/// <summary> Initializing constructor. </summary>
/// <param name="appResourceName"> The ressource name of the application. <see cref="System.String"/> </param>
/// <param name="shellResourceName"> The ressource name of the root shell. <see cref="System.String"/> </param>
/// <param name="fallbackResources"> The fallback ressources to apply. <see cref="Xt.XtFallbackRessources"/> </param>
public XtApplicationShell(string appResourceName, string shellResourceName, Xt.XtFallbackRessources fallbackResources)
{
if (_instance != null)
{
Console.WriteLine(CLASS_NAME + "::ctr () ERROR: Already an instance created.");
}
_appResourceName = appResourceName;
IntPtr argv = (string.IsNullOrEmpty(shellResourceName) ? IntPtr.Zero : (new XtStringArray(shellResourceName, '|')).Data);
TInt argc = (TInt)(argv != IntPtr.Zero ? 1 : 0);
_shell = Xtlib.XtAppInitialize(ref _appContext, _appResourceName, IntPtr.Zero, 0, ref argc,
argv, fallbackResources.Marshal(), IntPtr.Zero, 0);
_instance = this;
}