livetrax/scripts/select_every_2nd_region.lua

ardour {
	["type"]    = "EditorAction",
	name        = "Region Select/2",
	license     = "MIT",
	author      = "Ardour Team",
	description = [[select every 2nd region on all selected tracks]]
}

-- select every 2nd region on all selected tracks
function factory () return function ()

	local sl = ArdourUI.SelectionList () -- empty selection list

	local sel = Editor:get_selection () -- get current selection
	-- for each selected track/bus..
	for route in sel.tracks:routelist ():iter () do
		-- consider only tracks
		local track = route:to_track ()
		if track:isnil() then
			goto continue
		end

		local skip = false;
		-- iterate over all regions of the given track
		for region in track:playlist():region_list():iter() do
			if skip then
				-- skip every 2nd region
				skip = false;
			else
				skip = true;
				-- get RegionView (GUI object to be selected)
				local rv = Editor:regionview_from_region (region)
				-- add it to the list of Objects to be selected
				sl:push_back (rv);
			end
		end
		::continue::
	end

	-- set/replace current selection in the editor
	Editor:set_selection (sl, ArdourUI.SelectionOp.Set);
end end