Struct AVMusicTrack 

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

Available on crate feature AVAudioSequencer only.

A collection of music events which will be sent to a given destination, and which can be offset, muted, etc. independently of events in other tracks.

AVMusicTrack is not a container of AVMusicEvents - it will not hold references to AVMusicEvents that are added, so an application should maintain its own if it is desired.

See also Apple’s documentation

Implementations

impl AVMusicTrack

pub unsafe fn destinationAudioUnit(&self) -> Option<Retained<AVAudioUnit>>

Available on crate features AVAudioNode and AVAudioUnit only.

The AVAudioUnit which will receive the track’s events

This is mutually exclusive with setting a destination MIDIEndpoint. The AU must already be attached to an audio engine, and the track must be part of the AVAudioSequencer associated with that engine. When playing, the track will send its events to that AVAudioUnit. The destination AU cannot be changed while the track’s sequence is playing.

pub unsafe fn setDestinationAudioUnit( &self, destination_audio_unit: Option<&AVAudioUnit>, )

Available on crate features AVAudioNode and AVAudioUnit only.

Setter for destinationAudioUnit.

pub unsafe fn destinationMIDIEndpoint(&self) -> MIDIEndpointRef

Available on crate feature objc2-core-midi only.

pub unsafe fn setDestinationMIDIEndpoint( &self, destination_midi_endpoint: MIDIEndpointRef, )

Available on crate feature objc2-core-midi only.

Setter for destinationMIDIEndpoint.

pub unsafe fn loopRange(&self) -> AVBeatRange

Available on crate feature AVAudioTypes only.

The timestamp range in beats for the loop

The loop is set by specifying its beat range.

pub unsafe fn setLoopRange(&self, loop_range: AVBeatRange)

Available on crate feature AVAudioTypes only.

Setter for loopRange.

pub unsafe fn isLoopingEnabled(&self) -> bool

Determines whether or not the track is looped.

If loopRange has not been set, the full track will be looped.

pub unsafe fn setLoopingEnabled(&self, looping_enabled: bool)

Setter for isLoopingEnabled.

pub unsafe fn numberOfLoops(&self) -> NSInteger

The number of times that the track’s loop will repeat

If set to AVMusicTrackLoopCountForever, the track will loop forever. Otherwise, legal values start with 1.

pub unsafe fn setNumberOfLoops(&self, number_of_loops: NSInteger)

Setter for numberOfLoops.

pub unsafe fn offsetTime(&self) -> AVMusicTimeStamp

Available on crate feature AVAudioTypes only.

Offset the track’s start time to the specified time in beats

By default this value is zero.

pub unsafe fn setOffsetTime(&self, offset_time: AVMusicTimeStamp)

Available on crate feature AVAudioTypes only.

Setter for offsetTime.

pub unsafe fn isMuted(&self) -> bool

Whether the track is muted

pub unsafe fn setMuted(&self, muted: bool)

Setter for isMuted.

pub unsafe fn isSoloed(&self) -> bool

Whether the track is soloed

pub unsafe fn setSoloed(&self, soloed: bool)

Setter for isSoloed.

pub unsafe fn lengthInBeats(&self) -> AVMusicTimeStamp

Available on crate feature AVAudioTypes only.

The total duration of the track in beats

This will return the beat of the last event in the track plus any additional time that may be needed for fading out of ending notes or round a loop point to musical bar, etc. If this has not been set by the user, the track length will always be adjusted to the end of the last active event in a track and is adjusted dynamically as events are added or removed.

The property will return the maximum of the user-set track length, or the calculated length.

pub unsafe fn setLengthInBeats(&self, length_in_beats: AVMusicTimeStamp)

Available on crate feature AVAudioTypes only.

Setter for lengthInBeats.

pub unsafe fn lengthInSeconds(&self) -> NSTimeInterval

The total duration of the track in seconds

This will return time of the last event in the track plus any additional time that may be needed for fading out of ending notes or round a loop point to musical bar, etc. If this has not been set by the user, the track length will always be adjusted to the end of the last active event in a track and is adjusted dynamically as events are added or removed.

The property will return the maximum of the user-set track length, or the calculated length.

pub unsafe fn setLengthInSeconds(&self, length_in_seconds: NSTimeInterval)

Setter for lengthInSeconds.

pub unsafe fn timeResolution(&self) -> NSUInteger

The time resolution value for the sequence, in ticks (pulses) per quarter note (PPQN)

If a MIDI file was used to construct the containing sequence, the resolution will be what was in the file. If you want to keep a time resolution when writing a new file, you can retrieve this value and then specify it when calling -[AVAudioSequencer writeToFile:flags:withResolution]. It has no direct bearing on the rendering or notion of time of the sequence itself, just its representation in MIDI files. By default this is set to either 480 if the sequence was created manually, or a value based on what was in a MIDI file if the sequence was created from a MIDI file.

This can only be retrieved from the tempo track.

impl AVMusicTrack

Methods declared on superclass NSObject.

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

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

impl AVMusicTrack

AVMusicTrackEditor.

pub unsafe fn usesAutomatedParameters(&self) -> bool

Indicates whether the track is an automation track.

If set to YES, this can be used to contain, parameter automation events, exclusively. Adding any other event types will generate exceptions.

If a track already contains non-parameter events, setting this to YES will generate an exception.

pub unsafe fn setUsesAutomatedParameters(&self, uses_automated_parameters: bool)

Setter for usesAutomatedParameters.

pub unsafe fn addEvent_atBeat( &self, event: &AVMusicEvent, beat: AVMusicTimeStamp, )

Available on crate features AVAudioTypes and AVMusicEvents only.

Adds an AVMusicEvent’s contents to a track at the specified AVMusicTimeStamp.

Parameter event: the event to be added

Parameter beat: the AVMusicTimeStamp

Because event contents are copied into the track, the same event may be added multiple times at different timestamps.

There are restrictions on which AVMusicEvent subclasses may be added to different tracks:

• Only AVExtendedTempoEvents and AVMIDIMetaEvents with certain AVMIDIMetaEventTypes can be added to an AVMusicSequence’s tempo track (see AVMIDIMetaEvent).

• AVParameterEvents can only be added to automation tracks (see AVParameterEvent).

• All other event subclasses cannot be added to tempo or automation tracks.

pub unsafe fn moveEventsInRange_byAmount( &self, range: AVBeatRange, beat_amount: AVMusicTimeStamp, )

Available on crate feature AVAudioTypes only.

Shift the beat location of all events in the given beat range by the amount specified.

Parameter range: the range of beats. Must be a valid AVBeatRange.

Parameter beatAmount: the amount in beats to shift each event. The amount may be positive or negative.

pub unsafe fn clearEventsInRange(&self, range: AVBeatRange)

Available on crate feature AVAudioTypes only.

Removes all events in the given beat range, erasing that portion of the AVMusicTrack.

Parameter range: the range of beats. Must be a valid AVBeatRange.

All events outside of the specified range left unmodified.

pub unsafe fn cutEventsInRange(&self, range: AVBeatRange)

Available on crate feature AVAudioTypes only.

Removes all events in the given beat range, splicing out that portion of the AVMusicTrack.

Parameter range: the range of beats. Must be a valid AVBeatRange.

All events past the end of the specified range will be shifted backward by the duration of the range.

pub unsafe fn copyEventsInRange_fromTrack_insertAtBeat( &self, range: AVBeatRange, source_track: &AVMusicTrack, insert_start_beat: AVMusicTimeStamp, )

Available on crate feature AVAudioTypes only.

Copies all events in the given beat range from the specified AVMusicTrack, splicing them into the current AVMusicTrack.

Parameter range: the range of beats. Must be a valid AVBeatRange.

Parameter sourceTrack: the AVMusicTrack to copy the events from.

Parameter insertStartBeat: the start beat at which the copied events should be spliced in.

All events originally at or past insertStartBeat will be shifted forward by the duration of the copied-in range.

pub unsafe fn copyAndMergeEventsInRange_fromTrack_mergeAtBeat( &self, range: AVBeatRange, source_track: &AVMusicTrack, merge_start_beat: AVMusicTimeStamp, )

Available on crate feature AVAudioTypes only.

Copies all events in the given beat range from the specified AVMusicTrack, merging them into the current AVMusicTrack.

Parameter range: the range of beats. Must be a valid AVBeatRange.

Parameter sourceTrack: the AVMusicTrack to copy the events from.

Parameter insertStartBeat: the start beat at which the copied events should be merged.

All events originally at or past mergeStartBeat will be left unmodified.

Copying events from track to track follows the same type-exclusion rules as adding events: The operation will generate an exception.

pub unsafe fn enumerateEventsInRange_usingBlock( &self, range: AVBeatRange, block: AVMusicEventEnumerationBlock, )

Available on crate features AVAudioTypes and AVMusicEvents and block2 only.

Iterates through the AVMusicEvents within the AVMusicTrack whose timestamps fit within the range, calling the block for each.

Parameter block: the AVMusicEventEnumerationBlock to call for each event.

Each event returned via the block should be examined using NSObject(isKindOfClass:) to determine its subclass and then cast and accessed/edited accordingly.

The iteration may continue after removing an event.

The event objects returned via the block will not be the same instances which were added to the AVMusicTrack, though their contents will be identical.

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<AVMusicTrack> for AVMusicTrack

fn as_ref(&self) -> &Self

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

impl AsRef<AnyObject> for AVMusicTrack

fn as_ref(&self) -> &AnyObject

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

impl AsRef<NSObject> for AVMusicTrack

fn as_ref(&self) -> &NSObject

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

impl Borrow<AnyObject> for AVMusicTrack

fn borrow(&self) -> &AnyObject

Immutably borrows from an owned value.

impl Borrow<NSObject> for AVMusicTrack

fn borrow(&self) -> &NSObject

Immutably borrows from an owned value.

impl ClassType for AVMusicTrack

const NAME: &'static str = "AVMusicTrack"

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

type Super = NSObject

The superclass of this class.

type ThreadKind = <<AVMusicTrack 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 AVMusicTrack

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

Formats the value using the given formatter.

impl Deref for AVMusicTrack

type Target = NSObject

The resulting type after dereferencing.

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

Dereferences the value.

impl Hash for AVMusicTrack

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 AVMusicTrack

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

where Self: Sized,

Increment the reference count of the receiver.

impl NSObjectProtocol for AVMusicTrack

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 AVMusicTrack

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 AVMusicTrack

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

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

impl DowncastTarget for AVMusicTrack

impl Eq for AVMusicTrack