#[repr(C)]pub struct VNStatefulRequest { /* private fields */ }
VNRequest
and VNStatefulRequest
only.Expand description
A request that builds evidence over time by being reused on multiple images.
The request requires the use of CMSampleBuffers with timestamps as input; otherwise, a VNErrorTimeStampNotFound error will be returned. VNStatefulRequest is used as a base class of other requests, so no objects of this class should be created directly.
See also Apple’s documentation
Implementations§
Source§impl VNStatefulRequest
impl VNStatefulRequest
pub unsafe fn new() -> Retained<Self>
pub unsafe fn init(this: Allocated<Self>) -> Retained<Self>
pub unsafe fn initWithCompletionHandler( this: Allocated<Self>, completion_handler: VNRequestCompletionHandler, ) -> Retained<Self>
block2
only.Sourcepub unsafe fn initWithFrameAnalysisSpacing_completionHandler(
this: Allocated<Self>,
frame_analysis_spacing: CMTime,
completion_handler: VNRequestCompletionHandler,
) -> Retained<Self>
Available on crate features block2
and objc2-core-media
only.
pub unsafe fn initWithFrameAnalysisSpacing_completionHandler( this: Allocated<Self>, frame_analysis_spacing: CMTime, completion_handler: VNRequestCompletionHandler, ) -> Retained<Self>
block2
and objc2-core-media
only.Create a new video-based stateful request.
Parameter frameAnalysisSpacing
: The reciprocal of maximum rate at which buffers will be processed. The request will not process buffers that fall within the frameAnalysisSpacing after it has performed the analysis. The analysis is not done by wall time but by analysis of of the time stamps of the samplebuffers being processed.
Parameter completionHandler
: The block to be invoked after the request has completed its processing. The completion handler gets executed on the same dispatch queue as the request being executed.
Sourcepub unsafe fn minimumLatencyFrameCount(&self) -> NSInteger
pub unsafe fn minimumLatencyFrameCount(&self) -> NSInteger
The minimum number of frames that the request has to process on before reporting back any observation. This information is provided by the request once initialized with its required paramters.
Video based request often need a minimum number of frames before they can report back any observation. An example would be that a movement detection requires at least 5 frames to be detected. The minimumLatencyFrameCount for that request would report 5 and only after 5 frames have been processed an observation would be returned in the results. This latency is indicative of how responsive a request is in respect to the incoming data.
Sourcepub unsafe fn frameAnalysisSpacing(&self) -> CMTime
Available on crate feature objc2-core-media
only.
pub unsafe fn frameAnalysisSpacing(&self) -> CMTime
objc2-core-media
only.The reciprocal of maximum rate at which buffers will be processed.
The request will not process buffers that fall within the frameAnalysisSpacing
after it has performed the analysis. The analysis is not done by wall time but by analysis of of the time stamps of the samplebuffers being processed.
Methods from Deref<Target = VNImageBasedRequest>§
Sourcepub unsafe fn regionOfInterest(&self) -> CGRect
Available on crate feature objc2-core-foundation
only.
pub unsafe fn regionOfInterest(&self) -> CGRect
objc2-core-foundation
only.The region of the image in which the request will be performed. The rectangle is normalized to the dimensions of the image being processed and has its origin specified relative to the image’s lower-left corner.
The default value for this property is { { 0, 0 }, { 1, 1 } }. Setting this property to a rectangle that is outside of the normalized coordinate space will be accepted but result in the request failing to be performed.
Sourcepub unsafe fn setRegionOfInterest(&self, region_of_interest: CGRect)
Available on crate feature objc2-core-foundation
only.
pub unsafe fn setRegionOfInterest(&self, region_of_interest: CGRect)
objc2-core-foundation
only.Setter for regionOfInterest
.
Methods from Deref<Target = VNRequest>§
Sourcepub unsafe fn preferBackgroundProcessing(&self) -> bool
pub unsafe fn preferBackgroundProcessing(&self) -> bool
A hint used to minimize the resource burden of the request. Memory footprint, processing footprint and/or CPU/GPU contention will be reduced (depending on the request), at the potential cost of longer execution time. This can help, for example, with ensuring UI updates and rendering are not getting blocked by Vision processing.
Sourcepub unsafe fn setPreferBackgroundProcessing(
&self,
prefer_background_processing: bool,
)
pub unsafe fn setPreferBackgroundProcessing( &self, prefer_background_processing: bool, )
Setter for preferBackgroundProcessing
.
Sourcepub unsafe fn usesCPUOnly(&self) -> bool
👎Deprecated
pub unsafe fn usesCPUOnly(&self) -> bool
This property, if set to YES, signifies that the request should be performed exclusively on the CPU and not on the GPU. The default value is NO, which signifies that the request is free to leverage the GPU to accelerate any work the request may require.
Sourcepub unsafe fn setUsesCPUOnly(&self, uses_cpu_only: bool)
👎Deprecated
pub unsafe fn setUsesCPUOnly(&self, uses_cpu_only: bool)
Setter for usesCPUOnly
.
Sourcepub unsafe fn results(&self) -> Option<Retained<NSArray<VNObservation>>>
Available on crate feature VNObservation
only.
pub unsafe fn results(&self) -> Option<Retained<NSArray<VNObservation>>>
VNObservation
only.The collection of VNObservations generated by the processing of the request.
The only valid time to access this property is after the request has been processed by a request handler. If the request failed, this property will be nil; otherwise, it will be an array of zero or more VNObservation subclasses specific to the VNRequest subclass.
Sourcepub unsafe fn completionHandler(&self) -> VNRequestCompletionHandler
Available on crate feature block2
only.
pub unsafe fn completionHandler(&self) -> VNRequestCompletionHandler
block2
only.The completion handler block that will be invoked after the request has completed processing.
Sourcepub unsafe fn revision(&self) -> NSUInteger
pub unsafe fn revision(&self) -> NSUInteger
The specific algorithm or implementation revision that is to be used to perform the request.
Sourcepub unsafe fn setRevision(&self, revision: NSUInteger)
pub unsafe fn setRevision(&self, revision: NSUInteger)
Setter for revision
.
Sourcepub unsafe fn cancel(&self)
pub unsafe fn cancel(&self)
Tries to abort the request as soon as possible. Results will be nil. The completionHandler (if present) will be called with an error of VNErrorRequestCancelled.
Sourcepub unsafe fn supportedComputeStageDevicesAndReturnError(
&self,
) -> Result<Retained<NSDictionary<VNComputeStage, NSArray<ProtocolObject<dyn MLComputeDeviceProtocol>>>>, Retained<NSError>>
Available on crate features VNTypes
and objc2-core-ml
only.
pub unsafe fn supportedComputeStageDevicesAndReturnError( &self, ) -> Result<Retained<NSDictionary<VNComputeStage, NSArray<ProtocolObject<dyn MLComputeDeviceProtocol>>>>, Retained<NSError>>
VNTypes
and objc2-core-ml
only.Obtain the collection of compute device per stage that are supported by the request.
This method’s result is based on the current state of configuration of the target request at the time of the call.
Parameter error
: The address of a variable that will be populated with the error that describes the failure. If the caller does not require this information, NULL can be passed.
Returns: A dictionary of per-stage supported compute devices, or nil
if an error occurs.
Sourcepub unsafe fn computeDeviceForComputeStage(
&self,
compute_stage: &VNComputeStage,
) -> Option<Retained<ProtocolObject<dyn MLComputeDeviceProtocol>>>
Available on crate features VNTypes
and objc2-core-ml
only.
pub unsafe fn computeDeviceForComputeStage( &self, compute_stage: &VNComputeStage, ) -> Option<Retained<ProtocolObject<dyn MLComputeDeviceProtocol>>>
VNTypes
and objc2-core-ml
only.Determine what the currently configured compute device is for a specific compute stage.
Parameter computeStage
: The compute stage to be introspected.
Returns: The currently assigned compute device, or nil
if there is no explicit assignment.
Sourcepub unsafe fn setComputeDevice_forComputeStage(
&self,
compute_device: Option<&ProtocolObject<dyn MLComputeDeviceProtocol>>,
compute_stage: &VNComputeStage,
)
Available on crate features VNTypes
and objc2-core-ml
only.
pub unsafe fn setComputeDevice_forComputeStage( &self, compute_device: Option<&ProtocolObject<dyn MLComputeDeviceProtocol>>, compute_stage: &VNComputeStage, )
VNTypes
and objc2-core-ml
only.Assign a specific compute device for a compute stage.
It is important to note that any compute device can be configured for a given compute stage. Only when the request is performed is the validity of the (compute device / compute stage) assignments checked. Valid compute devices for a request’s compute stages can be obtained via -supportedComputeStageDevicesAndReturnError:
.
Parameter computeDevice
: The compute device to assign to the compute stage. Passing nil for this parameter will remove any explicit compute device assignment, allowing Vision to select which device to use.
Parameter computeStage
: The compute stage being configured.
Methods from Deref<Target = NSObject>§
Sourcepub fn doesNotRecognizeSelector(&self, sel: Sel) -> !
pub fn doesNotRecognizeSelector(&self, sel: Sel) -> !
Handle messages the object doesn’t recognize.
See Apple’s documentation for details.
Methods from Deref<Target = AnyObject>§
Sourcepub fn class(&self) -> &'static AnyClass
pub fn class(&self) -> &'static AnyClass
Dynamically find the class of this object.
§Panics
May panic if the object is invalid (which may be the case for objects
returned from unavailable init
/new
methods).
§Example
Check that an instance of NSObject
has the precise class NSObject
.
use objc2::ClassType;
use objc2::runtime::NSObject;
let obj = NSObject::new();
assert_eq!(obj.class(), NSObject::class());
Sourcepub unsafe fn get_ivar<T>(&self, name: &str) -> &Twhere
T: Encode,
👎Deprecated: this is difficult to use correctly, use Ivar::load
instead.
pub unsafe fn get_ivar<T>(&self, name: &str) -> &Twhere
T: Encode,
Ivar::load
instead.Use Ivar::load
instead.
§Safety
The object must have an instance variable with the given name, and it
must be of type T
.
See Ivar::load_ptr
for details surrounding this.
Sourcepub fn downcast_ref<T>(&self) -> Option<&T>where
T: DowncastTarget,
pub fn downcast_ref<T>(&self) -> Option<&T>where
T: DowncastTarget,
Attempt to downcast the object to a class of type T
.
This is the reference-variant. Use Retained::downcast
if you want
to convert a retained object to another type.
§Mutable classes
Some classes have immutable and mutable variants, such as NSString
and NSMutableString
.
When some Objective-C API signature says it gives you an immutable class, it generally expects you to not mutate that, even though it may technically be mutable “under the hood”.
So using this method to convert a NSString
to a NSMutableString
,
while not unsound, is generally frowned upon unless you created the
string yourself, or the API explicitly documents the string to be
mutable.
See Apple’s documentation on mutability and on
isKindOfClass:
for more details.
§Generic classes
Objective-C generics are called “lightweight generics”, and that’s because they aren’t exposed in the runtime. This makes it impossible to safely downcast to generic collections, so this is disallowed by this method.
You can, however, safely downcast to generic collections where all the
type-parameters are AnyObject
.
§Panics
This works internally by calling isKindOfClass:
. That means that the
object must have the instance method of that name, and an exception
will be thrown (if CoreFoundation is linked) or the process will abort
if that is not the case. In the vast majority of cases, you don’t need
to worry about this, since both root objects NSObject
and
NSProxy
implement this method.
§Examples
Cast an NSString
back and forth from NSObject
.
use objc2::rc::Retained;
use objc2_foundation::{NSObject, NSString};
let obj: Retained<NSObject> = NSString::new().into_super();
let string = obj.downcast_ref::<NSString>().unwrap();
// Or with `downcast`, if we do not need the object afterwards
let string = obj.downcast::<NSString>().unwrap();
Try (and fail) to cast an NSObject
to an NSString
.
use objc2_foundation::{NSObject, NSString};
let obj = NSObject::new();
assert!(obj.downcast_ref::<NSString>().is_none());
Try to cast to an array of strings.
use objc2_foundation::{NSArray, NSObject, NSString};
let arr = NSArray::from_retained_slice(&[NSObject::new()]);
// This is invalid and doesn't type check.
let arr = arr.downcast_ref::<NSArray<NSString>>();
This fails to compile, since it would require enumerating over the array to ensure that each element is of the desired type, which is a performance pitfall.
Downcast when processing each element instead.
use objc2_foundation::{NSArray, NSObject, NSString};
let arr = NSArray::from_retained_slice(&[NSObject::new()]);
for elem in arr {
if let Some(data) = elem.downcast_ref::<NSString>() {
// handle `data`
}
}
Trait Implementations§
Source§impl AsRef<AnyObject> for VNStatefulRequest
impl AsRef<AnyObject> for VNStatefulRequest
Source§impl AsRef<NSObject> for VNStatefulRequest
impl AsRef<NSObject> for VNStatefulRequest
Source§impl AsRef<VNImageBasedRequest> for VNStatefulRequest
impl AsRef<VNImageBasedRequest> for VNStatefulRequest
Source§fn as_ref(&self) -> &VNImageBasedRequest
fn as_ref(&self) -> &VNImageBasedRequest
Source§impl AsRef<VNRequest> for VNStatefulRequest
impl AsRef<VNRequest> for VNStatefulRequest
Source§impl AsRef<VNStatefulRequest> for VNDetectHumanBodyPose3DRequest
Available on crate feature VNDetectHumanBodyPose3DRequest
only.
impl AsRef<VNStatefulRequest> for VNDetectHumanBodyPose3DRequest
VNDetectHumanBodyPose3DRequest
only.Source§fn as_ref(&self) -> &VNStatefulRequest
fn as_ref(&self) -> &VNStatefulRequest
Source§impl AsRef<VNStatefulRequest> for VNDetectTrajectoriesRequest
Available on crate feature VNDetectTrajectoriesRequest
only.
impl AsRef<VNStatefulRequest> for VNDetectTrajectoriesRequest
VNDetectTrajectoriesRequest
only.Source§fn as_ref(&self) -> &VNStatefulRequest
fn as_ref(&self) -> &VNStatefulRequest
Source§impl AsRef<VNStatefulRequest> for VNGeneratePersonSegmentationRequest
Available on crate feature VNGeneratePersonSegmentationRequest
only.
impl AsRef<VNStatefulRequest> for VNGeneratePersonSegmentationRequest
VNGeneratePersonSegmentationRequest
only.Source§fn as_ref(&self) -> &VNStatefulRequest
fn as_ref(&self) -> &VNStatefulRequest
Source§impl AsRef<VNStatefulRequest> for VNStatefulRequest
impl AsRef<VNStatefulRequest> for VNStatefulRequest
Source§impl AsRef<VNStatefulRequest> for VNTrackHomographicImageRegistrationRequest
Available on crate feature VNTrackHomographicImageRegistrationRequest
only.
impl AsRef<VNStatefulRequest> for VNTrackHomographicImageRegistrationRequest
VNTrackHomographicImageRegistrationRequest
only.Source§fn as_ref(&self) -> &VNStatefulRequest
fn as_ref(&self) -> &VNStatefulRequest
Source§impl AsRef<VNStatefulRequest> for VNTrackOpticalFlowRequest
Available on crate feature VNTrackOpticalFlowRequest
only.
impl AsRef<VNStatefulRequest> for VNTrackOpticalFlowRequest
VNTrackOpticalFlowRequest
only.Source§fn as_ref(&self) -> &VNStatefulRequest
fn as_ref(&self) -> &VNStatefulRequest
Source§impl AsRef<VNStatefulRequest> for VNTrackTranslationalImageRegistrationRequest
Available on crate feature VNTrackTranslationalImageRegistrationRequest
only.
impl AsRef<VNStatefulRequest> for VNTrackTranslationalImageRegistrationRequest
VNTrackTranslationalImageRegistrationRequest
only.Source§fn as_ref(&self) -> &VNStatefulRequest
fn as_ref(&self) -> &VNStatefulRequest
Source§impl Borrow<AnyObject> for VNStatefulRequest
impl Borrow<AnyObject> for VNStatefulRequest
Source§impl Borrow<NSObject> for VNStatefulRequest
impl Borrow<NSObject> for VNStatefulRequest
Source§impl Borrow<VNImageBasedRequest> for VNStatefulRequest
impl Borrow<VNImageBasedRequest> for VNStatefulRequest
Source§fn borrow(&self) -> &VNImageBasedRequest
fn borrow(&self) -> &VNImageBasedRequest
Source§impl Borrow<VNRequest> for VNStatefulRequest
impl Borrow<VNRequest> for VNStatefulRequest
Source§impl Borrow<VNStatefulRequest> for VNDetectHumanBodyPose3DRequest
Available on crate feature VNDetectHumanBodyPose3DRequest
only.
impl Borrow<VNStatefulRequest> for VNDetectHumanBodyPose3DRequest
VNDetectHumanBodyPose3DRequest
only.Source§fn borrow(&self) -> &VNStatefulRequest
fn borrow(&self) -> &VNStatefulRequest
Source§impl Borrow<VNStatefulRequest> for VNDetectTrajectoriesRequest
Available on crate feature VNDetectTrajectoriesRequest
only.
impl Borrow<VNStatefulRequest> for VNDetectTrajectoriesRequest
VNDetectTrajectoriesRequest
only.Source§fn borrow(&self) -> &VNStatefulRequest
fn borrow(&self) -> &VNStatefulRequest
Source§impl Borrow<VNStatefulRequest> for VNGeneratePersonSegmentationRequest
Available on crate feature VNGeneratePersonSegmentationRequest
only.
impl Borrow<VNStatefulRequest> for VNGeneratePersonSegmentationRequest
VNGeneratePersonSegmentationRequest
only.Source§fn borrow(&self) -> &VNStatefulRequest
fn borrow(&self) -> &VNStatefulRequest
Source§impl Borrow<VNStatefulRequest> for VNTrackHomographicImageRegistrationRequest
Available on crate feature VNTrackHomographicImageRegistrationRequest
only.
impl Borrow<VNStatefulRequest> for VNTrackHomographicImageRegistrationRequest
VNTrackHomographicImageRegistrationRequest
only.Source§fn borrow(&self) -> &VNStatefulRequest
fn borrow(&self) -> &VNStatefulRequest
Source§impl Borrow<VNStatefulRequest> for VNTrackOpticalFlowRequest
Available on crate feature VNTrackOpticalFlowRequest
only.
impl Borrow<VNStatefulRequest> for VNTrackOpticalFlowRequest
VNTrackOpticalFlowRequest
only.Source§fn borrow(&self) -> &VNStatefulRequest
fn borrow(&self) -> &VNStatefulRequest
Source§impl Borrow<VNStatefulRequest> for VNTrackTranslationalImageRegistrationRequest
Available on crate feature VNTrackTranslationalImageRegistrationRequest
only.
impl Borrow<VNStatefulRequest> for VNTrackTranslationalImageRegistrationRequest
VNTrackTranslationalImageRegistrationRequest
only.Source§fn borrow(&self) -> &VNStatefulRequest
fn borrow(&self) -> &VNStatefulRequest
Source§impl ClassType for VNStatefulRequest
impl ClassType for VNStatefulRequest
Source§const NAME: &'static str = "VNStatefulRequest"
const NAME: &'static str = "VNStatefulRequest"
Source§type Super = VNImageBasedRequest
type Super = VNImageBasedRequest
Source§type ThreadKind = <<VNStatefulRequest as ClassType>::Super as ClassType>::ThreadKind
type ThreadKind = <<VNStatefulRequest as ClassType>::Super as ClassType>::ThreadKind
Source§impl CopyingHelper for VNStatefulRequest
impl CopyingHelper for VNStatefulRequest
Source§type Result = VNStatefulRequest
type Result = VNStatefulRequest
Self
if the type has no
immutable counterpart. Read moreSource§impl Debug for VNStatefulRequest
impl Debug for VNStatefulRequest
Source§impl Deref for VNStatefulRequest
impl Deref for VNStatefulRequest
Source§impl Hash for VNStatefulRequest
impl Hash for VNStatefulRequest
Source§impl Message for VNStatefulRequest
impl Message for VNStatefulRequest
Source§impl NSCopying for VNStatefulRequest
impl NSCopying for VNStatefulRequest
Source§impl NSObjectProtocol for VNStatefulRequest
impl NSObjectProtocol for VNStatefulRequest
Source§fn isEqual(&self, other: Option<&AnyObject>) -> bool
fn isEqual(&self, other: Option<&AnyObject>) -> bool
Source§fn hash(&self) -> usize
fn hash(&self) -> usize
Source§fn isKindOfClass(&self, cls: &AnyClass) -> bool
fn isKindOfClass(&self, cls: &AnyClass) -> bool
Source§fn is_kind_of<T>(&self) -> bool
fn is_kind_of<T>(&self) -> bool
isKindOfClass
directly, or cast your objects with AnyObject::downcast_ref