// This file was generated by gir (https://github.com/gtk-rs/gir)
// from gir-files (https://github.com/gtk-rs/gir-files)
// DO NOT EDIT

use Bus;
use Caps;
use Clock;
use ClockTime;
use Context;
use ElementFactory;
use Error;
use Message;
use Object;
use Pad;
use PadLinkCheck;
use PadTemplate;
use Plugin;
use State;
use StateChange;
use StateChangeReturn;
use URIType;
use ffi;
use glib;
use glib::object::Downcast;
use glib::object::IsA;
use glib::signal::SignalHandlerId;
use glib::signal::connect;
use glib::translate::*;
use glib_ffi;
use gobject_ffi;
use std::boxed::Box as Box_;
use std::mem;
use std::mem::transmute;
use std::ptr;

glib_wrapper! {
    /// GstElement is the abstract base class needed to construct an element that
    /// can be used in a GStreamer pipeline. Please refer to the plugin writers
    /// guide for more information on creating `Element` subclasses.
    ///
    /// The name of a `Element` can be get with `gst_element_get_name` and set with
    /// `gst_element_set_name`. For speed, GST_ELEMENT_NAME() can be used in the
    /// core when using the appropriate locking. Do not use this in plug-ins or
    /// applications in order to retain ABI compatibility.
    ///
    /// Elements can have pads (of the type `Pad`). These pads link to pads on
    /// other elements. `Buffer` flow between these linked pads.
    /// A `Element` has a `glib::List` of `Pad` structures for all their input (or sink)
    /// and output (or source) pads.
    /// Core and plug-in writers can add and remove pads with `ElementExt::add_pad`
    /// and `ElementExt::remove_pad`.
    ///
    /// An existing pad of an element can be retrieved by name with
    /// `ElementExt::get_static_pad`. A new dynamic pad can be created using
    /// `ElementExt::request_pad` with a `PadTemplate`.
    /// An iterator of all pads can be retrieved with `ElementExt::iterate_pads`.
    ///
    /// Elements can be linked through their pads.
    /// If the link is straightforward, use the `ElementExt::link`
    /// convenience function to link two elements, or `ElementExt::link_many`
    /// for more elements in a row.
    /// Use `ElementExt::link_filtered` to link two elements constrained by
    /// a specified set of `Caps`.
    /// For finer control, use `ElementExt::link_pads` and
    /// `ElementExt::link_pads_filtered` to specify the pads to link on
    /// each element by name.
    ///
    /// Each element has a state (see `State`). You can get and set the state
    /// of an element with `ElementExt::get_state` and `ElementExt::set_state`.
    /// Setting a state triggers a `StateChange`. To get a string representation
    /// of a `State`, use `Element::state_get_name`.
    ///
    /// You can get and set a `Clock` on an element using `ElementExt::get_clock`
    /// and `ElementExt::set_clock`.
    /// Some elements can provide a clock for the pipeline if
    /// the `ElementFlags::ProvideClock` flag is set. With the
    /// `ElementExt::provide_clock` method one can retrieve the clock provided by
    /// such an element.
    /// Not all elements require a clock to operate correctly. If the
    /// `ElementFlags::RequireClock`() flag is set, a clock should be set on the
    /// element with `ElementExt::set_clock`.
    ///
    /// Note that clock selection and distribution is normally handled by the
    /// toplevel `Pipeline` so the clock functions are only to be used in very
    /// specific situations.
    ///
    /// # Implements
    ///
    /// [`ElementExt`](trait.ElementExt.html), [`GstObjectExt`](trait.GstObjectExt.html), [`glib::object::ObjectExt`](../glib/object/trait.ObjectExt.html)
    pub struct Element(Object<ffi::GstElement, ffi::GstElementClass>): Object;

    match fn {
        get_type => || ffi::gst_element_get_type(),
    }
}

impl Element {
    /// Creates an element for handling the given URI.
    /// ## `type_`
    /// Whether to create a source or a sink
    /// ## `uri`
    /// URI to create an element for
    /// ## `elementname`
    /// Name of created element, can be `None`.
    ///
    /// # Returns
    ///
    /// a new element or `None` if none
    /// could be created
    pub fn make_from_uri<'a, P: Into<Option<&'a str>>>(type_: URIType, uri: &str, elementname: P) -> Result<Element, Error> {
        assert_initialized_main_thread!();
        let elementname = elementname.into();
        let elementname = elementname.to_glib_none();
        unsafe {
            let mut error = ptr::null_mut();
            let ret = ffi::gst_element_make_from_uri(type_.to_glib(), uri.to_glib_none().0, elementname.0, &mut error);
            if error.is_null() { Ok(from_glib_none(ret)) } else { Err(from_glib_full(error)) }
        }
    }

    pub fn register<'a, P: Into<Option<&'a Plugin>>>(plugin: P, name: &str, rank: u32, type_: glib::types::Type) -> bool {
        assert_initialized_main_thread!();
        let plugin = plugin.into();
        let plugin = plugin.to_glib_none();
        unsafe {
            from_glib(ffi::gst_element_register(plugin.0, name.to_glib_none().0, rank, type_.to_glib()))
        }
    }
}

unsafe impl Send for Element {}
unsafe impl Sync for Element {}

/// Trait containing all `Element` methods.
///
/// # Implementors
///
/// [`Bin`](struct.Bin.html), [`Element`](struct.Element.html), [`TagSetter`](struct.TagSetter.html), [`TocSetter`](struct.TocSetter.html)
pub trait ElementExt {
    /// Abort the state change of the element. This function is used
    /// by elements that do asynchronous state changes and find out
    /// something is wrong.
    ///
    /// This function should be called with the STATE_LOCK held.
    ///
    /// MT safe.
    fn abort_state(&self);

    /// Adds a pad (link point) to `self`. `pad`'s parent will be set to `self`;
    /// see `GstObjectExt::set_parent` for refcounting information.
    ///
    /// Pads are not automatically activated so elements should perform the needed
    /// steps to activate the pad in case this pad is added in the PAUSED or PLAYING
    /// state. See `PadExt::set_active` for more information about activating pads.
    ///
    /// The pad and the element should be unlocked when calling this function.
    ///
    /// This function will emit the `Element::pad-added` signal on the element.
    /// ## `pad`
    /// the `Pad` to add to the element.
    ///
    /// # Returns
    ///
    /// `true` if the pad could be added. This function can fail when
    /// a pad with the same name already existed or the pad already had another
    /// parent.
    ///
    /// MT safe.
    fn add_pad<P: IsA<Pad>>(&self, pad: &P) -> Result<(), glib::error::BoolError>;

    //#[cfg(any(feature = "v1_10", feature = "dox"))]
    //fn call_async(&self, func: /*Unknown conversion*//*Unimplemented*/ElementCallAsyncFunc, destroy_notify: /*Unknown conversion*//*Unimplemented*/DestroyNotify);

    /// Perform `transition` on `self`.
    ///
    /// This function must be called with STATE_LOCK held and is mainly used
    /// internally.
    /// ## `transition`
    /// the requested transition
    ///
    /// # Returns
    ///
    /// the `StateChangeReturn` of the state transition.
    fn change_state(&self, transition: StateChange) -> StateChangeReturn;

    /// Commit the state change of the element and proceed to the next
    /// pending state if any. This function is used
    /// by elements that do asynchronous state changes.
    /// The core will normally call this method automatically when an
    /// element returned `StateChangeReturn::Success` from the state change function.
    ///
    /// If after calling this method the element still has not reached
    /// the pending state, the next state change is performed.
    ///
    /// This method is used internally and should normally not be called by plugins
    /// or applications.
    ///
    /// This function must be called with STATE_LOCK held.
    /// ## `ret`
    /// The previous state return value
    ///
    /// # Returns
    ///
    /// The result of the commit state change.
    ///
    /// MT safe.
    fn continue_state(&self, ret: StateChangeReturn) -> StateChangeReturn;

    /// Creates a pad for each pad template that is always available.
    /// This function is only useful during object initialization of
    /// subclasses of `Element`.
    fn create_all_pads(&self);

    //#[cfg(any(feature = "v1_14", feature = "dox"))]
    //fn foreach_pad<P: Into<Option</*Unimplemented*/Fundamental: Pointer>>>(&self, func: /*Unknown conversion*//*Unimplemented*/ElementForeachPadFunc, user_data: P) -> bool;

    //#[cfg(any(feature = "v1_14", feature = "dox"))]
    //fn foreach_sink_pad<P: Into<Option</*Unimplemented*/Fundamental: Pointer>>>(&self, func: /*Unknown conversion*//*Unimplemented*/ElementForeachPadFunc, user_data: P) -> bool;

    //#[cfg(any(feature = "v1_14", feature = "dox"))]
    //fn foreach_src_pad<P: Into<Option</*Unimplemented*/Fundamental: Pointer>>>(&self, func: /*Unknown conversion*//*Unimplemented*/ElementForeachPadFunc, user_data: P) -> bool;

    /// Returns the base time of the element. The base time is the
    /// absolute time of the clock when this element was last put to
    /// PLAYING. Subtracting the base time from the clock time gives
    /// the running time of the element.
    ///
    /// # Returns
    ///
    /// the base time of the element.
    ///
    /// MT safe.
    fn get_base_time(&self) -> ClockTime;

    /// Returns the bus of the element. Note that only a `Pipeline` will provide a
    /// bus for the application.
    ///
    /// # Returns
    ///
    /// the element's `Bus`. unref after
    /// usage.
    ///
    /// MT safe.
    fn get_bus(&self) -> Option<Bus>;

    /// Gets the currently configured clock of the element. This is the clock as was
    /// last set with `ElementExt::set_clock`.
    ///
    /// Elements in a pipeline will only have their clock set when the
    /// pipeline is in the PLAYING state.
    ///
    /// # Returns
    ///
    /// the `Clock` of the element. unref after usage.
    ///
    /// MT safe.
    fn get_clock(&self) -> Option<Clock>;

    /// Looks for an unlinked pad to which the given pad can link. It is not
    /// guaranteed that linking the pads will work, though it should work in most
    /// cases.
    ///
    /// This function will first attempt to find a compatible unlinked ALWAYS pad,
    /// and if none can be found, it will request a compatible REQUEST pad by looking
    /// at the templates of `self`.
    /// ## `pad`
    /// the `Pad` to find a compatible one for.
    /// ## `caps`
    /// the `Caps` to use as a filter.
    ///
    /// # Returns
    ///
    /// the `Pad` to which a link
    ///  can be made, or `None` if one cannot be found. `GstObjectExt::unref`
    ///  after usage.
    fn get_compatible_pad<'a, P: IsA<Pad>, Q: Into<Option<&'a Caps>>>(&self, pad: &P, caps: Q) -> Option<Pad>;

    /// Retrieves a pad template from `self` that is compatible with `compattempl`.
    /// Pads from compatible templates can be linked together.
    /// ## `compattempl`
    /// the `PadTemplate` to find a compatible
    ///  template for
    ///
    /// # Returns
    ///
    /// a compatible `PadTemplate`,
    ///  or `None` if none was found. No unreferencing is necessary.
    fn get_compatible_pad_template(&self, compattempl: &PadTemplate) -> Option<PadTemplate>;

    /// Gets the context with `context_type` set on the element or NULL.
    ///
    /// MT safe.
    /// ## `context_type`
    /// a name of a context to retrieve
    ///
    /// # Returns
    ///
    /// A `Context` or NULL
    fn get_context(&self, context_type: &str) -> Option<Context>;

    /// Gets the contexts set on the element.
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// List of `Context`
    fn get_contexts(&self) -> Vec<Context>;

    /// Retrieves the factory that was used to create this element.
    ///
    /// # Returns
    ///
    /// the `ElementFactory` used for creating this
    ///  element. no refcounting is needed.
    fn get_factory(&self) -> Option<ElementFactory>;

    /// Retrieves a pad from the element by name (e.g. "src_\%d"). This version only
    /// retrieves request pads. The pad should be released with
    /// `ElementExt::release_request_pad`.
    ///
    /// This method is slower than manually getting the pad template and calling
    /// `ElementExt::request_pad` if the pads should have a specific name (e.g.
    /// `name` is "src_1" instead of "src_\%u").
    /// ## `name`
    /// the name of the request `Pad` to retrieve.
    ///
    /// # Returns
    ///
    /// requested `Pad` if found,
    ///  otherwise `None`. Release after usage.
    fn get_request_pad(&self, name: &str) -> Option<Pad>;

    /// Returns the start time of the element. The start time is the
    /// running time of the clock when this element was last put to PAUSED.
    ///
    /// Usually the start_time is managed by a toplevel element such as
    /// `Pipeline`.
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// the start time of the element.
    fn get_start_time(&self) -> ClockTime;

    /// Gets the state of the element.
    ///
    /// For elements that performed an ASYNC state change, as reported by
    /// `ElementExt::set_state`, this function will block up to the
    /// specified timeout value for the state change to complete.
    /// If the element completes the state change or goes into
    /// an error, this function returns immediately with a return value of
    /// `StateChangeReturn::Success` or `StateChangeReturn::Failure` respectively.
    ///
    /// For elements that did not return `StateChangeReturn::Async`, this function
    /// returns the current and pending state immediately.
    ///
    /// This function returns `StateChangeReturn::NoPreroll` if the element
    /// successfully changed its state but is not able to provide data yet.
    /// This mostly happens for live sources that only produce data in
    /// `State::Playing`. While the state change return is equivalent to
    /// `StateChangeReturn::Success`, it is returned to the application to signal that
    /// some sink elements might not be able to complete their state change because
    /// an element is not producing data to complete the preroll. When setting the
    /// element to playing, the preroll will complete and playback will start.
    /// ## `state`
    /// a pointer to `State` to hold the state.
    ///  Can be `None`.
    /// ## `pending`
    /// a pointer to `State` to hold the pending
    ///  state. Can be `None`.
    /// ## `timeout`
    /// a `ClockTime` to specify the timeout for an async
    ///  state change or `GST_CLOCK_TIME_NONE` for infinite timeout.
    ///
    /// # Returns
    ///
    /// `StateChangeReturn::Success` if the element has no more pending state
    ///  and the last state change succeeded, `StateChangeReturn::Async` if the
    ///  element is still performing a state change or
    ///  `StateChangeReturn::Failure` if the last state change failed.
    ///
    /// MT safe.
    fn get_state(&self, timeout: ClockTime) -> (StateChangeReturn, State, State);

    /// Retrieves a pad from `self` by name. This version only retrieves
    /// already-existing (i.e. 'static') pads.
    /// ## `name`
    /// the name of the static `Pad` to retrieve.
    ///
    /// # Returns
    ///
    /// the requested `Pad` if
    ///  found, otherwise `None`. unref after usage.
    ///
    /// MT safe.
    fn get_static_pad(&self, name: &str) -> Option<Pad>;

    /// Checks if the state of an element is locked.
    /// If the state of an element is locked, state changes of the parent don't
    /// affect the element.
    /// This way you can leave currently unused elements inside bins. Just lock their
    /// state before changing the state from `State::Null`.
    ///
    /// MT safe.
    ///
    /// # Returns
    ///
    /// `true`, if the element's state is locked.
    fn is_locked_state(&self) -> bool;

    //fn iterate_pads(&self) -> /*Ignored*/Option<Iterator>;

    //fn iterate_sink_pads(&self) -> /*Ignored*/Option<Iterator>;

    //fn iterate_src_pads(&self) -> /*Ignored*/Option<Iterator>;

    /// Links `self` to `dest`. The link must be from source to
    /// destination; the other direction will not be tried. The function looks for
    /// existing pads that aren't linked yet. It will request new pads if necessary.
    /// Such pads need to be released manually when unlinking.
    /// If multiple links are possible, only one is established.
    ///
    /// Make sure you have added your elements to a bin or pipeline with
    /// `BinExt::add` before trying to link them.
    /// ## `dest`
    /// the `Element` containing the destination pad.
    ///
    /// # Returns
    ///
    /// `true` if the elements could be linked, `false` otherwise.
    fn link<P: IsA<Element>>(&self, dest: &P) -> Result<(), glib::error::BoolError>;

    /// Links `self` to `dest` using the given caps as filtercaps.
    /// The link must be from source to
    /// destination; the other direction will not be tried. The function looks for
    /// existing pads that aren't linked yet. It will request new pads if necessary.
    /// If multiple links are possible, only one is established.
    ///
    /// Make sure you have added your elements to a bin or pipeline with
    /// `BinExt::add` before trying to link them.
    /// ## `dest`
    /// the `Element` containing the destination pad.
    /// ## `filter`
    /// the `Caps` to filter the link,
    ///  or `None` for no filter.
    ///
    /// # Returns
    ///
    /// `true` if the pads could be linked, `false` otherwise.
    fn link_filtered<'a, P: IsA<Element>, Q: Into<Option<&'a Caps>>>(&self, dest: &P, filter: Q) -> Result<(), glib::error::BoolError>;

    //fn link_many<P: IsA<Element>>(&self, element_2: &P, : /*Unknown conversion*//*Unimplemented*/Fundamental: VarArgs) -> bool;

    /// Links the two named pads of the source and destination elements.
    /// Side effect is that if one of the pads has no parent, it becomes a
    /// child of the parent of the other element. If they have different
    /// parents, the link fails.
    /// ## `srcpadname`
    /// the name of the `Pad` in source element
    ///  or `None` for any pad.
    /// ## `dest`
    /// the `Element` containing the destination pad.
    /// ## `destpadname`
    /// the name of the `Pad` in destination element,
    /// or `None` for any pad.
    ///
    /// # Returns
    ///
    /// `true` if the pads could be linked, `false` otherwise.
    fn link_pads<'a, 'b, P: Into<Option<&'a str>>, Q: IsA<Element>, R: Into<Option<&'b str>>>(&self, srcpadname: P, dest: &Q, destpadname: R) -> Result<(), glib::error::BoolError>;

    /// Links the two named pads of the source and destination elements. Side effect
    /// is that if one of the pads has no parent, it becomes a child of the parent of
    /// the other element. If they have different parents, the link fails. If `caps`
    /// is not `None`, makes sure that the caps of the link is a subset of `caps`.
    /// ## `srcpadname`
    /// the name of the `Pad` in source element
    ///  or `None` for any pad.
    /// ## `dest`
    /// the `Element` containing the destination pad.
    /// ## `destpadname`
    /// the name of the `Pad` in destination element
    ///  or `None` for any pad.
    /// ## `filter`
    /// the `Caps` to filter the link,
    ///  or `None` for no filter.
    ///
    /// # Returns
    ///
    /// `true` if the pads could be linked, `false` otherwise.
    fn link_pads_filtered<'a, 'b, 'c, P: Into<Option<&'a str>>, Q: IsA<Element>, R: Into<Option<&'b str>>, S: Into<Option<&'c Caps>>>(&self, srcpadname: P, dest: &Q, destpadname: R, filter: S) -> Result<(), glib::error::BoolError>;

    /// Links the two named pads of the source and destination elements.
    /// Side effect is that if one of the pads has no parent, it becomes a
    /// child of the parent of the other element. If they have different
    /// parents, the link fails.
    ///
    /// Calling `ElementExt::link_pads_full` with `flags` == `PadLinkCheck::Default`
    /// is the same as calling `ElementExt::link_pads` and the recommended way of
    /// linking pads with safety checks applied.
    ///
    /// This is a convenience function for `PadExt::link_full`.
    /// ## `srcpadname`
    /// the name of the `Pad` in source element
    ///  or `None` for any pad.
    /// ## `dest`
    /// the `Element` containing the destination pad.
    /// ## `destpadname`
    /// the name of the `Pad` in destination element,
    /// or `None` for any pad.
    /// ## `flags`
    /// the `PadLinkCheck` to be performed when linking pads.
    ///
    /// # Returns
    ///
    /// `true` if the pads could be linked, `false` otherwise.
    fn link_pads_full<'a, 'b, P: Into<Option<&'a str>>, Q: IsA<Element>, R: Into<Option<&'b str>>>(&self, srcpadname: P, dest: &Q, destpadname: R, flags: PadLinkCheck) -> Result<(), glib::error::BoolError>;

    /// Brings the element to the lost state. The current state of the
    /// element is copied to the pending state so that any call to
    /// `ElementExt::get_state` will return `StateChangeReturn::Async`.
    ///
    /// An ASYNC_START message is posted. If the element was PLAYING, it will
    /// go to PAUSED. The element will be restored to its PLAYING state by
    /// the parent pipeline when it prerolls again.
    ///
    /// This is mostly used for elements that lost their preroll buffer
    /// in the `State::Paused` or `State::Playing` state after a flush,
    /// they will go to their pending state again when a new preroll buffer is
    /// queued. This function can only be called when the element is currently
    /// not in error or an async state change.
    ///
    /// This function is used internally and should normally not be called from
    /// plugins or applications.
    fn lost_state(&self);

    //fn message_full<'a, 'b, P: Into<Option<&'a str>>, Q: Into<Option<&'b str>>>(&self, type_: /*Ignored*/MessageType, domain: /*Ignored*/glib::Quark, code: i32, text: P, debug: Q, file: &str, function: &str, line: i32);

    //#[cfg(any(feature = "v1_10", feature = "dox"))]
    //fn message_full_with_details<'a, 'b, P: Into<Option<&'a str>>, Q: Into<Option<&'b str>>>(&self, type_: /*Ignored*/MessageType, domain: /*Ignored*/glib::Quark, code: i32, text: P, debug: Q, file: &str, function: &str, line: i32, structure: &mut Structure);

    /// Use this function to signal that the element does not expect any more pads
    /// to show up in the current pipeline. This function should be called whenever
    /// pads have been added by the element itself. Elements with `PadPresence::Sometimes`
    /// pad templates use this in combination with autopluggers to figure out that
    /// the element is done initializing its pads.
    ///
    /// This function emits the `Element::no-more-pads` signal.
    ///
    /// MT safe.
    fn no_more_pads(&self);

    /// Post a message on the element's `Bus`. This function takes ownership of the
    /// message; if you want to access the message after this call, you should add an
    /// additional reference before calling.
    /// ## `message`
    /// a `Message` to post
    ///
    /// # Returns
    ///
    /// `true` if the message was successfully posted. The function returns
    /// `false` if the element did not have a bus.
    ///
    /// MT safe.
    fn post_message(&self, message: &Message) -> Result<(), glib::error::BoolError>;

    /// Get the clock provided by the given element.
    /// > An element is only required to provide a clock in the PAUSED
    /// > state. Some elements can provide a clock in other states.
    ///
    /// # Returns
    ///
    /// the GstClock provided by the
    /// element or `None` if no clock could be provided. Unref after usage.
    ///
    /// MT safe.
    fn provide_clock(&self) -> Option<Clock>;

    /// Makes the element free the previously requested pad as obtained
    /// with `ElementExt::request_pad`.
    ///
    /// This does not unref the pad. If the pad was created by using
    /// `ElementExt::request_pad`, `ElementExt::release_request_pad` needs to be
    /// followed by `GstObjectExt::unref` to free the `pad`.
    ///
    /// MT safe.
    /// ## `pad`
    /// the `Pad` to release.
    fn release_request_pad<P: IsA<Pad>>(&self, pad: &P);

    /// Removes `pad` from `self`. `pad` will be destroyed if it has not been
    /// referenced elsewhere using `GstObjectExt::unparent`.
    ///
    /// This function is used by plugin developers and should not be used
    /// by applications. Pads that were dynamically requested from elements
    /// with `ElementExt::request_pad` should be released with the
    /// `ElementExt::release_request_pad` function instead.
    ///
    /// Pads are not automatically deactivated so elements should perform the needed
    /// steps to deactivate the pad in case this pad is removed in the PAUSED or
    /// PLAYING state. See `PadExt::set_active` for more information about
    /// deactivating pads.
    ///
    /// The pad and the element should be unlocked when calling this function.
    ///
    /// This function will emit the `Element::pad-removed` signal on the element.
    /// ## `pad`
    /// the `Pad` to remove from the element.
    ///
    /// # Returns
    ///
    /// `true` if the pad could be removed. Can return `false` if the
    /// pad does not belong to the provided element.
    ///
    /// MT safe.
    fn remove_pad<P: IsA<Pad>>(&self, pad: &P) -> Result<(), glib::error::BoolError>;

    /// Retrieves a request pad from the element according to the provided template.
    /// Pad templates can be looked up using
    /// `ElementFactory::get_static_pad_templates`.
    ///
    /// The pad should be released with `ElementExt::release_request_pad`.
    /// ## `templ`
    /// a `PadTemplate` of which we want a pad of.
    /// ## `name`
    /// the name of the request `Pad`
    /// to retrieve. Can be `None`.
    /// ## `caps`
    /// the caps of the pad we want to
    /// request. Can be `None`.
    ///
    /// # Returns
    ///
    /// requested `Pad` if found,
    ///  otherwise `None`. Release after usage.
    fn request_pad<'a, 'b, P: Into<Option<&'a str>>, Q: Into<Option<&'b Caps>>>(&self, templ: &PadTemplate, name: P, caps: Q) -> Option<Pad>;

    /// Set the base time of an element. See `ElementExt::get_base_time`.
    ///
    /// MT safe.
    /// ## `time`
    /// the base time to set.
    fn set_base_time(&self, time: ClockTime);

    /// Sets the bus of the element. Increases the refcount on the bus.
    /// For internal use only, unless you're testing elements.
    ///
    /// MT safe.
    /// ## `bus`
    /// the `Bus` to set.
    fn set_bus<'a, P: Into<Option<&'a Bus>>>(&self, bus: P);

    /// Sets the clock for the element. This function increases the
    /// refcount on the clock. Any previously set clock on the object
    /// is unreffed.
    /// ## `clock`
    /// the `Clock` to set for the element.
    ///
    /// # Returns
    ///
    /// `true` if the element accepted the clock. An element can refuse a
    /// clock when it, for example, is not able to slave its internal clock to the
    /// `clock` or when it requires a specific clock to operate.
    ///
    /// MT safe.
    fn set_clock<'a, P: IsA<Clock> + 'a, Q: Into<Option<&'a P>>>(&self, clock: Q) -> Result<(), glib::error::BoolError>;

    /// Sets the context of the element. Increases the refcount of the context.
    ///
    /// MT safe.
    /// ## `context`
    /// the `Context` to set.
    fn set_context(&self, context: &Context);

    /// Locks the state of an element, so state changes of the parent don't affect
    /// this element anymore.
    ///
    /// MT safe.
    /// ## `locked_state`
    /// `true` to lock the element's state
    ///
    /// # Returns
    ///
    /// `true` if the state was changed, `false` if bad parameters were given
    /// or the elements state-locking needed no change.
    fn set_locked_state(&self, locked_state: bool) -> bool;

    /// Set the start time of an element. The start time of the element is the
    /// running time of the element when it last went to the PAUSED state. In READY
    /// or after a flushing seek, it is set to 0.
    ///
    /// Toplevel elements like `Pipeline` will manage the start_time and
    /// base_time on its children. Setting the start_time to `GST_CLOCK_TIME_NONE`
    /// on such a toplevel element will disable the distribution of the base_time to
    /// the children and can be useful if the application manages the base_time
    /// itself, for example if you want to synchronize capture from multiple
    /// pipelines, and you can also ensure that the pipelines have the same clock.
    ///
    /// MT safe.
    /// ## `time`
    /// the base time to set.
    fn set_start_time(&self, time: ClockTime);

    /// Sets the state of the element. This function will try to set the
    /// requested state by going through all the intermediary states and calling
    /// the class's state change function for each.
    ///
    /// This function can return `StateChangeReturn::Async`, in which case the
    /// element will perform the remainder of the state change asynchronously in
    /// another thread.
    /// An application can use `ElementExt::get_state` to wait for the completion
    /// of the state change or it can wait for a `MessageType::AsyncDone` or
    /// `MessageType::StateChanged` on the bus.
    ///
    /// State changes to `State::Ready` or `State::Null` never return
    /// `StateChangeReturn::Async`.
    /// ## `state`
    /// the element's new `State`.
    ///
    /// # Returns
    ///
    /// Result of the state change using `StateChangeReturn`.
    ///
    /// MT safe.
    fn set_state(&self, state: State) -> StateChangeReturn;

    /// Tries to change the state of the element to the same as its parent.
    /// If this function returns `false`, the state of element is undefined.
    ///
    /// # Returns
    ///
    /// `true`, if the element's state could be synced to the parent's state.
    ///
    /// MT safe.
    fn sync_state_with_parent(&self) -> Result<(), glib::error::BoolError>;

    /// Unlinks all source pads of the source element with all sink pads
    /// of the sink element to which they are linked.
    ///
    /// If the link has been made using `ElementExt::link`, it could have created an
    /// requestpad, which has to be released using `ElementExt::release_request_pad`.
    /// ## `dest`
    /// the sink `Element` to unlink.
    fn unlink<P: IsA<Element>>(&self, dest: &P);

    //fn unlink_many<P: IsA<Element>>(&self, element_2: &P, : /*Unknown conversion*//*Unimplemented*/Fundamental: VarArgs);

    /// Unlinks the two named pads of the source and destination elements.
    ///
    /// This is a convenience function for `PadExt::unlink`.
    /// ## `srcpadname`
    /// the name of the `Pad` in source element.
    /// ## `dest`
    /// a `Element` containing the destination pad.
    /// ## `destpadname`
    /// the name of the `Pad` in destination element.
    fn unlink_pads<P: IsA<Element>>(&self, srcpadname: &str, dest: &P, destpadname: &str);

    /// This signals that the element will not generate more dynamic pads.
    /// Note that this signal will usually be emitted from the context of
    /// the streaming thread.
    fn connect_no_more_pads<F: Fn(&Self) + Send + Sync + 'static>(&self, f: F) -> SignalHandlerId;

    /// a new `Pad` has been added to the element. Note that this signal will
    /// usually be emitted from the context of the streaming thread. Also keep in
    /// mind that if you add new elements to the pipeline in the signal handler
    /// you will need to set them to the desired target state with
    /// `ElementExt::set_state` or `ElementExt::sync_state_with_parent`.
    /// ## `new_pad`
    /// the pad that has been added
    fn connect_pad_added<F: Fn(&Self, &Pad) + Send + Sync + 'static>(&self, f: F) -> SignalHandlerId;

    /// a `Pad` has been removed from the element
    /// ## `old_pad`
    /// the pad that has been removed
    fn connect_pad_removed<F: Fn(&Self, &Pad) + Send + Sync + 'static>(&self, f: F) -> SignalHandlerId;
}

impl<O: IsA<Element> + IsA<glib::object::Object>> ElementExt for O {
    fn abort_state(&self) {
        unsafe {
            ffi::gst_element_abort_state(self.to_glib_none().0);
        }
    }

    fn add_pad<P: IsA<Pad>>(&self, pad: &P) -> Result<(), glib::error::BoolError> {
        unsafe {
            glib::error::BoolError::from_glib(ffi::gst_element_add_pad(self.to_glib_none().0, pad.to_glib_none().0), "Failed to add pad")
        }
    }

    //#[cfg(any(feature = "v1_10", feature = "dox"))]
    //fn call_async(&self, func: /*Unknown conversion*//*Unimplemented*/ElementCallAsyncFunc, destroy_notify: /*Unknown conversion*//*Unimplemented*/DestroyNotify) {
    //    unsafe { TODO: call ffi::gst_element_call_async() }
    //}

    fn change_state(&self, transition: StateChange) -> StateChangeReturn {
        unsafe {
            from_glib(ffi::gst_element_change_state(self.to_glib_none().0, transition.to_glib()))
        }
    }

    fn continue_state(&self, ret: StateChangeReturn) -> StateChangeReturn {
        unsafe {
            from_glib(ffi::gst_element_continue_state(self.to_glib_none().0, ret.to_glib()))
        }
    }

    fn create_all_pads(&self) {
        unsafe {
            ffi::gst_element_create_all_pads(self.to_glib_none().0);
        }
    }

    //#[cfg(any(feature = "v1_14", feature = "dox"))]
    //fn foreach_pad<P: Into<Option</*Unimplemented*/Fundamental: Pointer>>>(&self, func: /*Unknown conversion*//*Unimplemented*/ElementForeachPadFunc, user_data: P) -> bool {
    //    unsafe { TODO: call ffi::gst_element_foreach_pad() }
    //}

    //#[cfg(any(feature = "v1_14", feature = "dox"))]
    //fn foreach_sink_pad<P: Into<Option</*Unimplemented*/Fundamental: Pointer>>>(&self, func: /*Unknown conversion*//*Unimplemented*/ElementForeachPadFunc, user_data: P) -> bool {
    //    unsafe { TODO: call ffi::gst_element_foreach_sink_pad() }
    //}

    //#[cfg(any(feature = "v1_14", feature = "dox"))]
    //fn foreach_src_pad<P: Into<Option</*Unimplemented*/Fundamental: Pointer>>>(&self, func: /*Unknown conversion*//*Unimplemented*/ElementForeachPadFunc, user_data: P) -> bool {
    //    unsafe { TODO: call ffi::gst_element_foreach_src_pad() }
    //}

    fn get_base_time(&self) -> ClockTime {
        unsafe {
            from_glib(ffi::gst_element_get_base_time(self.to_glib_none().0))
        }
    }

    fn get_bus(&self) -> Option<Bus> {
        unsafe {
            from_glib_full(ffi::gst_element_get_bus(self.to_glib_none().0))
        }
    }

    fn get_clock(&self) -> Option<Clock> {
        unsafe {
            from_glib_full(ffi::gst_element_get_clock(self.to_glib_none().0))
        }
    }

    fn get_compatible_pad<'a, P: IsA<Pad>, Q: Into<Option<&'a Caps>>>(&self, pad: &P, caps: Q) -> Option<Pad> {
        let caps = caps.into();
        let caps = caps.to_glib_none();
        unsafe {
            from_glib_full(ffi::gst_element_get_compatible_pad(self.to_glib_none().0, pad.to_glib_none().0, caps.0))
        }
    }

    fn get_compatible_pad_template(&self, compattempl: &PadTemplate) -> Option<PadTemplate> {
        unsafe {
            from_glib_none(ffi::gst_element_get_compatible_pad_template(self.to_glib_none().0, compattempl.to_glib_none().0))
        }
    }

    fn get_context(&self, context_type: &str) -> Option<Context> {
        unsafe {
            from_glib_full(ffi::gst_element_get_context(self.to_glib_none().0, context_type.to_glib_none().0))
        }
    }

    fn get_contexts(&self) -> Vec<Context> {
        unsafe {
            FromGlibPtrContainer::from_glib_full(ffi::gst_element_get_contexts(self.to_glib_none().0))
        }
    }

    fn get_factory(&self) -> Option<ElementFactory> {
        unsafe {
            from_glib_none(ffi::gst_element_get_factory(self.to_glib_none().0))
        }
    }

    fn get_request_pad(&self, name: &str) -> Option<Pad> {
        unsafe {
            from_glib_full(ffi::gst_element_get_request_pad(self.to_glib_none().0, name.to_glib_none().0))
        }
    }

    fn get_start_time(&self) -> ClockTime {
        unsafe {
            from_glib(ffi::gst_element_get_start_time(self.to_glib_none().0))
        }
    }

    fn get_state(&self, timeout: ClockTime) -> (StateChangeReturn, State, State) {
        unsafe {
            let mut state = mem::uninitialized();
            let mut pending = mem::uninitialized();
            let ret = from_glib(ffi::gst_element_get_state(self.to_glib_none().0, &mut state, &mut pending, timeout.to_glib()));
            (ret, from_glib(state), from_glib(pending))
        }
    }

    fn get_static_pad(&self, name: &str) -> Option<Pad> {
        unsafe {
            from_glib_full(ffi::gst_element_get_static_pad(self.to_glib_none().0, name.to_glib_none().0))
        }
    }

    fn is_locked_state(&self) -> bool {
        unsafe {
            from_glib(ffi::gst_element_is_locked_state(self.to_glib_none().0))
        }
    }

    //fn iterate_pads(&self) -> /*Ignored*/Option<Iterator> {
    //    unsafe { TODO: call ffi::gst_element_iterate_pads() }
    //}

    //fn iterate_sink_pads(&self) -> /*Ignored*/Option<Iterator> {
    //    unsafe { TODO: call ffi::gst_element_iterate_sink_pads() }
    //}

    //fn iterate_src_pads(&self) -> /*Ignored*/Option<Iterator> {
    //    unsafe { TODO: call ffi::gst_element_iterate_src_pads() }
    //}

    fn link<P: IsA<Element>>(&self, dest: &P) -> Result<(), glib::error::BoolError> {
        unsafe {
            glib::error::BoolError::from_glib(ffi::gst_element_link(self.to_glib_none().0, dest.to_glib_none().0), "Failed to link elements")
        }
    }

    fn link_filtered<'a, P: IsA<Element>, Q: Into<Option<&'a Caps>>>(&self, dest: &P, filter: Q) -> Result<(), glib::error::BoolError> {
        let filter = filter.into();
        let filter = filter.to_glib_none();
        unsafe {
            glib::error::BoolError::from_glib(ffi::gst_element_link_filtered(self.to_glib_none().0, dest.to_glib_none().0, filter.0), "Failed to link elements")
        }
    }

    //fn link_many<P: IsA<Element>>(&self, element_2: &P, : /*Unknown conversion*//*Unimplemented*/Fundamental: VarArgs) -> bool {
    //    unsafe { TODO: call ffi::gst_element_link_many() }
    //}

    fn link_pads<'a, 'b, P: Into<Option<&'a str>>, Q: IsA<Element>, R: Into<Option<&'b str>>>(&self, srcpadname: P, dest: &Q, destpadname: R) -> Result<(), glib::error::BoolError> {
        let srcpadname = srcpadname.into();
        let srcpadname = srcpadname.to_glib_none();
        let destpadname = destpadname.into();
        let destpadname = destpadname.to_glib_none();
        unsafe {
            glib::error::BoolError::from_glib(ffi::gst_element_link_pads(self.to_glib_none().0, srcpadname.0, dest.to_glib_none().0, destpadname.0), "Failed to link pads")
        }
    }

    fn link_pads_filtered<'a, 'b, 'c, P: Into<Option<&'a str>>, Q: IsA<Element>, R: Into<Option<&'b str>>, S: Into<Option<&'c Caps>>>(&self, srcpadname: P, dest: &Q, destpadname: R, filter: S) -> Result<(), glib::error::BoolError> {
        let srcpadname = srcpadname.into();
        let srcpadname = srcpadname.to_glib_none();
        let destpadname = destpadname.into();
        let destpadname = destpadname.to_glib_none();
        let filter = filter.into();
        let filter = filter.to_glib_none();
        unsafe {
            glib::error::BoolError::from_glib(ffi::gst_element_link_pads_filtered(self.to_glib_none().0, srcpadname.0, dest.to_glib_none().0, destpadname.0, filter.0), "Failed to link pads")
        }
    }

    fn link_pads_full<'a, 'b, P: Into<Option<&'a str>>, Q: IsA<Element>, R: Into<Option<&'b str>>>(&self, srcpadname: P, dest: &Q, destpadname: R, flags: PadLinkCheck) -> Result<(), glib::error::BoolError> {
        let srcpadname = srcpadname.into();
        let srcpadname = srcpadname.to_glib_none();
        let destpadname = destpadname.into();
        let destpadname = destpadname.to_glib_none();
        unsafe {
            glib::error::BoolError::from_glib(ffi::gst_element_link_pads_full(self.to_glib_none().0, srcpadname.0, dest.to_glib_none().0, destpadname.0, flags.to_glib()), "Failed to link pads")
        }
    }

    fn lost_state(&self) {
        unsafe {
            ffi::gst_element_lost_state(self.to_glib_none().0);
        }
    }

    //fn message_full<'a, 'b, P: Into<Option<&'a str>>, Q: Into<Option<&'b str>>>(&self, type_: /*Ignored*/MessageType, domain: /*Ignored*/glib::Quark, code: i32, text: P, debug: Q, file: &str, function: &str, line: i32) {
    //    unsafe { TODO: call ffi::gst_element_message_full() }
    //}

    //#[cfg(any(feature = "v1_10", feature = "dox"))]
    //fn message_full_with_details<'a, 'b, P: Into<Option<&'a str>>, Q: Into<Option<&'b str>>>(&self, type_: /*Ignored*/MessageType, domain: /*Ignored*/glib::Quark, code: i32, text: P, debug: Q, file: &str, function: &str, line: i32, structure: &mut Structure) {
    //    unsafe { TODO: call ffi::gst_element_message_full_with_details() }
    //}

    fn no_more_pads(&self) {
        unsafe {
            ffi::gst_element_no_more_pads(self.to_glib_none().0);
        }
    }

    fn post_message(&self, message: &Message) -> Result<(), glib::error::BoolError> {
        unsafe {
            glib::error::BoolError::from_glib(ffi::gst_element_post_message(self.to_glib_none().0, message.to_glib_full()), "Failed to post message")
        }
    }

    fn provide_clock(&self) -> Option<Clock> {
        unsafe {
            from_glib_full(ffi::gst_element_provide_clock(self.to_glib_none().0))
        }
    }

    fn release_request_pad<P: IsA<Pad>>(&self, pad: &P) {
        unsafe {
            ffi::gst_element_release_request_pad(self.to_glib_none().0, pad.to_glib_none().0);
        }
    }

    fn remove_pad<P: IsA<Pad>>(&self, pad: &P) -> Result<(), glib::error::BoolError> {
        unsafe {
            glib::error::BoolError::from_glib(ffi::gst_element_remove_pad(self.to_glib_none().0, pad.to_glib_none().0), "Failed to remove pad")
        }
    }

    fn request_pad<'a, 'b, P: Into<Option<&'a str>>, Q: Into<Option<&'b Caps>>>(&self, templ: &PadTemplate, name: P, caps: Q) -> Option<Pad> {
        let name = name.into();
        let name = name.to_glib_none();
        let caps = caps.into();
        let caps = caps.to_glib_none();
        unsafe {
            from_glib_full(ffi::gst_element_request_pad(self.to_glib_none().0, templ.to_glib_none().0, name.0, caps.0))
        }
    }

    fn set_base_time(&self, time: ClockTime) {
        unsafe {
            ffi::gst_element_set_base_time(self.to_glib_none().0, time.to_glib());
        }
    }

    fn set_bus<'a, P: Into<Option<&'a Bus>>>(&self, bus: P) {
        let bus = bus.into();
        let bus = bus.to_glib_none();
        unsafe {
            ffi::gst_element_set_bus(self.to_glib_none().0, bus.0);
        }
    }

    fn set_clock<'a, P: IsA<Clock> + 'a, Q: Into<Option<&'a P>>>(&self, clock: Q) -> Result<(), glib::error::BoolError> {
        let clock = clock.into();
        let clock = clock.to_glib_none();
        unsafe {
            glib::error::BoolError::from_glib(ffi::gst_element_set_clock(self.to_glib_none().0, clock.0), "Failed to set clock")
        }
    }

    fn set_context(&self, context: &Context) {
        unsafe {
            ffi::gst_element_set_context(self.to_glib_none().0, context.to_glib_none().0);
        }
    }

    fn set_locked_state(&self, locked_state: bool) -> bool {
        unsafe {
            from_glib(ffi::gst_element_set_locked_state(self.to_glib_none().0, locked_state.to_glib()))
        }
    }

    fn set_start_time(&self, time: ClockTime) {
        unsafe {
            ffi::gst_element_set_start_time(self.to_glib_none().0, time.to_glib());
        }
    }

    fn set_state(&self, state: State) -> StateChangeReturn {
        unsafe {
            from_glib(ffi::gst_element_set_state(self.to_glib_none().0, state.to_glib()))
        }
    }

    fn sync_state_with_parent(&self) -> Result<(), glib::error::BoolError> {
        unsafe {
            glib::error::BoolError::from_glib(ffi::gst_element_sync_state_with_parent(self.to_glib_none().0), "Failed to sync state with parent")
        }
    }

    fn unlink<P: IsA<Element>>(&self, dest: &P) {
        unsafe {
            ffi::gst_element_unlink(self.to_glib_none().0, dest.to_glib_none().0);
        }
    }

    //fn unlink_many<P: IsA<Element>>(&self, element_2: &P, : /*Unknown conversion*//*Unimplemented*/Fundamental: VarArgs) {
    //    unsafe { TODO: call ffi::gst_element_unlink_many() }
    //}

    fn unlink_pads<P: IsA<Element>>(&self, srcpadname: &str, dest: &P, destpadname: &str) {
        unsafe {
            ffi::gst_element_unlink_pads(self.to_glib_none().0, srcpadname.to_glib_none().0, dest.to_glib_none().0, destpadname.to_glib_none().0);
        }
    }

    fn connect_no_more_pads<F: Fn(&Self) + Send + Sync + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe {
            let f: Box_<Box_<Fn(&Self) + Send + Sync + 'static>> = Box_::new(Box_::new(f));
            connect(self.to_glib_none().0, "no-more-pads",
                transmute(no_more_pads_trampoline::<Self> as usize), Box_::into_raw(f) as *mut _)
        }
    }

    fn connect_pad_added<F: Fn(&Self, &Pad) + Send + Sync + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe {
            let f: Box_<Box_<Fn(&Self, &Pad) + Send + Sync + 'static>> = Box_::new(Box_::new(f));
            connect(self.to_glib_none().0, "pad-added",
                transmute(pad_added_trampoline::<Self> as usize), Box_::into_raw(f) as *mut _)
        }
    }

    fn connect_pad_removed<F: Fn(&Self, &Pad) + Send + Sync + 'static>(&self, f: F) -> SignalHandlerId {
        unsafe {
            let f: Box_<Box_<Fn(&Self, &Pad) + Send + Sync + 'static>> = Box_::new(Box_::new(f));
            connect(self.to_glib_none().0, "pad-removed",
                transmute(pad_removed_trampoline::<Self> as usize), Box_::into_raw(f) as *mut _)
        }
    }
}

unsafe extern "C" fn no_more_pads_trampoline<P>(this: *mut ffi::GstElement, f: glib_ffi::gpointer)
where P: IsA<Element> {
    let f: &&(Fn(&P) + Send + Sync + 'static) = transmute(f);
    f(&Element::from_glib_borrow(this).downcast_unchecked())
}

unsafe extern "C" fn pad_added_trampoline<P>(this: *mut ffi::GstElement, new_pad: *mut ffi::GstPad, f: glib_ffi::gpointer)
where P: IsA<Element> {
    let f: &&(Fn(&P, &Pad) + Send + Sync + 'static) = transmute(f);
    f(&Element::from_glib_borrow(this).downcast_unchecked(), &from_glib_borrow(new_pad))
}

unsafe extern "C" fn pad_removed_trampoline<P>(this: *mut ffi::GstElement, old_pad: *mut ffi::GstPad, f: glib_ffi::gpointer)
where P: IsA<Element> {
    let f: &&(Fn(&P, &Pad) + Send + Sync + 'static) = transmute(f);
    f(&Element::from_glib_borrow(this).downcast_unchecked(), &from_glib_borrow(old_pad))
}