In OpenOffice, how do I check if my XComponentContext has been closed?

Question

I have a small application that generates three different template documents in OOo Writer. When one of the three "generate" buttons is clicked, this is part of the code that is executed (in C#):

// Connect to OOo
if (componentContext == null)
    componentContext = uno.util.Bootstrap.bootstrap();
XMultiServiceFactory multiServiceFactory =
    (XMultiServiceFactory) componentContext.getServiceManager();
XComponentLoader loader = (XComponentLoader)
    multiServiceFactory.createInstance
        ("com.sun.star.frame.Desktop");

// Initialize class members document, text, and cursor
document = (XTextDocument) loader.loadComponentFromURL
    ("private:factory/swriter", "_blank", 0,
     new PropertyValue[0]);
text = document.getText();
cursor = text.createTextCursor();

The following steps cause a crash:

1. The user generates a document.
2. The user closes the document (closing OOo).
3. The user tries to generate another document.

This exception is thrown:

unoidl.com.sun.star.lang.DisposedException: URP-Bridge: disposed(tid=4) Unexpected connection closure

How do I check to make sure the connection is still open before trying to generate another chart? And how do I reconnect if it has been closed?

Edit: More specifically, this is the complete error message:

Marshaling clicked signal
Exception in Gtk# callback delegate
  Note: Applications can use GLib.ExceptionManager.UnhandledException to handle the exception.
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> unoidl.com.sun.star.lang.DisposedException: URP-Bridge: disposed(tid=4) Unexpected connection closure
  at com.sun.star.bridges.mono_uno.UnoInterfaceProxy.ConstructReturnMessage (Any result, System.Object[] args, uno.Typelib.InterfaceMethodTypeDescription* methodTD, IMethodCallMessage callmsg, Any exception) [0x00000] 
  at com.sun.star.bridges.mono_uno.UnoInterfaceProxy.Invoke (IMessage request) [0x00000] 
  at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke (System.Runtime.Remoting.Proxies.RealProxy rp, IMessage msg, System.Exception& exc, System.Object[]& out_args) [0x00000] 
  --- End of inner exception stack trace ---
  at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] 
  at System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) [0x00000] 
  at System.Delegate.DynamicInvokeImpl (System.Object[] args) [0x00000] 
  at System.MulticastDelegate.DynamicInvokeImpl (System.Object[] args) [0x00000] 
  at System.Delegate.DynamicInvoke (System.Object[] args) [0x00000] 
  at GLib.Signal.ClosureInvokedCB (System.Object o, GLib.ClosureInvokedArgs args) [0x00000] 
  at GLib.SignalClosure.Invoke (GLib.ClosureInvokedArgs args) [0x00000] 
  at GLib.SignalClosure.MarshalCallback (IntPtr raw_closure, IntPtr return_val, UInt32 n_param_vals, IntPtr param_values, IntPtr invocation_hint, IntPtr marshal_data) [0x00000] 
   at GLib.ExceptionManager.RaiseUnhandledException(System.Exception e, Boolean is_terminal)
   at GLib.SignalClosure.MarshalCallback(IntPtr raw_closure, IntPtr return_val, UInt32 n_param_vals, IntPtr param_values, IntPtr invocation_hint, IntPtr marshal_data)
   at Gtk.Application.gtk_main()
   at Gtk.Application.Run()
   at TestDrive.MainClass.Main(System.String[] args) in /home/matthew/Dropbox/OpenSBS-mono/TestDrive/Main.cs:line 28

The application was terminated by a signal: SIGHUP

If I get rid of the line if (componentContext == null) (i.e., always try to connect, even when we have already connected), I get a stacktrace accompanied by this message:

=================================================================
Got a SIGSEGV while executing native code. This usually indicates
a fatal error in the mono runtime or one of the native libraries 
used by your application.
=================================================================

• Discussion on OOoForum.org

Answer 1

This is just a guess. You could use XComponent.addEventListener and listen for the disposing event.

eg:

class App :  XEventListener
{
    private XComponentLoader m_loader;

    private XComponentLoader Loader
    {
        get
        {
            if (m_loader == null)
            {
                m_loader = (XComponentLoader)multiServiceFactory.createInstance("com.sun.star.frame.Desktop");
                XComponent comp = (XComponent)m_loader;
                comp.addEventListener(this);
            }
            return m_loader;
        }
    }

    private void disposing(EventObject Source)
    {
        m_loader = null;
    }
}