// Define an enum'd event ID something like this:
ID_EVENT_QUEUED_FROM_OTHER_THREAD

// Connect it to a handler
FXDEFMAP(MyApp) MyAppMap[]={
	...
	FXMAPFUNC( SEL_IO_READ, ID_EVENT_QUEUED_FROM_OTHER_THREAD, onCommand),
	...
};

// After you make the application associate a signal with the event:
	app->addInput( HandleSignal, INPUT_READ, this, ID_EVENT_QUEUED_FROM_OTHER_THREAD);

// When the signal is set it will call the handler in the GUI thread
onCommand

void ParseTree( SGFXLayersCallback *callback, FXTreeItem *item )
{
	if (!item)
		return;
		
	while(item) {
		/* Do something with the item */
		callback->Callback( this, _tree, item );
		/* Traverse Children */
		ParseTree( callback, item->getFirst() );
		/* Get the next item */
		item=item->getNext();
	}
}

ParseTree( callback, m_tree->getFirst() );

// Connect it to something (like Right mouse button)
FXDEFMAP(SessionPane) SessionPaneMap[]={
	...
	FXMAPFUNC( SEL_RIGHTBUTTONPRESS,	SessionPane::ID_LIST_SESSIONS,	SessionPane::showContextMenu),
	...
};

long SessionPane::showContextMenu( FXObject* sender, FXSelector sel, void *ptr)
{
	FXEvent* event= (FXEvent*)ptr;
	FXMenuPane *pPopupMenu = new FXMenuPane(this);

	new FXMenuCommand( pPopupMenu, "Hide this message type", NULL, this, ID_HIDE_MESSAGE_TYPE);
	new FXMenuSeparator( pPopupMenu, LAYOUT_FILL_X );

	pPopupMenu->create();
	pPopupMenu->popup(NULL, event->root_x,event->root_y);
	getApp()->runModalWhileShown(pPopupMenu);

	delete pPopupMenu;

	return 1;
}

class ExampleDialog : public FXDialogBox
{
private:
	FXDECLARE(ExampleDialog)
	ExampleDialog() {}

public:
	ExampleDialog( FXApp *pOwner);
	~ExampleDialog(void) {}
};

FXDEFMAP(ExampleDialog) ExampleDialogMap[] = { 0 };
FXIMPLEMENT(ExampleDialog,FXDialogBox,ExampleDialogMap,ARRAYNUMBER(ExampleDialogMap))

ExampleDialog::ExampleDialog( FXApp *pOwner)
: FXDialogBox( pOwner, "Choose Run Mode", DECOR_ALL)
{
	new FXLabel( this, "Text");
	new FXButton( this, "Button");

	FXList *pList;
	pList = new FXList( this, 0, 0, LIST_NORMAL | LAYOUT_FILL_X);

	pList->appendItem( "item 1");
	pList->appendItem( "item 2");

	FXComposite *pFrame;
	pFrame = new FXHorizontalFrame( this);

	new FXButton( pFrame, "Okay", 0, this, ID_ACCEPT);
	new FXButton( pFrame, "Cancel", 0, this, ID_CANCEL);

	create();
}

	ExampleDialog dialog( foxAppPointer);
	
	// Modal:
	if ( dialog.execute()) {
	    // Okay was clicked
	} else {
	    // Dialog was cancelled
	}
	
	// Nonmodal:
	dialog.show();

class SessionPane : public FXVerticalFrame
{
private:
	// You Must FXDECLARE the derived class:
	FXDECLARE(SessionPane);

	// You Must have a no parameter constructor ( it is used by serialization )
protected:
	SessionPane() {};

// Your other stuff goes here	
}

FXDEFMAP(SessionPane) SessionPaneMap[]={
	0
};

FXIMPLEMENT(SessionPane,FXVerticalFrame,SessionPaneMap,ARRAYNUMBER(SessionPaneMap))