[gst-devel] Re: [gst-cvs] jdahlin gst-plugins: gst-plugins/ gst-plugins/sys/v4l/

[Benjamin Otte]

On Fri, 13 Aug 2004, Ronald Bultje wrote:

> The only serious complaint that was/is left is that I abuse GObject-style
> macros. If that's still a complaint, then I propose renaming those macros
> to GST_SOME_INTERFACE_CHECK() and GST_IS_SOME_INTERFACE_CHECK() and using
> standard macros for the cast/is macros. That should please everyone, but
> can only be done in 0.9 because it's API breakage.
>
libgstui has a GstVideoWidget with this function:
gst_video_widget_set_overlay (GstVideoWidget *widget, GstXOverlay
*overlay)
This function obiously wants something that is an overlay, because
otherwise it can't embed it. On the other hand I want to be able to set
xvimagesink before I set it to READY. And I really don't want a
return_if_fail because it's not yet READY.
(FWIW, I currently have an #undef GST_IS_X_OVERLAY, #define
GST_IS_X_OVERLAY (glib_representation) in an explicit unbreak.h header.

I'm also opposed to GstImplementsInterface because it puts functionality
for an interface in a totally different location. The check wether the
functions for interface X are supported, should go into interface X
itself, not into some layer above. It's not much code to add it to
each of those interfaces seperately (mixer and overlay, are there any
others) and it doesn't confuse people implementing interfaces for other
elements ("Did you add this to the implements_interface function?" -
"What?") - especially when they implement interfaces that don't need this
functionality, like say GstTagSetter.

And it still breaks everything I learned about objects.

Benjamin