libui: Add option to run event processing in a loop instead of in app.run()

libui/include/ui/App.h

@@ -35,6 +35,8 @@ namespace ui
             m_should_close = b;
         }
 
+        void set_nonblocking();
+
         void set_main_window(Window* window)
         {
             check(!m_main_window);
@@ -51,6 +53,8 @@ namespace ui
 
         Result<void> handle_ipc_event(u8 id);
 
+        bool process_events();
+
         static App& the();
 
       private:

libui/src/App.cpp

@@ -50,8 +50,8 @@ namespace ui
 
     Result<int> App::run()
     {
-        check(m_main_window);
-        while (!m_should_close) { TRY(os::IPC::check_for_messages(*m_client)); }
+        while (process_events())
+            ;
         return 0;
     }
 
@@ -135,4 +135,16 @@ namespace ui
         default: fail("Unexpected IPC request from server!");
         }
     }
+
+    void App::set_nonblocking()
+    {
+        fcntl(m_client->fd(), F_SETFL, O_NONBLOCK);
+    }
+
+    bool App::process_events()
+    {
+        check(m_main_window);
+        os::IPC::check_for_messages(*m_client).release_value();
+        return !m_should_close;
+    }
 }