Struct AVCaptureExternalDisplayConfigurator 

pub struct AVCaptureExternalDisplayConfigurator { /* private fields */ }

Available on crate feature AVCaptureExternalDisplayConfigurator only.

A configurator class allowing you to configure properties of an external display to match the camera’s active video format.

An AVCaptureExternalDisplayConfigurator allows you to configure a connected external display to output a clean feed using a CALayer. Using the configurator, you can opt into automatic adjustment of the external display’s color space and / or frame rate to match your device’s capture configuration. These adjustments are only applied to the external display, not to the device.

• Note: Not all displays support the same configuration options as the device’s capture formats. Your adjustments to the external display are applied with utmost effort to accurately represent the capture device. When your capture device’s AVCaptureDevice/activeFormat is unavailable on the external display, the configurator automatically chooses the closest available format.

See also Apple’s documentation

Implementations

impl AVCaptureExternalDisplayConfigurator

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

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

pub unsafe fn initWithDevice_previewLayer_configuration( this: Allocated<Self>, device: &AVCaptureDevice, preview_layer: &CALayer, configuration: &AVCaptureExternalDisplayConfiguration, ) -> Retained<Self>

Available on crate feature AVCaptureDevice and crate feature objc2-quartz-core and non-watchOS only.

An external display configurator instance that attempts to synchronize the preview layer configuration with the device capture configuration.

• Parameter device: The device for which to monitor the configuration.
• Parameter previewLayer: The layer that is being used on an external display for displaying the camera preview.
• Parameter configuration: A configuration specifying which aspects of the camera’s active format to monitor and configure on the external display.
• Returns: an AVCaptureExternalDisplayConfigurator instance.

An AVCaptureExternalDisplayConfigurator is only applicable to external displays. It determines which properties to configure on the external display based on your provided configuration (see AVCaptureExternalDisplayConfiguration). The configurator observes changes to your camera’’s configuration, and when changes are observed, it modifies the external display’s properties to match.

If multiple configurators are linked to the same external display ,the last one created becomes the active configurator for the external display (see active).

• Important: An NSInvalidArgumentException is thrown if any of the AVCaptureExternalDisplayConfiguration options are not supported.

pub unsafe fn device(&self) -> Option<Retained<AVCaptureDevice>>

Available on crate feature AVCaptureDevice only.

The device for which the coordinator configures the preview layer.

The value of this property is the AVCaptureDevice instance you provided when instantiating the configurator. AVCaptureExternalDisplayConfigurator holds a weak reference to the device. If the device is released, this property returns nil.

pub unsafe fn previewLayer(&self) -> Option<Retained<CALayer>>

Available on crate feature objc2-quartz-core and non-watchOS only.

The layer for which the configurator adjusts display properties to match the device’s state.

The value of this property is the CALayer instance that you provided when instantiating the configurator. You may specify either an AVCaptureVideoPreviewLayer or another CALayer instance that displays a camera’s video preview. AVCaptureExternalDisplayConfiguratorholds a weak reference to the layer. If the layer is released, this property returns nil.

pub unsafe fn isActive(&self) -> bool

This property tells you whether the configurator is actively configuring the external display.

When this property returns true, the external display is successfully configured to match the device. If it returnsfalse, the configurator is not making any configuration changes to the external display. If another AVCaptureExternalDisplayConfigurator instance takes over the configuration of the external display, this property returns false.

pub unsafe fn stop(&self)

Forces the external display configurator to asynchronously stop configuring the external display.

Call stop to force the AVCaptureExternalDisplayConfigurator to asynchronously stop configuring the external display. Once stopped, the active property changes to false and the activeExternalDisplayFrameRate becomes 0.

pub unsafe fn activeExternalDisplayFrameRate(&self) -> c_double

The currently configured frame rate on the external display that’s displaying the preview layer.

Observe this property to determine if the configured frame rate matches the max frame rate (AVCaptureDevice/activeVideoMinFrameDuration) of the device. When the active property becomes false, this property changes to 0.

pub unsafe fn isMatchingFrameRateSupported() -> bool

Whether the external display supports matching frame rate to a capture device.

If true, you may instantiate a configurator with a configuration specifying AVCaptureExternalDisplayConfiguration/shouldMatchFrameRate set to true.

pub unsafe fn isBypassingColorSpaceConversionSupported() -> bool

Whether the external display supports bypassing color space conversion.

If true, you may instantiate a configurator with a configuration specifying AVCaptureExternalDisplayConfiguration/bypassColorSpaceConversion set to true.

pub unsafe fn isPreferredResolutionSupported() -> bool

Whether the external display supports configuration to your preferred resolution.

If true, you may instantiate a configurator with a configuration specifying AVCaptureExternalDisplayConfiguration/preferredResolution set to true.

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<AVCaptureExternalDisplayConfigurator> for AVCaptureExternalDisplayConfigurator

fn as_ref(&self) -> &Self

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

impl AsRef<AnyObject> for AVCaptureExternalDisplayConfigurator

fn as_ref(&self) -> &AnyObject

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

impl AsRef<NSObject> for AVCaptureExternalDisplayConfigurator

fn as_ref(&self) -> &NSObject

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

impl Borrow<AnyObject> for AVCaptureExternalDisplayConfigurator

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for AVCaptureExternalDisplayConfigurator

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for AVCaptureExternalDisplayConfigurator

const NAME: &'static str = "AVCaptureExternalDisplayConfigurator"

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

type Super = NSObject

The superclass of this class.

type ThreadKind = <<AVCaptureExternalDisplayConfigurator 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 AVCaptureExternalDisplayConfigurator

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

Formats the value using the given formatter.

impl Deref for AVCaptureExternalDisplayConfigurator

type Target = NSObject

The resulting type after dereferencing.

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

Dereferences the value.

impl Hash for AVCaptureExternalDisplayConfigurator

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 AVCaptureExternalDisplayConfigurator

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

where Self: Sized,

Increment the reference count of the receiver.

impl NSObjectProtocol for AVCaptureExternalDisplayConfigurator

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 AVCaptureExternalDisplayConfigurator

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 AVCaptureExternalDisplayConfigurator

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

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

impl DowncastTarget for AVCaptureExternalDisplayConfigurator

impl Eq for AVCaptureExternalDisplayConfigurator