Start/stop recording if not running/already running

include/Process.hpp

@@ -0,0 +1,14 @@
+#pragma once
+
+namespace gsr {
+    enum class GsrMode {
+        Replay,
+        Record,
+        Stream,
+        Unknown
+    };
+
+    // Arguments ending with NULL
+    bool exec_program_daemonized(const char **args);
+    bool is_gpu_screen_recorder_running(int &gsr_pid, GsrMode &mode);
+}

include/gui/Button.hpp

@@ -2,6 +2,7 @@
 
 #include "Widget.hpp"
 #include <string>
+#include <functional>
 
 namespace gsr {
     class Button : public Widget {
@@ -9,6 +10,8 @@ namespace gsr {
         Button(mgl::vec2f size);
         void on_event(mgl::Event &event, mgl::Window &window) override;
         void draw(mgl::Window &window) override;
+
+        std::function<void()> on_click;
     private:
         mgl::vec2f size;
         bool mouse_inside = false;