1 files changed, 47 insertions, 5 deletions

diff --git a/src/c_fl_single_window.cpp b/src/c_fl_single_window.cpp
index ec9a315..75fbd67 100644
--- a/src/c_fl_single_window.cpp
+++ b/src/c_fl_single_window.cpp
@@ -4,29 +4,71 @@
 #include "c_fl_single_window.h"
 
 
+typedef void (hook)(void*);
+typedef hook* hook_p;
+
+
+
+
+class My_Single_Window : public Fl_Single_Window {
+    public:
+        using Fl_Single_Window::Fl_Single_Window;
+        friend void single_window_set_draw_hook(SINGLEWINDOW n, void * d);
+        friend void fl_single_window_draw(SINGLEWINDOW n);
+    protected:
+        void draw();
+        void real_draw();
+        hook_p draw_hook;
+};
+
+
+void My_Single_Window::draw() {
+    (*draw_hook)(this->user_data());
+}
+
+
+void My_Single_Window::real_draw() {
+    Fl_Single_Window::draw();
+}
+
+
+void single_window_set_draw_hook(SINGLEWINDOW n, void * d) {
+    reinterpret_cast<My_Single_Window*>(n)->draw_hook = reinterpret_cast<hook_p>(d);
+}
+
+
+void fl_single_window_draw(SINGLEWINDOW n) {
+    reinterpret_cast<My_Single_Window*>(n)->real_draw();
+}
+
+
+
+
 SINGLEWINDOW new_fl_single_window(int x, int y, int w, int h, char* label) {
-    Fl_Single_Window *sw = new Fl_Single_Window(x, y, w, h, label);
+    My_Single_Window *sw = new My_Single_Window(x, y, w, h, label);
     return sw;
 }
 
 
 SINGLEWINDOW new_fl_single_window2(int x, int y) {
-    Fl_Single_Window *sw = new Fl_Single_Window(x, y);
+    My_Single_Window *sw = new My_Single_Window(x, y);
     return sw;
 }
 
 
 void free_fl_single_window(SINGLEWINDOW w) {
-    delete reinterpret_cast<Fl_Single_Window*>(w);
+    delete reinterpret_cast<My_Single_Window*>(w);
 }
 
 
+
+
 void fl_single_window_show(SINGLEWINDOW w) {
-    reinterpret_cast<Fl_Single_Window*>(w)->show();
+    reinterpret_cast<My_Single_Window*>(w)->show();
 }
 
 
 void fl_single_window_flush(SINGLEWINDOW w) {
-    reinterpret_cast<Fl_Single_Window*>(w)->flush();
+    reinterpret_cast<My_Single_Window*>(w)->flush();
 }