Function engine_handle_cmd

native-activity/app/src/main/cpp/main.cpp:236–266

* The callback for native_app_glue's Activity lifecycle event queue. */

 * The callback for native_app_glue's Activity lifecycle event queue.
 */
static void engine_handle_cmd(android_app* app, int32_t cmd) {
  auto* engine = (Engine*)app->userData;
  // There are a lot of lifecycle events that we're ignoring here. See
  // android_native_app_glue.h for the complete list that native_app_glue
  // handles (which may not be complete if Activity adds new lifecycle
  // methods!)
  //
  // Most applications will need to handle many more of than just this set.
  // We're getting away with ignoring most events because this app doesn't do
  // anything interesting.
  switch (cmd) {
    case APP_CMD_INIT_WINDOW:
      // https://developer.android.com/ndk/reference/struct/a-native-activity-callbacks#onnativewindowcreated
      engine->AttachWindow();
      break;
    case APP_CMD_TERM_WINDOW:
      // https://developer.android.com/ndk/reference/struct/a-native-activity-callbacks#onnativewindowdestroyed
      engine->DetachWindow();
      break;
    case APP_CMD_GAINED_FOCUS:
      // https://developer.android.com/ndk/reference/struct/a-native-activity-callbacks#onwindowfocuschanged
      engine->Resume();
      break;
    case APP_CMD_LOST_FOCUS:
      // https://developer.android.com/ndk/reference/struct/a-native-activity-callbacks#onwindowfocuschanged
      engine->Pause();
      break;
    default:
      break;
  }
}

/**
 * `android_main()` is the entry point for an app using `native_app_glue`.