small fixes

src/app_cloud.cpp

@@ -22,7 +22,7 @@ void App::cloud_upload()
     }
     else
     {
-        std::thread([this] {
+        auto upload_thread = [this] {
             std::string path = data_path + "/" + doc_name + ".ppi";
             if (ui::Canvas::I->m_unsaved)
             {
@@ -52,7 +52,25 @@ void App::cloud_upload()
             layout[main_id]->update();
             async_redraw();
             async_end();
-        }).detach();
+        };
+
+        auto m = layout[main_id]->add_child<NodeMessageBox>();
+        m->m_title->set_text("Publish document");
+        m->m_message->set_text("Would you like to upload this document to the public domain?");
+        m->btn_ok->m_text->set_text("Yes");
+        m->btn_cancel->m_text->set_text("No");
+        m->btn_ok->on_click = [this, m, upload_thread](Node*) {
+            std::thread(upload_thread).detach();
+            async_start();
+            m->destroy();
+            async_end();
+        };
+        m->btn_cancel->on_click = [this, m, upload_thread](Node*) {
+            async_start();
+            m->destroy();
+            async_end();
+        };
+
     }
 }