Struct SNTimeDurationConstraint 

pub struct SNTimeDurationConstraint { /* private fields */ }

Available on crate feature SNTimeDurationConstraint only.

Constrains CMTime durations to a subset of legal values.

SNTimeDurationConstraint is a union type, which, based on the value of its type property, may assume one of several forms. Instance properties may be used to extract information from an object, but certain properties are only valid to exercise under certain circumstances. Before accessing a particular property, refer to its documentation to understand what type value is required in order for that property to be valid.

See also Apple’s documentation

Implementations

impl SNTimeDurationConstraint

pub unsafe fn type(&self) -> SNTimeDurationConstraintType

The time constraint type.

The value of this property dictates whether or not other properties associated with this class can be validly accessed. Please refer to the documentation of other individual properties to understand their relationship to this one. This property is always valid to access.

pub unsafe fn enumeratedDurations(&self) -> Retained<NSArray<NSValue>>

If the constraint type is enumerated, then the set of discrete allowable time durations.

• Returns: If the constraint type is enumerated, an array of CMTime structures (boxed in NSValue instances) representing the set of allowable time durations. The durations will always be provided sorted in order of ascending time. If the constraint type is not enumerated, an empty array will be returned.

The type property should be queried before this property is accessed. This property will only yield meaningful values if the constraint type is considered to be ‘enumerated’. The constraint type is considered to be ‘enumerated’ if the type property is equal to SNTimeDurationConstraintTypeEnumerated.

pub unsafe fn durationRange(&self) -> CMTimeRange

Available on crate feature objc2-core-media only.

If the constraint type is range, then the range of allowable window durations.

• Returns: If the constraint type is range, a CMTimeRange representing the range of allowable window durations. If the constraint type is not range, kCMTimeRangeInvalid.

The type property should be queried before this property is accessed. This property will only yield meaningful values if the constraint type is considered to be ‘range’. The constraint type is considered to be ‘range’ if the type property is equal to SNTimeDurationConstraintTypeRange.

pub unsafe fn initWithEnumeratedDurations( this: Allocated<Self>, enumerated_durations: &NSArray<NSValue>, ) -> Retained<Self>

Initializes an enumerated-type constraint.

• Parameter enumeratedDurations: A discrete set of duration values (represented as CMTime values boxed in NSValue instances) permitted by this constraint.

• Returns: An instance whose type is SNTimeDurationConstraintTypeEnumerated, and which constrains duration values to the provided set of discrete values.

pub unsafe fn initWithDurationRange( this: Allocated<Self>, duration_range: CMTimeRange, ) -> Retained<Self>

Available on crate feature objc2-core-media only.

Initializes a range-type constraint.

• Parameter durationRange: A continuous range of duration values (represented as CMTime values) permitted by this constraint.

• Returns: An instance whose type is SNTimeDurationConstraintTypeRange, and which constrains durations values to the provided range.

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

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

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 SNTimeDurationConstraint

fn as_ref(&self) -> &AnyObject

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

impl AsRef<NSObject> for SNTimeDurationConstraint

fn as_ref(&self) -> &NSObject

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

impl AsRef<SNTimeDurationConstraint> for SNTimeDurationConstraint

fn as_ref(&self) -> &Self

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

impl Borrow<AnyObject> for SNTimeDurationConstraint

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for SNTimeDurationConstraint

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for SNTimeDurationConstraint

const NAME: &'static str = "SNTimeDurationConstraint"

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

type Super = NSObject

The superclass of this class.

type ThreadKind = <<SNTimeDurationConstraint 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 SNTimeDurationConstraint

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

Formats the value using the given formatter.

impl Deref for SNTimeDurationConstraint

type Target = NSObject

The resulting type after dereferencing.

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

Dereferences the value.

impl Hash for SNTimeDurationConstraint

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 SNTimeDurationConstraint

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

where Self: Sized,

Increment the reference count of the receiver.

impl NSObjectProtocol for SNTimeDurationConstraint

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 SNTimeDurationConstraint

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 SNTimeDurationConstraint

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

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

impl DowncastTarget for SNTimeDurationConstraint

impl Eq for SNTimeDurationConstraint