Add native parent handle argument to Window constructor.

include/window.hpp

@@ -75,7 +75,7 @@ struct Window {
 	std::map<std::string, std::weak_ptr<Image>> imageCache;
 	std::map<std::string, std::weak_ptr<Svg>> svgCache;
 
-	Window();
+	Window(void* handle = NULL);
 	~Window();
 	void run();
 	/** Takes a screenshot of each module */

src/window.cpp

@@ -214,7 +214,7 @@ static void errorCallback(int error, const char* description) {
 	WARN("GLFW error %d: %s", error, description);
 }
 
-Window::Window() {
+Window::Window(void* handle) {
 	internal = new Internal;
 	int err;
 
@@ -235,6 +235,9 @@ Window::Window() {
 	glfwWindowHint(GLFW_COCOA_RETINA_FRAMEBUFFER, GLFW_TRUE);
 #endif
 
+	if (handle)
+		glfwWindowHintPointer(GLFW_NATIVE_PARENT_HANDLE, handle);
+
 	// Create window
 	win = glfwCreateWindow(800, 600, "", NULL, NULL);
 	if (!win) {