gstreamer_editing_services/auto/

asset.rs

// This file was generated by gir (https://github.com/gtk-rs/gir)
// from gir-files (https://github.com/gtk-rs/gir-files)
// from gst-gir-files (https://gitlab.freedesktop.org/gstreamer/gir-files-rs.git)
// DO NOT EDIT

use crate::{ffi, Extractable, MetaContainer};
use glib::{
    prelude::*,
    signal::{connect_raw, SignalHandlerId},
    translate::*,
};
use std::{boxed::Box as Box_, pin::Pin};

glib::wrapper! {
    /// A [`Asset`][crate::Asset] in the GStreamer Editing Services represents a resources
    /// that can be used. In particular, any class that implements the
    /// [`Extractable`][crate::Extractable] interface may have some associated assets with a
    /// corresponding [`extractable-type`][struct@crate::Asset#extractable-type], from which its objects can be
    /// extracted using [`AssetExt::extract()`][crate::prelude::AssetExt::extract()]. Some examples would be
    /// [`Clip`][crate::Clip], [`Formatter`][crate::Formatter] and [`TrackElement`][crate::TrackElement].
    ///
    /// All assets that are created within GES are stored in a cache; one per
    /// each [`id`][struct@crate::Asset#id] and [`extractable-type`][struct@crate::Asset#extractable-type] pair. These assets can
    /// be fetched, and initialized if they do not yet exist in the cache,
    /// using [`request_with_type()`][Self::request_with_type()].
    ///
    /// **⚠️ The following code is in  c ⚠️**
    ///
    /// ``` c
    /// GESAsset *effect_asset;
    /// GESEffect *effect;
    ///
    /// // You create an asset for an effect
    /// effect_asset = ges_asset_request (GES_TYPE_EFFECT, "agingtv", NULL);
    ///
    /// // And now you can extract an instance of GESEffect from that asset
    /// effect = GES_EFFECT (ges_asset_extract (effect_asset));
    ///
    /// ```
    ///
    /// The advantage of using assets, rather than simply creating the object
    /// directly, is that the currently loaded resources can be listed with
    /// `ges_list_assets()` and displayed to an end user. For example, to show
    /// which media files have been loaded, and a standard list of effects. In
    /// fact, the GES library already creates assets for [`TransitionClip`][crate::TransitionClip] and
    /// [`Formatter`][crate::Formatter], which you can use to list all the available transition
    /// types and supported formats.
    ///
    /// The other advantage is that [`Asset`][crate::Asset] implements [`MetaContainer`][crate::MetaContainer], so
    /// metadata can be set on the asset, with some subclasses automatically
    /// creating this metadata on initiation.
    ///
    /// For example, to display information about the supported formats, you
    /// could do the following:
    ///
    /// ```text
    ///    GList *formatter_assets, *tmp;
    ///
    ///    //  List all  the transitions
    ///    formatter_assets = ges_list_assets (GES_TYPE_FORMATTER);
    ///
    ///    // Print some infos about the formatter GESAsset
    ///    for (tmp = formatter_assets; tmp; tmp = tmp->next) {
    ///      gst_print ("Name of the formatter: %s, file extension it produces: %s",
    ///        ges_meta_container_get_string (
    ///          GES_META_CONTAINER (tmp->data), GES_META_FORMATTER_NAME),
    ///        ges_meta_container_get_string (
    ///          GES_META_CONTAINER (tmp->data), GES_META_FORMATTER_EXTENSION));
    ///    }
    ///
    ///    g_list_free (transition_assets);
    ///
    /// ```
    ///
    /// ## ID
    ///
    /// Each asset is uniquely defined in the cache by its
    /// [`extractable-type`][struct@crate::Asset#extractable-type] and [`id`][struct@crate::Asset#id]. Depending on the
    /// [`extractable-type`][struct@crate::Asset#extractable-type], the [`id`][struct@crate::Asset#id] can be used to parametrise
    /// the creation of the object upon extraction. By default, a class that
    /// implements [`Extractable`][crate::Extractable] will only have a single associated asset,
    /// with an [`id`][struct@crate::Asset#id] set to the type name of its objects. However, this
    /// is overwritten by some implementations, which allow a class to have
    /// multiple associated assets. For example, for [`TransitionClip`][crate::TransitionClip] the
    /// [`id`][struct@crate::Asset#id] will be a nickname of the [`vtype`][struct@crate::TransitionClip#vtype]. You
    /// should check the documentation for each extractable type to see if they
    /// differ from the default.
    ///
    /// Moreover, each [`extractable-type`][struct@crate::Asset#extractable-type] may also associate itself
    /// with a specific asset subclass. In such cases, when their asset is
    /// requested, an asset of this subclass will be returned instead.
    ///
    /// ## Managing
    ///
    /// You can use a [`Project`][crate::Project] to easily manage the assets of a
    /// [`Timeline`][crate::Timeline].
    ///
    /// ## Proxies
    ///
    /// Some assets can (temporarily) act as the [`proxy`][struct@crate::Asset#proxy] of another
    /// asset. When the original asset is requested from the cache, the proxy
    /// will be returned in its place. This can be useful if, say, you want
    /// to substitute a [`UriClipAsset`][crate::UriClipAsset] corresponding to a high resolution
    /// media file with the asset of a lower resolution stand in.
    ///
    /// An asset may even have several proxies, the first of which will act as
    /// its default and be returned on requests, but the others will be ordered
    /// to take its place once it is removed. You can add a proxy to an asset,
    /// or set its default, using [`AssetExt::set_proxy()`][crate::prelude::AssetExt::set_proxy()], and you can remove
    /// them with [`AssetExt::unproxy()`][crate::prelude::AssetExt::unproxy()].
    ///
    /// ## Properties
    ///
    ///
    /// #### `extractable-type`
    ///  The [`Extractable`][crate::Extractable] object type that can be extracted from the asset.
    ///
    /// Readable | Writeable | Construct Only
    ///
    ///
    /// #### `id`
    ///  The ID of the asset. This should be unique amongst all assets with
    /// the same [`extractable-type`][struct@crate::Asset#extractable-type]. Depending on the associated
    /// [`Extractable`][crate::Extractable] implementation, this id may convey some information
    /// about the [`glib::Object`][crate::glib::Object] that should be extracted. Note that, as such, the
    /// ID will have an expected format, and you can not choose this value
    /// arbitrarily. By default, this will be set to the type name of the
    /// [`extractable-type`][struct@crate::Asset#extractable-type], but you should check the documentation
    /// of the extractable type to see whether they differ from the
    /// default behaviour.
    ///
    /// Readable | Writeable | Construct Only
    ///
    ///
    /// #### `proxy`
    ///  The default proxy for this asset, or [`None`] if it has no proxy. A
    /// proxy will act as a substitute for the original asset when the
    /// original is requested (see [`Asset::request_with_type()`][crate::Asset::request_with_type()]).
    ///
    /// Setting this property will not usually remove the existing proxy, but
    /// will replace it as the default (see [`AssetExt::set_proxy()`][crate::prelude::AssetExt::set_proxy()]).
    ///
    /// Readable | Writeable
    ///
    ///
    /// #### `proxy-target`
    ///  The asset that this asset is a proxy for, or [`None`] if it is not a
    /// proxy for another asset.
    ///
    /// Note that even if this asset is acting as a proxy for another asset,
    /// but this asset is not the default [`proxy`][struct@crate::Asset#proxy], then `proxy`-target
    /// will *still* point to this other asset. So you should check the
    /// [`proxy`][struct@crate::Asset#proxy] property of `target`-proxy before assuming it is the
    /// current default proxy for the target.
    ///
    /// Note that the [`notify`][struct@crate::glib::Object#notify] for this property is emitted after
    /// the [`proxy`][struct@crate::Asset#proxy] [`notify`][struct@crate::glib::Object#notify] for the corresponding (if any)
    /// asset it is now the proxy of/no longer the proxy of.
    ///
    /// Readable
    ///
    /// # Implements
    ///
    /// [`AssetExt`][trait@crate::prelude::AssetExt], [`trait@glib::ObjectExt`], [`MetaContainerExt`][trait@crate::prelude::MetaContainerExt]
    #[doc(alias = "GESAsset")]
    pub struct Asset(Object<ffi::GESAsset, ffi::GESAssetClass>) @implements MetaContainer;

    match fn {
        type_ => || ffi::ges_asset_get_type(),
    }
}

impl Asset {
    pub const NONE: Option<&'static Asset> = None;

    /// Indicate that an existing [`Asset`][crate::Asset] in the cache should be reloaded
    /// upon the next request. This can be used when some condition has
    /// changed, which may require that an existing asset should be updated.
    /// For example, if an external resource has changed or now become
    /// available.
    ///
    /// Note, the asset is not immediately changed, but will only actually
    /// reload on the next call to [`request_with_type()`][Self::request_with_type()] or
    /// [`request_async_with_type()`][Self::request_async_with_type()].
    /// ## `extractable_type`
    /// The [`extractable-type`][struct@crate::Asset#extractable-type] of the asset that
    /// needs reloading
    /// ## `id`
    /// The [`id`][struct@crate::Asset#id] of the asset asset that needs
    /// reloading
    ///
    /// # Returns
    ///
    /// [`true`] if the specified asset exists in the cache and could be
    /// marked for reloading.
    #[doc(alias = "ges_asset_needs_reload")]
    #[doc(alias = "needs_reload")]
    pub fn needs_reload_with_type(extractable_type: glib::types::Type, id: Option<&str>) -> bool {
        assert_initialized_main_thread!();
        unsafe {
            from_glib(ffi::ges_asset_needs_reload(
                extractable_type.into_glib(),
                id.to_glib_none().0,
            ))
        }
    }

    /// Returns an asset with the given properties. If such an asset already
    /// exists in the cache (it has been previously created in GES), then a
    /// reference to the existing asset is returned. Otherwise, a newly created
    /// asset is returned, and also added to the cache.
    ///
    /// If the requested asset has been loaded with an error, then `error` is
    /// set, if given, and [`None`] will be returned instead.
    ///
    /// Note that the given `id` may not be exactly the [`id`][struct@crate::Asset#id] that is
    /// set on the returned asset. For instance, it may be adjusted into a
    /// standard format. Or, if a [`Extractable`][crate::Extractable] type does not have its
    /// extraction parametrised, as is the case by default, then the given `id`
    /// may be ignored entirely and the [`id`][struct@crate::Asset#id] set to some standard, in
    /// which case a [`None`] `id` can be given.
    ///
    /// Similarly, the given `extractable_type` may not be exactly the
    /// [`extractable-type`][struct@crate::Asset#extractable-type] that is set on the returned asset. Instead,
    /// the actual extractable type may correspond to a subclass of the given
    /// `extractable_type`, depending on the given `id`.
    ///
    /// Moreover, depending on the given `extractable_type`, the returned asset
    /// may belong to a subclass of [`Asset`][crate::Asset].
    ///
    /// Finally, if the requested asset has a [`proxy`][struct@crate::Asset#proxy], then the proxy
    /// that is found at the end of the chain of proxies is returned (a proxy's
    /// proxy will take its place, and so on, unless it has no proxy).
    ///
    /// Some asset subclasses only support asynchronous construction of its
    /// assets, such as [`UriClip`][crate::UriClip]. For such assets this method will fail, and
    /// you should use [`request_async_with_type()`][Self::request_async_with_type()] instead. In the case of
    /// [`UriClip`][crate::UriClip], you can use [`UriClipAsset::request_sync()`][crate::UriClipAsset::request_sync()] if you only
    /// want to wait for the request to finish.
    /// ## `extractable_type`
    /// The [`extractable-type`][struct@crate::Asset#extractable-type] of the asset
    /// ## `id`
    /// The [`id`][struct@crate::Asset#id] of the asset
    ///
    /// # Returns
    ///
    /// A reference to the requested
    /// asset, or [`None`] if an error occurred.
    #[doc(alias = "ges_asset_request")]
    #[doc(alias = "request")]
    pub fn request_with_type(
        extractable_type: glib::types::Type,
        id: Option<&str>,
    ) -> Result<Option<Asset>, glib::Error> {
        assert_initialized_main_thread!();
        unsafe {
            let mut error = std::ptr::null_mut();
            let ret = ffi::ges_asset_request(
                extractable_type.into_glib(),
                id.to_glib_none().0,
                &mut error,
            );
            if error.is_null() {
                Ok(from_glib_full(ret))
            } else {
                Err(from_glib_full(error))
            }
        }
    }

    /// Requests an asset with the given properties asynchronously (see
    /// [`request_with_type()`][Self::request_with_type()]). When the asset has been initialized or fetched
    /// from the cache, the given callback function will be called. The
    /// asset can then be retrieved in the callback using the
    /// `ges_asset_request_finish()` method on the given `GAsyncResult`.
    ///
    /// Note that the source object passed to the callback will be the
    /// [`Asset`][crate::Asset] corresponding to the request, but it may not have loaded
    /// correctly and therefore can not be used as is. Instead,
    /// `ges_asset_request_finish()` should be used to fetch a usable asset, or
    /// indicate that an error occurred in the asset's creation.
    ///
    /// Note that the callback will be called in the `GMainLoop` running under
    /// the same `GMainContext` that `ges_init()` was called in. So, if you wish
    /// the callback to be invoked outside the default `GMainContext`, you can
    /// call `g_main_context_push_thread_default()` in a new thread before
    /// calling `ges_init()`.
    ///
    /// Example of an asynchronous asset request:
    /// **⚠️ The following code is in  c ⚠️**
    ///
    /// ``` c
    /// // The request callback
    /// static void
    /// asset_loaded_cb (GESAsset * source, GAsyncResult * res, gpointer user_data)
    /// {
    ///   GESAsset *asset;
    ///   GError *error = NULL;
    ///
    ///   asset = ges_asset_request_finish (res, &error);
    ///   if (asset) {
    ///    gst_print ("The file: %s is usable as a GESUriClip",
    ///        ges_asset_get_id (asset));
    ///   } else {
    ///    gst_print ("The file: %s is *not* usable as a GESUriClip because: %s",
    ///        ges_asset_get_id (source), error->message);
    ///   }
    ///
    ///   gst_object_unref (asset);
    /// }
    ///
    /// // The request:
    /// ges_asset_request_async (GES_TYPE_URI_CLIP, some_uri, NULL,
    ///    (GAsyncReadyCallback) asset_loaded_cb, user_data);
    /// ```
    /// ## `extractable_type`
    /// The [`extractable-type`][struct@crate::Asset#extractable-type] of the asset
    /// ## `id`
    /// The [`id`][struct@crate::Asset#id] of the asset
    /// ## `cancellable`
    /// An object to allow cancellation of the
    /// asset request, or [`None`] to ignore
    /// ## `callback`
    /// A function to call when the initialization is finished
    #[doc(alias = "ges_asset_request_async")]
    #[doc(alias = "request_async")]
    pub fn request_async_with_type<P: FnOnce(Result<Asset, glib::Error>) + 'static>(
        extractable_type: glib::types::Type,
        id: Option<&str>,
        cancellable: Option<&impl IsA<gio::Cancellable>>,
        callback: P,
    ) {
        assert_initialized_main_thread!();

        let main_context = glib::MainContext::ref_thread_default();
        let is_main_context_owner = main_context.is_owner();
        let has_acquired_main_context = (!is_main_context_owner)
            .then(|| main_context.acquire().ok())
            .flatten();
        assert!(
            is_main_context_owner || has_acquired_main_context.is_some(),
            "Async operations only allowed if the thread is owning the MainContext"
        );

        let user_data: Box_<glib::thread_guard::ThreadGuard<P>> =
            Box_::new(glib::thread_guard::ThreadGuard::new(callback));
        unsafe extern "C" fn request_async_with_type_trampoline<
            P: FnOnce(Result<Asset, glib::Error>) + 'static,
        >(
            _source_object: *mut glib::gobject_ffi::GObject,
            res: *mut gio::ffi::GAsyncResult,
            user_data: glib::ffi::gpointer,
        ) {
            let mut error = std::ptr::null_mut();
            let ret = ffi::ges_asset_request_finish(res, &mut error);
            let result = if error.is_null() {
                Ok(from_glib_full(ret))
            } else {
                Err(from_glib_full(error))
            };
            let callback: Box_<glib::thread_guard::ThreadGuard<P>> =
                Box_::from_raw(user_data as *mut _);
            let callback: P = callback.into_inner();
            callback(result);
        }
        let callback = request_async_with_type_trampoline::<P>;
        unsafe {
            ffi::ges_asset_request_async(
                extractable_type.into_glib(),
                id.to_glib_none().0,
                cancellable.map(|p| p.as_ref()).to_glib_none().0,
                Some(callback),
                Box_::into_raw(user_data) as *mut _,
            );
        }
    }

    pub fn request_async_with_type_future(
        extractable_type: glib::types::Type,
        id: Option<&str>,
    ) -> Pin<Box_<dyn std::future::Future<Output = Result<Asset, glib::Error>> + 'static>> {
        skip_assert_initialized!();
        let id = id.map(ToOwned::to_owned);
        Box_::pin(gio::GioFuture::new(&(), move |_obj, cancellable, send| {
            Self::request_async_with_type(
                extractable_type,
                id.as_ref().map(::std::borrow::Borrow::borrow),
                Some(cancellable),
                move |res| {
                    send.resolve(res);
                },
            );
        }))
    }
}

unsafe impl Send for Asset {}
unsafe impl Sync for Asset {}

/// Trait containing all [`struct@Asset`] methods.
///
/// # Implementors
///
/// [`Asset`][struct@crate::Asset], [`ClipAsset`][struct@crate::ClipAsset], [`Project`][struct@crate::Project], [`TrackElementAsset`][struct@crate::TrackElementAsset]
pub trait AssetExt: IsA<Asset> + 'static {
    /// Extracts a new [`extractable-type`][struct@crate::Asset#extractable-type] object from the asset. The
    /// [`id`][struct@crate::Asset#id] of the asset may determine the properties and state of the
    /// newly created object.
    ///
    /// # Returns
    ///
    /// A newly created object, or [`None`] if an
    /// error occurred.
    #[doc(alias = "ges_asset_extract")]
    fn extract(&self) -> Result<Extractable, glib::Error> {
        unsafe {
            let mut error = std::ptr::null_mut();
            let ret = ffi::ges_asset_extract(self.as_ref().to_glib_none().0, &mut error);
            if error.is_null() {
                Ok(from_glib_none(ret))
            } else {
                Err(from_glib_full(error))
            }
        }
    }

    /// Retrieve the error that was set on the asset when it was loaded.
    ///
    /// # Returns
    ///
    /// The error set on `asset`, or
    /// [`None`] if no error occurred when `asset` was loaded.
    #[doc(alias = "ges_asset_get_error")]
    #[doc(alias = "get_error")]
    fn error(&self) -> Option<glib::Error> {
        unsafe { from_glib_none(ffi::ges_asset_get_error(self.as_ref().to_glib_none().0)) }
    }

    /// Gets the [`extractable-type`][struct@crate::Asset#extractable-type] of the asset.
    ///
    /// # Returns
    ///
    /// The extractable type of `self`.
    #[doc(alias = "ges_asset_get_extractable_type")]
    #[doc(alias = "get_extractable_type")]
    #[doc(alias = "extractable-type")]
    fn extractable_type(&self) -> glib::types::Type {
        unsafe {
            from_glib(ffi::ges_asset_get_extractable_type(
                self.as_ref().to_glib_none().0,
            ))
        }
    }

    /// Gets the [`id`][struct@crate::Asset#id] of the asset.
    ///
    /// # Returns
    ///
    /// The ID of `self`.
    #[doc(alias = "ges_asset_get_id")]
    #[doc(alias = "get_id")]
    fn id(&self) -> glib::GString {
        unsafe { from_glib_none(ffi::ges_asset_get_id(self.as_ref().to_glib_none().0)) }
    }

    /// Gets the default [`proxy`][struct@crate::Asset#proxy] of the asset.
    ///
    /// # Returns
    ///
    /// The default proxy of `self`.
    #[doc(alias = "ges_asset_get_proxy")]
    #[doc(alias = "get_proxy")]
    #[must_use]
    fn proxy(&self) -> Option<Asset> {
        unsafe { from_glib_none(ffi::ges_asset_get_proxy(self.as_ref().to_glib_none().0)) }
    }

    /// Gets the [`proxy-target`][struct@crate::Asset#proxy-target] of the asset.
    ///
    /// Note that the proxy target may have loaded with an error, so you should
    /// call [`error()`][Self::error()] on the returned target.
    ///
    /// # Returns
    ///
    /// The asset that `self` is a proxy
    /// of.
    #[doc(alias = "ges_asset_get_proxy_target")]
    #[doc(alias = "get_proxy_target")]
    #[doc(alias = "proxy-target")]
    #[must_use]
    fn proxy_target(&self) -> Option<Asset> {
        unsafe {
            from_glib_none(ffi::ges_asset_get_proxy_target(
                self.as_ref().to_glib_none().0,
            ))
        }
    }

    /// Get all the proxies that the asset has. The first item of the list will
    /// be the default [`proxy`][struct@crate::Asset#proxy]. The second will be the proxy that is
    /// 'next in line' to be default, and so on.
    ///
    /// # Returns
    ///
    /// The list of proxies
    /// that `self` has.
    #[doc(alias = "ges_asset_list_proxies")]
    fn list_proxies(&self) -> Vec<Asset> {
        unsafe {
            FromGlibPtrContainer::from_glib_none(ffi::ges_asset_list_proxies(
                self.as_ref().to_glib_none().0,
            ))
        }
    }

    /// Sets the [`proxy`][struct@crate::Asset#proxy] for the asset.
    ///
    /// If `proxy` is among the existing proxies of the asset (see
    /// [`list_proxies()`][Self::list_proxies()]) it will be moved to become the default
    /// proxy. Otherwise, if `proxy` is not [`None`], it will be added to the list
    /// of proxies, as the new default. The previous default proxy will become
    /// 'next in line' for if the new one is removed, and so on. As such, this
    /// will **not** actually remove the previous default proxy (use
    /// [`unproxy()`][Self::unproxy()] for that).
    ///
    /// Note that an asset can only act as a proxy for one other asset.
    ///
    /// As a special case, if `proxy` is [`None`], then this method will actually
    /// remove **all** proxies from the asset.
    /// ## `proxy`
    /// A new default proxy for `self`
    ///
    /// # Returns
    ///
    /// [`true`] if `proxy` was successfully set as the default for
    /// `self`.
    #[doc(alias = "ges_asset_set_proxy")]
    #[doc(alias = "proxy")]
    fn set_proxy(&self, proxy: Option<&impl IsA<Asset>>) -> Result<(), glib::error::BoolError> {
        unsafe {
            glib::result_from_gboolean!(
                ffi::ges_asset_set_proxy(
                    self.as_ref().to_glib_none().0,
                    proxy.map(|p| p.as_ref()).to_glib_none().0
                ),
                "Failed to set proxy"
            )
        }
    }

    /// Removes the proxy from the available list of proxies for the asset. If
    /// the given proxy is the default proxy of the list, then the next proxy
    /// in the available list (see [`list_proxies()`][Self::list_proxies()]) will become the
    /// default. If there are no other proxies, then the asset will no longer
    /// have a default [`proxy`][struct@crate::Asset#proxy].
    /// ## `proxy`
    /// An existing proxy of `self`
    ///
    /// # Returns
    ///
    /// [`true`] if `proxy` was successfully removed from `self`'s proxy
    /// list.
    #[doc(alias = "ges_asset_unproxy")]
    fn unproxy(&self, proxy: &impl IsA<Asset>) -> Result<(), glib::error::BoolError> {
        unsafe {
            glib::result_from_gboolean!(
                ffi::ges_asset_unproxy(
                    self.as_ref().to_glib_none().0,
                    proxy.as_ref().to_glib_none().0
                ),
                "Failed to unproxy asset"
            )
        }
    }

    #[doc(alias = "proxy")]
    fn connect_proxy_notify<F: Fn(&Self) + Send + Sync + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe extern "C" fn notify_proxy_trampoline<
            P: IsA<Asset>,
            F: Fn(&P) + Send + Sync + 'static,
        >(
            this: *mut ffi::GESAsset,
            _param_spec: glib::ffi::gpointer,
            f: glib::ffi::gpointer,
        ) {
            let f: &F = &*(f as *const F);
            f(Asset::from_glib_borrow(this).unsafe_cast_ref())
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                c"notify::proxy".as_ptr() as *const _,
                Some(std::mem::transmute::<*const (), unsafe extern "C" fn()>(
                    notify_proxy_trampoline::<Self, F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }

    #[doc(alias = "proxy-target")]
    fn connect_proxy_target_notify<F: Fn(&Self) + Send + Sync + 'static>(
        &self,
        f: F,
    ) -> SignalHandlerId {
        unsafe extern "C" fn notify_proxy_target_trampoline<
            P: IsA<Asset>,
            F: Fn(&P) + Send + Sync + 'static,
        >(
            this: *mut ffi::GESAsset,
            _param_spec: glib::ffi::gpointer,
            f: glib::ffi::gpointer,
        ) {
            let f: &F = &*(f as *const F);
            f(Asset::from_glib_borrow(this).unsafe_cast_ref())
        }
        unsafe {
            let f: Box_<F> = Box_::new(f);
            connect_raw(
                self.as_ptr() as *mut _,
                c"notify::proxy-target".as_ptr() as *const _,
                Some(std::mem::transmute::<*const (), unsafe extern "C" fn()>(
                    notify_proxy_target_trampoline::<Self, F> as *const (),
                )),
                Box_::into_raw(f),
            )
        }
    }
}

impl<O: IsA<Asset>> AssetExt for O {}