Struct NSObject

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

Expand description

The root class of most Objective-C class hierarchies.

This represents the NSObject class. The name “NSObject” also refers to a protocol, see NSObjectProtocol for that.

This class has been defined in objc since macOS 10.8, but is also re-exported under objc2_foundation::NSObject, you might want to use that path instead.

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impl NSObject

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pub fn new() -> Retained<NSObject>

Create a new empty NSObject.

This method is a shorthand for calling alloc and then init.

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

Initialize an already allocated object.

See Apple’s documentation for details.

§Example

use objc2::runtime::NSObject;
use objc2::AnyThread;

let obj = NSObject::init(NSObject::alloc());

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

Handle messages the object doesn’t recognize.

See Apple’s documentation for details.

Methods from Deref<Target = AnyObject>§

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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());

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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.

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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§

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

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type Super = AnyObject

The superclass of this class. Read more

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type ThreadKind = dyn AnyThread

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

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fn class() -> &'static AnyClass

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

Dereferences the value.

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impl Hash for NSObject

Hashing in Objective-C has the exact same requirement as in Rust:

If two objects are equal (as determined by the isEqual: method), they must have the same hash value.

See https://developer.apple.com/documentation/objectivec/1418956-nsobject/1418859-hash

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

Feeds this value into the given Hasher. Read more

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

Feeds a slice of this type into the given Hasher. Read more

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impl Message for NSObject

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fn retain(&self) -> Retained<Self>
where Self: Sized,

Increment the reference count of the receiver. Read more

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impl NSObjectNSArchiverCallback for NSObject

Available on crate feature NSArchiver only.

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unsafe fn classForArchiver(&self) -> Option<&'static AnyClass>

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unsafe fn replacementObjectForArchiver( &self, archiver: &NSArchiver, ) -> Option<Retained<AnyObject>>

👎Deprecated

Available on crate feature NSCoder only.

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impl NSObjectNSClassDescriptionPrimitives for NSObject

Available on crate feature NSClassDescription only.

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Available on crate feature NSString only.

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unsafe fn isCaseInsensitiveLike(&self, object: &NSString) -> bool

Available on crate feature NSString only.

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impl NSObjectNSDelayedPerforming for NSObject

Available on crate feature NSRunLoop only.

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unsafe fn performSelector_withObject_afterDelay_inModes( &self, a_selector: Sel, an_argument: Option<&AnyObject>, delay: NSTimeInterval, modes: &NSArray<NSRunLoopMode>, )

Available on crate features NSArray and NSDate and NSObjCRuntime and NSString only.

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unsafe fn performSelector_withObject_afterDelay( &self, a_selector: Sel, an_argument: Option<&AnyObject>, delay: NSTimeInterval, )

Available on crate feature NSDate only.

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impl NSObjectNSKeyValueCoding for NSObject

Available on crate feature NSKeyValueCoding only.

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unsafe fn setObservationInfo(&self, observation_info: *mut c_void)

Setter for observationInfo.

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impl NSObjectNSKeyValueSharedObserverRegistration for NSObject

Available on crate feature NSKeyValueSharedObservers only.

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unsafe fn setSharedObservers( &self, shared_observers: Option<&NSKeyValueSharedObserversSnapshot>, )

Register shared observations. Read more

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impl NSObjectNSKeyedArchiverObjectSubstitution for NSObject

Available on crate feature NSKeyedArchiver only.

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unsafe fn classForKeyedArchiver(&self) -> Option<&'static AnyClass>

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unsafe fn replacementObjectForKeyedArchiver( &self, archiver: &NSKeyedArchiver, ) -> Option<Retained<AnyObject>>

Available on crate feature NSCoder only.

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unsafe fn classFallbacksForKeyedArchiver() -> Retained<NSArray<NSString>>

Available on crate features NSArray and NSString only.

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unsafe fn indicesOfObjectsByEvaluatingObjectSpecifier( &self, specifier: &NSScriptObjectSpecifier, ) -> Option<Retained<NSArray<NSNumber>>>

Available on crate features NSArray and NSValue only.

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impl NSObjectNSScripting for NSObject

Available on crate feature NSObjectScripting only.

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unsafe fn scriptingValueForSpecifier( &self, object_specifier: &NSScriptObjectSpecifier, ) -> Option<Retained<AnyObject>>

Available on crate feature NSScriptObjectSpecifiers only.

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unsafe fn scriptingProperties( &self, ) -> Option<Retained<NSDictionary<NSString, AnyObject>>>

Available on crate features NSDictionary and NSString only.

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unsafe fn setScriptingProperties( &self, scripting_properties: Option<&NSDictionary<NSString, AnyObject>>, )

Available on crate features NSDictionary and NSString only.

Setter for scriptingProperties.

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unsafe fn copyScriptingValue_forKey_withProperties( &self, value: &AnyObject, key: &NSString, properties: &NSDictionary<NSString, AnyObject>, ) -> Option<Retained<AnyObject>>

Available on crate features NSDictionary and NSString only.

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unsafe fn newScriptingObjectOfClass_forValueForKey_withContentsValue_properties( &self, object_class: &AnyClass, key: &NSString, contents_value: Option<&AnyObject>, properties: &NSDictionary<NSString, AnyObject>, ) -> Option<Retained<AnyObject>>

Available on crate features NSDictionary and NSString only.

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impl NSObjectNSScriptingComparisonMethods for NSObject

Available on crate feature NSScriptWhoseTests only.

unsafe fn performSelectorOnMainThread_withObject_waitUntilDone_modes( &self, a_selector: Sel, arg: Option<&AnyObject>, wait: bool, array: Option<&NSArray<NSString>>, )

Available on crate features NSArray and NSString only.

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unsafe fn performSelectorOnMainThread_withObject_waitUntilDone( &self, a_selector: Sel, arg: Option<&AnyObject>, wait: bool, )

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unsafe fn performSelector_onThread_withObject_waitUntilDone_modes( &self, a_selector: Sel, thr: &NSThread, arg: Option<&AnyObject>, wait: bool, array: Option<&NSArray<NSString>>, )

Available on crate features NSArray and NSString only.

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unsafe fn performSelector_onThread_withObject_waitUntilDone( &self, a_selector: Sel, thr: &NSThread, arg: Option<&AnyObject>, wait: bool, )

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unsafe fn performSelectorInBackground_withObject( &self, a_selector: Sel, arg: Option<&AnyObject>, )

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impl NSObjectProtocol for NSObject

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fn isEqual(&self, other: Option<&AnyObject>) -> bool
where Self: Sized + Message,

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

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fn hash(&self) -> usize
where Self: Sized + Message,

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

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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. Read more

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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

Objective-C equality has approximately the same semantics as Rust equality (although less aptly specified).

At the very least, equality is expected to be symmetric and transitive, and that’s about the best we can do.

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

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

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

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

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impl RefEncode for NSObject

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const ENCODING_REF: Encoding = <AnyObject as crate::RefEncode>::ENCODING_REF

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

The type returned in the event of a conversion error.

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fn try_from(value: U) -> Result<T, <T as TryFrom>::Error>

Performs the conversion.

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impl<T, U> TryInto for T
where U: TryFrom<T>,

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type Error = >::Error

The type returned in the event of a conversion error.

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fn try_into(self) -> Result<U, >::Error>

Performs the conversion.

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Struct NSObjectCopy item path

Implementations§

impl NSObject

pub fn new() -> Retained<NSObject>

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

§Example

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

Methods from Deref<Target = AnyObject>§

pub fn class(&self) -> &'static AnyClass

§Panics

§Example

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

§Safety

pub fn downcast_ref<T>(&self) -> Option<&T>where T: DowncastTarget,

§Mutable classes

§Generic classes

§Panics

§Examples

Trait Implementations§

impl AsRef<AnyObject> for NSObject

fn as_ref(&self) -> &AnyObject

impl AsRef<NSObject> for NSAffineTransform

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSAppleEventDescriptor

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSAppleEventManager

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSAppleScript

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSArchiver

fn as_ref(&self) -> &NSObject

impl<ObjectType: ?Sized + Message> AsRef<NSObject> for NSArray<ObjectType>

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSAssertionHandler

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSAttributedString

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSAttributedStringMarkdownParsingOptions

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSAttributedStringMarkdownSourcePosition

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSAutoreleasePool

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSBackgroundActivityScheduler

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSBlockOperation

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSBundle

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSBundleResourceRequest

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSByteCountFormatter

fn as_ref(&self) -> &NSObject

impl<KeyType: ?Sized + Message, ObjectType: ?Sized + Message> AsRef<NSObject> for NSCache<KeyType, ObjectType>

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSCachedURLResponse

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSCalendar

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSCalendarDate

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSCharacterSet

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSClassDescription

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSCloneCommand

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSCloseCommand

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSCoder

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSComparisonPredicate

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSCompoundPredicate

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSCondition

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSConditionLock

fn as_ref(&self) -> &NSObject

impl AsRef<NSObject> for NSConnection

Struct NSObject

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

pub fn downcast_ref<T>(&self) -> Option<&T>
where T: DowncastTarget,