Struct CIFaceFeature 

pub struct CIFaceFeature { /* private fields */ }

Available on crate feature CIFeature only.

Information about a face detected in a still or video image.

Note: In macOS 10.13, iOS 11, and tvOS 11 or later, the Vision framework replaces this class for identifying and analyzing image features. See VNDetectFaceRectanglesRequest. See <doc ://com.apple.documentation/documentation/vision/vndetectfacerectanglesrequest>)

The properties of a CIFaceFeature object provide information about the face’s eyes and mouth. A face object in a video can also have properties that track its location over time, tracking ID and frame count.

See also Apple’s documentation

Implementations

impl CIFaceFeature

pub unsafe fn bounds(&self) -> CGRect

Available on crate feature objc2-core-foundation only.

A rectangle indicating the position and extent of the face feature in image coordinates.

pub unsafe fn hasLeftEyePosition(&self) -> bool

A Boolean value that indicates whether the detector found the face’s left eye.

pub unsafe fn leftEyePosition(&self) -> CGPoint

Available on crate feature objc2-core-foundation only.

The image coordinate of the center of the left eye.

Note: The left eye is on the left side of the face from the observer’s perspective. It is not the left eye from the subject’s perspective.

pub unsafe fn hasRightEyePosition(&self) -> bool

A Boolean value that indicates whether the detector found the face’s right eye.

pub unsafe fn rightEyePosition(&self) -> CGPoint

Available on crate feature objc2-core-foundation only.

The image coordinate of the center of the right eye.

Note: The right eye is on the right side of the face from the observer’s perspective. It is not the right eye from the subject’s perspective.

pub unsafe fn hasMouthPosition(&self) -> bool

A Boolean value that indicates whether the detector found the face’s mouth.

pub unsafe fn mouthPosition(&self) -> CGPoint

Available on crate feature objc2-core-foundation only.

The image coordinate of the center of the mouth.

pub unsafe fn hasTrackingID(&self) -> bool

A Boolean value that indicates whether the face object has a tracking ID.

pub unsafe fn trackingID(&self) -> c_int

The tracking identifier of the face object.

Core Image provides a tracking identifier for faces it detects in a video stream, which you can use to identify when a CIFaceFeature objects detected in one video frame is the same face detected in a previous video frame.

This identifier persists only as long as a face is in the frame and is not associated with a specific face. In other words, if a face moves out of the video frame and comes back into the frame later, another ID is assigned. (Core Image detects faces, but does not recognize specific faces.)

pub unsafe fn hasTrackingFrameCount(&self) -> bool

A Boolean value that indicates the face object has a tracking frame count.

pub unsafe fn trackingFrameCount(&self) -> c_int

The tracking frame count of the face.

pub unsafe fn hasFaceAngle(&self) -> bool

A Boolean value that indicates whether information about face rotation is available.

pub unsafe fn faceAngle(&self) -> c_float

The rotation of the face.

Rotation is measured counterclockwise in degrees, with zero indicating that a line drawn between the eyes is horizontal relative to the image orientation.

pub unsafe fn hasSmile(&self) -> bool

A Boolean value that indicates whether a smile is detected in the face.

To detect smiles, /CIDetector/featuresInImage:options: needs to be called with the CIDetectorSmile option set to true.

pub unsafe fn leftEyeClosed(&self) -> bool

A Boolean value that indicates whether a closed left eye is detected in the face.

To detect closed eyes, /CIDetector/featuresInImage:options: needs to be called with the CIDetectorEyeBlink option set to true.

pub unsafe fn rightEyeClosed(&self) -> bool

A Boolean value that indicates whether a closed right eye is detected in the face.

To detect closed eyes, /CIDetector/featuresInImage:options: needs to be called with the CIDetectorEyeBlink option set to true.

impl CIFaceFeature

Methods declared on superclass NSObject.

pub unsafe fn init(this: Allocated<Self>) -> Retained<Self>

pub unsafe fn new() -> Retained<Self>

Methods from Deref<Target = CIFeature>

pub unsafe fn type(&self) -> Retained<NSString>

The type of feature that was discovered.

The type can be one of:

• CIFeatureTypeFace
• CIFeatureTypeRectangle
• CIFeatureTypeQRCode
• CIFeatureTypeText

pub unsafe fn bounds(&self) -> CGRect

Available on crate feature objc2-core-foundation only.

The rectangle that bounds the location of discovered feature.

The rectangle is in the cartesian coordinate system of the image.

Methods from Deref<Target = NSObject>

pub fn doesNotRecognizeSelector(&self, sel: Sel) -> !

Handle messages the object doesn’t recognize.

See Apple’s documentation for details.

Methods from Deref<Target = AnyObject>

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());

pub unsafe fn get_ivar<T>(&self, name: &str) -> &T

where T: Encode,

👎Deprecated: this is difficult to use correctly, use 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.

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

impl AsRef<AnyObject> for CIFaceFeature

fn as_ref(&self) -> &AnyObject

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<CIFaceFeature> for CIFaceFeature

fn as_ref(&self) -> &Self

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<CIFeature> for CIFaceFeature

fn as_ref(&self) -> &CIFeature

Converts this type into a shared reference of the (usually inferred) input type.

impl AsRef<NSObject> for CIFaceFeature

fn as_ref(&self) -> &NSObject

Converts this type into a shared reference of the (usually inferred) input type.

impl Borrow<AnyObject> for CIFaceFeature

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<CIFeature> for CIFaceFeature

fn borrow(&self) -> &CIFeature

Immutably borrows from an owned value.

impl Borrow<NSObject> for CIFaceFeature

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for CIFaceFeature

const NAME: &'static str = "CIFaceFeature"

The name of the Objective-C class that this type represents.

type Super = CIFeature

The superclass of this class.

type ThreadKind = <<CIFaceFeature as ClassType>::Super as ClassType>::ThreadKind

Whether the type can be used from any thread, or from only the main thread.

fn class() -> &'static AnyClass

Get a reference to the Objective-C class that this type represents.

fn as_super(&self) -> &Self::Super

Get an immutable reference to the superclass.

impl Debug for CIFaceFeature

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deref for CIFaceFeature

type Target = CIFeature

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl Hash for CIFaceFeature

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Message for CIFaceFeature

fn retain(&self) -> Retained<Self>

where Self: Sized,

Increment the reference count of the receiver.

impl NSObjectProtocol for CIFaceFeature

fn isEqual(&self, other: Option<&AnyObject>) -> bool

where Self: Sized + Message,

Check whether the object is equal to an arbitrary other object.

fn hash(&self) -> usize

where Self: Sized + Message,

An integer that can be used as a table address in a hash table structure.

fn isKindOfClass(&self, cls: &AnyClass) -> bool

where Self: Sized + Message,

Check if the object is an instance of the class, or one of its subclasses.

fn is_kind_of<T>(&self) -> bool

where T: ClassType, Self: Sized + Message,

👎Deprecated: use isKindOfClass directly, or cast your objects with AnyObject::downcast_ref

Check if the object is an instance of the class type, or one of its subclasses.

fn isMemberOfClass(&self, cls: &AnyClass) -> bool

where Self: Sized + Message,

Check if the object is an instance of a specific class, without checking subclasses.

fn respondsToSelector(&self, aSelector: Sel) -> bool

where Self: Sized + Message,

Check whether the object implements or inherits a method with the given selector.

fn conformsToProtocol(&self, aProtocol: &AnyProtocol) -> bool

where Self: Sized + Message,

Check whether the object conforms to a given protocol.

fn description(&self) -> Retained<NSObject>

where Self: Sized + Message,

A textual representation of the object.

fn debugDescription(&self) -> Retained<NSObject>

where Self: Sized + Message,

A textual representation of the object to use when debugging.

fn isProxy(&self) -> bool

where Self: Sized + Message,

Check whether the receiver is a subclass of the NSProxy root class instead of the usual NSObject.

fn retainCount(&self) -> usize

where Self: Sized + Message,

The reference count of the object.

impl PartialEq for CIFaceFeature

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl RefEncode for CIFaceFeature

const ENCODING_REF: Encoding = <CIFeature as ::objc2::RefEncode>::ENCODING_REF

The Objective-C type-encoding for a reference of this type.

impl DowncastTarget for CIFaceFeature

impl Eq for CIFaceFeature