runcode: add "watch variables" feature (#186)

* runcode: add watch variables feature

* runcode: fix inaccessible watch function

* runcode: fix some stuff now that I have finally tested

Author: qaisjp

[admin]/runcode/client.lua

@@ -1,5 +1,6 @@
 me = localPlayer
 
+-- Primary functionality
 local function runString (commandstring)
 	outputChatBoxR("Executing client-side command: "..commandstring)
 	local notReturned
@@ -47,3 +48,94 @@ end
 
 addEvent("doCrun", true)
 addEventHandler("doCrun", root, runString)
+
+-- Variable watching feature
+local watchFuncs = {}
+local watchKeys = {}
+local watchFunc_G = function(k)
+	return _G[k]
+end
+
+local function watchRender()
+	local sw, y = guiGetScreenSize()
+	local strings = {}
+	local maxWidth = 0
+
+	-- Offset bottom by some more
+	y = y - 20
+
+	for _, key in ipairs(watchKeys) do
+		local results = { pcall(watchFuncs[key], key) }
+		for i, v in ipairs(results) do
+			results[i] = tostring(v)
+		end
+
+		local text = table.concat(results, ", ")
+		table.insert(strings, key .. ": " .. text)
+
+		local textWidth = dxGetTextWidth(text)
+		if textWidth > maxWidth then
+			maxWidth = textWidth
+		end
+	end
+
+	for _, text in ipairs(strings) do
+		y = y - 20
+		dxDrawText(text, sw - 100 - maxWidth, y)
+	end
+end
+
+local function watch(key, v)
+	-- Error checking
+	if type(v) ~= "string" and type(v) ~= "function" and type(v) ~= "nil" then
+		error("Unexpected watch value of type " .. type(v) .. " for key " .. key)
+		return
+	end
+
+	-- Remove if missing value
+	if not v then
+		-- Don't do anything if key doesn't exist
+		if not watchFuncs[key] then
+			return false
+		end
+
+		watchFuncs[key] = nil
+
+		table.remove(watchKeys, table.find(watchKeys, key))
+		table.sort(watchKeys)
+
+		-- Remove event handler if we have no keys left
+		if #watchKeys == 0 then
+			removeEventHandler("onClientRender", root, watchRender)
+		end
+
+		return true
+	end
+
+	-- Only insert key if it doesn't already exist
+	if not watchFuncs[key] then
+		table.insert(watchKeys, key)
+		table.sort(watchKeys)
+
+		-- Add event handler if this is our first key
+		if #watchKeys == 1 then
+			addEventHandler("onClientRender", root, watchRender)
+		end
+	end
+
+	-- Set watchFunc as global watcher, if v is string
+	if type(v) == "string" then
+		watchFuncs[key] = watchFunc_G
+	elseif type(v) == "function" then
+		watchFuncs[key] = v
+	else
+		assert(false, "never reached")
+	end
+
+	return true
+end
+
+runcode = {
+	me = localPlayer,
+	watch = watch
+}

[admin]/runcode/shared_util.lua

@@ -8,3 +8,11 @@ _players = setmetatable({}, {
     -- Disable setting of items in _players
     __newindex = function() end,
 })
+
+function table.find(t, needle)
+    for i, val in pairs(t) do
+        if val == needle then
+            return i
+        end
+    end
+end