change font but not frame size?

change font but not frame size?

[David Reitter]

Is it possible to change the font in a frame (default face) without  
changing the frame's pixel size?

`set-frame-font' has a `keep-size' argument, which would do the job,  
except that it enlarges/shrinks the frame first before bringing it  
back to the original size. That is a rather ugly effect, and when you  
try to increase font sizes gradually, or switch between different sets  
of faces in a frame, such an animation is very annoying. How can I  
avoid that?

Is there a way to block the screen update and "freeze" the frame until  
it is at its correct size?

Re: change font but not frame size?

[Eric Hanchrow]

I have some absurdly complex code in my .emacs that adjusts the frame
size after setting the font size, in an attempt to make it the same
size it was originally, more or less sorta kinda.  Lemme know if you'd
like to look at it (it isn't pretty).
-- 
The people I know who do great work think that they suck, but
that everyone else sucks even more.

        -- Paul Graham

Re: change font but not frame size?

[David Reitter]

On Dec 16, 3:44 pm, Eric Hanchrow <off...@blarg.net> wrote:

> I have some absurdly complex code in my .emacs that adjusts the frame
> size after setting the font size, in an attempt to make it the same
> size it was originally, more or less sorta kinda.  Lemme know if you'd
> like to look at it (it isn't pretty).

Sure. I've tried some absurdly complex things as well - such as
creating an invisible frame, setting the font there, reading out the
resulting char-height, and then trying to set the new height of the
frame and its new font in one go with modify-frame-parameters. It
didn't work (on several levels!).

Post the code here - I'm interested!

Re: change font but not frame size?

[Eric Hanchrow]

>>>>> "David" == David Reitter <david.reitter@gmail.com> writes:

    David> Post the code here - I'm interested!

I'm not certain that this is all of it; there may be some bits
scattered throughout my .emacs that this stuff requires, but that I've
overlooked.

(defun current-font-size (frame)
  (let ((fontname (cdr (assq 'font (frame-parameters frame)))))

    (string-match
     ;; todo -- figure out how to factor out the common
     ;; subexpression.  rx is a macro.
     (rx (and
          (repeat 6 (and "-" (zero-or-more (not (any "-")))))
          "-"
          (submatch (+ (any "0123456789")))
          (repeat 7   (and "-" (zero-or-more (not (any "-"))))))
         )
     fontname)
    (let ((size (match-string 1 fontname)))

      ;; sometimes, on OS X, fontname will be something silly like
      ;; "fontset-mac", which has no size field.  Thus "size" will be
      ;; nil, and "read"  will prompt in the minibuffer, which is
      ;; annoying.  So we just pick a reasonable default value.
      (when (not size)
        (setq size "12"))

      (read size))))

(defun enlarge-font (frame ratio)
  (set-font-size (round (* ratio (current-font-size frame)))))

(let ((bigger  (lambda () "Enlarge the font by 20%." (interactive) (enlarge-font (selected-frame) 1.2)))
      (smaller (lambda () "Reduce the font by 17%."  (interactive) (enlarge-font (selected-frame) (/ 1 1.2)))))
  (global-set-key (kbd "C--") smaller)
  (global-set-key (kbd "C-+") bigger)
  (case system-type
    ((windows-nt darwin)
     (global-set-key (kbd "<C-wheel-up>"  ) smaller)
     (global-set-key (kbd "<C-wheel-down>") bigger))
    (t

     (global-set-key (kbd "<C-mouse-4>"   ) smaller)
     (global-set-key (kbd "<C-mouse-5>"   ) bigger))))

(defun set-font-size (desired-size)
  "Use Bitstream Vera Sans if we can, and try to preserve the
frame size in pixels (which probably only works on GNU Emacs 22
and later), regardless of the current screen resolution."
  (interactive "NHeight in pixels: ")
  (when (eq system-type 'berkeley-unix)
    (error "Alas, I don't know how to set the font on BSD"))
  (let* ((fn (format

              (cond
               ((eq window-system 'mac)
                "-*-courier-medium-r-normal--%d-*-*-*-*-*-*-*")
               ((featurep 'gtk)
                "Bitstream Vera Sans Mono-%d")
               (t
                "-*-Bitstream Vera Sans Mono-Medium-r-*-*-%d-*-*-*-*-*-*-*"))
              desired-size))
         (args (append (list fn)
                       (if (< 21 emacs-major-version)
                           (list t)
                         nil))))
    (apply 'set-frame-font args)))

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