Struct PHASEDucker

Source

pub struct PHASEDucker { /* private fields */ }

Available on crate feature PHASEDucker only.

Expand description

A PHASEDucker is used to describe ducking behavior across different groups.

Implementations§

Source §

pub unsafe fn initWithEngine_sourceGroups_targetGroups_gain_attackTime_releaseTime_attackCurve_releaseCurve( this: Allocated<Self>, engine: &PHASEEngine, source_groups: &NSSet<PHASEGroup>, target_groups: &NSSet<PHASEGroup>, gain: c_double, attack_time: c_double, release_time: c_double, attack_curve: PHASECurveType, release_curve: PHASECurveType, ) -> Retained<Self>

Available on crate features PHASEEngine and PHASEGroup and PHASETypes only.

Whenever a generator node from any source group plays, all the generator nodes in the target groups will be ducked by the given gain using the given attack and release times.

Note: The ducker is initialially inactive. The client must call activate() to make it active. Once a ducker is active, it will listen for generator nodes to start playback in source groups. Once triggered, it will duck its target groups. Deactivating a ducker will make it stop listening. Furthermore, it will enter the release phase if it has been previously triggered. Dealloc’ing a ducker will force the ducker into its release phase if it is actively ducking and remove it from the system when it finishes.

Parameter engine: The engine to register this ducker with.

Parameter sourceGroups: The source groups that will trigger the ducker when a sound in one of the source groups starts playback.

Parameter targetGroups: The target groups that will be ducked when a sound in one of the source groups triggers the ducker.

Parameter gain: The linear gain scalar to apply when the ducker is engaged. 0 means full attenuation. 1 is no attenuation. Values are clamped to the range [0, 1].

Parameter attackTime: The time for the attenuation gain to ramp into effect. This value is scaled by unitsPerSecond internally, so can be provided at the client’s native time scale.

Parameter releaseTime: The time for the ducked sounds to ramp back to their original level. This value is scaled by unitsPerSecond internally, so can be provided at the client’s native time scale.

Parameter attackCurve: The type of curve function to use during the attack phase of gain reduction.

Parameter releaseCurve: The type of curve function to use during the release phase of gain reduction.

Source

pub unsafe fn activate(&self)

Activates the ducker

Source

pub unsafe fn deactivate(&self)

Deactivates the ducker

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pub unsafe fn sourceGroups(&self) -> Retained<NSSet<PHASEGroup>>

Available on crate feature PHASEGroup only.

The source groups that will trigger the ducker when a sound in one of the source groups starts playback.

Source

pub unsafe fn targetGroups(&self) -> Retained<NSSet<PHASEGroup>>

Available on crate feature PHASEGroup only.

The target groups that will be ducked when a sound in one of the source groups triggers the ducker.

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pub unsafe fn isActive(&self) -> bool

YES if the ducker is active; otherwise, NO.

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pub unsafe fn gain(&self) -> c_double

Linear gain scalar.

Note: Values are clamped to the range [0, 1]. Default value is 1.

Source

pub unsafe fn attackTime(&self) -> c_double

The time for the attenuation gain to ramp into effect.

Note: The attack time is scaled by unitsPerSecond internally, so can be provided at the client’s native time scale.

Source

pub unsafe fn releaseTime(&self) -> c_double

The time for the ducked sounds to ramp back to their original level.

Note: The release time is scaled by unitsPerSecond internally, so can be provided at the client’s native time scale.

Source

pub unsafe fn attackCurve(&self) -> PHASECurveType

Available on crate feature PHASETypes only.

The type of curve function to use during the attack phase of gain reduction.

Source

pub unsafe fn releaseCurve(&self) -> PHASECurveType

Available on crate feature PHASETypes only.

The type of curve function to use during the release phase of gain reduction.

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

The identifier that uniquely represents this ducker.

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`
    }
}