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::{Device, Element, LoggableError, ffi};
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    unsafe {
85        let instance = &*(ptr as *mut T::Instance);
86        let imp = instance.imp();
87
88        match imp.create_element(
89            Option::<glib::GString>::from_glib_borrow(name)
90                .as_ref()
91                .as_ref()
92                .map(|s| s.as_str()),
93        ) {
94            Ok(element) => {
95                // The reference we're going to return, the initial reference is going to
96                // be dropped here now
97                let element = element.into_glib_ptr();
98                // See https://gitlab.freedesktop.org/gstreamer/gstreamer/issues/444
99                glib::gobject_ffi::g_object_force_floating(
100                    element as *mut glib::gobject_ffi::GObject,
101                );
102                element
103            }
104            Err(err) => {
105                err.log_with_imp(imp);
106                ptr::null_mut()
107            }
108        }
109    }
110}
111
112unsafe extern "C" fn device_reconfigure_element<T: DeviceImpl>(
113    ptr: *mut ffi::GstDevice,
114    element: *mut ffi::GstElement,
115) -> glib::ffi::gboolean {
116    unsafe {
117        let instance = &*(ptr as *mut T::Instance);
118        let imp = instance.imp();
119
120        match imp.reconfigure_element(&from_glib_borrow(element)) {
121            Ok(()) => true,
122            Err(err) => {
123                err.log_with_imp(imp);
124                false
125            }
126        }
127        .into_glib()
128    }
129}
gstreamer/subclass/device.rs

gstreamer/subclass/
device.rs
