Initializations and cleanups

Initialization

The following steps are the outline of the startup steps of LMMS:

1. Parse command-line arguments to check if LMMS needs GUI.

2. Initialize QCoreApplication for command-line-only tasks, MainApplication otherwise.

3. Complete parsing command-line arguments.

4. Setup miscellaneous environments, e.g., RNG, HiDPI scaling.

5. Load the configuration file and translations.

6. Initialize the core by calling Engine::init() for CLI cases. When running with GUI, GuiApplication will initialize it later.

7. Complete remaining steps.

   • For command-line tasks, handle it in the main().

   • Otherwise:

   • Start the GUI by instantiating GuiApplication.

   • Show the GUI and create/load a project.

Main routine

After initializing everything, LMMS runs the main event loop by calling app->exec(). Once the event loop returns, the cleanup steps start.

Cleanup

The following steps are the outline of the shutdown steps of LMMS:

1. Delete the application instance(either QCoreApplication or MainApplication)

2. In the CLI case, destroy the core. It's not the case if the GUI was launched because the destructor of MainWindow calls Engine::destroy().