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| author | Titus von der Malsburg <malsburg@posteo.de> | 2022-04-29 15:14:09 +0200 |
|---|---|---|
| committer | Lars Ingebrigtsen <larsi@gnus.org> | 2022-04-29 15:14:09 +0200 |
| commit | 91418d27e9c528fd9062c74a4ce58b657366a8c5 (patch) | |
| tree | a3086a3164d75c103ac812c34dd1f7e114e09450 /lisp/window.el | |
| parent | fa52782f5c4eaef7138534766dfc8a29465785b2 (diff) | |
| download | emacs-91418d27e9c528fd9062c74a4ce58b657366a8c5.tar.gz emacs-91418d27e9c528fd9062c74a4ce58b657366a8c5.tar.bz2 emacs-91418d27e9c528fd9062c74a4ce58b657366a8c5.zip | |
Add new functions for computing character metrics for windows
* doc/lispref/display.texi (Size of Displayed Text): Document the
char functions.
* doc/lispref/windows.texi (Window Sizes): Document
window-max-characters-per-line.
* lisp/window.el (window-char-pixel-width)
(window-char-pixel-height)
(window-max-characters-per-line): New functions (bug#19395).
Diffstat (limited to 'lisp/window.el')
| -rw-r--r-- | lisp/window.el | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/lisp/window.el b/lisp/window.el index dc33eb8a12a..bb4d51da5f5 100644 --- a/lisp/window.el +++ b/lisp/window.el @@ -10480,6 +10480,58 @@ displaying that processes's buffer." (put 'shrink-window-horizontally 'repeat-map 'resize-window-repeat-map) (put 'shrink-window 'repeat-map 'resize-window-repeat-map) +(defun window-char-pixel-width (&optional window face) + "Return average character width for the font of FACE used in WINDOW. +WINDOW must be a live window and defaults to the selected one. + +If FACE is nil or omitted, the default face is used. If FACE is +remapped (see `face-remapping-alist'), the function returns the +information for the remapped face." + (with-selected-window (window-normalize-window window t) + (let* ((face (if face face 'default)) + (info (font-info (face-font face))) + (width (aref info 11))) + (if (> width 0) + width + (aref info 10))))) + +(defun window-char-pixel-height (&optional window face) + "Return character height for the font of FACE used in WINDOW. +WINDOW must be a live window and defaults to the selected one. + +If FACE is nil or omitted, the default face is used. If FACE is +remapped (see `face-remapping-alist'), the function returns the +information for the remapped face." + (with-selected-window (window-normalize-window window t) + (let* ((face (if face face 'default)) + (info (font-info (face-font face)))) + (aref info 3)))) + +(defun window-max-characters-per-line (&optional window face) + "Return the number of characters that can be displayed on one line in WINDOW. +WINDOW must be a live window and defaults to the selected one. + +The character width of FACE is used for the calculation. If FACE +is nil or omitted, the default face is used. If FACE is +remapped (see `face-remapping-alist'), the function uses the +remapped face. + +This function is different from `window-body-width' in two +ways. First, it accounts for the portions of the line reserved +for the continuation glyph. Second, it accounts for the size of +the font, which may have been adjusted, e.g., using +`text-scale-increase')." + (with-selected-window (window-normalize-window window t) + (let* ((window-width (window-body-width window t)) + (font-width (window-char-pixel-width window face)) + (ncols (/ window-width font-width))) + (if (and (display-graphic-p) + overflow-newline-into-fringe + (/= (frame-parameter nil 'left-fringe) 0) + (/= (frame-parameter nil 'right-fringe) 0)) + ncols + (1- ncols))))) + (provide 'window) ;;; window.el ends here |