Commit b1978229 authored by Eli Zaretskii's avatar Eli Zaretskii

Allow querying font by name for its height and other info. (Bug#19395)

 src/font.c (Ffont_info): Add more font information to the vector
 returned by the function, inspired by query-font.  Doc fix.

 doc/lispref/display.texi (Low-Level Font): Document font-info and query-font.

 lisp/international/mule-diag.el (describe-font-internal): Display
 additional info returned by font-info.
 lisp/linum.el (linum--face-width): Rename from linum--face-height,
 and use the new functionality of font-info.
 (linum-update-window): Use linum--face-width and frame-char-width,
 instead of approximating with height.

 etc/NEWS: Mention the enhancement in font-info.
parent 687ae680
2014-12-18 Eli Zaretskii <eliz@gnu.org>
* display.texi (Low-Level Font): Document font-info and query-font.
2014-12-16 Nicolas Petton <petton.nicolas@gmail.com>
* sequences.texi (Seq Library): Add documentation for seq.el.
......
......@@ -3349,9 +3349,9 @@ The script that the font must support (a symbol).
@item :otf
@cindex OpenType font
The font must be an OpenType font that supports these OpenType
features, provided Emacs is compiled with support for @samp{libotf} (a
library for performing complex text layout in certain scripts). The
value must be a list of the form
features, provided Emacs is compiled with a library, such as
@samp{libotf} on GNU/Linux, that supports complex text layout for
scripts which need that. The value must be a list of the form
@smallexample
@code{(@var{script-tag} @var{langsys-tag} @var{gsub} @var{gpos})}
......@@ -3450,6 +3450,124 @@ If the optional argument @var{fold-wildcards} is non-@code{nil},
consecutive wildcards in the XLFD are folded into one.
@end defun
The following two functions return important information about a font.
@defun font-info name &optional frame
This function returns information about a font specified by its
@var{name}, a string, as it is used on @var{frame}. If @var{frame} is
omitted or @code{nil}, it defaults to the selected frame.
The value returned by the function is a vector of the form
@code{[@var{opened-name} @var{full-name} @var{size} @var{height}
@var{baseline-offset} @var{relative-compose} @var{default-ascent}
@var{max-width} @var{ascent} @var{descent} @var{space-width}
@var{average-width} @var{filename} @var{capability}]}. Here's the
description of each components of this vector:
@table @var
@item opened-name
The name used to open the font, a string.
@item full-name
The full name of the font, a string.
@item size
The pixel size of the font.
@item height
The height of the font in pixels.
@item baseline-offset
The offset in pixels from the @acronym{ASCII} baseline, positive
upward.
@item relative-compose
@itemx default-ascent
Numbers controlling how to compose characters.
@item ascent
@itemx descent
The ascent and descent of this font. The sum of these two numbers
should be equal to the value of @var{height} above.
@item space-width
The width, in pixels, of the font's space character.
@item average-width
The average width of the font characters. If this is zero, Emacs uses
the value of @var{space-width} instead, when it calculates text layout
on display.
@item filename
The file name of the font as a string. This can be @code{nil} if the
font back-end does not provide a way to find out the font's file name.
@item capability
A list whose first element is a symbol representing the font type, one
of @code{x}, @code{opentype}, @code{truetype}, @code{type1},
@code{pcf}, or @code{bdf}. For OpenType fonts, the list includes 2
additional elements describing the @sc{gsub} and @sc{gpos} features
supported by the font. Each of these elements is a list of the form
@code{((@var{script} (@var{langsys} @var{feature} @dots{}) @dots{})
@dots{})}, where @var{script} is a symbol representing an OpenType
script tag, @var{langsys} is a symbol representing an OpenType langsys
tag (or @code{nil}, which stands for the default langsys), and each
@var{feature} is a symbol representing an OpenType feature tag.
@end table
@end defun
@defun query-font font-object
This function returns information about a @var{font-object}. (This is
in contrast to @code{font-info}, which takes the font name, a string,
as its argument.)
The value returned by the function is a vector of the form
@code{[@var{name} @var{filename} @var{pixel-size} @var{max-width}
@var{ascent} @var{descent} @var{space-width} @var{average-width}
@var{capability}]}. Here's the description of each components of this
vector:
@table @var
@item name
The font name, a string.
@item filename
The file name of the font as a string. This can be @code{nil} if the
font back-end does not provide a way to find out the font's file name.
@item pixel-size
The pixel size of the font used to open the font.
@item max-width
The maximum advance width of the font.
@item ascent
@itemx descent
The ascent and descent of this font. The sum of these two numbers
gives the font height.
@item space-width
The width, in pixels, of the font's space character.
@item average-width
The average width of the font characters. If this is zero, Emacs uses
the value of @var{space-width} instead, when it calculates text layout
on display.
@item capability
A list whose first element is a symbol representing the font type, one
of @code{x}, @code{opentype}, @code{truetype}, @code{type1},
@code{pcf}, or @code{bdf}. For OpenType fonts, the list includes 2
additional elements describing the @sc{gsub} and @sc{gpos} features
supported by the font. Each of these elements is a list of the form
@code{((@var{script} (@var{langsys} @var{feature} @dots{}) @dots{})
@dots{})}, where @var{script} is a symbol representing an OpenType
script tag, @var{langsys} is a symbol representing an OpenType langsys
tag (or @code{nil}, which stands for the default langsys), and each
@var{feature} is a symbol representing an OpenType feature tag.
@end table
@end defun
@node Fringes
@section Fringes
@cindex fringes
......
......@@ -108,6 +108,17 @@ environment. For the time being this is implemented for modern POSIX
systems and for MS-Windows, for other systems they fall back to their
counterparts `string-lessp' and `string-equal'.
*** The ls-lisp package uses `string-collate-lessp' to sort file names.
If you want the old, locale-independent sorting, customize the new
option `ls-lisp-use-string-collate' to a nil value.
*** The MS-Windows specific variable `w32-collate-ignore-punctuation',
if set to a non-nil value, causes the above 2 functions to ignore
symbol and punctuation characters when collating strings. This
emulates the behavior of modern Posix platforms when the locale's
codeset is "UTF-8" (as in "en_US.UTF-8"). This is needed because
MS-Windows doesn't support UTF-8 as codeset in its locales.
+++
** The new function `bidi-find-overridden-directionality' allows to
find characters whose directionality was, perhaps maliciously,
......@@ -122,17 +133,6 @@ the visual appearance both of the copied text and the text at
destination, even when the copied text includes mixed bidirectional
text and directional control characters.
*** The ls-lisp package uses `string-collate-lessp' to sort file names.
If you want the old, locale-independent sorting, customize the new
option `ls-lisp-use-string-collate' to a nil value.
*** The MS-Windows specific variable `w32-collate-ignore-punctuation',
if set to a non-nil value, causes the above 2 functions to ignore
symbol and punctuation characters when collating strings. This
emulates the behavior of modern Posix platforms when the locale's
codeset is "UTF-8" (as in "en_US.UTF-8"). This is needed because
MS-Windows doesn't support UTF-8 as codeset in its locales.
** New variable `ns-use-fullscreen-animation' controls animation for
non-native NS fullscreen. The default is nil. Set to t to enable
animation when entering and leaving fullscreen. For native OSX fullscreen
......@@ -159,6 +159,10 @@ fontification during full screen scrolling operations, giving less
hesitant operation during auto-repeat of C-v, M-v at the cost of
possible inaccuracies in the end position.
** The function `font-info' now returns more details about a font.
In particular, it now returns the average width of the font's
characters, which can be used for geometry-related calculations.
* Editing Changes in Emacs 25.1
......
2014-12-18 Eli Zaretskii <eliz@gnu.org>
* international/mule-diag.el (describe-font-internal): Display
additional info returned by font-info.
* linum.el (linum--face-width): Rename from linum--face-height,
and use the new functionality of font-info.
(linum-update-window): Use linum--face-width and frame-char-width,
instead of approximating with height.
2014-12-18 Dmitry Gutov <dgutov@yandex.ru>
* vc/vc-svn.el (vc-svn-dir-status-files): Revert the 2014-12-02
......
......@@ -825,10 +825,18 @@ but still contains full information about each coding system."
The IGNORED argument is ignored."
(print-list "name (opened by):" (aref font-info 0))
(print-list " full name:" (aref font-info 1))
(and (aref font-info 12)
(print-list " file name:" (aref font-info 12)))
(print-list " size:" (format "%2d" (aref font-info 2)))
(print-list " height:" (format "%2d" (aref font-info 3)))
(print-list " baseline-offset:" (format "%2d" (aref font-info 4)))
(print-list "relative-compose:" (format "%2d" (aref font-info 5))))
(print-list "relative-compose:" (format "%2d" (aref font-info 5)))
(print-list " default-ascent:" (format "%2d" (aref font-info 6)))
(print-list " ascent:" (format "%2d" (aref font-info 8)))
(print-list " descent:" (format "%2d" (aref font-info 9)))
(print-list " average-width:" (format "%2d" (aref font-info 11)))
(print-list " space-width:" (format "%2d" (aref font-info 10)))
(print-list " max-width:" (format "%2d" (aref font-info 7))))
;;;###autoload
(defun describe-font (fontname)
......
......@@ -138,8 +138,13 @@ Linum mode is a buffer-local minor mode."
(mapc #'delete-overlay linum-available)
(setq linum-available nil))))
(defun linum--face-height (face)
(aref (font-info (face-font face)) 2))
(defun linum--face-width (face)
(let ((info (font-info (face-font face)))
width)
(setq width (aref info 11))
(if (<= width 0)
(setq width (aref info 10)))
width))
(defun linum-update-window (win)
"Update line numbers for the portion visible in window WIN."
......@@ -183,10 +188,8 @@ Linum mode is a buffer-local minor mode."
(setq line (1+ line)))
(when (display-graphic-p)
(setq width (ceiling
;; We'd really want to check the widths rather than the
;; heights, but it's a start.
(/ (* width 1.0 (linum--face-height 'linum))
(frame-char-height)))))
(/ (* width 1.0 (linum--face-width 'linum))
(frame-char-width)))))
(set-window-margins win width (cdr (window-margins win)))))
(defun linum-after-change (beg end _len)
......
2014-12-18 Eli Zaretskii <eliz@gnu.org>
* font.c (Ffont_info): Add more font information to the vector
returned by the function, inspired by query-font. Doc fix.
(Bug#19395)
2014-12-18 Stefan Monnier <monnier@iro.umontreal.ca>
* keyboard.c (input_was_pending): New var.
......
......@@ -4921,8 +4921,11 @@ If FRAME is omitted or nil, use the selected frame. */)
DEFUN ("font-info", Ffont_info, Sfont_info, 1, 2, 0,
doc: /* Return information about a font named NAME on frame FRAME.
If FRAME is omitted or nil, use the selected frame.
The returned value is a vector of OPENED-NAME, FULL-NAME, SIZE,
HEIGHT, BASELINE-OFFSET, RELATIVE-COMPOSE, and DEFAULT-ASCENT,
The returned value is a vector:
[ OPENED-NAME FULL-NAME SIZE HEIGHT BASELINE-OFFSET RELATIVE-COMPOSE
DEFAULT-ASCENT MAX-WIDTH ASCENT DESCENT SPACE-WIDTH AVERAGE-WIDTH
CAPABILITY ]
where
OPENED-NAME is the name used for opening the font,
FULL-NAME is the full name of the font,
......@@ -4930,7 +4933,33 @@ where
HEIGHT is the pixel-height of the font (i.e., ascent + descent),
BASELINE-OFFSET is the upward offset pixels from ASCII baseline,
RELATIVE-COMPOSE and DEFAULT-ASCENT are the numbers controlling
how to compose characters.
how to compose characters,
MAX-WIDTH is the maximum advance width of the font,
ASCENT, DESCENT, SPACE-WIDTH, AVERAGE-WIDTH are metrics of the font
in pixels,
FILENAME is the font file name, a string (or nil if the font backend
doesn't provide a file name).
CAPABILITY is a list whose first element is a symbol representing the
font format, one of x, opentype, truetype, type1, pcf, or bdf.
The remaining elements describe the details of the font capabilities,
as follows:
If the font is OpenType font, the form of the list is
\(opentype GSUB GPOS)
where GSUB shows which "GSUB" features the font supports, and GPOS
shows which "GPOS" features the font supports. Both GSUB and GPOS are
lists of the form:
\((SCRIPT (LANGSYS FEATURE ...) ...) ...)
where
SCRIPT is a symbol representing OpenType script tag.
LANGSYS is a symbol representing OpenType langsys tag, or nil
representing the default langsys.
FEATURE is a symbol representing OpenType feature tag.
If the font is not an OpenType font, there are no elements
in CAPABILITY except the font format symbol.
If the named font is not yet loaded, return nil. */)
(Lisp_Object name, Lisp_Object frame)
{
......@@ -4966,7 +4995,7 @@ If the named font is not yet loaded, return nil. */)
return Qnil;
font = XFONT_OBJECT (font_object);
info = make_uninit_vector (7);
info = make_uninit_vector (14);
ASET (info, 0, AREF (font_object, FONT_NAME_INDEX));
ASET (info, 1, AREF (font_object, FONT_FULLNAME_INDEX));
ASET (info, 2, make_number (font->pixel_size));
......@@ -4974,6 +5003,16 @@ If the named font is not yet loaded, return nil. */)
ASET (info, 4, make_number (font->baseline_offset));
ASET (info, 5, make_number (font->relative_compose));
ASET (info, 6, make_number (font->default_ascent));
ASET (info, 7, make_number (font->max_width));
ASET (info, 8, make_number (font->ascent));
ASET (info, 9, make_number (font->descent));
ASET (info, 10, make_number (font->space_width));
ASET (info, 11, make_number (font->average_width));
ASET (info, 12, AREF (font_object, FONT_FILE_INDEX));
if (font->driver->otf_capability)
ASET (info, 13, Fcons (Qopentype, font->driver->otf_capability (font)));
else
ASET (info, 13, Qnil);
#if 0
/* As font_object is still in FONT_OBJLIST of the entity, we can't
......
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