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Étienne Fildadut edited this page May 17, 2021 · 2 revisions

Candran should be usable with LÖVE without modification, just make sure to install it for Lua 5.1 as LÖVE, using LuaJIT, will look for Lua 5.1 libraries only: luarocks install --lua-version=5.1 candran

Then put require("candran").setup() in your main.lua and you should be good to go.

You may then want to rewrite error messages to show correct Candran line numbers. You can do so easily by redefining love.errorhandler to use candran.messageHandler on traces. For example, modifying the default love.errorhandler of LÖVE 11, you should only need to load the following file into your project:

local utf8 = require("utf8")
local candran = require("candran").setup()

local function error_printer(msg, layer)
	print(candran.messageHandler(debug.traceback("Error: " .. tostring(msg), 1+(layer or 1)):gsub("\n[^\n]+$", ""), true))
end

function love.errorhandler(msg)
	msg = candran.messageHandler(tostring(msg), true)

	error_printer(msg, 2)

	if not love.window or not love.graphics or not love.event then
		return
	end

	if not love.graphics.isCreated() or not love.window.isOpen() then
		local success, status = pcall(love.window.setMode, 800, 600)
		if not success or not status then
			return
		end
	end

	-- Reset state.
	if love.mouse then
		love.mouse.setVisible(true)
		love.mouse.setGrabbed(false)
		love.mouse.setRelativeMode(false)
		if love.mouse.isCursorSupported() then
			love.mouse.setCursor()
		end
	end
	if love.joystick then
		-- Stop all joystick vibrations.
		for i,v in ipairs(love.joystick.getJoysticks()) do
			v:setVibration()
		end
	end
	if love.audio then love.audio.stop() end

	love.graphics.reset()
	local font = love.graphics.setNewFont(14)

	love.graphics.setColor(1, 1, 1, 1)

	local trace = candran.messageHandler(debug.traceback(), true)

	love.graphics.origin()

	local sanitizedmsg = {}
	for char in msg:gmatch(utf8.charpattern) do
		table.insert(sanitizedmsg, char)
	end
	sanitizedmsg = table.concat(sanitizedmsg)

	local err = {}

	table.insert(err, "Error\n")
	table.insert(err, sanitizedmsg)

	if #sanitizedmsg ~= #msg then
		table.insert(err, "Invalid UTF-8 string in error message.")
	end

	table.insert(err, "\n")

	for l in trace:gmatch("(.-)\n") do
		if not l:match("boot.lua") then
			l = l:gsub("stack traceback:", "Traceback\n")
			table.insert(err, l)
		end
	end

	local p = table.concat(err, "\n")

	p = p:gsub("\t", "")
	p = p:gsub("%[string \"(.-)\"%]", "%1")

	local function draw()
		local pos = 70
		love.graphics.clear(89/255, 157/255, 220/255)
		love.graphics.printf(p, pos, pos, love.graphics.getWidth() - pos)
		love.graphics.present()
	end

	local fullErrorText = p
	local function copyToClipboard()
		if not love.system then return end
		love.system.setClipboardText(fullErrorText)
		p = p .. "\nCopied to clipboard!"
		draw()
	end

	if love.system then
		p = p .. "\n\nPress Ctrl+C or tap to copy this error"
	end

	return function()
		love.event.pump()

		for e, a, b, c in love.event.poll() do
			if e == "quit" then
				return 1
			elseif e == "keypressed" and a == "escape" then
				return 1
			elseif e == "keypressed" and a == "c" and love.keyboard.isDown("lctrl", "rctrl") then
				copyToClipboard()
			elseif e == "touchpressed" then
				local name = love.window.getTitle()
				if #name == 0 or name == "Untitled" then name = "Game" end
				local buttons = {"OK", "Cancel"}
				if love.system then
					buttons[3] = "Copy to clipboard"
				end
				local pressed = love.window.showMessageBox("Quit "..name.."?", "", buttons)
				if pressed == 1 then
					return 1
				elseif pressed == 3 then
					copyToClipboard()
				end
			end
		end

		draw()

		if love.timer then
			love.timer.sleep(0.1)
		end
	end

end

To distribute your project, you may not want to distribute Candran along with it. You can easily precompile all you Candran files using canc. For example, if you're on Linux, find . -name '*.can' -exec canc {} \;. Don't forget to then remove require("candran").setup() and your custom error screen.

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