Changing font size of all the buffers including the status line and the characters shown in electric-buffer

[ISHIKAWA,chiaki]

Hi,

I run Emacs under linux. I am happy with Emacs and most of my writing 
document is done using Emacs even if the final draft is created using MS 
Word by request.
Thanks to the support of unicode these days, handling Japanese as well 
as English is great.


One gripe. Ever since I switched to 4K display (well actually, it is 
more like 3840x2160 @30Hz  due to my poor graphics adapter), one thing 
bothers me.

It is the font size of Emacs. The default is way too small on this 4K 
display and I would like to show the characters and big and beautiful. 
There are times when I want to see as many characters possible. But most 
of the times, I want to see big and crisp characters due to my age.

Anyway, I checked Emacs Wiki.
https://www.emacswiki.org/emacs/SetFonts
There does NOT seem to be a universal method that can enlarge the font size
of buffers including one for electric-buffer mode and status line in one go.


Inside a buffer, I can do c-x c-+ to enlarge the font of the text INSIDE 
that buffer, but the characters shown on the window pane, so to speak 
does not become larger, neither the characters on the status line.
Of course, each time a new buffer/window by visiting a new file is 
created, it is shown  in the small default size.
(I am a bit bothered by the description of a potential bug in the wiki:
--- quote
BUG? – If you use a fontset with Xft, `|C-x C-+|’ this does not scale 
the secondary font. For example, If you use a fontset – 
|dejavu-sans-mono| for latin, |NanumGothic_Coding| for hangul(Korean) – 
, increasing the text size does not scale the Korean characters. – cinsk 
<https://www.emacswiki.org/emacs/cinsk>

---end quote
I am using Japanese fonts with ordinary ASCII English fonts.
As far as I can tell, somehow my Japanese text buffer with interspersed 
ASCII roman characters and digits do get resized properly with c-x c-+ 
keystrokes.
Maybe I am not using a "fontset" currently.
I recall setting the size using X11 resources long time ago, and now I 
have just realized that the discrepancy of the sizes of Japanese fonts 
and ASCII English fonts which I experienced are due to this "BUG".
It happened maybe two or three major versions ago of Emacs. Japanese 
fonts got the desired size, but English fonts remained small.
It was so annoying that I believe I disabled the choice of Japanese font 
size using X11 resources. It happened many months ago on non-4K display.

And I notice this c-x c-+ does not work for electric-buffer mode. Inside 
electric-buffer mode, c-x is eaten by the electric buffer mode itself 
and so this doesn't work.

So I probably have to do something about the size of various fonts 
either in my .emacs start up or maybe using X11 resource properly(?).
There seems to be a method to selectively change the size of a given 
font used inside a buffer.
It is a bit unfriendly and beside I have no idea if the size of fonts 
used for status line and electric-buffer-mode is tweaked in the similar 
manner.

Any thoughts/tips?

Yes, I agree it is wonderful that one can tweak each font for frame, 
buffer, etc. as much as one wants, but there ought to be a single 
wrapper that allows one to say, I want all the font to be 150 pixel 
height or 1.4 times the current size to move to a new display terminal 
with different physical pixel size. Hmm, it DOES sound to be a good 
exercise to use X11 resources, but I suspect there are Windows users who 
need this global font size change including electric-buffer mode buffer 
and status line and so non-X11 solution is preferred.


TIA

Chiaki