Remove unnecessary sealing of ImplExt traits and enforce type hierarchy more strictly

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/-/merge_requests/1563>

examples/src/bin/subclass_vfuncs/iirfilter/mod.rs

@@ -27,7 +27,7 @@ pub trait IirFilterExt: IsA<IirFilter> {
 impl<O: IsA<IirFilter>> IirFilterExt for O {}
 
 /// Trait to implement in `IirFilter` subclasses.
-pub trait IirFilterImpl: AudioFilterImpl {
+pub trait IirFilterImpl: AudioFilterImpl + ObjectSubclass<Type: IsA<IirFilter>> {
     /// Called whenever the sample rate is changing.
     fn set_rate(&self, rate: u32) {
         self.parent_set_rate(rate);

gstreamer-allocators/src/subclass/dma_buf_allocator.rs

@@ -1,6 +1,9 @@
-use glib::subclass::prelude::*;
+use glib::{prelude::*, subclass::prelude::*};
 
 use crate::{subclass::fd_allocator::FdAllocatorImpl, DmaBufAllocator};
 
-pub trait DmaBufAllocatorImpl: FdAllocatorImpl {}
+pub trait DmaBufAllocatorImpl:
+    FdAllocatorImpl + ObjectSubclass<Type: IsA<DmaBufAllocator>>
+{
+}
 unsafe impl<T: DmaBufAllocatorImpl> IsSubclassable<T> for DmaBufAllocator {}

gstreamer-allocators/src/subclass/fd_allocator.rs

@@ -1,7 +1,7 @@
-use glib::subclass::prelude::*;
+use glib::{prelude::*, subclass::prelude::*};
 
 use crate::FdAllocator;
 use gst::subclass::prelude::AllocatorImpl;
 
-pub trait FdAllocatorImpl: AllocatorImpl {}
+pub trait FdAllocatorImpl: AllocatorImpl + ObjectSubclass<Type: IsA<FdAllocator>> {}
 unsafe impl<T: FdAllocatorImpl> IsSubclassable<T> for FdAllocator {}

gstreamer-audio/src/subclass/audio_aggregator.rs

@@ -7,7 +7,7 @@ use gst_base::{prelude::*, subclass::prelude::*};
 
 use crate::{ffi, AudioAggregator, AudioAggregatorPad};
 
-pub trait AudioAggregatorImpl: AudioAggregatorImplExt + AggregatorImpl {
+pub trait AudioAggregatorImpl: AggregatorImpl + ObjectSubclass<Type: IsA<AudioAggregator>> {
     fn create_output_buffer(&self, num_frames: u32) -> Option<gst::Buffer> {
         self.parent_create_output_buffer(num_frames)
     }
@@ -26,12 +26,7 @@ pub trait AudioAggregatorImpl: AudioAggregatorImplExt + AggregatorImpl {
     }
 }
 
-mod sealed {
+pub trait AudioAggregatorImplExt: AudioAggregatorImpl {
-    pub trait Sealed {}
-    impl<T: super::AudioAggregatorImplExt> Sealed for T {}
-}
-
-pub trait AudioAggregatorImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_create_output_buffer(&self, num_frames: u32) -> Option<gst::Buffer> {
         unsafe {
             let data = Self::type_data();

gstreamer-audio/src/subclass/audio_aggregator_convert_pad.rs

@@ -1,10 +1,13 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
-use gst_base::subclass::prelude::*;
+use gst_base::{prelude::*, subclass::prelude::*};
 
 use super::prelude::AudioAggregatorPadImpl;
 use crate::AudioAggregatorConvertPad;
 
-pub trait AudioAggregatorConvertPadImpl: AudioAggregatorPadImpl {}
+pub trait AudioAggregatorConvertPadImpl:
+    AudioAggregatorPadImpl + ObjectSubclass<Type: IsA<AudioAggregatorConvertPad>>
+{
+}
 
 unsafe impl<T: AudioAggregatorConvertPadImpl> IsSubclassable<T> for AudioAggregatorConvertPad {}

gstreamer-audio/src/subclass/audio_aggregator_pad.rs

@@ -7,7 +7,9 @@ use gst_base::{prelude::*, subclass::prelude::*};
 
 use crate::{ffi, AudioAggregatorPad};
 
-pub trait AudioAggregatorPadImpl: AudioAggregatorPadImplExt + AggregatorPadImpl {
+pub trait AudioAggregatorPadImpl:
+    AggregatorPadImpl + ObjectSubclass<Type: IsA<AudioAggregatorPad>>
+{
     const HANDLE_CONVERSION: bool = false;
 
     fn update_conversion_info(&self) {
@@ -24,12 +26,7 @@ pub trait AudioAggregatorPadImpl: AudioAggregatorPadImplExt + AggregatorPadImpl
     }
 }
 
-mod sealed {
+pub trait AudioAggregatorPadImplExt: AudioAggregatorPadImpl {
-    pub trait Sealed {}
-    impl<T: super::AudioAggregatorPadImplExt> Sealed for T {}
-}
-
-pub trait AudioAggregatorPadImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_update_conversion_info(&self) {
         unsafe {
             let data = Self::type_data();

gstreamer-audio/src/subclass/audio_base_sink.rs

@@ -1,9 +1,9 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
-use gst_base::subclass::prelude::*;
+use gst_base::{prelude::*, subclass::prelude::*};
 
 use crate::AudioBaseSink;
 
-pub trait AudioBaseSinkImpl: BaseSinkImpl {}
+pub trait AudioBaseSinkImpl: BaseSinkImpl + ObjectSubclass<Type: IsA<AudioBaseSink>> {}
 
 unsafe impl<T: AudioBaseSinkImpl> IsSubclassable<T> for AudioBaseSink {}

gstreamer-audio/src/subclass/audio_base_src.rs

@@ -1,9 +1,9 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
-use gst_base::subclass::prelude::*;
+use gst_base::{prelude::*, subclass::prelude::*};
 
 use crate::AudioBaseSrc;
 
-pub trait AudioBaseSrcImpl: BaseSrcImpl {}
+pub trait AudioBaseSrcImpl: BaseSrcImpl + ObjectSubclass<Type: IsA<AudioBaseSrc>> {}
 
 unsafe impl<T: AudioBaseSrcImpl> IsSubclassable<T> for AudioBaseSrc {}

gstreamer-audio/src/subclass/audio_decoder.rs

@@ -7,7 +7,7 @@ use gst::subclass::prelude::*;
 
 use crate::{ffi, prelude::*, AudioDecoder};
 
-pub trait AudioDecoderImpl: AudioDecoderImplExt + ElementImpl {
+pub trait AudioDecoderImpl: ElementImpl + ObjectSubclass<Type: IsA<AudioDecoder>> {
     fn open(&self) -> Result<(), gst::ErrorMessage> {
         self.parent_open()
     }
@@ -86,12 +86,7 @@ pub trait AudioDecoderImpl: AudioDecoderImplExt + ElementImpl {
     }
 }
 
-mod sealed {
+pub trait AudioDecoderImplExt: AudioDecoderImpl {
-    pub trait Sealed {}
-    impl<T: super::AudioDecoderImplExt> Sealed for T {}
-}
-
-pub trait AudioDecoderImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_open(&self) -> Result<(), gst::ErrorMessage> {
         unsafe {
             let data = Self::type_data();

gstreamer-audio/src/subclass/audio_encoder.rs

@@ -7,7 +7,7 @@ use gst::subclass::prelude::*;
 
 use crate::{ffi, prelude::*, AudioEncoder, AudioInfo};
 
-pub trait AudioEncoderImpl: AudioEncoderImplExt + ElementImpl {
+pub trait AudioEncoderImpl: ElementImpl + ObjectSubclass<Type: IsA<AudioEncoder>> {
     fn open(&self) -> Result<(), gst::ErrorMessage> {
         self.parent_open()
     }
@@ -82,12 +82,7 @@ pub trait AudioEncoderImpl: AudioEncoderImplExt + ElementImpl {
     }
 }
 
-mod sealed {
+pub trait AudioEncoderImplExt: AudioEncoderImpl {
-    pub trait Sealed {}
-    impl<T: super::AudioEncoderImplExt> Sealed for T {}
-}
-
-pub trait AudioEncoderImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_open(&self) -> Result<(), gst::ErrorMessage> {
         unsafe {
             let data = Self::type_data();

gstreamer-audio/src/subclass/audio_filter.rs

@@ -5,7 +5,7 @@ use gst_base::{prelude::*, subclass::prelude::*};
 
 use crate::{ffi, AudioFilter, AudioInfo};
 
-pub trait AudioFilterImpl: AudioFilterImplExt + BaseTransformImpl {
+pub trait AudioFilterImpl: BaseTransformImpl + ObjectSubclass<Type: IsA<AudioFilter>> {
     fn allowed_caps() -> &'static gst::Caps {
         Self::parent_allowed_caps()
     }
@@ -15,12 +15,7 @@ pub trait AudioFilterImpl: AudioFilterImplExt + BaseTransformImpl {
     }
 }
 
-mod sealed {
+pub trait AudioFilterImplExt: AudioFilterImpl {
-    pub trait Sealed {}
-    impl<T: super::AudioFilterImplExt> Sealed for T {}
-}
-
-pub trait AudioFilterImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_setup(&self, info: &AudioInfo) -> Result<(), gst::LoggableError> {
         unsafe {
             let data = Self::type_data();

gstreamer-audio/src/subclass/audio_sink.rs

@@ -7,7 +7,7 @@ use gst_base::subclass::prelude::*;
 use super::prelude::*;
 use crate::{ffi, AudioRingBufferSpec, AudioSink};
 
-pub trait AudioSinkImpl: AudioSinkImplExt + AudioBaseSinkImpl {
+pub trait AudioSinkImpl: AudioBaseSinkImpl + ObjectSubclass<Type: IsA<AudioSink>> {
     fn close(&self) -> Result<(), LoggableError> {
         self.parent_close()
     }
@@ -37,12 +37,7 @@ pub trait AudioSinkImpl: AudioSinkImplExt + AudioBaseSinkImpl {
     }
 }
 
-mod sealed {
+pub trait AudioSinkImplExt: AudioSinkImpl {
-    pub trait Sealed {}
-    impl<T: super::AudioSinkImplExt> Sealed for T {}
-}
-
-pub trait AudioSinkImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_close(&self) -> Result<(), LoggableError> {
         unsafe {
             let data = Self::type_data();

gstreamer-audio/src/subclass/audio_src.rs

@@ -9,7 +9,7 @@ use gst_base::subclass::prelude::*;
 use super::prelude::*;
 use crate::{ffi, AudioRingBufferSpec, AudioSrc};
 
-pub trait AudioSrcImpl: AudioSrcImplExt + AudioBaseSrcImpl {
+pub trait AudioSrcImpl: AudioBaseSrcImpl + ObjectSubclass<Type: IsA<AudioSrc>> {
     fn close(&self) -> Result<(), LoggableError> {
         self.parent_close()
     }
@@ -39,12 +39,7 @@ pub trait AudioSrcImpl: AudioSrcImplExt + AudioBaseSrcImpl {
     }
 }
 
-mod sealed {
+pub trait AudioSrcImplExt: AudioSrcImpl {
-    pub trait Sealed {}
-    impl<T: super::AudioSrcImplExt> Sealed for T {}
-}
-
-pub trait AudioSrcImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_close(&self) -> Result<(), LoggableError> {
         unsafe {
             let data = Self::type_data();

gstreamer-base/src/subclass/aggregator.rs

@@ -7,7 +7,7 @@ use gst::subclass::prelude::*;
 
 use crate::{ffi, Aggregator, AggregatorPad};
 
-pub trait AggregatorImpl: AggregatorImplExt + ElementImpl {
+pub trait AggregatorImpl: ElementImpl + ObjectSubclass<Type: IsA<Aggregator>> {
     fn flush(&self) -> Result<gst::FlowSuccess, gst::FlowError> {
         self.parent_flush()
     }
@@ -135,12 +135,7 @@ pub trait AggregatorImpl: AggregatorImplExt + ElementImpl {
     }
 }
 
-mod sealed {
+pub trait AggregatorImplExt: AggregatorImpl {
-    pub trait Sealed {}
-    impl<T: super::AggregatorImplExt> Sealed for T {}
-}
-
-pub trait AggregatorImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_flush(&self) -> Result<gst::FlowSuccess, gst::FlowError> {
         unsafe {
             let data = Self::type_data();

gstreamer-base/src/subclass/aggregator_pad.rs

@@ -5,7 +5,7 @@ use gst::subclass::prelude::*;
 
 use crate::{ffi, Aggregator, AggregatorPad};
 
-pub trait AggregatorPadImpl: AggregatorPadImplExt + PadImpl {
+pub trait AggregatorPadImpl: PadImpl + ObjectSubclass<Type: IsA<AggregatorPad>> {
     fn flush(&self, aggregator: &Aggregator) -> Result<gst::FlowSuccess, gst::FlowError> {
         self.parent_flush(aggregator)
     }
@@ -15,12 +15,7 @@ pub trait AggregatorPadImpl: AggregatorPadImplExt + PadImpl {
     }
 }
 
-mod sealed {
+pub trait AggregatorPadImplExt: AggregatorPadImpl {
-    pub trait Sealed {}
-    impl<T: super::AggregatorPadImplExt> Sealed for T {}
-}
-
-pub trait AggregatorPadImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_flush(&self, aggregator: &Aggregator) -> Result<gst::FlowSuccess, gst::FlowError> {
         unsafe {
             let data = Self::type_data();

gstreamer-base/src/subclass/base_parse.rs

@@ -7,7 +7,7 @@ use gst::subclass::prelude::*;
 
 use crate::{ffi, prelude::*, BaseParse, BaseParseFrame};
 
-pub trait BaseParseImpl: BaseParseImplExt + ElementImpl {
+pub trait BaseParseImpl: ElementImpl + ObjectSubclass<Type: IsA<BaseParse>> {
     fn start(&self) -> Result<(), gst::ErrorMessage> {
         self.parent_start()
     }
@@ -36,12 +36,7 @@ pub trait BaseParseImpl: BaseParseImplExt + ElementImpl {
     }
 }
 
-mod sealed {
+pub trait BaseParseImplExt: BaseParseImpl {
-    pub trait Sealed {}
-    impl<T: super::BaseParseImplExt> Sealed for T {}
-}
-
-pub trait BaseParseImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_start(&self) -> Result<(), gst::ErrorMessage> {
         unsafe {
             let data = Self::type_data();

gstreamer-base/src/subclass/base_sink.rs

@@ -7,7 +7,7 @@ use gst::subclass::prelude::*;
 
 use crate::{ffi, BaseSink};
 
-pub trait BaseSinkImpl: BaseSinkImplExt + ElementImpl {
+pub trait BaseSinkImpl: ElementImpl + ObjectSubclass<Type: IsA<BaseSink>> {
     fn start(&self) -> Result<(), gst::ErrorMessage> {
         self.parent_start()
     }
@@ -68,12 +68,7 @@ pub trait BaseSinkImpl: BaseSinkImplExt + ElementImpl {
     }
 }
 
-mod sealed {
+pub trait BaseSinkImplExt: BaseSinkImpl {
-    pub trait Sealed {}
-    impl<T: super::BaseSinkImplExt> Sealed for T {}
-}
-
-pub trait BaseSinkImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_start(&self) -> Result<(), gst::ErrorMessage> {
         unsafe {
             let data = Self::type_data();

gstreamer-base/src/subclass/base_src.rs

@@ -20,7 +20,7 @@ pub enum CreateSuccess {
     NewBufferList(gst::BufferList),
 }
 
-pub trait BaseSrcImpl: BaseSrcImplExt + ElementImpl {
+pub trait BaseSrcImpl: ElementImpl + ObjectSubclass<Type: IsA<BaseSrc>> {
     fn start(&self) -> Result<(), gst::ErrorMessage> {
         self.parent_start()
     }
@@ -108,12 +108,7 @@ pub trait BaseSrcImpl: BaseSrcImplExt + ElementImpl {
     }
 }
 
-mod sealed {
+pub trait BaseSrcImplExt: BaseSrcImpl {
-    pub trait Sealed {}
-    impl<T: super::BaseSrcImplExt> Sealed for T {}
-}
-
-pub trait BaseSrcImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_start(&self) -> Result<(), gst::ErrorMessage> {
         unsafe {
             let data = Self::type_data();

gstreamer-base/src/subclass/base_transform.rs

@@ -14,7 +14,7 @@ pub enum BaseTransformMode {
     Both,
 }
 
-pub trait BaseTransformImpl: BaseTransformImplExt + ElementImpl {
+pub trait BaseTransformImpl: ElementImpl + ObjectSubclass<Type: IsA<BaseTransform>> {
     const MODE: BaseTransformMode;
     const PASSTHROUGH_ON_SAME_CAPS: bool;
     const TRANSFORM_IP_ON_PASSTHROUGH: bool;
@@ -154,12 +154,7 @@ pub trait BaseTransformImpl: BaseTransformImplExt + ElementImpl {
     }
 }
 
-mod sealed {
+pub trait BaseTransformImplExt: BaseTransformImpl {
-    pub trait Sealed {}
-    impl<T: super::BaseTransformImplExt> Sealed for T {}
-}
-
-pub trait BaseTransformImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_start(&self) -> Result<(), gst::ErrorMessage> {
         unsafe {
             let data = Self::type_data();

gstreamer-base/src/subclass/push_src.rs

@@ -3,12 +3,12 @@
 use std::ptr;
 
 use glib::{prelude::*, subclass::prelude::*, translate::*};
-use gst::prelude::*;
+use gst::{prelude::*, subclass::prelude::*};
 
 use super::base_src::{BaseSrcImpl, CreateSuccess};
 use crate::{ffi, prelude::*, PushSrc};
 
-pub trait PushSrcImpl: PushSrcImplExt + BaseSrcImpl {
+pub trait PushSrcImpl: BaseSrcImpl + ObjectSubclass<Type: IsA<PushSrc>> {
     fn fill(&self, buffer: &mut gst::BufferRef) -> Result<gst::FlowSuccess, gst::FlowError> {
         PushSrcImplExt::parent_fill(self, buffer)
     }
@@ -22,12 +22,7 @@ pub trait PushSrcImpl: PushSrcImplExt + BaseSrcImpl {
     }
 }
 
-mod sealed {
+pub trait PushSrcImplExt: PushSrcImpl {
-    pub trait Sealed {}
-    impl<T: super::PushSrcImplExt> Sealed for T {}
-}
-
-pub trait PushSrcImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_fill(&self, buffer: &mut gst::BufferRef) -> Result<gst::FlowSuccess, gst::FlowError> {
         unsafe {
             let data = Self::type_data();

gstreamer-editing-services/src/subclass/formatter.rs

@@ -3,7 +3,7 @@
 use crate::{ffi, prelude::*, Formatter};
 use glib::{subclass::prelude::*, translate::*};
 
-pub trait FormatterImpl: FormatterImplExt + ObjectImpl + Send + Sync {
+pub trait FormatterImpl: ObjectImpl + ObjectSubclass<Type: IsA<Formatter>> + Send + Sync {
     fn can_load_uri(&self, uri: &str) -> Result<(), glib::Error> {
         self.parent_can_load_uri(uri)
     }
@@ -22,12 +22,7 @@ pub trait FormatterImpl: FormatterImplExt + ObjectImpl + Send + Sync {
     }
 }
 
-mod sealed {
+pub trait FormatterImplExt: FormatterImpl {
-    pub trait Sealed {}
-    impl<T: super::FormatterImplExt> Sealed for T {}
-}
-
-pub trait FormatterImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_can_load_uri(&self, uri: &str) -> Result<(), glib::Error> {
         unsafe {
             let data = Self::type_data();

gstreamer-gl/src/subclass/gl_base_filter.rs

@@ -5,7 +5,7 @@ use gst_base::subclass::prelude::*;
 
 use crate::{ffi, prelude::*, GLBaseFilter};
 
-pub trait GLBaseFilterImpl: GLBaseFilterImplExt + BaseTransformImpl {
+pub trait GLBaseFilterImpl: BaseTransformImpl + ObjectSubclass<Type: IsA<GLBaseFilter>> {
     fn gl_set_caps(&self, incaps: &Caps, outcaps: &Caps) -> Result<(), LoggableError> {
         self.parent_gl_set_caps(incaps, outcaps)
     }
@@ -19,12 +19,7 @@ pub trait GLBaseFilterImpl: GLBaseFilterImplExt + BaseTransformImpl {
     }
 }
 
-mod sealed {
+pub trait GLBaseFilterImplExt: GLBaseFilterImpl {
-    pub trait Sealed {}
-    impl<T: super::GLBaseFilterImplExt> Sealed for T {}
-}
-
-pub trait GLBaseFilterImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_gl_set_caps(&self, incaps: &Caps, outcaps: &Caps) -> Result<(), LoggableError> {
         unsafe {
             let data = Self::type_data();

gstreamer-gl/src/subclass/gl_base_src.rs

@@ -5,7 +5,7 @@ use gst_base::subclass::prelude::*;
 
 use crate::{ffi, prelude::*, GLBaseSrc, GLMemory, GLAPI};
 
-pub trait GLBaseSrcImpl: GLBaseSrcImplExt + PushSrcImpl {
+pub trait GLBaseSrcImpl: PushSrcImpl + ObjectSubclass<Type: IsA<GLBaseSrc>> {
     const SUPPORTED_GL_API: GLAPI;
 
     fn gl_start(&self) -> Result<(), LoggableError> {
@@ -21,12 +21,7 @@ pub trait GLBaseSrcImpl: GLBaseSrcImplExt + PushSrcImpl {
     }
 }
 
-mod sealed {
+pub trait GLBaseSrcImplExt: GLBaseSrcImpl {
-    pub trait Sealed {}
-    impl<T: super::GLBaseSrcImplExt> Sealed for T {}
-}
-
-pub trait GLBaseSrcImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_gl_start(&self) -> Result<(), LoggableError> {
         unsafe {
             let data = Self::type_data();

gstreamer-gl/src/subclass/gl_filter.rs

@@ -13,7 +13,7 @@ pub enum GLFilterMode {
     Texture,
 }
 
-pub trait GLFilterImpl: GLFilterImplExt + GLBaseFilterImpl {
+pub trait GLFilterImpl: GLBaseFilterImpl + ObjectSubclass<Type: IsA<GLFilter>> {
     const MODE: GLFilterMode;
     // rustdoc-stripper-ignore-next
     /// Calls [`add_rgba_pad_templates`](ffi::gst_gl_filter_add_rgba_pad_templates)
@@ -46,12 +46,7 @@ pub trait GLFilterImpl: GLFilterImplExt + GLBaseFilterImpl {
     }
 }
 
-mod sealed {
+pub trait GLFilterImplExt: GLFilterImpl {
-    pub trait Sealed {}
-    impl<T: super::GLFilterImplExt> Sealed for T {}
-}
-
-pub trait GLFilterImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_set_caps(&self, incaps: &Caps, outcaps: &Caps) -> Result<(), LoggableError> {
         unsafe {
             let data = Self::type_data();

gstreamer-pbutils/src/subclass/audio_visualizer.rs

@@ -7,7 +7,7 @@ use crate::{ffi, AudioVisualizer};
 
 pub struct AudioVisualizerSetupToken<'a>(pub(crate) &'a AudioVisualizer);
 
-pub trait AudioVisualizerImpl: AudioVisualizerImplExt + ElementImpl {
+pub trait AudioVisualizerImpl: ElementImpl + ObjectSubclass<Type: IsA<AudioVisualizer>> {
     fn setup(&self, token: &AudioVisualizerSetupToken) -> Result<(), LoggableError> {
         self.parent_setup(token)
     }
@@ -28,12 +28,7 @@ pub trait AudioVisualizerImpl: AudioVisualizerImplExt + ElementImpl {
     }
 }
 
-mod sealed {
+pub trait AudioVisualizerImplExt: AudioVisualizerImpl {
-    pub trait Sealed {}
-    impl<T: super::AudioVisualizerImplExt> Sealed for T {}
-}
-
-pub trait AudioVisualizerImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_setup(&self, token: &AudioVisualizerSetupToken) -> Result<(), LoggableError> {
         assert_eq!(
             self.obj().as_ptr() as *mut ffi::GstAudioVisualizer,

gstreamer-play/src/subclass/play_video_renderer.rs

@@ -4,7 +4,7 @@ use glib::{prelude::*, subclass::prelude::*, translate::*};
 
 use crate::{ffi, Play, PlayVideoRenderer};
 
-pub trait PlayVideoRendererImpl: ObjectImpl {
+pub trait PlayVideoRendererImpl: ObjectImpl + ObjectSubclass<Type: IsA<PlayVideoRenderer>> {
     fn create_video_sink(&self, play: &Play) -> gst::Element;
 }
 
@@ -16,12 +16,7 @@ unsafe impl<T: PlayVideoRendererImpl> IsImplementable<T> for PlayVideoRenderer {
     }
 }
 
-mod sealed {
+pub trait PlayVideoRendererImplExt: PlayVideoRendererImpl {
-    pub trait Sealed {}
-    impl<T: super::PlayVideoRendererImplExt> Sealed for T {}
-}
-
-pub trait PlayVideoRendererImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_create_video_sink(&self, play: &Play) -> gst::Element {
         unsafe {
             let type_data = Self::type_data();

gstreamer-player/src/subclass/player_video_renderer.rs

@@ -4,7 +4,9 @@ use glib::{prelude::*, subclass::prelude::*, translate::*};
 
 use crate::{ffi, Player, PlayerVideoRenderer};
 
-pub trait PlayerVideoRendererImpl: ObjectImpl {
+pub trait PlayerVideoRendererImpl:
+    ObjectImpl + ObjectSubclass<Type: IsA<PlayerVideoRenderer>>
+{
     fn create_video_sink(&self, player: &Player) -> gst::Element;
 }
 
@@ -16,12 +18,7 @@ unsafe impl<T: PlayerVideoRendererImpl> IsImplementable<T> for PlayerVideoRender
     }
 }
 
-mod sealed {
+pub trait PlayerVideoRendererImplExt: PlayerVideoRendererImpl {
-    pub trait Sealed {}
-    impl<T: super::PlayerVideoRendererImplExt> Sealed for T {}
-}
-
-pub trait PlayerVideoRendererImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_create_video_sink(&self, player: &Player) -> gst::Element {
         unsafe {
             let type_data = Self::type_data();

gstreamer-rtp/src/subclass/rtp_base_depayload.rs

@@ -7,7 +7,7 @@ use gst::subclass::prelude::*;
 
 use crate::{ffi, prelude::*, RTPBaseDepayload};
 
-pub trait RTPBaseDepayloadImpl: RTPBaseDepayloadImplExt + ElementImpl {
+pub trait RTPBaseDepayloadImpl: ElementImpl + ObjectSubclass<Type: IsA<RTPBaseDepayload>> {
     fn set_caps(&self, caps: &gst::Caps) -> Result<(), gst::LoggableError> {
         self.parent_set_caps(caps)
     }
@@ -28,12 +28,7 @@ pub trait RTPBaseDepayloadImpl: RTPBaseDepayloadImplExt + ElementImpl {
     }
 }
 
-mod sealed {
+pub trait RTPBaseDepayloadImplExt: RTPBaseDepayloadImpl {
-    pub trait Sealed {}
-    impl<T: super::RTPBaseDepayloadImplExt> Sealed for T {}
-}
-
-pub trait RTPBaseDepayloadImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_set_caps(&self, caps: &gst::Caps) -> Result<(), gst::LoggableError> {
         unsafe {
             let data = Self::type_data();

gstreamer-rtp/src/subclass/rtp_base_payload.rs

@@ -5,7 +5,7 @@ use gst::subclass::prelude::*;
 
 use crate::{ffi, prelude::*, RTPBasePayload};
 
-pub trait RTPBasePayloadImpl: RTPBasePayloadImplExt + ElementImpl {
+pub trait RTPBasePayloadImpl: ElementImpl + ObjectSubclass<Type: IsA<RTPBasePayload>> {
     fn caps(&self, pad: &gst::Pad, filter: Option<&gst::Caps>) -> gst::Caps {
         self.parent_caps(pad, filter)
     }
@@ -31,12 +31,7 @@ pub trait RTPBasePayloadImpl: RTPBasePayloadImplExt + ElementImpl {
     }
 }
 
-mod sealed {
+pub trait RTPBasePayloadImplExt: RTPBasePayloadImpl {
-    pub trait Sealed {}
-    impl<T: super::RTPBasePayloadImplExt> Sealed for T {}
-}
-
-pub trait RTPBasePayloadImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_caps(&self, pad: &gst::Pad, filter: Option<&gst::Caps>) -> gst::Caps {
         unsafe {
             let data = Self::type_data();

gstreamer-rtp/src/subclass/rtp_header_extension.rs

@@ -4,8 +4,11 @@ use glib::{prelude::*, subclass::prelude::*, translate::*};
 
 use super::prelude::*;
 use crate::ffi;
+use crate::RTPHeaderExtension;
 
-pub trait RTPHeaderExtensionImpl: RTPHeaderExtensionImplExt + ElementImpl {
+pub trait RTPHeaderExtensionImpl:
+    ElementImpl + ObjectSubclass<Type: IsA<RTPHeaderExtension>>
+{
     const URI: &'static str;
 
     fn supported_flags(&self) -> crate::RTPHeaderExtensionFlags {
@@ -56,12 +59,7 @@ pub trait RTPHeaderExtensionImpl: RTPHeaderExtensionImplExt + ElementImpl {
     }
 }
 
-mod sealed {
+pub trait RTPHeaderExtensionImplExt: RTPHeaderExtensionImpl {
-    pub trait Sealed {}
-    impl<T: super::RTPHeaderExtensionImplExt> Sealed for T {}
-}
-
-pub trait RTPHeaderExtensionImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_supported_flags(&self) -> crate::RTPHeaderExtensionFlags {
         unsafe {
             let data = Self::type_data();
@@ -71,7 +69,7 @@ pub trait RTPHeaderExtensionImplExt: sealed::Sealed + ObjectSubclass {
                 .expect("no parent \"get_supported_flags\" implementation");
             from_glib(f(self
                 .obj()
-                .unsafe_cast_ref::<crate::RTPHeaderExtension>()
+                .unsafe_cast_ref::<RTPHeaderExtension>()
                 .to_glib_none()
                 .0))
         }
@@ -86,7 +84,7 @@ pub trait RTPHeaderExtensionImplExt: sealed::Sealed + ObjectSubclass {
                 .expect("no parent \"get_max_size\" implementation");
             f(
                 self.obj()
-                    .unsafe_cast_ref::<crate::RTPHeaderExtension>()
+                    .unsafe_cast_ref::<RTPHeaderExtension>()
                     .to_glib_none()
                     .0,
                 input.as_ptr(),
@@ -110,7 +108,7 @@ pub trait RTPHeaderExtensionImplExt: sealed::Sealed + ObjectSubclass {
 
             let res = f(
                 self.obj()
-                    .unsafe_cast_ref::<crate::RTPHeaderExtension>()
+                    .unsafe_cast_ref::<RTPHeaderExtension>()
                     .to_glib_none()
                     .0,
                 input.as_ptr(),
@@ -147,7 +145,7 @@ pub trait RTPHeaderExtensionImplExt: sealed::Sealed + ObjectSubclass {
             gst::result_from_gboolean!(
                 f(
                     self.obj()
-                        .unsafe_cast_ref::<crate::RTPHeaderExtension>()
+                        .unsafe_cast_ref::<RTPHeaderExtension>()
                         .to_glib_none()
                         .0,
                     read_flags.into_glib(),
@@ -169,7 +167,7 @@ pub trait RTPHeaderExtensionImplExt: sealed::Sealed + ObjectSubclass {
                 gst::result_from_gboolean!(
                     f(
                         self.obj()
-                            .unsafe_cast_ref::<crate::RTPHeaderExtension>()
+                            .unsafe_cast_ref::<RTPHeaderExtension>()
                             .to_glib_none()
                             .0,
                         caps.as_mut_ptr(),
@@ -194,7 +192,7 @@ pub trait RTPHeaderExtensionImplExt: sealed::Sealed + ObjectSubclass {
                 gst::result_from_gboolean!(
                     f(
                         self.obj()
-                            .unsafe_cast_ref::<crate::RTPHeaderExtension>()
+                            .unsafe_cast_ref::<RTPHeaderExtension>()
                             .to_glib_none()
                             .0,
                         caps.as_mut_ptr(),
@@ -220,7 +218,7 @@ pub trait RTPHeaderExtensionImplExt: sealed::Sealed + ObjectSubclass {
                 gst::result_from_gboolean!(
                     f(
                         self.obj()
-                            .unsafe_cast_ref::<crate::RTPHeaderExtension>()
+                            .unsafe_cast_ref::<RTPHeaderExtension>()
                             .to_glib_none()
                             .0,
                         direction.into_glib(),
@@ -249,7 +247,7 @@ pub trait RTPHeaderExtensionImplExt: sealed::Sealed + ObjectSubclass {
             gst::result_from_gboolean!(
                 f(
                     self.obj()
-                        .unsafe_cast_ref::<crate::RTPHeaderExtension>()
+                        .unsafe_cast_ref::<RTPHeaderExtension>()
                         .to_glib_none()
                         .0,
                     caps.as_mut_ptr(),
@@ -263,7 +261,7 @@ pub trait RTPHeaderExtensionImplExt: sealed::Sealed + ObjectSubclass {
 
 impl<T: RTPHeaderExtensionImpl> RTPHeaderExtensionImplExt for T {}
 
-unsafe impl<T: RTPHeaderExtensionImpl> IsSubclassable<T> for crate::RTPHeaderExtension {
+unsafe impl<T: RTPHeaderExtensionImpl> IsSubclassable<T> for RTPHeaderExtension {
     fn class_init(klass: &mut glib::Class<Self>) {
         Self::parent_class_init::<T>(klass);
         let klass = klass.as_mut();

gstreamer-rtsp-server/src/subclass/rtsp_auth.rs

@@ -4,7 +4,7 @@ use crate::{ffi, RTSPAuth, RTSPContext};
 use glib::{prelude::*, subclass::prelude::*, translate::*};
 use libc::c_char;
 
-pub trait RTSPAuthImpl: RTSPAuthImplExt + ObjectImpl + Send + Sync {
+pub trait RTSPAuthImpl: ObjectImpl + ObjectSubclass<Type: IsA<RTSPAuth>> + Send + Sync {
     fn authenticate(&self, ctx: &RTSPContext) -> bool {
         self.parent_authenticate(ctx)
     }
@@ -18,12 +18,7 @@ pub trait RTSPAuthImpl: RTSPAuthImplExt + ObjectImpl + Send + Sync {
     }
 }
 
-mod sealed {
+pub trait RTSPAuthImplExt: RTSPAuthImpl {
-    pub trait Sealed {}
-    impl<T: super::RTSPAuthImplExt> Sealed for T {}
-}
-
-pub trait RTSPAuthImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_authenticate(&self, ctx: &RTSPContext) -> bool {
         unsafe {
             let data = Self::type_data();

gstreamer-rtsp-server/src/subclass/rtsp_client.rs

@@ -4,7 +4,7 @@ use glib::{prelude::*, subclass::prelude::*, translate::*};
 
 use crate::{ffi, RTSPClient};
 
-pub trait RTSPClientImpl: RTSPClientImplExt + ObjectImpl + Send + Sync {
+pub trait RTSPClientImpl: ObjectImpl + ObjectSubclass<Type: IsA<RTSPClient>> + Send + Sync {
     fn create_sdp(&self, media: &crate::RTSPMedia) -> Option<gst_sdp::SDPMessage> {
         self.parent_create_sdp(media)
     }
@@ -155,12 +155,7 @@ pub trait RTSPClientImpl: RTSPClientImplExt + ObjectImpl + Send + Sync {
     }
 }
 
-mod sealed {
+pub trait RTSPClientImplExt: RTSPClientImpl {
-    pub trait Sealed {}
-    impl<T: super::RTSPClientImplExt> Sealed for T {}
-}
-
-pub trait RTSPClientImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_create_sdp(&self, media: &crate::RTSPMedia) -> Option<gst_sdp::SDPMessage> {
         unsafe {
             let data = Self::type_data();

gstreamer-rtsp-server/src/subclass/rtsp_media.rs

@@ -22,7 +22,7 @@ impl SDPInfo {
     }
 }
 
-pub trait RTSPMediaImpl: RTSPMediaImplExt + ObjectImpl + Send + Sync {
+pub trait RTSPMediaImpl: ObjectImpl + ObjectSubclass<Type: IsA<RTSPMedia>> + Send + Sync {
     fn handle_message(&self, message: &gst::MessageRef) -> bool {
         self.parent_handle_message(message)
     }
@@ -98,12 +98,7 @@ pub trait RTSPMediaImpl: RTSPMediaImplExt + ObjectImpl + Send + Sync {
     }
 }
 
-mod sealed {
+pub trait RTSPMediaImplExt: RTSPMediaImpl {
-    pub trait Sealed {}
-    impl<T: super::RTSPMediaImplExt> Sealed for T {}
-}
-
-pub trait RTSPMediaImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_handle_message(&self, message: &gst::MessageRef) -> bool {
         unsafe {
             let data = Self::type_data();

gstreamer-rtsp-server/src/subclass/rtsp_media_factory.rs

@@ -6,7 +6,9 @@ use glib::{prelude::*, subclass::prelude::*, translate::*};
 
 use crate::{ffi, RTSPMediaFactory};
 
-pub trait RTSPMediaFactoryImpl: RTSPMediaFactoryImplExt + ObjectImpl + Send + Sync {
+pub trait RTSPMediaFactoryImpl:
+    ObjectImpl + ObjectSubclass<Type: IsA<RTSPMediaFactory>> + Send + Sync
+{
     fn gen_key(&self, url: &gst_rtsp::RTSPUrl) -> Option<glib::GString> {
         self.parent_gen_key(url)
     }
@@ -36,12 +38,7 @@ pub trait RTSPMediaFactoryImpl: RTSPMediaFactoryImplExt + ObjectImpl + Send + Sy
     }
 }
 
-mod sealed {
+pub trait RTSPMediaFactoryImplExt: RTSPMediaFactoryImpl {
-    pub trait Sealed {}
-    impl<T: super::RTSPMediaFactoryImplExt> Sealed for T {}
-}
-
-pub trait RTSPMediaFactoryImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_gen_key(&self, url: &gst_rtsp::RTSPUrl) -> Option<glib::GString> {
         unsafe {
             let data = Self::type_data();

gstreamer-rtsp-server/src/subclass/rtsp_mount_points.rs

@@ -5,18 +5,15 @@ use gst_rtsp::ffi::GstRTSPUrl;
 
 use crate::{ffi, RTSPMountPoints};
 
-pub trait RTSPMountPointsImpl: RTSPMountPointsImplExt + ObjectImpl + Send + Sync {
+pub trait RTSPMountPointsImpl:
+    ObjectImpl + ObjectSubclass<Type: IsA<RTSPMountPoints>> + Send + Sync
+{
     fn make_path(&self, url: &gst_rtsp::RTSPUrl) -> Option<glib::GString> {
         self.parent_make_path(url)
     }
 }
 
-mod sealed {
+pub trait RTSPMountPointsImplExt: RTSPMountPointsImpl {
-    pub trait Sealed {}
-    impl<T: super::RTSPMountPointsImplExt> Sealed for T {}
-}
-
-pub trait RTSPMountPointsImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_make_path(&self, url: &gst_rtsp::RTSPUrl) -> Option<glib::GString> {
         unsafe {
             let data = Self::type_data();

gstreamer-rtsp-server/src/subclass/rtsp_onvif_client.rs

@@ -1,10 +1,13 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
-use glib::subclass::prelude::*;
+use glib::{prelude::*, subclass::prelude::*};
 
 use super::prelude::*;
 use crate::RTSPOnvifClient;
 
-pub trait RTSPOnvifClientImpl: RTSPClientImpl + Send + Sync {}
+pub trait RTSPOnvifClientImpl:
+    RTSPClientImpl + ObjectSubclass<Type: IsA<RTSPOnvifClient>> + Send + Sync
+{
+}
 
 unsafe impl<T: RTSPOnvifClientImpl> IsSubclassable<T> for RTSPOnvifClient {}

gstreamer-rtsp-server/src/subclass/rtsp_onvif_media.rs

@@ -1,10 +1,13 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
-use glib::subclass::prelude::*;
+use glib::{prelude::*, subclass::prelude::*};
 
 use super::prelude::*;
 use crate::RTSPOnvifMedia;
 
-pub trait RTSPOnvifMediaImpl: RTSPMediaImpl + Send + Sync {}
+pub trait RTSPOnvifMediaImpl:
+    RTSPMediaImpl + ObjectSubclass<Type: IsA<RTSPOnvifMedia>> + Send + Sync
+{
+}
 
 unsafe impl<T: RTSPOnvifMediaImpl> IsSubclassable<T> for RTSPOnvifMedia {}

gstreamer-rtsp-server/src/subclass/rtsp_onvif_media_factory.rs

@@ -6,19 +6,14 @@ use super::prelude::*;
 use crate::{ffi, RTSPOnvifMediaFactory};
 
 pub trait RTSPOnvifMediaFactoryImpl:
-    RTSPMediaFactoryImplExt + RTSPMediaFactoryImpl + Send + Sync
+    RTSPMediaFactoryImpl + ObjectSubclass<Type: IsA<RTSPOnvifMediaFactory>> + Send + Sync
 {
     fn has_backchannel_support(&self) -> bool {
         self.parent_has_backchannel_support()
     }
 }
 
-mod sealed {
+pub trait RTSPOnvifMediaFactoryImplExt: RTSPOnvifMediaFactoryImpl {
-    pub trait Sealed {}
-    impl<T: super::RTSPOnvifMediaFactoryImplExt> Sealed for T {}
-}
-
-pub trait RTSPOnvifMediaFactoryImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_has_backchannel_support(&self) -> bool {
         unsafe {
             let data = Self::type_data();

gstreamer-rtsp-server/src/subclass/rtsp_onvif_server.rs

@@ -1,10 +1,13 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
-use glib::subclass::prelude::*;
+use glib::{prelude::*, subclass::prelude::*};
 
 use super::prelude::*;
 use crate::RTSPOnvifServer;
 
-pub trait RTSPOnvifServerImpl: RTSPServerImpl + Send + Sync {}
+pub trait RTSPOnvifServerImpl:
+    RTSPServerImpl + ObjectSubclass<Type: IsA<RTSPOnvifServer>> + Send + Sync
+{
+}
 
 unsafe impl<T: RTSPOnvifServerImpl> IsSubclassable<T> for RTSPOnvifServer {}

gstreamer-rtsp-server/src/subclass/rtsp_server.rs

@@ -4,7 +4,7 @@ use glib::{prelude::*, subclass::prelude::*, translate::*};
 
 use crate::{ffi, RTSPServer};
 
-pub trait RTSPServerImpl: RTSPServerImplExt + ObjectImpl + Send + Sync {
+pub trait RTSPServerImpl: ObjectImpl + ObjectSubclass<Type: IsA<RTSPServer>> + Send + Sync {
     fn create_client(&self) -> Option<crate::RTSPClient> {
         self.parent_create_client()
     }
@@ -14,12 +14,7 @@ pub trait RTSPServerImpl: RTSPServerImplExt + ObjectImpl + Send + Sync {
     }
 }
 
-mod sealed {
+pub trait RTSPServerImplExt: RTSPServerImpl {
-    pub trait Sealed {}
-    impl<T: super::RTSPServerImplExt> Sealed for T {}
-}
-
-pub trait RTSPServerImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_create_client(&self) -> Option<crate::RTSPClient>;
 
     fn parent_client_connected(&self, client: &crate::RTSPClient);

gstreamer-video/src/subclass/navigation.rs

@@ -4,7 +4,7 @@ use glib::{prelude::*, subclass::prelude::*, translate::*};
 
 use crate::{ffi, Navigation};
 
-pub trait NavigationImpl: ObjectImpl {
+pub trait NavigationImpl: ObjectImpl + ObjectSubclass<Type: IsA<Navigation>> {
     fn send_event(&self, structure: gst::Structure);
 
     #[cfg(feature = "v1_22")]
@@ -16,12 +16,7 @@ pub trait NavigationImpl: ObjectImpl {
     }
 }
 
-mod sealed {
+pub trait NavigationImplExt: NavigationImpl {
-    pub trait Sealed {}
-    impl<T: super::NavigationImplExt> Sealed for T {}
-}
-
-pub trait NavigationImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_send_event(&self, structure: gst::Structure) {
         unsafe {
             let type_data = Self::type_data();

gstreamer-video/src/subclass/video_aggregator.rs

@@ -9,7 +9,7 @@ use crate::{ffi, VideoAggregator};
 
 pub struct AggregateFramesToken<'a>(pub(crate) &'a VideoAggregator);
 
-pub trait VideoAggregatorImpl: VideoAggregatorImplExt + AggregatorImpl {
+pub trait VideoAggregatorImpl: AggregatorImpl + ObjectSubclass<Type: IsA<VideoAggregator>> {
     fn update_caps(&self, caps: &gst::Caps) -> Result<gst::Caps, gst::LoggableError> {
         self.parent_update_caps(caps)
     }
@@ -30,12 +30,8 @@ pub trait VideoAggregatorImpl: VideoAggregatorImplExt + AggregatorImpl {
         self.parent_find_best_format(downstream_caps)
     }
 }
-mod sealed {
-    pub trait Sealed {}
-    impl<T: super::VideoAggregatorImplExt> Sealed for T {}
-}
 
-pub trait VideoAggregatorImplExt: sealed::Sealed + ObjectSubclass {
+pub trait VideoAggregatorImplExt: VideoAggregatorImpl {
     fn parent_update_caps(&self, caps: &gst::Caps) -> Result<gst::Caps, gst::LoggableError> {
         unsafe {
             let data = Self::type_data();

gstreamer-video/src/subclass/video_aggregator_convert_pad.rs

@@ -1,10 +1,13 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
-use gst_base::subclass::prelude::*;
+use gst_base::{prelude::*, subclass::prelude::*};
 
 use super::prelude::VideoAggregatorPadImpl;
 use crate::VideoAggregatorConvertPad;
 
-pub trait VideoAggregatorConvertPadImpl: VideoAggregatorPadImpl {}
+pub trait VideoAggregatorConvertPadImpl:
+    VideoAggregatorPadImpl + ObjectSubclass<Type: IsA<VideoAggregatorConvertPad>>
+{
+}
 
 unsafe impl<T: VideoAggregatorConvertPadImpl> IsSubclassable<T> for VideoAggregatorConvertPad {}

gstreamer-video/src/subclass/video_aggregator_pad.rs

@@ -7,7 +7,9 @@ use gst_base::{prelude::*, subclass::prelude::*};
 
 use crate::{ffi, subclass::AggregateFramesToken, VideoAggregator, VideoAggregatorPad};
 
-pub trait VideoAggregatorPadImpl: VideoAggregatorPadImplExt + AggregatorPadImpl {
+pub trait VideoAggregatorPadImpl:
+    AggregatorPadImpl + ObjectSubclass<Type: IsA<VideoAggregatorPad>>
+{
     fn update_conversion_info(&self) {
         self.parent_update_conversion_info()
     }
@@ -31,12 +33,7 @@ pub trait VideoAggregatorPadImpl: VideoAggregatorPadImplExt + AggregatorPadImpl
     }
 }
 
-mod sealed {
+pub trait VideoAggregatorPadImplExt: VideoAggregatorPadImpl {
-    pub trait Sealed {}
-    impl<T: super::VideoAggregatorPadImplExt> Sealed for T {}
-}
-
-pub trait VideoAggregatorPadImplExt: ObjectSubclass + sealed::Sealed {
     fn parent_update_conversion_info(&self) {
         unsafe {
             let data = Self::type_data();

gstreamer-video/src/subclass/video_decoder.rs

@@ -10,7 +10,7 @@ use crate::{
     VideoCodecFrame, VideoDecoder,
 };
 
-pub trait VideoDecoderImpl: VideoDecoderImplExt + ElementImpl {
+pub trait VideoDecoderImpl: ElementImpl + ObjectSubclass<Type: IsA<VideoDecoder>> {
     fn open(&self) -> Result<(), gst::ErrorMessage> {
         self.parent_open()
     }
@@ -107,11 +107,8 @@ pub trait VideoDecoderImpl: VideoDecoderImplExt + ElementImpl {
         self.parent_handle_missing_data(timestamp, duration)
     }
 }
-mod sealed {
+
-    pub trait Sealed {}
+pub trait VideoDecoderImplExt: VideoDecoderImpl {
-    impl<T: super::VideoDecoderImplExt> Sealed for T {}
-}
-pub trait VideoDecoderImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_open(&self) -> Result<(), gst::ErrorMessage> {
         unsafe {
             let data = Self::type_data();

gstreamer-video/src/subclass/video_encoder.rs

@@ -10,7 +10,7 @@ use crate::{
     VideoCodecFrame, VideoEncoder,
 };
 
-pub trait VideoEncoderImpl: VideoEncoderImplExt + ElementImpl {
+pub trait VideoEncoderImpl: ElementImpl + ObjectSubclass<Type: IsA<VideoEncoder>> {
     fn open(&self) -> Result<(), gst::ErrorMessage> {
         self.parent_open()
     }
@@ -85,12 +85,7 @@ pub trait VideoEncoderImpl: VideoEncoderImplExt + ElementImpl {
     }
 }
 
-mod sealed {
+pub trait VideoEncoderImplExt: VideoEncoderImpl {
-    pub trait Sealed {}
-    impl<T: super::VideoEncoderImplExt> Sealed for T {}
-}
-
-pub trait VideoEncoderImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_open(&self) -> Result<(), gst::ErrorMessage> {
         unsafe {
             let data = Self::type_data();

gstreamer-video/src/subclass/video_filter.rs

@@ -5,7 +5,7 @@ use gst_base::{prelude::*, subclass::prelude::*};
 
 use crate::{ffi, VideoFilter, VideoFrameExt, VideoFrameRef, VideoInfo};
 
-pub trait VideoFilterImpl: VideoFilterImplExt + BaseTransformImpl {
+pub trait VideoFilterImpl: BaseTransformImpl + ObjectSubclass<Type: IsA<VideoFilter>> {
     fn set_info(
         &self,
         incaps: &gst::Caps,
@@ -39,12 +39,7 @@ pub trait VideoFilterImpl: VideoFilterImplExt + BaseTransformImpl {
     }
 }
 
-mod sealed {
+pub trait VideoFilterImplExt: VideoFilterImpl {
-    pub trait Sealed {}
-    impl<T: super::VideoFilterImplExt> Sealed for T {}
-}
-
-pub trait VideoFilterImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_set_info(
         &self,
         incaps: &gst::Caps,

gstreamer-video/src/subclass/video_sink.rs

@@ -5,18 +5,13 @@ use gst_base::subclass::prelude::*;
 
 use crate::{ffi, VideoSink};
 
-pub trait VideoSinkImpl: VideoSinkImplExt + BaseSinkImpl + ElementImpl {
+pub trait VideoSinkImpl: BaseSinkImpl + ObjectSubclass<Type: IsA<VideoSink>> {
     fn show_frame(&self, buffer: &gst::Buffer) -> Result<gst::FlowSuccess, gst::FlowError> {
         self.parent_show_frame(buffer)
     }
 }
 
-mod sealed {
+pub trait VideoSinkImplExt: VideoSinkImpl {
-    pub trait Sealed {}
-    impl<T: super::VideoSinkImplExt> Sealed for T {}
-}
-
-pub trait VideoSinkImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_show_frame(&self, buffer: &gst::Buffer) -> Result<gst::FlowSuccess, gst::FlowError> {
         unsafe {
             let data = Self::type_data();

gstreamer/src/subclass/allocator.rs

@@ -7,7 +7,7 @@ use glib::{bool_error, prelude::*, subclass::prelude::*, translate::*, BoolError
 use super::prelude::*;
 use crate::{ffi, AllocationParams, Allocator, Memory};
 
-pub trait AllocatorImpl: AllocatorImplExt + GstObjectImpl + Send + Sync {
+pub trait AllocatorImpl: GstObjectImpl + ObjectSubclass<Type: IsA<Allocator>> {
     fn alloc(&self, size: usize, params: Option<&AllocationParams>) -> Result<Memory, BoolError> {
         self.parent_alloc(size, params)
     }
@@ -17,12 +17,7 @@ pub trait AllocatorImpl: AllocatorImplExt + GstObjectImpl + Send + Sync {
     }
 }
 
-mod sealed {
+pub trait AllocatorImplExt: AllocatorImpl {
-    pub trait Sealed {}
-    impl<T: super::AllocatorImplExt> Sealed for T {}
-}
-
-pub trait AllocatorImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_alloc(
         &self,
         size: usize,

gstreamer/src/subclass/bin.rs

@@ -5,7 +5,7 @@ use glib::{prelude::*, subclass::prelude::*, translate::*};
 use super::prelude::*;
 use crate::{ffi, Bin, Element, LoggableError, Message};
 
-pub trait BinImpl: BinImplExt + ElementImpl {
+pub trait BinImpl: ElementImpl + ObjectSubclass<Type: IsA<Bin>> {
     fn add_element(&self, element: &Element) -> Result<(), LoggableError> {
         self.parent_add_element(element)
     }
@@ -23,12 +23,7 @@ pub trait BinImpl: BinImplExt + ElementImpl {
     }
 }
 
-mod sealed {
+pub trait BinImplExt: BinImpl {
-    pub trait Sealed {}
-    impl<T: super::BinImplExt> Sealed for T {}
-}
-
-pub trait BinImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_add_element(&self, element: &Element) -> Result<(), LoggableError> {
         unsafe {
             let data = Self::type_data();

gstreamer/src/subclass/buffer_pool.rs

@@ -12,7 +12,7 @@ use libc::c_char;
 use super::prelude::*;
 use crate::{ffi, BufferPool, BufferPoolAcquireParams, BufferPoolConfigRef};
 
-pub trait BufferPoolImpl: BufferPoolImplExt + GstObjectImpl + Send + Sync {
+pub trait BufferPoolImpl: GstObjectImpl + ObjectSubclass<Type: IsA<BufferPool>> {
     fn acquire_buffer(
         &self,
         params: Option<&BufferPoolAcquireParams>,
@@ -64,12 +64,7 @@ pub trait BufferPoolImpl: BufferPoolImplExt + GstObjectImpl + Send + Sync {
     }
 }
 
-mod sealed {
+pub trait BufferPoolImplExt: BufferPoolImpl {
-    pub trait Sealed {}
-    impl<T: super::BufferPoolImplExt> Sealed for T {}
-}
-
-pub trait BufferPoolImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_acquire_buffer(
         &self,
         params: Option<&BufferPoolAcquireParams>,

gstreamer/src/subclass/child_proxy.rs

@@ -5,7 +5,7 @@ use glib::{prelude::*, subclass::prelude::*, translate::*};
 use super::prelude::*;
 use crate::{ffi, ChildProxy};
 
-pub trait ChildProxyImpl: GstObjectImpl + Send + Sync {
+pub trait ChildProxyImpl: GstObjectImpl + ObjectSubclass<Type: IsA<ChildProxy>> {
     fn child_by_name(&self, name: &str) -> Option<glib::Object> {
         self.parent_child_by_name(name)
     }
@@ -21,12 +21,7 @@ pub trait ChildProxyImpl: GstObjectImpl + Send + Sync {
     }
 }
 
-mod sealed {
+pub trait ChildProxyImplExt: ChildProxyImpl {
-    pub trait Sealed {}
-    impl<T: super::ChildProxyImplExt> Sealed for T {}
-}
-
-pub trait ChildProxyImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_child_by_name(&self, name: &str) -> Option<glib::Object> {
         unsafe {
             let type_data = Self::type_data();

gstreamer/src/subclass/clock.rs

@@ -5,7 +5,7 @@ use glib::{prelude::*, subclass::prelude::*, translate::*};
 use super::prelude::*;
 use crate::{ffi, Clock, ClockError, ClockId, ClockReturn, ClockSuccess, ClockTime, ClockTimeDiff};
 
-pub trait ClockImpl: ClockImplExt + GstObjectImpl + Send + Sync {
+pub trait ClockImpl: GstObjectImpl + ObjectSubclass<Type: IsA<Clock>> {
     fn change_resolution(&self, old_resolution: ClockTime, new_resolution: ClockTime) -> ClockTime {
         self.parent_change_resolution(old_resolution, new_resolution)
     }
@@ -31,12 +31,7 @@ pub trait ClockImpl: ClockImplExt + GstObjectImpl + Send + Sync {
     }
 }
 
-mod sealed {
+pub trait ClockImplExt: ClockImpl {
-    pub trait Sealed {}
-    impl<T: super::ClockImplExt> Sealed for T {}
-}
-
-pub trait ClockImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_change_resolution(
         &self,
         old_resolution: ClockTime,

gstreamer/src/subclass/device.rs

@@ -7,7 +7,7 @@ use glib::{prelude::*, subclass::prelude::*, translate::*};
 use super::prelude::*;
 use crate::{ffi, Device, Element, LoggableError};
 
-pub trait DeviceImpl: DeviceImplExt + GstObjectImpl + Send + Sync {
+pub trait DeviceImpl: GstObjectImpl + ObjectSubclass<Type: IsA<Device>> {
     fn create_element(&self, name: Option<&str>) -> Result<Element, LoggableError> {
         self.parent_create_element(name)
     }
@@ -17,12 +17,7 @@ pub trait DeviceImpl: DeviceImplExt + GstObjectImpl + Send + Sync {
     }
 }
 
-mod sealed {
+pub trait DeviceImplExt: DeviceImpl {
-    pub trait Sealed {}
-    impl<T: super::DeviceImplExt> Sealed for T {}
-}
-
-pub trait DeviceImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_create_element(&self, name: Option<&str>) -> Result<Element, LoggableError> {
         unsafe {
             let data = Self::type_data();

gstreamer/src/subclass/device_provider.rs

@@ -64,7 +64,7 @@ impl DeviceProviderMetadata {
     }
 }
 
-pub trait DeviceProviderImpl: DeviceProviderImplExt + GstObjectImpl + Send + Sync {
+pub trait DeviceProviderImpl: GstObjectImpl + ObjectSubclass<Type: IsA<DeviceProvider>> {
     fn metadata() -> Option<&'static DeviceProviderMetadata> {
         None
     }
@@ -82,12 +82,7 @@ pub trait DeviceProviderImpl: DeviceProviderImplExt + GstObjectImpl + Send + Syn
     }
 }
 
-mod sealed {
+pub trait DeviceProviderImplExt: DeviceProviderImpl {
-    pub trait Sealed {}
-    impl<T: super::DeviceProviderImplExt> Sealed for T {}
-}
-
-pub trait DeviceProviderImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_probe(&self) -> Vec<Device> {
         unsafe {
             let data = Self::type_data();

gstreamer/src/subclass/element.rs

@@ -67,7 +67,7 @@ impl ElementMetadata {
     }
 }
 
-pub trait ElementImpl: ElementImplExt + GstObjectImpl + Send + Sync {
+pub trait ElementImpl: GstObjectImpl + ObjectSubclass<Type: IsA<Element>> {
     fn metadata() -> Option<&'static ElementMetadata> {
         None
     }
@@ -121,12 +121,7 @@ pub trait ElementImpl: ElementImplExt + GstObjectImpl + Send + Sync {
     }
 }
 
-mod sealed {
+pub trait ElementImplExt: ElementImpl {
-    pub trait Sealed {}
-    impl<T: super::ElementImplExt> Sealed for T {}
-}
-
-pub trait ElementImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_change_state(
         &self,
         transition: StateChange,

gstreamer/src/subclass/ghost_pad.rs

@@ -1,10 +1,10 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
-use glib::subclass::prelude::*;
+use glib::{prelude::*, subclass::prelude::*};
 
 use super::prelude::*;
 use crate::GhostPad;
 
-pub trait GhostPadImpl: ProxyPadImpl {}
+pub trait GhostPadImpl: ProxyPadImpl + ObjectSubclass<Type: IsA<GhostPad>> {}
 
 unsafe impl<T: GhostPadImpl> IsSubclassable<T> for GhostPad {}

gstreamer/src/subclass/object.rs

@@ -1,7 +1,10 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
-use glib::subclass::prelude::*;
+use glib::{prelude::*, subclass::prelude::*};
 
-pub trait GstObjectImpl: ObjectImpl {}
+pub trait GstObjectImpl:
+    ObjectImpl + ObjectSubclass<Type: IsA<crate::Object>> + Send + Sync
+{
+}
 
 unsafe impl<T: GstObjectImpl> IsSubclassable<T> for crate::Object {}

gstreamer/src/subclass/pad.rs

@@ -5,7 +5,7 @@ use glib::{prelude::*, subclass::prelude::*, translate::*};
 use super::prelude::*;
 use crate::{ffi, Pad};
 
-pub trait PadImpl: PadImplExt + GstObjectImpl + Send + Sync {
+pub trait PadImpl: GstObjectImpl + ObjectSubclass<Type: IsA<Pad>> {
     fn linked(&self, peer: &Pad) {
         self.parent_linked(peer)
     }
@@ -15,12 +15,7 @@ pub trait PadImpl: PadImplExt + GstObjectImpl + Send + Sync {
     }
 }
 
-mod sealed {
+pub trait PadImplExt: PadImpl {
-    pub trait Sealed {}
-    impl<T: super::PadImplExt> Sealed for T {}
-}
-
-pub trait PadImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_linked(&self, peer: &Pad) {
         unsafe {
             let data = Self::type_data();

gstreamer/src/subclass/pipeline.rs

@@ -1,10 +1,10 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
-use glib::subclass::prelude::*;
+use glib::{prelude::*, subclass::prelude::*};
 
 use super::prelude::*;
 use crate::Pipeline;
 
-pub trait PipelineImpl: BinImpl {}
+pub trait PipelineImpl: BinImpl + ObjectSubclass<Type: IsA<Pipeline>> {}
 
 unsafe impl<T: PipelineImpl> IsSubclassable<T> for Pipeline {}

gstreamer/src/subclass/preset.rs

@@ -1,9 +1,9 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
-use glib::subclass::prelude::*;
+use glib::{prelude::*, subclass::prelude::*};
 
 use crate::Preset;
 
-pub trait PresetImpl: super::element::ElementImpl {}
+pub trait PresetImpl: super::element::ElementImpl + ObjectSubclass<Type: IsA<Preset>> {}
 
 unsafe impl<T: PresetImpl> IsImplementable<T> for Preset {}

gstreamer/src/subclass/proxy_pad.rs

@@ -1,10 +1,10 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
-use glib::subclass::prelude::*;
+use glib::{prelude::*, subclass::prelude::*};
 
 use super::prelude::*;
 use crate::ProxyPad;
 
-pub trait ProxyPadImpl: PadImpl {}
+pub trait ProxyPadImpl: PadImpl + ObjectSubclass<Type: IsA<ProxyPad>> {}
 
 unsafe impl<T: ProxyPadImpl> IsSubclassable<T> for ProxyPad {}

gstreamer/src/subclass/system_clock.rs

@@ -1,10 +1,10 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
-use glib::subclass::prelude::*;
+use glib::{prelude::*, subclass::prelude::*};
 
 use super::prelude::*;
 use crate::SystemClock;
 
-pub trait SystemClockImpl: ClockImpl {}
+pub trait SystemClockImpl: ClockImpl + ObjectSubclass<Type: IsA<SystemClock>> {}
 
 unsafe impl<T: SystemClockImpl> IsSubclassable<T> for SystemClock {}

gstreamer/src/subclass/tag_setter.rs

@@ -1,9 +1,12 @@
 // Take a look at the license at the top of the repository in the LICENSE file.
 
-use glib::subclass::prelude::*;
+use glib::{prelude::*, subclass::prelude::*};
 
 use crate::TagSetter;
 
-pub trait TagSetterImpl: super::element::ElementImpl {}
+pub trait TagSetterImpl:
+    super::element::ElementImpl + ObjectSubclass<Type: IsA<TagSetter>>
+{
+}
 
 unsafe impl<T: TagSetterImpl> IsImplementable<T> for TagSetter {}

gstreamer/src/subclass/task_pool.rs

@@ -6,12 +6,12 @@ use std::{
     sync::{Arc, Mutex},
 };
 
-use glib::{ffi::gpointer, subclass::prelude::*, translate::*};
+use glib::{ffi::gpointer, prelude::*, subclass::prelude::*, translate::*};
 
 use super::prelude::*;
 use crate::{ffi, TaskHandle, TaskPool};
 
-pub trait TaskPoolImpl: GstObjectImpl + Send + Sync {
+pub trait TaskPoolImpl: GstObjectImpl + ObjectSubclass<Type: IsA<TaskPool>> {
     // rustdoc-stripper-ignore-next
     /// Handle to be returned from the `push` function to allow the caller to wait for the task's
     /// completion.

gstreamer/src/subclass/tracer.rs

@@ -10,7 +10,7 @@ use crate::{
 };
 
 #[allow(unused_variables)]
-pub trait TracerImpl: TracerImplExt + GstObjectImpl + Send + Sync {
+pub trait TracerImpl: GstObjectImpl + ObjectSubclass<Type: IsA<Tracer>> {
     fn bin_add_post(&self, ts: u64, bin: &Bin, element: &Element, success: bool) {}
     fn bin_add_pre(&self, ts: u64, bin: &Bin, element: &Element) {}
     fn bin_remove_post(&self, ts: u64, bin: &Bin, success: bool) {}
@@ -85,7 +85,7 @@ pub trait TracerImpl: TracerImplExt + GstObjectImpl + Send + Sync {
 
 unsafe impl<T: TracerImpl> IsSubclassable<T> for Tracer {}
 
-pub trait TracerImplExt: ObjectSubclass {
+pub trait TracerImplExt: TracerImpl {
     // rustdoc-stripper-ignore-next
     /// Register a corresponding hook to be called for this tracer when certain events occur.
     ///

gstreamer/src/subclass/uri_handler.rs

@@ -6,19 +6,16 @@ use glib::{prelude::*, subclass::prelude::*, translate::*};
 
 use crate::{ffi, URIHandler, URIType};
 
-pub trait URIHandlerImpl: super::element::ElementImpl {
+pub trait URIHandlerImpl:
+    super::element::ElementImpl + ObjectSubclass<Type: IsA<URIHandler>>
+{
     const URI_TYPE: URIType;
     fn protocols() -> &'static [&'static str];
     fn uri(&self) -> Option<String>;
     fn set_uri(&self, uri: &str) -> Result<(), glib::Error>;
 }
 
-mod sealed {
+pub trait URIHandlerImplExt: URIHandlerImpl {
-    pub trait Sealed {}
-    impl<T: super::URIHandlerImplExt> Sealed for T {}
-}
-
-pub trait URIHandlerImplExt: sealed::Sealed + ObjectSubclass {
     fn parent_protocols() -> Vec<String> {
         unsafe {
             let type_data = Self::type_data();