Dynamic size at startup

[jgoguen]

What Operating System(s) are you running on?

Linux X11, Linux Wayland, macOS

Which Wayland compositor or X11 Window manager(s) are you using?

Mutter

WezTerm version

20240203-110809-5046fc22

Ask your question!

I'm trying to have WezTerm dynamically resize only at startup based on the size of the monitor it's active on. I know about config.initial_rows and config.initial_cols, and I know about `gui_window:set_inner_size(), but I'm having trouble setting these dynamically when WezTerm starts.

To start, I'm getting the active screen like this:

local screen = wezterm.gui.screens()["active"]

If I do this in wezterm.lua outside of a callback, WezTerm hangs as soon as I save and I can't open it anymore, so I don't think I can use it to calculate values for initial_cols and initial_rows. This makes sense to me, since there wouldn't necessarily be a screen or even a GUI at this point, but I wanted to try it anyway just in case.

What I tried, and expect to work, is using the gui-attached event. I have this in wezterm.lua right at the end of my config:

wezterm.on("gui-attached", function()
    local screen = wezterm.gui.screens()["active"]
    for _, window in ipairs(wezterm.mux.all_windows()) do
        window:gui_window():set_inner_size(screen["width"] / 3, screen["height"] / 3)
    end
end)

Yes, I know this will have undesirable effects if I have multiple WezTerm windows open, but that's incredibly rare for me and I don't see how to get just "this window".

With the callback above, WezTerm does start but doesn't resize. There has to be something I'm missing here, am I calling the wrong function, or is there another event I should be using?

[abatkin]

I have also been trying to do this, and unsuccessfully tried a number of things before stumbling upon this discussion. Using the snippet above, I am seeing slightly different behavior: it panics in the event handler when calling wezterm.gui.screens() (connection.rs#L207).

wezterm 20240818_002147_24542037

[mattmc3]

Have you seen this discussion about centering the window on startup? #5501

wezterm.on("gui-startup", function(cmd)
	local screen = wezterm.gui.screens().main
	local ratio = 0.7
	local width, height = screen.width * ratio, screen.height * ratio
	local tab, pane, window = wezterm.mux.spawn_window(cmd or {
		position = { x = (screen.width - width) / 2, y = (screen.height - height) / 2 },
	})
	-- window:gui_window():maximize()
	window:gui_window():set_inner_size(width, height)
end)

You may be able to start with this and modify to your needs.

[abatkin]

Yeah, I had something similar to this written out a while ago (obviously untested), but the problem is that wezterm.gui.screens() causes a panic when used in gui-startup events, at least on my Fedora 40 (Wayland) machines.

Maybe I should open an issue, if this is unexpected?

[mattmc3]

That sounds like it's worth filing a bug report, yes.