Trait objc2_foundation::NSObjectProtocol

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pub unsafe trait NSObjectProtocol {
    // Provided methods
    fn isEqual(&self, other: &AnyObject) -> bool
       where Self: Sized + Message { ... }
    fn hash(&self) -> usize
       where Self: Sized + Message { ... }
    fn isKindOfClass(&self, cls: &AnyClass) -> bool
       where Self: Sized + Message { ... }
    fn is_kind_of<T>(&self) -> bool
       where T: ClassType,
             Self: Sized + Message { ... }
    fn isMemberOfClass(&self, cls: &AnyClass) -> bool
       where Self: Sized + Message { ... }
    fn respondsToSelector(&self, aSelector: Sel) -> bool
       where Self: Sized + Message { ... }
    fn conformsToProtocol(&self, aProtocol: &AnyProtocol) -> bool
       where Self: Sized + Message { ... }
    fn description(&self) -> Id<NSObject>
       where Self: Sized + Message { ... }
    fn debugDescription(&self) -> Id<NSObject>
       where Self: Sized + Message { ... }
    fn isProxy(&self) -> bool
       where Self: Sized + Message { ... }
    fn retainCount(&self) -> usize
       where Self: Sized + Message { ... }
}

Expand description

The methods that are fundamental to most Objective-C objects.

This represents the NSObject protocol.

You should rarely need to use this for anything other than as a trait bound in extern_protocol!, to allow your protocol to implement Debug Hash, PartialEq and Eq.

This trait is exported under objc2_foundation::NSObjectProtocol, you probably want to use that path instead.

§Safety

Like with other protocols, the type must represent a class that implements the NSObject protocol.

Provided Methods§

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

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

Most objects that implement NSObjectProtocol also implements the PartialEq trait. If the objects you are comparing are of the same type, you likely want to use that instead.

See Apple’s documentation for details.

source

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

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

Most objects that implement NSObjectProtocol also implements the Hash trait, you likely want to use that instead.

See Apple’s documentation for details.

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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.

See Apple’s documentation for more details on what you may (and what you may not) do with this information.

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fn is_kind_of<T>(&self) -> bool
where T: ClassType, Self: Sized + Message,

Check if the object is an instance of the class type, or one of its subclasses.

See isKindOfClass for details.

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fn isMemberOfClass(&self, cls: &AnyClass) -> bool
where Self: Sized + Message,

Check if the object is an instance of a specific class, without checking subclasses.

Note that this is rarely what you want, the specific class of an object is considered a private implementation detail. Use isKindOfClass instead to check whether an object is an instance of a given class.

See Apple’s documentation for more details.

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fn respondsToSelector(&self, aSelector: Sel) -> bool
where Self: Sized + Message,

Check whether the object implements or inherits a method with the given selector.

See Apple’s documentation for more details.

§Example

Check whether NSApplication has the effectiveAppearance method before calling it, to support systems older than macOS 10.14 where the method was added.

use objc2_app_kit::{NSApplication, NSAppearance, NSAppearanceNameAqua};
use objc2::runtime::NSObjectProtocol;
use objc2::sel;

let appearance = if obj.respondsToSelector(sel!(effectiveAppearance)) {
    NSApplication::sharedApplication(mtm).effectiveAppearance()
} else {
    unsafe { NSAppearance::appearanceNamed(NSAppearanceNameAqua).unwrap() }
};

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fn conformsToProtocol(&self, aProtocol: &AnyProtocol) -> bool
where Self: Sized + Message,

Check whether the object conforms to a given protocol.

See Apple’s documentation for details.

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fn description(&self) -> Id<NSObject>
where Self: Sized + Message,

A textual representation of the object.

The returned class is NSString, but since that is defined in objc2-foundation, and NSObjectProtocol is defined in objc2, the declared return type is unfortunately restricted to be NSObject. It is always safe to cast the return value of this to NSString.

You might want to use the Debug impl of the object instead, or if the object implements Display, the to_string method.

§Example

use objc2::rc::Id;
use objc2_foundation::{NSObject, NSObjectProtocol, NSString};

// SAFETY: Descriptions are always `NSString`.
let desc: Id<NSString> = unsafe { Id::cast(obj.description()) };
println!("{desc:?}");

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fn debugDescription(&self) -> Id<NSObject>
where Self: Sized + Message,

A textual representation of the object to use when debugging.

Like with description, the return type of this is always NSString.

LLVM’s po command uses this property to create a textual representation of the object. The default implemention returns the same value as description. Override either to provide custom object descriptions.

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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.

See Apple’s documentation for details.

§Example

use objc2::runtime::{NSObject, NSObjectProtocol};

let obj = NSObject::new();
assert!(!obj.isProxy());

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

The reference count of the object.

This can rarely be useful when debugging memory management issues, though beware that in most real-world scenarios, your object may be retained by several autorelease pools, especially when debug assertions are enabled, so this value may not represent what you’d expect.

§Example

use objc2::ClassType;
use objc2::runtime::{NSObject, NSObjectProtocol};

let obj = NSObject::new();
assert_eq!(obj.retainCount(), 1);
let obj2 = obj.clone();
assert_eq!(obj.retainCount(), 2);
drop(obj2);
assert_eq!(obj.retainCount(), 1);

Trait objc2_foundation::NSObjectProtocolCopy item path

§Safety

Provided Methods§

fn isEqual(&self, other: &AnyObject) -> boolwhere Self: Sized + Message,

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

fn isKindOfClass(&self, cls: &AnyClass) -> boolwhere Self: Sized + Message,

fn is_kind_of<T>(&self) -> boolwhere T: ClassType, Self: Sized + Message,

fn isMemberOfClass(&self, cls: &AnyClass) -> boolwhere Self: Sized + Message,

fn respondsToSelector(&self, aSelector: Sel) -> boolwhere Self: Sized + Message,

§Example

fn conformsToProtocol(&self, aProtocol: &AnyProtocol) -> boolwhere Self: Sized + Message,

fn description(&self) -> Id<NSObject>where Self: Sized + Message,

§Example

fn debugDescription(&self) -> Id<NSObject>where Self: Sized + Message,

fn isProxy(&self) -> boolwhere Self: Sized + Message,

§Example

fn retainCount(&self) -> usizewhere Self: Sized + Message,

§Example

Trait Implementations§

impl ProtocolType for dyn NSObjectProtocol

const NAME: &'static str = "NSObject"

fn protocol() -> Option<&'static AnyProtocol>

impl<T> ImplementedBy<T> for dyn NSObjectProtocolwhere T: Message + NSObjectProtocol + ?Sized,

impl<T> ImplementedBy<T> for dyn NSObjectProtocol + Sendwhere T: Message + NSObjectProtocol + Send + ?Sized,

impl<T> ImplementedBy<T> for dyn NSObjectProtocol + Sync + Sendwhere T: Message + NSObjectProtocol + Send + Sync + ?Sized,

impl<T> ImplementedBy<T> for dyn NSObjectProtocol + Syncwhere T: Message + NSObjectProtocol + Sync + ?Sized,

Implementors§

impl NSObjectProtocol for NSAffineTransform

impl NSObjectProtocol for NSAppleEventDescriptor

impl NSObjectProtocol for NSAppleEventManager

impl NSObjectProtocol for NSAppleScript

impl NSObjectProtocol for NSArchiver

impl NSObjectProtocol for NSAssertionHandler

impl NSObjectProtocol for NSAttributedString

impl NSObjectProtocol for NSAttributedStringMarkdownParsingOptions

impl NSObjectProtocol for NSAttributedStringMarkdownSourcePosition

impl NSObjectProtocol for NSAutoreleasePool

impl NSObjectProtocol for NSBackgroundActivityScheduler

impl NSObjectProtocol for NSBlockOperation

impl NSObjectProtocol for NSBundle

impl NSObjectProtocol for NSBundleResourceRequest

impl NSObjectProtocol for NSByteCountFormatter

impl NSObjectProtocol for NSCachedURLResponse

impl NSObjectProtocol for NSCalendar

impl NSObjectProtocol for NSCalendarDate

impl NSObjectProtocol for NSCharacterSet

impl NSObjectProtocol for NSClassDescription

impl NSObjectProtocol for NSCloneCommand

impl NSObjectProtocol for NSCloseCommand

impl NSObjectProtocol for NSCoder

impl NSObjectProtocol for NSComparisonPredicate

impl NSObjectProtocol for NSCompoundPredicate

impl NSObjectProtocol for NSCondition

impl NSObjectProtocol for NSConditionLock

impl NSObjectProtocol for NSConnection

impl NSObjectProtocol for NSConstantString

impl NSObjectProtocol for NSCountCommand

impl NSObjectProtocol for NSCreateCommand

impl NSObjectProtocol for NSData

impl NSObjectProtocol for NSDataDetector

impl NSObjectProtocol for NSDate

impl NSObjectProtocol for NSDateComponents

impl NSObjectProtocol for NSDateComponentsFormatter

impl NSObjectProtocol for NSDateFormatter

impl NSObjectProtocol for NSDateInterval

impl NSObjectProtocol for NSDateIntervalFormatter

impl NSObjectProtocol for NSDecimalNumber

impl NSObjectProtocol for NSDecimalNumberHandler

impl NSObjectProtocol for NSDeleteCommand

impl NSObjectProtocol for NSDimension

impl NSObjectProtocol for NSDistantObject

impl NSObjectProtocol for NSDistantObjectRequest

impl NSObjectProtocol for NSDistributedLock

impl NSObjectProtocol for NSDistributedNotificationCenter

impl NSObjectProtocol for NSEnergyFormatter

impl NSObjectProtocol for NSError

impl NSObjectProtocol for NSException

impl NSObjectProtocol for NSExistsCommand

impl NSObjectProtocol for NSExpression

impl NSObjectProtocol for NSExtensionContext

Trait objc2_foundation::NSObjectProtocol

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

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

fn isKindOfClass(&self, cls: &AnyClass) -> bool
where Self: Sized + Message,

fn is_kind_of<T>(&self) -> bool
where T: ClassType, Self: Sized + Message,

fn isMemberOfClass(&self, cls: &AnyClass) -> bool
where Self: Sized + Message,

fn respondsToSelector(&self, aSelector: Sel) -> bool
where Self: Sized + Message,

fn conformsToProtocol(&self, aProtocol: &AnyProtocol) -> bool
where Self: Sized + Message,

fn description(&self) -> Id<NSObject>
where Self: Sized + Message,

fn debugDescription(&self) -> Id<NSObject>
where Self: Sized + Message,

fn isProxy(&self) -> bool
where Self: Sized + Message,

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

impl<T> ImplementedBy<T> for dyn NSObjectProtocol
where T: Message + NSObjectProtocol + ?Sized,

impl<T> ImplementedBy<T> for dyn NSObjectProtocol + Send
where T: Message + NSObjectProtocol + Send + ?Sized,

impl<T> ImplementedBy<T> for dyn NSObjectProtocol + Sync + Send
where T: Message + NSObjectProtocol + Send + Sync + ?Sized,

impl<T> ImplementedBy<T> for dyn NSObjectProtocol + Sync
where T: Message + NSObjectProtocol + Sync + ?Sized,