gstreamer/deviceprovider: Add support for subclassing gst::DeviceProvider

This commit is contained in:
Sebastian Dröge 2019-09-11 22:59:49 +03:00
parent 9df56faf48
commit 6dcd255815
2 changed files with 178 additions and 0 deletions

View file

@ -0,0 +1,174 @@
// Copyright (C) 2019 Sebastian Dröge <sebastian@centricular.com>
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
use glib_sys;
use gst_sys;
use glib::translate::*;
use glib::subclass::prelude::*;
use Device;
use DeviceProvider;
use DeviceProviderClass;
use LoggableError;
pub trait DeviceProviderImpl: DeviceProviderImplExt + ObjectImpl + Send + Sync + 'static {
fn probe(&self, device_provider: &DeviceProvider) -> Vec<Device> {
self.parent_probe(device_provider)
}
fn start(&self, device_provider: &DeviceProvider) -> Result<(), LoggableError> {
self.parent_start(device_provider)
}
fn stop(&self, device_provider: &DeviceProvider) {
self.parent_stop(device_provider)
}
}
pub trait DeviceProviderImplExt {
fn parent_probe(&self, device_provider: &DeviceProvider) -> Vec<Device>;
fn parent_start(&self, device_provider: &DeviceProvider) -> Result<(), LoggableError>;
fn parent_stop(&self, device_provider: &DeviceProvider);
}
impl<T: DeviceProviderImpl + ObjectImpl> DeviceProviderImplExt for T {
fn parent_probe(&self, device_provider: &DeviceProvider) -> Vec<Device> {
unsafe {
let data = self.get_type_data();
let parent_class =
data.as_ref().get_parent_class() as *mut gst_sys::GstDeviceProviderClass;
if let Some(f) = (*parent_class).probe {
FromGlibPtrContainer::from_glib_full(f(device_provider.to_glib_none().0))
} else {
Vec::new()
}
}
}
fn parent_start(&self, device_provider: &DeviceProvider) -> Result<(), LoggableError> {
unsafe {
let data = self.get_type_data();
let parent_class =
data.as_ref().get_parent_class() as *mut gst_sys::GstDeviceProviderClass;
let f = (*parent_class).start.ok_or_else(|| {
gst_loggable_error!(::CAT_RUST, "Parent function `start` is not defined")
})?;
gst_result_from_gboolean!(
f(device_provider.to_glib_none().0),
::CAT_RUST,
"Failed to start the device provider using the parent function"
)
}
}
fn parent_stop(&self, device_provider: &DeviceProvider) {
unsafe {
let data = self.get_type_data();
let parent_class =
data.as_ref().get_parent_class() as *mut gst_sys::GstDeviceProviderClass;
if let Some(f) = (*parent_class).stop {
f(device_provider.to_glib_none().0);
}
}
}
}
pub unsafe trait DeviceProviderClassSubclassExt: Sized + 'static {
fn set_metadata(
&mut self,
long_name: &str,
classification: &str,
description: &str,
author: &str,
) {
unsafe {
gst_sys::gst_device_provider_class_set_metadata(
self as *mut Self as *mut gst_sys::GstDeviceProviderClass,
long_name.to_glib_none().0,
classification.to_glib_none().0,
description.to_glib_none().0,
author.to_glib_none().0,
);
}
}
fn add_metadata(&mut self, key: &str, value: &str) {
unsafe {
gst_sys::gst_device_provider_class_add_metadata(
self as *mut Self as *mut gst_sys::GstDeviceProviderClass,
key.to_glib_none().0,
value.to_glib_none().0,
);
}
}
}
unsafe impl DeviceProviderClassSubclassExt for DeviceProviderClass {}
unsafe impl<T: ObjectSubclass + DeviceProviderImpl> IsSubclassable<T> for DeviceProviderClass {
fn override_vfuncs(&mut self) {
<glib::ObjectClass as IsSubclassable<T>>::override_vfuncs(self);
unsafe {
let klass = &mut *(self as *mut Self as *mut gst_sys::GstDeviceProviderClass);
klass.probe = Some(device_provider_probe::<T>);
klass.start = Some(device_provider_start::<T>);
klass.stop = Some(device_provider_stop::<T>);
}
}
}
unsafe extern "C" fn device_provider_probe<T: ObjectSubclass>(
ptr: *mut gst_sys::GstDeviceProvider,
) -> *mut glib_sys::GList
where
T: DeviceProviderImpl,
{
glib_floating_reference_guard!(ptr);
let instance = &*(ptr as *mut T::Instance);
let imp = instance.get_impl();
let wrap: DeviceProvider = from_glib_borrow(ptr);
imp.probe(&wrap).to_glib_full()
}
unsafe extern "C" fn device_provider_start<T: ObjectSubclass>(
ptr: *mut gst_sys::GstDeviceProvider,
) -> glib_sys::gboolean
where
T: DeviceProviderImpl,
{
glib_floating_reference_guard!(ptr);
let instance = &*(ptr as *mut T::Instance);
let imp = instance.get_impl();
let wrap: DeviceProvider = from_glib_borrow(ptr);
match imp.start(&wrap) {
Ok(()) => true,
Err(err) => {
err.log_with_object(&wrap);
false
}
}
.to_glib()
}
unsafe extern "C" fn device_provider_stop<T: ObjectSubclass>(ptr: *mut gst_sys::GstDeviceProvider)
where
T: DeviceProviderImpl,
{
glib_floating_reference_guard!(ptr);
let instance = &*(ptr as *mut T::Instance);
let imp = instance.get_impl();
let wrap: DeviceProvider = from_glib_borrow(ptr);
imp.stop(&wrap);
}

View file

@ -29,6 +29,7 @@ pub mod pad;
pub mod pipeline;
pub mod device;
pub mod device_provider;
pub mod uri_handler;
@ -36,6 +37,9 @@ pub mod prelude {
pub use super::bin::{BinImpl, BinImplExt};
pub use super::child_proxy::ChildProxyImpl;
pub use super::device::{DeviceImpl, DeviceImplExt};
pub use super::device_provider::{
DeviceProviderClassSubclassExt, DeviceProviderImpl, DeviceProviderImplExt,
};
pub use super::element::{ElementClassSubclassExt, ElementImpl, ElementImplExt};
pub use super::ghost_pad::GhostPadImpl;
pub use super::pad::{PadImpl, PadImplExt};