gstreamer/subclass/
device.rs

1// Take a look at the license at the top of the repository in the LICENSE file.
2
3use std::ptr;
4
5use glib::{prelude::*, subclass::prelude::*, translate::*};
6
7use super::prelude::*;
8use crate::{ffi, Device, Element, LoggableError};
9
10pub trait DeviceImpl: GstObjectImpl + ObjectSubclass<Type: IsA<Device>> {
11    fn create_element(&self, name: Option<&str>) -> Result<Element, LoggableError> {
12        self.parent_create_element(name)
13    }
14
15    fn reconfigure_element(&self, element: &Element) -> Result<(), LoggableError> {
16        self.parent_reconfigure_element(element)
17    }
18}
19
20pub trait DeviceImplExt: DeviceImpl {
21    fn parent_create_element(&self, name: Option<&str>) -> Result<Element, LoggableError> {
22        unsafe {
23            let data = Self::type_data();
24            let parent_class = data.as_ref().parent_class() as *mut ffi::GstDeviceClass;
25            if let Some(f) = (*parent_class).create_element {
26                let ptr = f(
27                    self.obj().unsafe_cast_ref::<Device>().to_glib_none().0,
28                    name.to_glib_none().0,
29                );
30
31                // Don't steal floating reference here but pass it further to the caller
32                Option::<_>::from_glib_full(ptr).ok_or_else(|| {
33                    loggable_error!(
34                        crate::CAT_RUST,
35                        "Failed to create element using the parent function"
36                    )
37                })
38            } else {
39                Err(loggable_error!(
40                    crate::CAT_RUST,
41                    "Parent function `create_element` is not defined"
42                ))
43            }
44        }
45    }
46
47    fn parent_reconfigure_element(&self, element: &Element) -> Result<(), LoggableError> {
48        unsafe {
49            let data = Self::type_data();
50            let parent_class = data.as_ref().parent_class() as *mut ffi::GstDeviceClass;
51            let f = (*parent_class).reconfigure_element.ok_or_else(|| {
52                loggable_error!(
53                    crate::CAT_RUST,
54                    "Parent function `reconfigure_element` is not defined"
55                )
56            })?;
57            result_from_gboolean!(
58                f(
59                    self.obj().unsafe_cast_ref::<Device>().to_glib_none().0,
60                    element.to_glib_none().0
61                ),
62                crate::CAT_RUST,
63                "Failed to reconfigure the element using the parent function"
64            )
65        }
66    }
67}
68
69impl<T: DeviceImpl> DeviceImplExt for T {}
70
71unsafe impl<T: DeviceImpl> IsSubclassable<T> for Device {
72    fn class_init(klass: &mut glib::Class<Self>) {
73        Self::parent_class_init::<T>(klass);
74        let klass = klass.as_mut();
75        klass.create_element = Some(device_create_element::<T>);
76        klass.reconfigure_element = Some(device_reconfigure_element::<T>);
77    }
78}
79
80unsafe extern "C" fn device_create_element<T: DeviceImpl>(
81    ptr: *mut ffi::GstDevice,
82    name: *const libc::c_char,
83) -> *mut ffi::GstElement {
84    let instance = &*(ptr as *mut T::Instance);
85    let imp = instance.imp();
86
87    match imp.create_element(
88        Option::<glib::GString>::from_glib_borrow(name)
89            .as_ref()
90            .as_ref()
91            .map(|s| s.as_str()),
92    ) {
93        Ok(element) => {
94            // The reference we're going to return, the initial reference is going to
95            // be dropped here now
96            let element = element.into_glib_ptr();
97            // See https://gitlab.freedesktop.org/gstreamer/gstreamer/issues/444
98            glib::gobject_ffi::g_object_force_floating(element as *mut glib::gobject_ffi::GObject);
99            element
100        }
101        Err(err) => {
102            err.log_with_imp(imp);
103            ptr::null_mut()
104        }
105    }
106}
107
108unsafe extern "C" fn device_reconfigure_element<T: DeviceImpl>(
109    ptr: *mut ffi::GstDevice,
110    element: *mut ffi::GstElement,
111) -> glib::ffi::gboolean {
112    let instance = &*(ptr as *mut T::Instance);
113    let imp = instance.imp();
114
115    match imp.reconfigure_element(&from_glib_borrow(element)) {
116        Ok(()) => true,
117        Err(err) => {
118            err.log_with_imp(imp);
119            false
120        }
121    }
122    .into_glib()
123}
gstreamer/subclass/device.rs

gstreamer/subclass/
device.rs
