request save on exit wip

engine/app.cpp

@@ -17,6 +17,7 @@ void android_async_unlock(struct engine* engine);
 void async_lock();
 void async_swap();
 void async_unlock();
+void destroy_window();
 #endif
 
 using namespace ui;
@@ -29,6 +30,30 @@ void App::create()
     height = 1080/2;
 }
 
+bool App::request_close()
+{
+    static bool dialog_already_opened = false;
+    if (ui::Canvas::I->m_unsaved && !dialog_already_opened)
+    {
+        async_start();
+        auto* m = layout[main_id]->add_child<NodeMessageBox>();
+        m->m_title->set_text("Unsaved document");
+        m->m_message->set_text("Would you like to save before closing?");
+        m->btn_ok->m_text->set_text("Yes");
+        m->btn_ok->on_click = [](Node*) {
+        };
+        m->btn_cancel->m_text->set_text("No");
+        m->btn_cancel->on_click = [](Node*) {
+            destroy_window();
+            PostQuitMessage(0);
+        };
+        async_redraw();
+        async_end();
+        dialog_already_opened = true;
+    }
+    return false;
+}
+
 void App::clear()
 {
     glClearColor(.1f, .1f, .1f, 1.f);