[Feature Request] Allow non-hacked iconless modeline with bar and vanilla height

[memeplex]

Is your feature request related to a problem? Please describe.

In darwin, there is a hardcoded scale factor of 1.68 x font height for a modeline with icons, and of 1.25 x font height for a modeline without icons.

One reason against this, although not the most important, is that it seems arbitrary. What is the rationale for special-casing darwin? Probably there is one, but it's not documented anywhere.

Another reason, and again not the most important, is that 1.68 is arguably excessive.

Now, the most important reason for me is that all this is precluding the possibility of setting a modeline without icons but with a bar that is exactly the height of the vanilla modeline. There are known issues with having modelines with height != font height:

• Truncated org-attach popup tarsius/moody#34
• [Bug] Clipped org mode tag menu #480
• https://debbugs.gnu.org/cgi/bugreport.cgi?bug=38181

This issues have been traditionally worked around by installing before advices that force a redisplay before a window is fit to its buffer. That workaround is not without its own problems, which are discussed in the linked issues. But in any case, short of an unlikely change upstream, the solution will always involve the sequence redisplay-fit-redisplay, which produces a little flickering because the window is displayed twice in quick sequence, with a different size each time. There will also be a small but unavoidable gap in the fitted window as described here.

Describe the solution you'd like

The above makes it desirable to allow a less fancy modeline (i.e. no icons) that still provides the full set of capabilities of doom-modeline, including its bar, and that doesn't install nor require any unnecessary hack (because of its vanilla height).

So the proposal is two-folded:

• Allow non-scaled darwin toolbars.
• Don't install redisplay hacks when modeline height = char height.