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: 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: 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::.  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::.  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'.  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)) => # 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.