The Gauge class is a dialog containing a custom gauge control. This is used for the dialog to adjust the game speed, as well as the dialog for the sound volume.
Sets up the gauge dialog with gaugePos as the position of the gauge.
Performs the dialog's actions. Handles the button presses, obtains the events, and updates the gauge as needed.
Handles the dialogs input.
It checks if the user presses the arrow keys or uses the joystick and adjusts the gauge accordingly. It returns a pointer to the object (control) selected. If none is selected,
it returns NULL.
Updates the gauge position and draws the updated gauge control.