Struct AVCaption 

pub struct AVCaption { /* private fields */ }

Available on crate feature AVCaption only.

An instance of AVCaption represents a unit of text that is active at a particular time range.

A caption contains one meaningful sentence, paragraph, or otherwise known as a caption cue. Within the active time range, it may perform animation (e.g. Karaoke), rolling-up, changes the visibility, or any other dynamic styling.

See also Apple’s documentation

Implementations

impl AVCaption

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

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

pub unsafe fn initWithText_timeRange( this: Allocated<Self>, text: &NSString, time_range: CMTimeRange, ) -> Retained<Self>

Available on crate feature objc2-core-media only.

Initializes an instance of AVCaption with the given text and time range.

Parameter text: The text for the new caption object. See text property for the available character sets and other restrictions.

Parameter timeRange: The time range for the new caption object.

Returns: An instance of AVCaption that carries the given text and time range.

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

The text content of the caption.

The text may contain any of the line breaking character sequences (LF, CR, or CF+LF) and separating the lines in the presentation.

The Apple iTT format supports all Unicode code points allowed in a XML document. Any XML special characters such as ’ & ’ are converted to a corresponding character reference syntax when written to the destination file.

CEA608 closed captions support the following Unicode characters. Range: U+0020 - U+005F Range: U+0061 - U+007E Range: U+00A1 - U+00A5 Characters: U+00A9, U+00AB, U+00AE, U+00B0, U+00BB, U+00BD, U+00BF Range: U+00C0-U+00C5 Range: U+00C7-U+00CF Range: U+00D1-U+00D6 Range: U+00D8-U+00DC Range: U+00DF-U+00E5 Range: U+00E7-U+00EF Range: U+00F1-U+00FC Range: U+2018-U+2019 Range: U+2018-U+201D Character: U+2022 Range: U+2120-U+2122 Characters: U+2501, U+2503, U+250F, U+2513, U+2517, U+251B, U+2588, U+266A

CEA608 closed captions don’t support the line breaking character sequences (LF, CR, or CF+LF).

pub unsafe fn timeRange(&self) -> CMTimeRange

Available on crate feature objc2-core-media only.

The time range during which the caption should be presented.

Apple iTT format doesn’t allow two captions to have overlapped time range except when the two captions are associated with different regions.

CEA608 closed caption time ranges can’t start with zero, because the decoder needs some transmission time. CEA608 closed caption time ranges should be aligned with the video frame rate because this is how often the commands are delivered.

impl AVCaption

Styling.

pub unsafe fn textColorAtIndex_range( &self, index: NSInteger, out_range: *mut NSRange, ) -> Option<Retained<CGColor>>

Available on crate feature objc2-core-graphics only.

The color of the character(s).

A value of NULL means that the color is not specified. The caller must release the returned object via CGColorRelease. The range parameter receives UTF-16 code unit index range the style is effective. The range will indicate where the current style returned (including NULL) will be active and allows discovery of the next change in the style.

CEA608 closed captions support the following 8 colors with 1.0 alpha value. White (RGB:1.0, 1.0, 1.0) Red (RGB:1.0, 0.0, 0.0) Blue (RGB:0.0, 0.0, 1.0) Green (RGB:0.0, 1.0, 0.0) Yellow (RGB:1.0, 1.0, 0.0) Cyan (RGB:0.0, 1.0, 1.0) Magenta (RGB:1.0, 0.0, 1.0) Black (RGB:0.0, 0.0, 0.0)

Safety

out_range must be a valid pointer or null.

pub unsafe fn backgroundColorAtIndex_range( &self, index: NSInteger, out_range: *mut NSRange, ) -> Option<Retained<CGColor>>

Available on crate feature objc2-core-graphics only.

The background color of the character(s).

A value of NULL means that the color is not specified. The caller must release the returned object via CGColorRelease. The range parameter receives UTF-16 code unit index range the style is effective. After returning from the call, the range will indicate where the current style returned (including NULL) will be active and allows discovery of the next change in the style.

iTT format ignores this property.

CEA608 closed captions support the following 8 colors with 1.0, 0.5 and 0.0 alpha values. White (RGB:1.0, 1.0, 1.0) Red (RGB:1.0, 0.0, 0.0) Blue (RGB:0.0, 0.0, 1.0) Green (RGB:0.0, 1.0, 0.0) Yellow (RGB:1.0, 1.0, 0.0) Cyan (RGB:0.0, 1.0, 1.0) Magenta (RGB:1.0, 0.0, 1.0) Black (RGB:0.0, 0.0, 0.0)

Safety

out_range must be a valid pointer or null.

pub unsafe fn fontWeightAtIndex_range( &self, index: NSInteger, out_range: *mut NSRange, ) -> AVCaptionFontWeight

Indicates the font weight of the character(s).

The range parameter receives UTF-16 code unit index range the style is effective. After returning from the call, the range will indicate where the current style returned will be active and allows discovery of the next change in the style.

CEA608 closed captions ignore this property.

A visible distinction between AVCaptionFontWeightNormal and AVCaptionFontWeightBold may not exist if the font used has only one weight. This can be more common with CJK fonts where individual fonts can be quite large in terms of storage. Nevertheless, AVCaption still carries the font weight semantics so if the same AVCaption is applied to a different font having multiple weights, the distinction will become visible.

Safety

out_range must be a valid pointer or null.

pub unsafe fn fontStyleAtIndex_range( &self, index: NSInteger, out_range: *mut NSRange, ) -> AVCaptionFontStyle

Indicates the font style of the character(s).

The range parameter receives UTF-16 code unit index range the style is effective. After returning from the call, the range will indicate where the current style returned will be active and allows discovery of the next change in the style.

Some writing systems may not have italic glyphs for characters and so fonts with italic forms are not available. For example, Japanese fonts do not typically have italic forms for most characters although there may be special cases for Latin characters. Nevertheless, AVCaption still carries the font style semantics even though there may be no visible rendering distinction between using AVCaptionFontStyleNormal and AVCaptionFontStyleItalic with that language.

Safety

out_range must be a valid pointer or null.

pub unsafe fn decorationAtIndex_range( &self, index: NSInteger, out_range: *mut NSRange, ) -> AVCaptionDecoration

Character decoration

The value of OR-ed value of AVCaptionDecoration as NSInteger. The range parameter receives UTF-16 code unit index range the style is effective. After returning from the call, the range will indicate where the current style returned will be active and allows discovery of the next change in the style.

CEA608 closed captions support only AVCaptionDecorationNone and AVCaptionDecorationUnderline.

Safety

out_range must be a valid pointer or null.

pub unsafe fn textCombineAtIndex_range( &self, index: NSInteger, out_range: *mut NSRange, ) -> AVCaptionTextCombine

Text combine (Tate-Chu-Yoko)

The style is effective only in a vertical text region.

When specified, the renderer combines all the characters in the style range so that their glyph areas consume the nominal bounding box of a single em square of the surrounding vertical text.

Safety

out_range must be a valid pointer or null.

pub unsafe fn rubyAtIndex_range( &self, index: NSInteger, out_range: *mut NSRange, ) -> Option<Retained<AVCaptionRuby>>

Get Ruby associated with the characters.

The range parameter receives UTF-16 code unit index range where the ruby text is applied. After returning from the call, the range will indicate where the current style returned (including NULL) will be active and allows discovery of the next change in the style.

It returns nil when the text doesn’t have a ruby at the position.

CEA608 closed captions ignore this property.

Safety

out_range must be a valid pointer or null.

impl AVCaption

Region.

pub unsafe fn region(&self) -> Option<Retained<AVCaptionRegion>>

The region where the caption is placed.

It can be nil when the underlying caption format doesn’t support or use regions.

pub unsafe fn textAlignment(&self) -> AVCaptionTextAlignment

The text alignment within the containing region.

This property throws an exception if a value is set which is not a valid AVCaptionTextAlignment.

impl AVCaption

Animation.

pub unsafe fn animation(&self) -> AVCaptionAnimation

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.

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());

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<AVCaption> for AVCaption

fn as_ref(&self) -> &Self

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

impl AsRef<AVCaption> for AVMutableCaption

fn as_ref(&self) -> &AVCaption

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

impl AsRef<AnyObject> for AVCaption

fn as_ref(&self) -> &AnyObject

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

impl AsRef<NSObject> for AVCaption

fn as_ref(&self) -> &NSObject

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

impl Borrow<AVCaption> for AVMutableCaption

fn borrow(&self) -> &AVCaption

Immutably borrows from an owned value.

impl Borrow<AnyObject> for AVCaption

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for AVCaption

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for AVCaption

const NAME: &'static str = "AVCaption"

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

type Super = NSObject

The superclass of this class.

type ThreadKind = <<AVCaption 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 CopyingHelper for AVCaption

type Result = AVCaption

The immutable counterpart of the type, or Self if the type has no immutable counterpart.

impl Debug for AVCaption

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

Formats the value using the given formatter.

impl Deref for AVCaption

type Target = NSObject

The resulting type after dereferencing.

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

Dereferences the value.

impl Hash for AVCaption

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 AVCaption

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

where Self: Sized,

Increment the reference count of the receiver.

impl MutableCopyingHelper for AVCaption

type Result = AVMutableCaption

The mutable counterpart of the type, or Self if the type has no mutable counterpart.

impl NSCoding for AVCaption

unsafe fn encodeWithCoder(&self, coder: &NSCoder)

where Self: Sized + Message,

Safety

unsafe fn initWithCoder( this: Allocated<Self>, coder: &NSCoder, ) -> Option<Retained<Self>>

where Self: Sized + Message,

Safety

impl NSCopying for AVCaption

fn copy(&self) -> Retained<Self::Result>

where Self: Sized + Message + CopyingHelper,

Returns a new instance that’s a copy of the receiver.

unsafe fn copyWithZone(&self, zone: *mut NSZone) -> Retained<Self::Result>

where Self: Sized + Message + CopyingHelper,

Returns a new instance that’s a copy of the receiver.

impl NSMutableCopying for AVCaption

fn mutableCopy(&self) -> Retained<Self::Result>

where Self: Sized + Message + MutableCopyingHelper,

Returns a new instance that’s a mutable copy of the receiver.

unsafe fn mutableCopyWithZone( &self, zone: *mut NSZone, ) -> Retained<Self::Result>

where Self: Sized + Message + MutableCopyingHelper,

Returns a new instance that’s a mutable copy of the receiver.

impl NSObjectProtocol for AVCaption

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 NSSecureCoding for AVCaption

fn supportsSecureCoding() -> bool

where Self: Sized + ClassType,

impl PartialEq for AVCaption

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 AVCaption

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

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

impl DowncastTarget for AVCaption

impl Eq for AVCaption