Trait gstreamer::subclass::prelude::DeviceProviderImpl
source · pub trait DeviceProviderImpl: DeviceProviderImplExt + GstObjectImpl + Send + Sync {
// Provided methods
fn metadata() -> Option<&'static DeviceProviderMetadata> { ... }
fn probe(&self) -> Vec<Device> { ... }
fn start(&self) -> Result<(), LoggableError> { ... }
fn stop(&self) { ... }
}
Provided Methods§
fn metadata() -> Option<&'static DeviceProviderMetadata>
sourcefn probe(&self) -> Vec<Device>
fn probe(&self) -> Vec<Device>
Returns a list of devices that are currently available. This should never block. The devices should not have a parent and should be floating.
sourcefn start(&self) -> Result<(), LoggableError>
fn start(&self) -> Result<(), LoggableError>
Starts providering the devices. This will cause GST_MESSAGE_DEVICE_ADDED
and GST_MESSAGE_DEVICE_REMOVED
messages to be posted on the provider’s bus
when devices are added or removed from the system.
Since the DeviceProvider
is a singleton,
DeviceProviderExt::start()
may already have been called by another
user of the object, DeviceProviderExt::stop()
needs to be called the same
number of times.
After this function has been called, DeviceProviderExtManual::devices()
will
return the same objects that have been received from the
GST_MESSAGE_DEVICE_ADDED
messages and will no longer probe.
§Returns
true
if the device providering could be started
sourcefn stop(&self)
fn stop(&self)
Decreases the use-count by one. If the use count reaches zero, this
DeviceProvider
will stop providering the devices. This needs to be
called the same number of times that DeviceProviderExt::start()
was called.