plugin: Add PluginSettings context item, render it in settings screen

plugin/src/Components/PluginSettings.lua

@@ -0,0 +1,119 @@
+--[[
+	Persistent plugin settings that can be accessed via Roact context.
+]]
+
+local Rojo = script:FindFirstAncestor("Rojo")
+
+local Roact = require(Rojo.Roact)
+
+local defaultSettings = {
+	openScriptsExternally = false,
+}
+
+local Settings = {}
+Settings.__index = Settings
+
+function Settings.fromPlugin(plugin)
+	local values = {}
+
+	for name, defaultValue in pairs(defaultSettings) do
+		local savedValue = plugin:GetSetting("Rojo_" .. name)
+
+		if savedValue == nil then
+			values[name] = defaultValue
+		else
+			values[name] = savedValue
+		end
+	end
+
+	return setmetatable({
+		__values = values,
+		__plugin = plugin,
+		__updateListeners = {},
+	}, Settings)
+end
+
+function Settings:get(name)
+	if defaultSettings[name] == nil then
+		error("Invalid setings name " .. tostring(name), 2)
+	end
+
+	return self.__values[name]
+end
+
+function Settings:set(name, value)
+	self.__plugin:SetSetting(name, value)
+	self.__values[name] = value
+
+	for callback in pairs(self.__updateListeners) do
+		callback(name, value)
+	end
+end
+
+function Settings:onUpdate(newCallback)
+	local newListeners = {}
+	for callback in pairs(self.__updateListeners) do
+		newListeners[callback] = true
+	end
+
+	newListeners[newCallback] = true
+	self.__updateListeners = newListeners
+
+	return function()
+		local newListeners = {}
+		for callback in pairs(self.__updateListeners) do
+			if callback ~= newCallback then
+				newListeners[callback] = true
+			end
+		end
+
+		self.__updateListeners = newListeners
+	end
+end
+
+local Context = Roact.createContext(nil)
+
+local StudioProvider = Roact.Component:extend("StudioProvider")
+
+function StudioProvider:init()
+	self.settings = Settings.fromPlugin(self.props.plugin)
+end
+
+function StudioProvider:render()
+	return Roact.createElement(Context.Provider, {
+		value = self.settings,
+	}, self.props[Roact.Children])
+end
+
+local InternalConsumer = Roact.Component:extend("InternalConsumer")
+
+function InternalConsumer:render()
+	return self.props.render(self.props.settings)
+end
+
+function InternalConsumer:didMount()
+	self.disconnect = self.props.settings:onUpdate(function()
+		-- Trigger a dummy state update to update the settings consumer.
+		self:setState({})
+	end)
+end
+
+function InternalConsumer:willUnmount()
+	self.disconnect()
+end
+
+local function with(callback)
+	return Roact.createElement(Context.Consumer, {
+		render = function(settings)
+			return Roact.createElement(InternalConsumer, {
+				settings = settings,
+				render = callback,
+			})
+		end,
+	})
+end
+
+return {
+	StudioProvider = StudioProvider,
+	with = with,
+}