instantiator list, a list of such
+ conses, or nearly any other reasonable form. More specifically,
+ VALUE can be anything accepted by `canonicalize-spec-list'.
+
+ LOCALE, TAG-SET, and HOW-TO-ADD are the same as in
+ `add-spec-to-specifier'.
+
+ Note that `set-specifier' is exactly complementary to
+ `specifier-specs' except in the case where SPECIFIER has no specs
+ at all in it but `nil' is a valid instantiator (in that case,
+ `specifier-specs' will return `nil' (meaning no specs) and
+ `set-specifier' will interpret the `nil' as meaning "I'm adding a
+ global instantiator and its value is `nil'"), or in strange cases
+ where there is an ambiguity between a spec-list and an inst-list,
+ etc. (The built-in specifier types are designed in such a way as
+ to avoid any such ambiguities.)
+
+ If you want to work with spec-lists, you should probably not use
+ these functions, but should use the lower-level functions
+ `specifier-spec-list' and `add-spec-list-to-specifier'. These
+ functions always work with fully-qualified spec-lists; thus, there
+ is no ambiguity.
+
+ - Function: canonicalize-inst-pair inst-pair specifier-type &optional
+ noerror
+ This function canonicalizes the given INST-PAIR.
+
+ SPECIFIER-TYPE specifies the type of specifier that this SPEC-LIST
+ will be used for.
+
+ Canonicalizing means converting to the full form for an inst-pair,
+ i.e. `(TAG-SET . INSTANTIATOR)'. A single, untagged instantiator
+ is given a tag set of `nil' (the empty set), and a single tag is
+ converted into a tag set consisting only of that tag.
+
+ If NOERROR is non-`nil', signal an error if the inst-pair is
+ invalid; otherwise return `t'.
+
+ - Function: canonicalize-inst-list inst-list specifier-type &optional
+ noerror
+ This function canonicalizes the given INST-LIST (a list of
+ inst-pairs).
+
+ SPECIFIER-TYPE specifies the type of specifier that this INST-LIST
+ will be used for.
+
+ Canonicalizing means converting to the full form for an inst-list,
+ i.e. `((TAG-SET . INSTANTIATOR) ...)'. This function accepts a
+ single inst-pair or any abbreviation thereof or a list of
+ (possibly abbreviated) inst-pairs. (See `canonicalize-inst-pair'.)
+
+ If NOERROR is non-`nil', signal an error if the inst-list is
+ invalid; otherwise return `t'.
+
+ - Function: canonicalize-spec spec specifier-type &optional noerror
+ This function canonicalizes the given SPEC (a specification).
+
+ SPECIFIER-TYPE specifies the type of specifier that this SPEC-LIST
+ will be used for.
+
+ Canonicalizing means converting to the full form for a spec, i.e.
+ `(LOCALE (TAG-SET . INSTANTIATOR) ...)'. This function accepts a
+ possibly abbreviated inst-list or a cons of a locale and a
+ possibly abbreviated inst-list. (See `canonicalize-inst-list'.)
+
+ If NOERROR is `nil', signal an error if the specification is
+ invalid; otherwise return `t'.
+
+ - Function: canonicalize-spec-list spec-list specifier-type &optional
+ noerror
+ This function canonicalizes the given SPEC-LIST (a list of
+ specifications).
+
+ SPECIFIER-TYPE specifies the type of specifier that this SPEC-LIST
+ will be used for.
+
+ Canonicalizing means converting to the full form for a spec-list,
+ i.e. `((LOCALE (TAG-SET . INSTANTIATOR) ...) ...)'. This
+ function accepts a possibly abbreviated specification or a list of
+ such things. (See `canonicalize-spec'.) This is the function used
+ to convert spec-lists accepted by `set-specifier' and such into a
+ form suitable for `add-spec-list-to-specifier'.
+
+ This function tries extremely hard to resolve any ambiguities, and
+ the built-in specifier types (font, image, toolbar, etc.) are
+ designed so that there won't be any ambiguities.
+
+ If NOERROR is `nil', signal an error if the spec-list is invalid;
+ otherwise return `t'.
+
+\1f
File: lispref.info, Node: Retrieving Specifications, Next: Specifier Tag Functions, Prev: Adding Specifications, Up: Specifiers
Retrieving the Specifications from a Specifier
or the symbol `global'), a spec-list consisting of the
specification for that locale will be returned.
- If LOCALE is a locale type (i.e. a symbol `window', `buffer',
- `frame', or `device'), a spec-list of the specifications for all
- locales of that type will be returned.
+ If LOCALE is a locale type (i.e. one of the symbols `window',
+ `buffer', `frame', or `device'), a spec-list of the specifications
+ for all locales of that type will be returned.
If LOCALE is `nil' or the symbol `all', a spec-list of all
specifications in SPECIFIER will be returned.
Only instantiators where TAG-SET (a list of zero or more tags) is
a subset of (or possibly equal to) the instantiator's tag set are
- returned. (The default value of` nil' is a subset of all tag sets,
+ returned. (The default value of `nil' is a subset of all tag sets,
so in this case no instantiators will be screened out.) If EXACT-P
is non-`nil', however, TAG-SET must be equal to an instantiator's
tag set for the instantiator to be returned.
particular device class or device type and/or to mark instantiators
added by a particular package so that they can be later removed.
- A specifier tag set consists of a list of zero of more specifier
+ A specifier tag set consists of a list of zero or more specifier
tags, each of which is a symbol that is recognized by XEmacs as a tag.
(The valid device types and device classes are always tags, as are any
tags defined by `define-specifier-tag'.) It is called a "tag set" (as
`font', `image', `face-boolean', or `toolbar'.
For more information on particular types of specifiers, see the
- functions `generic-specifier-p', `integer-specifier-p',
- `natnum-specifier-p', `boolean-specifier-p', `color-specifier-p',
- `font-specifier-p', `image-specifier-p',
- `face-boolean-specifier-p', and `toolbar-specifier-p'.
+ functions `make-generic-specifier', `make-integer-specifier',
+ `make-natnum-specifier', `make-boolean-specifier',
+ `make-color-specifier', `make-font-specifier',
+ `make-image-specifier', `make-face-boolean-specifier', and
+ `make-toolbar-specifier'.
- Function: make-specifier-and-init type spec-list &optional
dont-canonicalize
and the SPEC-LIST must already be in full form. See
`canonicalize-spec-list'.
+ - Function: make-integer-specifier spec-list
+ Return a new `integer' specifier object with the given
+ specification list. SPEC-LIST can be a list of specifications
+ (each of which is a cons of a locale and a list of instantiators),
+ a single instantiator, or a list of instantiators.
+
+ Valid instantiators for integer specifiers are integers.
+
+ - Function: make-boolean-specifier spec-list
+ Return a new `boolean' specifier object with the given
+ specification list. SPEC-LIST can be a list of specifications
+ (each of which is a cons of a locale and a list of instantiators),
+ a single instantiator, or a list of instantiators.
+
+ Valid instantiators for boolean specifiers are `t' and `nil'.
+
+ - Function: make-natnum-specifier spec-list
+ Return a new `natnum' specifier object with the given specification
+ list. SPEC-LIST can be a list of specifications (each of which is
+ a cons of a locale and a list of instantiators), a single
+ instantiator, or a list of instantiators.
+
+ Valid instantiators for natnum specifiers are non-negative
+ integers.
+
+ - Function: make-generic-specifier spec-list
+ Return a new `generic' specifier object with the given
+ specification list. SPEC-LIST can be a list of specifications
+ (each of which is a cons of a locale and a list of instantiators),
+ a single instantiator, or a list of instantiators.
+
+ Valid instantiators for generic specifiers are all Lisp values.
+ They are returned back unchanged when a specifier is instantiated.
+
+ - Function: make-display-table-specifier spec-list
+ Return a new `display-table' specifier object with the given spec
+ list. SPEC-LIST can be a list of specifications (each of which is
+ a cons of a locale and a list of instantiators), a single
+ instantiator, or a list of instantiators.
+
+ Valid instantiators for display-table specifiers are described in
+ detail in the doc string for `current-display-table' (*note Active
+ Display Table::).
+
\1f
File: lispref.info, Node: Specifier Validation Functions, Next: Other Specification Functions, Prev: Creating Specifiers, Up: Specifiers
and `global'. (`nil' is not valid.)
- Function: valid-specifier-locale-type-p locale-type
- Given a specifier LOCALE-TYPE, this function returns non-nil if it
- is valid. Valid locale types are the symbols `global', `device',
- `frame', `window', and `buffer'. (Note, however, that in functions
- that accept either a locale or a locale type, `global' is
- considered an individual locale.)
+ Given a specifier LOCALE-TYPE, this function returns non-`nil' if
+ it is valid. Valid locale types are the symbols `global',
+ `device', `frame', `window', and `buffer'. (Note, however, that in
+ functions that accept either a locale or a locale type, `global'
+ is considered an individual locale.)
- Function: valid-specifier-type-p specifier-type
Given a SPECIFIER-TYPE, this function returns non-`nil' if it is
tag set for the instantiator to be copied.
Optional argument HOW-TO-ADD specifies what to do with existing
- specifications in DEST. If nil, then whichever locales or locale
+ specifications in DEST. If `nil', then whichever locales or locale
types are copied will first be completely erased in DEST.
Otherwise, it is the same as in `add-spec-to-specifier'.
* Other Face Display Functions:: Other functions pertaining to how a
a face appears.
-\1f
-File: lispref.info, Node: Merging Faces, Next: Basic Face Functions, Up: Faces
-
-Merging Faces for Display
--------------------------
-
- Here are all the ways to specify which face to use for display of
-text:
-
- * With defaults. Each frame has a "default face", which is used for
- all text that doesn't somehow specify another face. The face named
- `default' applies to the text area, while the faces `left-margin'
- and `right-margin' apply to the left and right margin areas.
-
- * With text properties. A character may have a `face' property; if
- so, it's displayed with that face. (Text properties are actually
- implemented in terms of extents.) *Note Text Properties::.
-
- * With extents. An extent may have a `face' property, which applies
- to all the text covered by the extent; in addition, if the
- `highlight' property is set, the `highlight' property applies when
- the mouse moves over the extent or if the extent is explicitly
- highlighted. *Note Extents::.
-
- * With annotations. Annotations that are inserted into a buffer can
- specify their own face. (Annotations are actually implemented in
- terms of extents.) *Note Annotations::.
-
- If these various sources together specify more than one face for a
-particular character, XEmacs merges the properties of the various faces
-specified. Extents, text properties, and annotations all use the same
-underlying representation (as extents). When multiple extents cover one
-character, an extent with higher priority overrides those with lower
-priority. *Note Extents::. If no extent covers a particular character,
-the `default' face is used.
-
- If a background pixmap is specified, it determines what will be
-displayed in the background of text characters. If the background
-pixmap is actually a pixmap, with its colors specified, those colors are
-used; if it is a bitmap, the face's foreground and background colors are
-used to color it.
-
-\1f
-File: lispref.info, Node: Basic Face Functions, Next: Face Properties, Prev: Merging Faces, Up: Faces
-
-Basic Functions for Working with Faces
---------------------------------------
-
- The properties a face can specify include the font, the foreground
-color, the background color, the background pixmap, the underlining,
-the display table, and (for TTY devices) whether the text is to be
-highlighted, dimmed, blinking, or displayed in reverse video. The face
-can also leave these unspecified, causing them to assume the value of
-the corresponding property of the `default' face.
-
- Here are the basic primitives for working with faces.
-
- - Function: make-face name &optional doc-string temporary
- This function defines and returns a new face named NAME, initially
- with all properties unspecified. It does nothing if there is
- already a face named NAME. Optional argument DOC-STRING specifies
- an explanatory string used for descriptive purposes. If optional
- argument TEMPORARY is non-`nil', the face will automatically
- disappear when there are no more references to it anywhere in text
- or Lisp code (otherwise, the face will continue to exist
- indefinitely even if it is not used).
-
- - Function: face-list &optional temporary
- This function returns a list of the names of all defined faces. If
- TEMPORARY is `nil', only the permanent faces are included. If it
- is `t', only the temporary faces are included. If it is any other
- non-`nil' value both permanent and temporary are included.
-
- - Function: facep object
- This function returns whether the given object is a face.
-
- - Function: copy-face old-face new-name &optional locale how-to-add
- This function defines a new face named NEW-NAME which is a copy of
- the existing face named OLD-FACE. If there is already a face
- named NEW-NAME, then it alters the face to have the same
- properties as OLD-FACE. LOCALE and HOW-TO-ADD let you copy just
- parts of the old face rather than the whole face, and are as in
- `copy-specifier' (*note Specifiers::).
-
-\1f
-File: lispref.info, Node: Face Properties, Next: Face Convenience Functions, Prev: Basic Face Functions, Up: Faces
-
-Face Properties
----------------
-
- You can examine and modify the properties of an existing face with
-the following functions.
-
- The following symbols have predefined meanings:
-
-`foreground'
- The foreground color of the face.
-
-`background'
- The background color of the face.
-
-`font'
- The font used to display text covered by this face.
-
-`display-table'
- The display table of the face.
-
-`background-pixmap'
- The pixmap displayed in the background of the face. Only used by
- faces on X devices.
-
-`underline'
- Underline all text covered by this face.
-
-`highlight'
- Highlight all text covered by this face. Only used by faces on TTY
- devices.
-
-`dim'
- Dim all text covered by this face. Only used by faces on TTY
- devices.
-
-`blinking'
- Blink all text covered by this face. Only used by faces on TTY
- devices.
-
-`reverse'
- Reverse the foreground and background colors. Only used by faces
- on TTY devices.
-
-`doc-string'
- Description of what the face's normal use is. NOTE: This is not a
- specifier, unlike all the other built-in properties, and cannot
- contain locale-specific values.
-
- - Function: set-face-property face property value &optional locale tag
- how-to-add
- This function changes a property of a FACE.
-
- 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
- font or color) 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
- `face-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 `face-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: remove-face-property face property &optional local tag-set
- exact-p
- This function removes a property of a FACE.
-
- For built-in properties, this is analogous to `remove-specifier'.
- For more information, *Note Other Specification Functions::.
-
- When PROPERTY is not a built-in property, this function will just
- remove its value if LOCALE is `nil' or `all'. However, if LOCALE
- is other than that, this function will attempt to remove VALUE as
- the instantiator for the given LOCALE with `remove-specifier'. If
- the value of the property is not a specifier, it will be converted
- into a `generic' specifier automatically.
-
- - Function: face-property face property &optional locale
- This function returns FACE's value of the given PROPERTY.
-
- If LOCALE is omitted, the FACE'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 not or not may 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. strings
- specifying a font or color name), 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
- `face-property-instance' actually does all this, and is used to
- determine how to display the face.
-
- - Function: face-property-instance face property &optional domain
- default no-fallback
- This function returns the instance of FACE'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 will typically be a color-instance,
- font-instance, or pixmap-instance object, and you can query it
- using the appropriate object-specific functions. For example, you
- could use `color-instance-rgb-components' to find out the RGB
- (red, green, and blue) components of how the `background' property
- of the `highlight' face is 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 color for
- the frame that window is on; or perhaps the same color was
- specified but the window is on a different X server, and that X
- server has different RGB values for the color 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 a 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::.
-
-\1f
-File: lispref.info, Node: Face Convenience Functions, Next: Other Face Display Functions, Prev: Face Properties, Up: Faces
-
-Face Convenience Functions
---------------------------
-
- - Function: set-face-foreground face color &optional locale tag
- how-to-add
- - Function: set-face-background face color &optional locale tag
- how-to-add
- These functions set the foreground (respectively, background)
- color of face FACE to COLOR. The argument COLOR should be a
- string (the name of a color) or a color object as returned by
- `make-color' (*note Colors::).
-
- - Function: set-face-background-pixmap face pixmap &optional locale
- tag how-to-add
- This function sets the background pixmap of face FACE to PIXMAP.
- The argument PIXMAP should be a string (the name of a bitmap or
- pixmap file; the directories listed in the variable
- `x-bitmap-file-path' will be searched) or a glyph object as
- returned by `make-glyph' (*note Glyphs::). The argument may also
- be a list of the form `(WIDTH HEIGHT DATA)' where WIDTH and HEIGHT
- are the size in pixels, and DATA is a string, containing the raw
- bits of the bitmap.
-
- - Function: set-face-font face font &optional locale tag how-to-add
- This function sets the font of face FACE. The argument FONT
- should be a string or a font object as returned by `make-font'
- (*note Fonts::).
-
- - Function: set-face-underline-p face underline-p &optional locale tag
- how-to-add
- This function sets the underline property of face FACE.
-
- - Function: face-foreground face &optional locale
- - Function: face-background face &optional locale
- These functions return the foreground (respectively, background)
- color specifier of face FACE. *Note Colors::.
-
- - Function: face-background-pixmap face &optional locale
- This function return the background-pixmap glyph object of face
- FACE.
-
- - Function: face-font face &optional locale
- This function returns the font specifier of face FACE. (Note:
- This is not the same as the function `face-font' in FSF Emacs.)
- *Note Fonts::.
-
- - Function: face-font-name face &optional domain
- This function returns the name of the font of face FACE, or `nil'
- if it is unspecified. This is basically equivalent to `(font-name
- (face-font FACE) DOMAIN)' except that it does not cause an error
- if FACE's font is `nil'. (This function is named `face-font' in
- FSF Emacs.)
-
- - Function: face-underline-p face &optional locale
- This function returns the underline property of face FACE.
-
- - Function: face-foreground-instance face &optional domain
- - Function: face-background-instance face &optional domain
- These functions return the foreground (respectively, background)
- color specifier of face FACE. *Note Colors::.
-
- - Function: face-background-pixmap-instance face &optional domain
- This function return the background-pixmap glyph object of face
- FACE.
-
- - Function: face-font-instance face &optional domain
- This function returns the font specifier of face FACE. *Note
- Fonts::.
-
-\1f
-File: lispref.info, Node: Other Face Display Functions, Prev: Face Convenience Functions, Up: Faces
-
-Other Face Display Functions
-----------------------------
-
- - Function: invert-face face &optional locale
- Swap the foreground and background colors of face FACE. If the
- face doesn't specify both foreground and background, then its
- foreground and background are set to the default background and
- foreground.
-
- - Function: face-equal face1 face2 &optional domain
- This returns `t' if the faces FACE1 and FACE2 will display in the
- same way. DOMAIN is as in `face-property-instance'.
-
- - Function: face-differs-from-default-p face &optional domain
- This returns `t' if the face FACE displays differently from the
- default face. DOMAIN is as in `face-property-instance'.
-
-\1f
-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.
-
-\1f
-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.
-
-\1f
-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.
-
-\1f
-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).
-
-\1f
-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.
-
-\1f
-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'.
-
-\1f
-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.
-
-\1f
-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.
-
-\1f
-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.
-
projects / chise / xemacs-chise.git- / blobdiff