refactor rendering

include/td/misc/Signal.h

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <algorithm>
+#include <functional>
+#include <td/common/NonCopyable.h>
+#include <vector>
+
+namespace td {
+namespace utils {
+
+template <typename... Args>
+class Signal : private NonCopyable {
+  private:
+	using CallBack = std::function<void(Args...)>;
+
+	std::vector<CallBack> m_Callbacks;
+
+  public:
+	void Connect(CallBack&& a_Callback) {
+		m_Callbacks.push_back(std::move(a_Callback));
+	}
+
+	void operator()(Args... args) const {
+		for (const CallBack& callback : m_Callbacks) {
+			callback(args...);
+		}
+	}
+};
+
+}  // namespace utils
+}  // namespace td