Add support for subclassing ghost pads

gst-plugin/src/ghost_pad.rs

@@ -0,0 +1,89 @@
+// Copyright (C) 2018 Sebastian Dröge <sebastian@centricular.com>
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use std::mem;
+use std::ptr;
+
+use glib_ffi;
+use gobject_ffi;
+use gst_ffi;
+
+use glib;
+use glib::translate::*;
+use gst;
+use gst::prelude::*;
+
+use gobject_subclass::anyimpl::*;
+use gobject_subclass::object::*;
+
+use pad::*;
+
+pub trait GhostPadImpl<T: GhostPadBase>:
+    AnyImpl + ObjectImpl<T> + PadImpl<T> + Send + Sync + 'static
+{
+}
+
+any_impl!(GhostPadBase, GhostPadImpl);
+
+pub unsafe trait GhostPadBase: IsA<gst::GhostPad> + IsA<gst::Pad> + ObjectType {}
+
+pub unsafe trait GhostPadClassExt<T: GhostPadBase>
+where
+    T::ImplType: GhostPadImpl<T>,
+{
+    fn override_vfuncs(&mut self, _: &ClassInitToken) {}
+}
+
+glib_wrapper! {
+    pub struct GhostPad(Object<InstanceStruct<GhostPad>>):
+        [gst::GhostPad => gst_ffi::GstGhostPad,
+         gst::ProxyPad => gst_ffi::GstProxyPad,
+         gst::Pad => gst_ffi::GstPad,
+         gst::Object => gst_ffi::GstObject];
+
+    match fn {
+        get_type => || get_type::<GhostPad>(),
+    }
+}
+
+unsafe impl<T: IsA<gst::GhostPad> + IsA<gst::Pad> + ObjectType> GhostPadBase for T {}
+pub type GhostPadClass = ClassStruct<GhostPad>;
+
+// FIXME: Boilerplate
+unsafe impl GhostPadClassExt<GhostPad> for GhostPadClass {}
+unsafe impl PadClassExt<GhostPad> for GhostPadClass {}
+unsafe impl ObjectClassExt<GhostPad> for GhostPadClass {}
+
+unsafe impl Send for GhostPad {}
+unsafe impl Sync for GhostPad {}
+
+#[macro_export]
+macro_rules! box_ghost_pad_impl(
+    ($name:ident) => {
+        box_pad_impl!($name);
+
+        impl<T: GhostPadBase> GhostPadImpl<T> for Box<$name<T>>
+        {
+        }
+    };
+);
+box_ghost_pad_impl!(GhostPadImpl);
+
+impl ObjectType for GhostPad {
+    const NAME: &'static str = "RsGhostPad";
+    type ParentType = gst::GhostPad;
+    type ImplType = Box<GhostPadImpl<Self>>;
+    type InstanceStructType = InstanceStruct<Self>;
+
+    fn class_init(token: &ClassInitToken, klass: &mut GhostPadClass) {
+        PadClassExt::override_vfuncs(klass, token);
+        GhostPadClassExt::override_vfuncs(klass, token);
+    }
+
+    object_type_fns!();
+}

gst-plugin/src/lib.rs

@@ -51,3 +51,5 @@ pub mod uri_handler;
 
 #[macro_use]
 pub mod pad;
+#[macro_use]
+pub mod ghost_pad;