Re: retrieve user input in child widget embedding Ogre

[Vincent Delannoy <vincent delannoy irisa fr>]

OK, I eventually got my Ogre + Gtk app to work. For those interested, 
have a look at the GtkOgre app on the Ogre wiki, and replace 
gtk_ogre_realize() with this version (which creates a GdkWindow first, 
then passes it as external window handle to Ogre when creating the 
RenderWindow) :

static void gtk_ogre_realize(GtkWidget *widget)
{
  GtkOgre* ogre;

  g_return_if_fail(widget != NULL);
  g_return_if_fail(GTK_IS_OGRE(widget));

  ogre = GTK_OGRE(widget);

  g_return_if_fail(ogre->mRenderWindowName != NULL);
  g_return_if_fail(ogre->mRenderWindow == NULL);

  GdkWindow* parent = gtk_widget_get_parent_window(widget);

  //Create the GdkWindow:
  GdkWindowAttr attributes;
  memset(&attributes, 0, sizeof(attributes));

  //Set initial position and size of the Gdk::Window:
  attributes.x = widget->allocation.x;
  attributes.y = widget->allocation.y;
  attributes.width = widget->allocation.width;
  attributes.height = widget->allocation.height;

  //Set event mask as needed here
  attributes.event_mask = GDK_ALL_EVENTS_MASK;
  attributes.window_type = GDK_WINDOW_CHILD;
  attributes.wclass = GDK_INPUT_OUTPUT;

  GTK_WIDGET_UNSET_FLAGS(widget, GTK_NO_WINDOW);   
  widget->window = GDK_DRAWABLE(gdk_window_new(parent, &attributes, 
GDK_WA_X | GDK_WA_Y));

  Ogre::NameValuePairList params;
  params["externalWindowHandle"] = 
Ogre::StringConverter::toString((unsigned 
long)GDK_WINDOW_HWND(widget->window));

  ogre->mRenderWindow = 
Ogre::Root::getSingleton().createRenderWindow("GtkOgreWidget" + 
Ogre::StringConverter::toString(++s_wid),
           widget->allocation.width, widget->allocation.height, false, 
&params);
  
  gtk_widget_set_double_buffered(widget, FALSE);
  gdk_window_set_user_data(widget->window, G_OBJECT(widget));
  gdk_window_set_back_pixmap(widget->window, NULL, FALSE);

  /* Set realized flag */
  GTK_WIDGET_SET_FLAGS(widget, GTK_REALIZED);
}

Also, see this thread for details : 
http://www.ogre3d.org/phpBB2/viewtopic.php?t=21731&postdays=0&postorder=asc&start=0

Vincent Delannoy a écrit :
> Hi,
>
> I'm looking for a way to embed an Ogre3D visualisation in a GTK child 
> widget while still being able to receive keyboard/mouse events in such 
> a widget.
>
> The ogre-gtk example app from the Ogre wiki successfully displays Ogre 
> in child widgets, but for some reason, events can't be received 
> anymore, despite gtk-signal-connect'ing them, as well as setting 
> GDK_ALL_EVENTS_MASK on these widgets
>
> There must be a way around this problem since I know it to be working 
> with GTKmm.
>
> Does anyone have suggestions/sample code regarding this issue?