Draw action hotkeys for Classic ASCII glyphs mode in the corresponding panels

[definability]

When the Classic ASCII glyphs are enabled, the structure placement menu looks weird: the tile placeholders (definitely designed for the Premium graphics) look incomplete and are begging to be filled (see the picture)

The challenge here is drawing the hotkey in a precise position. I can take the position of the top overlay (compare dfhack.gui.getCurFocus() against dwarfmode/Building) and calculate the offsets manually. Will SC_VIEWSCREEN_CHANGED help me detect that the user called the build menu?

I can parse the tiles to determine which menus are active, but I would be happier to discover that the DFHack Lua API already has such features.
From the code snippet, I suspect there is a way to determine what building dialogue mode is currently enabled, but I need help determining how to fetch the currently active mode or, ideally, how to create a callback called when the mode is active

dfhack/library/lua/gui/buildings.lua

Lines 142 to 152 in 02bd218

	function BuildingDialog:initWorkshopMode()
	local choices = {}
	for i=0,df.workshop_type._last_item do
	if i~=df.workshop_type.Custom and (i~=df.workshop_type.Tool or self.use_tool_workshop) then
	self:addBuilding(choices, df.workshop_type[i], df.building_type.Workshop, i,-1,nil)
	end
	end
	self:pushContext('Workshops', choices)
	end

How do you like the idea, and could you help me with the implementation questions?

[quietust]

df.global.game.main_interface.construction contains all of the information for the building selection menu - .page[] contains each section, and .page[].bb_button[] contains the buttons themselves.

[definability]

Thanks. The formulae for the right frame size look tricky (I created them experimentally), but seem to be working for me
https://github.com/definability/dfhack-scripts/blob/f0287b3cb00fc04a6e0e3d9dc64d6ef718759dca/internal/visible-hotkeys/building-overlay.lua#L202-L213

[definability]

Thanks @quietust for your advice. It worked.
To close the discussion, I attach my implementation of this module. Hopefully, I will polish it and ask users whether they need this in the default DFHack script set

https://github.com/definability/dfhack-scripts/blob/f0287b3cb00fc04a6e0e3d9dc64d6ef718759dca/internal/visible-hotkeys/building-overlay.lua