Struct NSOperationQueue

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

Available on crate feature NSOperation only.

Apple’s documentation

Implementations

impl NSOperationQueue

pub unsafe fn progress(&self) -> Retained<NSProgress>

Available on crate feature NSProgress only.

The progress property represents a total progress of the operations executed in the queue. By default NSOperationQueue does not report progress until the totalUnitCount of the progress is set. When the totalUnitCount property of the progress is set the queue then opts into participating in progress reporting. When enabled, each operation will contribute 1 unit of completion to the overall progress of the queue for operations that are finished by the end of main (operations that override start and do not invoke super will not contribute to progress). Special attention to race conditions should be made when updating the totalUnitCount of the progress as well as care should be taken to avoid ‘backwards progress’. For example; when a NSOperationQueue’s progress is 5/10, representing 50% completed, and there are 90 more operations about to be added and the totalUnitCount that would then make the progress report as 5/100 which represents 5%. In this example it would mean that any progress bar would jump from displaying 50% back to 5%, which might not be desirable. In the cases where the totalUnitCount needs to be adjusted it is suggested to do this for thread-safety in a barrier by using the addBarrierBlock: API. This ensures that no un-expected execution state occurs adjusting into a potentially backwards moving progress scenario.

NSOperationQueue *queue = [[NSOperationQueue alloc] init]; queue.progress.totalUnitCount = 10;

pub unsafe fn addOperation(&self, op: &NSOperation)

pub unsafe fn addOperations_waitUntilFinished( &self, ops: &NSArray<NSOperation>, wait: bool, )

Available on crate feature NSArray only.

pub unsafe fn addOperationWithBlock(&self, block: &DynBlock<dyn Fn()>)

Available on crate feature block2 only.

pub unsafe fn addBarrierBlock(&self, barrier: &DynBlock<dyn Fn()>)

Available on crate feature block2 only.

Parameter barrier: A block to execute

The addBarrierBlock: method executes the block when the NSOperationQueue has finished all enqueued operations and prevents any subsequent operations to be executed until the barrier has been completed. This acts similarly to the dispatch_barrier_async function.

pub unsafe fn maxConcurrentOperationCount(&self) -> NSInteger

pub unsafe fn setMaxConcurrentOperationCount( &self, max_concurrent_operation_count: NSInteger, )

Setter for maxConcurrentOperationCount.

pub unsafe fn isSuspended(&self) -> bool

pub unsafe fn setSuspended(&self, suspended: bool)

Setter for isSuspended.

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

Available on crate feature NSString only.

pub unsafe fn setName(&self, name: Option<&NSString>)

Available on crate feature NSString only.

Setter for name.

pub unsafe fn qualityOfService(&self) -> NSQualityOfService

Available on crate feature NSObjCRuntime only.

pub unsafe fn setQualityOfService(&self, quality_of_service: NSQualityOfService)

Available on crate feature NSObjCRuntime only.

Setter for qualityOfService.

pub unsafe fn cancelAllOperations(&self)

pub unsafe fn waitUntilAllOperationsAreFinished(&self)

pub unsafe fn currentQueue() -> Option<Retained<NSOperationQueue>>

pub unsafe fn mainQueue() -> Retained<NSOperationQueue>

impl NSOperationQueue

Methods declared on superclass NSObject.

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

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

impl NSOperationQueue

NSDeprecated.

pub unsafe fn operations(&self) -> Retained<NSArray<NSOperation>>

👎Deprecated: access to operations is inherently a race condition, it should not be used. For barrier style behaviors please use addBarrierBlock: instead

Available on crate feature NSArray only.

pub unsafe fn operationCount(&self) -> NSUInteger

👎Deprecated

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 NSOperationQueue

fn as_ref(&self) -> &AnyObject

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

impl AsRef<NSObject> for NSOperationQueue

fn as_ref(&self) -> &NSObject

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

impl AsRef<NSOperationQueue> for NSOperationQueue

fn as_ref(&self) -> &Self

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

impl Borrow<AnyObject> for NSOperationQueue

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for NSOperationQueue

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for NSOperationQueue

const NAME: &'static str = "NSOperationQueue"

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

type Super = NSObject

The superclass of this class.

type ThreadKind = <<NSOperationQueue 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 NSOperationQueue

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

Formats the value using the given formatter.

impl Deref for NSOperationQueue

type Target = NSObject

The resulting type after dereferencing.

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

Dereferences the value.

impl Hash for NSOperationQueue

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 NSOperationQueue

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

where Self: Sized,

Increment the reference count of the receiver.

impl NSObjectProtocol for NSOperationQueue

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 NSProgressReporting for NSOperationQueue

unsafe fn progress(&self) -> Retained<NSProgress>

where Self: Sized + Message,

Available on crate feature NSProgress only.

impl PartialEq for NSOperationQueue

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 NSOperationQueue

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

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

impl DowncastTarget for NSOperationQueue

impl Eq for NSOperationQueue

impl Send for NSOperationQueue

impl Sync for NSOperationQueue