gstreamer-rs/gstreamer/src/subclass/device.rs

129 lines
4.2 KiB
Rust

// Take a look at the license at the top of the repository in the LICENSE file.
use std::ptr;
use glib::{prelude::*, subclass::prelude::*, translate::*};
use super::prelude::*;
use crate::{Device, Element, LoggableError};
pub trait DeviceImpl: DeviceImplExt + GstObjectImpl + Send + Sync {
fn create_element(&self, name: Option<&str>) -> Result<Element, LoggableError> {
self.parent_create_element(name)
}
fn reconfigure_element(&self, element: &Element) -> Result<(), LoggableError> {
self.parent_reconfigure_element(element)
}
}
mod sealed {
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();
let parent_class = data.as_ref().parent_class() as *mut ffi::GstDeviceClass;
if let Some(f) = (*parent_class).create_element {
let ptr = f(
self.obj().unsafe_cast_ref::<Device>().to_glib_none().0,
name.to_glib_none().0,
);
// Don't steal floating reference here but pass it further to the caller
Option::<_>::from_glib_full(ptr).ok_or_else(|| {
loggable_error!(
crate::CAT_RUST,
"Failed to create element using the parent function"
)
})
} else {
Err(loggable_error!(
crate::CAT_RUST,
"Parent function `create_element` is not defined"
))
}
}
}
fn parent_reconfigure_element(&self, element: &Element) -> Result<(), LoggableError> {
unsafe {
let data = Self::type_data();
let parent_class = data.as_ref().parent_class() as *mut ffi::GstDeviceClass;
let f = (*parent_class).reconfigure_element.ok_or_else(|| {
loggable_error!(
crate::CAT_RUST,
"Parent function `reconfigure_element` is not defined"
)
})?;
result_from_gboolean!(
f(
self.obj().unsafe_cast_ref::<Device>().to_glib_none().0,
element.to_glib_none().0
),
crate::CAT_RUST,
"Failed to reconfigure the element using the parent function"
)
}
}
}
impl<T: DeviceImpl> DeviceImplExt for T {}
unsafe impl<T: DeviceImpl> IsSubclassable<T> for Device {
fn class_init(klass: &mut glib::Class<Self>) {
Self::parent_class_init::<T>(klass);
let klass = klass.as_mut();
klass.create_element = Some(device_create_element::<T>);
klass.reconfigure_element = Some(device_reconfigure_element::<T>);
}
}
unsafe extern "C" fn device_create_element<T: DeviceImpl>(
ptr: *mut ffi::GstDevice,
name: *const libc::c_char,
) -> *mut ffi::GstElement {
let instance = &*(ptr as *mut T::Instance);
let imp = instance.imp();
match imp.create_element(
Option::<glib::GString>::from_glib_borrow(name)
.as_ref()
.as_ref()
.map(|s| s.as_str()),
) {
Ok(element) => {
// The reference we're going to return, the initial reference is going to
// be dropped here now
let element = element.into_glib_ptr();
// See https://gitlab.freedesktop.org/gstreamer/gstreamer/issues/444
glib::gobject_ffi::g_object_force_floating(element as *mut glib::gobject_ffi::GObject);
element
}
Err(err) => {
err.log_with_imp(imp);
ptr::null_mut()
}
}
}
unsafe extern "C" fn device_reconfigure_element<T: DeviceImpl>(
ptr: *mut ffi::GstDevice,
element: *mut ffi::GstElement,
) -> glib::ffi::gboolean {
let instance = &*(ptr as *mut T::Instance);
let imp = instance.imp();
match imp.reconfigure_element(&from_glib_borrow(element)) {
Ok(()) => true,
Err(err) => {
err.log_with_imp(imp);
false
}
}
.into_glib()
}