Struct AVExternalStorageDevice

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

Available on crate feature AVExternalStorageDevice only.

An AVExternalStorageDevice represents a physical external storage device connected to the device that can be used to store captured media assets.

Each instance of AVExternalStorageDevice corresponds to a physical external storage device where captured media assets can be stored. Instances of AVExternalStorageDevice cannot be created directly. An array of all currently available external storage devices can be obtained using AVExternalStorageDeviceDiscoverySession.

Instances of AVExternalStorageDevice can be used with AVCaptureFileOutput subclasses for writing media files.

See also Apple’s documentation

Implementations

impl AVExternalStorageDevice

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

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

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

Display name of the external storage device.

This property can be used for displaying the name of an external storage device in a user interface. Will return nil if we fail to extract information from external storage device.

pub unsafe fn freeSize(&self) -> NSInteger

Current free size in bytes.

This property represents the free size available on the external storage device. Will return -1 if we fail to extract information from external storage device.

pub unsafe fn totalSize(&self) -> NSInteger

Total storage size in bytes.

This property represents the total storage size available on the external storage device. Will return -1 if we fail to extract information from external storage device.

pub unsafe fn isConnected(&self) -> bool

Indicates whether the external storage device is connected and available to the system.

The property gives the current connection status of the external storage device.

pub unsafe fn uuid(&self) -> Option<Retained<NSUUID>>

A unique identifier for external storage device.

This property can be used to select a specific external storage device with ImageCapture framework APIs to read media assets. Will return nil if we fail to extract information from external storage device. For example the string value of this property will match the value from [ICDevice UUIDString].

pub unsafe fn isNotRecommendedForCaptureUse(&self) -> bool

Indicates whether the external storage device is not recommended for capture use.

This property is used to let the client know if the external storage device is not suitable for camera capture.

pub unsafe fn nextAvailableURLsWithPathExtensions_error( &self, extension_array: &NSArray<NSString>, ) -> Result<Retained<NSArray<NSURL>>, Retained<NSError>>

Next available security-scoped, DCF compliant URL array with different path extensions.

Parameter extensionArray: An array of path extensions for the next available URL requested.

Parameter outError: An out parameter with error information indicating why the URL could not be provided. If this method is successful, error will be nil.

Returns: An array of DCF compliant security-scoped URL with all the path extensions requested.

Configures the folder structure (create a DCIM folder if there isn’t one already) on the external storage device to provide the next available unique DCF compliant security-scoped URL array with different path extensions.

Security-scoped URL requires the use of startAccessingSecurityScopedResource, and stopAccessingSecurityScopedResource for access. [nextAvailableURL startAccessingSecurityScopedResource]; . . . // your code to capture image / video . . . [nextAvailableURL stopAccessingSecurityScopedResource];

Use the +requestAccessWithCompletionHandler: method to request access to external storage device before getting the next available URL array else an error will be thrown.

impl AVExternalStorageDevice

AVExternalStorageDeviceAuthorization.

pub unsafe fn authorizationStatus() -> AVAuthorizationStatus

Available on crate feature AVCaptureDevice only.

Returns the client’s authorization status for capturing onto an external storage device connected to this device.

This method returns the AVAuthorizationStatus of the client for capturing onto an external storage device connected to this device. If the status is AVAuthorizationStatusNotDetermined, you may use the +requestAccessWithCompletionHandler: method to request access by prompting the user.

pub unsafe fn requestAccessWithCompletionHandler(handler: &Block<dyn Fn(Bool)>)

Available on crate feature block2 only.

Requests access to capture onto an external storage device connected to this device, showing a dialog to the user if necessary.

Parameter handler: A completion handler block called with the result of requesting access to capture onto an external storage device.

Use this method to request access to capture onto an external storage device connected to this device.

This call will not block while the user is being asked for access, allowing the client to continue running. Until access has been granted, trying to capture into detected external storage devices will result in an error. The user is only asked for permission the first time the client requests access, later calls use the authorization status selected by the user.

The completion handler is called on an arbitrary dispatch queue. It is the client’s responsibility to ensure that any UIKit-related updates are called on the main queue or main thread as a result.

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.

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<AVExternalStorageDevice> for AVExternalStorageDevice

fn as_ref(&self) -> &Self

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

impl AsRef<AnyObject> for AVExternalStorageDevice

fn as_ref(&self) -> &AnyObject

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

impl AsRef<NSObject> for AVExternalStorageDevice

fn as_ref(&self) -> &NSObject

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

impl Borrow<AnyObject> for AVExternalStorageDevice

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for AVExternalStorageDevice

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for AVExternalStorageDevice

const NAME: &'static str = "AVExternalStorageDevice"

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

type Super = NSObject

The superclass of this class.

type ThreadKind = <<AVExternalStorageDevice 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 AVExternalStorageDevice

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

Formats the value using the given formatter.

impl Deref for AVExternalStorageDevice

type Target = NSObject

The resulting type after dereferencing.

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

Dereferences the value.

impl Hash for AVExternalStorageDevice

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 AVExternalStorageDevice

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

where Self: Sized,

Increment the reference count of the receiver.

impl NSObjectProtocol for AVExternalStorageDevice

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 AVExternalStorageDevice

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 AVExternalStorageDevice

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

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

impl DowncastTarget for AVExternalStorageDevice

impl Eq for AVExternalStorageDevice