python: expose glfw.Application.{swap_interval,main_loop_iteration}.

The first one was for some reason not exposed because it's a write-only
property (but all shaders have writeonly properites, so what's the
problem?), the second one got added in 2020.06 but the code here was not
updated.

doc/python/pages/changelog.rst

@@ -80,6 +80,8 @@ Changelog
     to make the window resizable on startup
 -   Exposed :ref:`platform.sdl2.Application.exit_event` and
     :ref:`platform.glfw.Application.exit_event`
+-   Exposed :ref:`platform.glfw.Application.swap_interval` and
+    :ref:`platform.glfw.Application.main_loop_iteration`
 -   Exposed :ref:`Color3.red()` and other convenience constructors (see
     :gh:`mosra/magnum-bindings#12`)
 -   Fixed issues with an in-source build (see :gh:`mosra/magnum-bindings#13`)

src/python/magnum/platform/glfw.cpp

@@ -188,7 +188,12 @@ void glfw(py::module_& m) {
     };
 
     py::class_<PublicizedApplication, PyApplication, ApplicationHolder<PublicizedApplication>> glfwApplication{m, "Application", "GLFW application"};
-    /** @todo def_property_writeonly for swap_interval */
+    glfwApplication
+        .def_property("swap_interval", nullptr,
+            [](PublicizedApplication& self, Int interval) {
+                self.setSwapInterval(interval);
+            }, "Swap interval")
+        .def("main_loop_iteration", &PyApplication::mainLoopIteration, "Run one iteration of application main loop");
 
     PyNonDestructibleClass<PublicizedApplication::ExitEvent> exitEvent_{glfwApplication, "ExitEvent", "Exit event"};
     PyNonDestructibleClass<PublicizedApplication::ViewportEvent> viewportEvent_{glfwApplication, "ViewportEvent", "Viewport event"};