Struct AVTimedMetadataGroup

#[repr(C)]
pub struct AVTimedMetadataGroup { /* private fields */ }

Available on crate feature AVTimedMetadataGroup only.

AVTimedMetadataGroup is used to represent a collection of metadata items that are valid for use during a specific range of time. For example, AVTimedMetadataGroups are used to represent chapters, optionally containing metadata items for chapter titles and chapter images.

See also Apple’s documentation

Implementations

impl AVTimedMetadataGroup

pub unsafe fn initWithItems_timeRange( this: Allocated<Self>, items: &NSArray<AVMetadataItem>, time_range: CMTimeRange, ) -> Retained<Self>

Available on crate features AVMetadataItem and objc2-core-media only.

Initializes an instance of AVTimedMetadataGroup with a collection of metadata items.

Parameter items: An NSArray of AVMetadataItems.

Parameter timeRange: The timeRange of the collection of AVMetadataItems.

Returns: An instance of AVTimedMetadataGroup.

pub unsafe fn initWithSampleBuffer( this: Allocated<Self>, sample_buffer: &CMSampleBuffer, ) -> Option<Retained<Self>>

Available on crate feature objc2-core-media only.

Initializes an instance of AVTimedMetadataGroup with a sample buffer.

Parameter sampleBuffer: A CMSampleBuffer with media type kCMMediaType_Metadata.

Returns: An instance of AVTimedMetadataGroup.

pub unsafe fn timeRange(&self) -> CMTimeRange

Available on crate feature objc2-core-media only.

pub unsafe fn items(&self) -> Retained<NSArray<AVMetadataItem>>

Available on crate feature AVMetadataItem only.

impl AVTimedMetadataGroup

Methods declared on superclass NSObject.

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

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

impl AVTimedMetadataGroup

AVTimedMetadataGroupSerializationSupport.

pub unsafe fn copyFormatDescription( &self, ) -> Option<Retained<CMMetadataFormatDescription>>

Available on crate feature objc2-core-media only.

Creates a format description based on the receiver’s items.

Returns: An instance of CMMetadataFormatDescription sufficient to describe the contents of all the items referenced by the receiver.

The returned format description is suitable for use as the format hint parameter when creating an instance of AVAssetWriterInput.

Each item referenced by the receiver must carry a non-nil value for its dataType property. An exception will be thrown if any item does not have a data type.

Methods from Deref<Target = AVMetadataGroup>

pub unsafe fn items(&self) -> Retained<NSArray<AVMetadataItem>>

Available on crate feature AVMetadataItem only.

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

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

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.

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<AVMetadataGroup> for AVTimedMetadataGroup

fn as_ref(&self) -> &AVMetadataGroup

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

impl AsRef<AVTimedMetadataGroup> for AVMutableTimedMetadataGroup

fn as_ref(&self) -> &AVTimedMetadataGroup

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

impl AsRef<AVTimedMetadataGroup> for AVTimedMetadataGroup

fn as_ref(&self) -> &Self

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

impl AsRef<AnyObject> for AVTimedMetadataGroup

fn as_ref(&self) -> &AnyObject

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

impl AsRef<NSObject> for AVTimedMetadataGroup

fn as_ref(&self) -> &NSObject

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

impl Borrow<AVMetadataGroup> for AVTimedMetadataGroup

fn borrow(&self) -> &AVMetadataGroup

Immutably borrows from an owned value.

impl Borrow<AVTimedMetadataGroup> for AVMutableTimedMetadataGroup

fn borrow(&self) -> &AVTimedMetadataGroup

Immutably borrows from an owned value.

impl Borrow<AnyObject> for AVTimedMetadataGroup

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for AVTimedMetadataGroup

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for AVTimedMetadataGroup

const NAME: &'static str = "AVTimedMetadataGroup"

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

type Super = AVMetadataGroup

The superclass of this class.

type ThreadKind = <<AVTimedMetadataGroup 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 CopyingHelper for AVTimedMetadataGroup

type Result = AVTimedMetadataGroup

The immutable counterpart of the type, or Self if the type has no immutable counterpart.

impl Debug for AVTimedMetadataGroup

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

Formats the value using the given formatter.

impl Deref for AVTimedMetadataGroup

type Target = AVMetadataGroup

The resulting type after dereferencing.

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

Dereferences the value.

impl Hash for AVTimedMetadataGroup

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 AVTimedMetadataGroup

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

where Self: Sized,

Increment the reference count of the receiver.

impl MutableCopyingHelper for AVTimedMetadataGroup

type Result = AVMutableTimedMetadataGroup

The mutable counterpart of the type, or Self if the type has no mutable counterpart.

impl NSCopying for AVTimedMetadataGroup

fn copy(&self) -> Retained<Self::Result>

where Self: Sized + Message + CopyingHelper,

Returns a new instance that’s a copy of the receiver.

unsafe fn copyWithZone(&self, zone: *mut NSZone) -> Retained<Self::Result>

where Self: Sized + Message + CopyingHelper,

Returns a new instance that’s a copy of the receiver.

impl NSMutableCopying for AVTimedMetadataGroup

fn mutableCopy(&self) -> Retained<Self::Result>

where Self: Sized + Message + MutableCopyingHelper,

Returns a new instance that’s a mutable copy of the receiver.

unsafe fn mutableCopyWithZone( &self, zone: *mut NSZone, ) -> Retained<Self::Result>

where Self: Sized + Message + MutableCopyingHelper,

Returns a new instance that’s a mutable copy of the receiver.

impl NSObjectProtocol for AVTimedMetadataGroup

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 AVTimedMetadataGroup

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 AVTimedMetadataGroup

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

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

impl DowncastTarget for AVTimedMetadataGroup

impl Eq for AVTimedMetadataGroup