tip/progress.lua

local ceil, floor = math.ceil, math.floor;
local write = io.write;
module("progress");

function new(total)
	total = total or 100;

	local anim = { '/', '-', '\\', '|' };
	local anim_max, anim_frame = #anim, 0;

	local completed, percent_complete = 0, 0;
	local needs_update = true;

	local function update_data(self, new_completed)
		completed = new_completed;
		local new_percent_complete = floor(100/(total/completed));
		if percent_complete ~= new_percent_complete then
			needs_update = true;
		end
		percent_complete = new_percent_complete;
		return needs_update;
	end
	
	local function update_progress_display()
		anim_frame = (anim_frame%anim_max) + 1;
		write("\n\027[K0% [", ("="):rep(floor(percent_complete/2)), percent_complete ~= 100 and ">" or "", (" "):rep((50-floor(percent_complete/2))-1), "] 100%");
		write("\n\027[K", anim[anim_frame], " ", percent_complete, "% complete"); --; ETA ", ceil((now()-start_time)/(bytes_completed/bytes_total)/60), "min");
		write("\027[3A\n");
		needs_update = false;
	end

	local function clear()
		write(("\n\027[K"):rep(3), "\027[3A");
	end
	return { refresh = update_progress_display, update = update_data, clear = clear };
end

return _M;