Subject: bug#75662: 30.0.93; FR: customization to move mode-line to the top

From: Daniel Mendler <[email-masked]>
Date: Sun, 19 Jan 2025 01:45:59 +0100

I have seen many experiments where people try to use the header-line as
mode-line and vice versa. However most packages assume that the
mode-line/header-line is in fact a mode-line/header-line and do not
handle such manual modification of the
mode-line-format/header-line-format well. This is the main motivation
for this feature request.

Furthermore conventional tiling window managers draw the window title
bars at the top of the windows. Therefore when using Emacs as window
manager via EXWM, people may prefer to have the mode-line at the top,
since it acts as window title bar.

I propose to add a customization option `mode-line-at' which can be set
to `top' or `bottom'. When set to `top` the mode-line will be moved to
the top. For the other lines such an option could be offered too,
`header-line-at`, `tab-bar-at`, `tab-line-at`, etc.

How difficult would it be to implement this feature? In Emacs 30, the
variable `tool-bar-position' has been added which makes it possible to
customize the tool bar position in a similar way. In this case the
change might have been simpler given that the toolbar is a graphical
element only, while the mode line may affect the display subsystem more
deeply?