-\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.
-