Struct AVAssetResourceLoadingContentInformationRequest

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pub struct AVAssetResourceLoadingContentInformationRequest { /* private fields */ }

Available on crate feature AVAssetResourceLoader only.

Expand description

Apple’s documentation

Implementations§

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

A UTI that indicates the type of data contained by the requested resource.

Before you finish loading an AVAssetResourceLoadingRequest, if its contentInformationRequest is not nil, you should set the value of this property to a UTI indicating the type of data contained by the requested resource.

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pub unsafe fn setContentType(&self, content_type: Option<&NSString>)

Setter for contentType.

This is copied when set.

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

An array showing the types of data which will be accepted as a valid response for the requested resource.

If an AVAssetResourceLoadingRequest’s contentInformationRequest is not nil, ensure that the value assigned to the contentType property is in this array. Otherwise, calling -finishLoading on the associated request will result in an exception.

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pub unsafe fn contentLength(&self) -> c_longlong

Indicates the length of the requested resource, in bytes.

Before you finish loading an AVAssetResourceLoadingRequest, if its contentInformationRequest is not nil, you should set the value of this property to the number of bytes contained by the requested resource.

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pub unsafe fn setContentLength(&self, content_length: c_longlong)

Setter for contentLength.

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pub unsafe fn isByteRangeAccessSupported(&self) -> bool

Indicates whether random access to arbitrary ranges of bytes of the resource is supported. Such support also allows portions of the resource to be requested more than once.

Before you finish loading an AVAssetResourceLoadingRequest, if its contentInformationRequest is not nil, you should set the value of this property to YES if you support random access to arbitrary ranges of bytes of the resource. If you do not set this property to YES for resources that must be loaded incrementally, loading of the resource may fail. Such resources include anything that contains media data.

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pub unsafe fn setByteRangeAccessSupported( &self, byte_range_access_supported: bool, )

Setter for isByteRangeAccessSupported.

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pub unsafe fn renewalDate(&self) -> Option<Retained<NSDate>>

For resources that expire, the date at which a new AVAssetResourceLoadingRequest will be issued for a renewal of this resource, if the media system still requires it.

Before you finish loading an AVAssetResourceLoadingRequest, if the resource is prone to expiry you should set the value of this property to the date at which a renewal should be triggered. This value should be set sufficiently early enough to allow an AVAssetResourceRenewalRequest, delivered to your delegate via -resourceLoader:shouldWaitForRenewalOfRequestedResource:, to finish before the actual expiry time. Otherwise media playback may fail.

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pub unsafe fn setRenewalDate(&self, renewal_date: Option<&NSDate>)

Setter for renewalDate.

This is copied when set.

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pub unsafe fn isEntireLengthAvailableOnDemand(&self) -> bool

Indicates whether asset data loading can expect data to be produced immediately.

Before you finish loading an AVAssetResourceLoadingRequest, if its contentInformationRequest is not nil, you may set this property to YES to indicate that all asset data can be produced immediately, e.g., because the data is fully cached, or because the custom URL scheme ultimately refers to files on local storage. This allows significant data flow optimizations. For backward compatibility, this property defaults to NO.

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pub unsafe fn setEntireLengthAvailableOnDemand( &self, entire_length_available_on_demand: bool, )

Setter for isEntireLengthAvailableOnDemand.

Methods from Deref<Target = NSObject>§

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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`
    }
}