Struct SHMediaLibrary

Source

pub struct SHMediaLibrary { /* private fields */ }

👎Deprecated: Use SHLibrary instead

Available on crate feature SHMediaLibrary only.

Expand description

An object that represents the user’s Shazam library.

Use SHMediaLibrary to add matched songs from the Shazam catalog to the user’s Shazam library.

Note: There’s no system permission necessary to write to the user’s Shazam library. Consider requesting permission from the user before adding songs to the library.

Implementations§

Source §

impl SHMediaLibrary

Source

pub unsafe fn defaultLibrary() -> Retained<SHMediaLibrary>

👎Deprecated: Use SHLibrary instead

An instance of the user’s default Shazam library.

Source

pub unsafe fn addMediaItems_completionHandler( &self, media_items: &NSArray<SHMediaItem>, completion_handler: &DynBlock<dyn Fn(*mut NSError)>, )

👎Deprecated: Use SHLibrary instead

Available on crate features SHMediaItem and block2 only.

Adds an array of songs to the user’s Shazam library.

Important: You can call this method from synchronous code using a completion handler, as shown on this page, or you can call it as an asynchronous method that has the following declaration:
func add(_ mediaItems: [SHMediaItem]) async throws
For information about concurrency and asynchronous code in Swift, see <doc ://com.apple.documentation/documentation/swift/calling-objective-c-apis-asynchronously>.

Saving a song to the user’s Shazam library also saves the following media item properties and their associated values:

SHMediaItemProperty/shazamID
SHMediaItemProperty/title
SHMediaItemProperty/subtitle, or SHMediaItemProperty/artist if the subtitle is unavailable

Note: Saving to the user’s Shazam library works only for songs with a valid SHMediaItemProperty/shazamID.

Parameters:
mediaItems: An array of media items that represents the songs to add to the library.
completionHandler: The system calls this completion block after adding the media items to the library.

This block takes the following parameters:

term error: An error object if a problem occurs when adding any item; otherwise, nil.

§Safety

completion_handler block must be sendable.

Source

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

👎Deprecated: Use SHLibrary instead

Source

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

👎Deprecated: Use SHLibrary instead

Methods from Deref<Target = NSObject>§

Source

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

Handle messages the object doesn’t recognize.

See Apple’s documentation for details.

Methods from Deref<Target = AnyObject>§

Source

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());

Source

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.

Source

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`
    }
}