bug#48307: Feature request: provide default keybindings to change the font size in all windows

[Clément Pit-Claudel]

On 5/9/21 6:03 PM, Gregory Heytings wrote:
> 
>>
>> Yup, probably.
>>
> 
> Why "probably"?  Is something missing?

I'm not sure: I don't know if this is the right implementation, or if there's 
something subtly wrong about it.  It looks good to me (though it's missing a 
command to go back to the original size), but since there are many 
implementations that use different strategies I had concluded that there must 
be some subtlety.

>> The performance isn't great,
>>
> 
> Of course, if you need to recalculate all fonts and redisplay all frames, it 
> takes some time.  But AFAICS the performance is similar to the one of, say, 
> Chromium or Visual Studio when you press C-+ and C--.  The effect is not 
> immediate.

There's something more subtle happening, because using text-scale-adjust is 
much faster, even on a frame with a single buffer.