Struct AVCaptureIndexPicker

Source

pub struct AVCaptureIndexPicker { /* private fields */ }

Available on crate features AVCaptureControl and AVCaptureIndexPicker only.

Expand description

An AVCaptureControl for selecting from a set of mutually exclusive values by index.

AVCaptureIndexPicker is ideal when the set of values is provided by an indexed container like NSArray, Array, or Sequence. Controls may be added to an AVCaptureSession using -[AVCaptureSession addControl:].

AVCaptureIndexPicker uses zero-based indexing.

Implementations§

Source §

impl AVCaptureIndexPicker

Source

pub unsafe fn initWithLocalizedTitle_symbolName_numberOfIndexes( this: Allocated<Self>, localized_title: &NSString, symbol_name: &NSString, number_of_indexes: NSInteger, ) -> Retained<Self>

Initializes an AVCaptureIndexPicker to pick between numberOfIndexes values.

Parameter localizedTitle: A localized string that describes the picker’s action.

Parameter symbolName: The name of a symbol to represent the picker.

Parameter numberOfIndexes: The number of indexes to pick between. numberOfIndexes must be greater than 0, otherwise an NSInvalidArgumentException is thrown.

Returns: An AVCaptureIndexPicker instance that picks between numberOfIndexes values.

Suitable when your picked values don’t need titles.

Source

pub unsafe fn initWithLocalizedTitle_symbolName_numberOfIndexes_localizedTitleTransform( this: Allocated<Self>, localized_title: &NSString, symbol_name: &NSString, number_of_indexes: NSInteger, localized_title_transform: &DynBlock<dyn Fn(NSInteger) -> NonNull<NSString> + '_>, ) -> Retained<Self>

Available on crate feature block2 only.

Initializes an AVCaptureIndexPicker to pick between numberOfIndexes values.

Parameter localizedTitle: A localized string that describes the picker’s action.

Parameter symbolName: The name of a symbol to represent the picker.

Parameter numberOfIndexes: The number of indexes to pick between. numberOfIndexes must be greater than 0, otherwise an NSInvalidArgumentException is thrown.

Parameter localizedTitleTransform: A transformation from index to localized title.

Returns: An AVCaptureIndexPicker instance that picks between numberOfIndexes values with a transformation from index to localized title.

Suitable when you want to provide a title for each picked value lazily.

§Safety

localized_title_transform block’s return must be a valid pointer.

Source

pub unsafe fn initWithLocalizedTitle_symbolName_localizedIndexTitles( this: Allocated<Self>, localized_title: &NSString, symbol_name: &NSString, localized_index_titles: &NSArray<NSString>, ) -> Retained<Self>

Initializes an AVCaptureIndexPicker to pick between localizedIndexTitles.count values.

Parameter localizedTitle: A localized string that describes the picker’s action.

Parameter symbolName: The name of a symbol to represent the picker.

Parameter localizedIndexTitles: The titles to use for each index. localizedIndexTitles must be greater than 0, otherwise an NSInvalidArgumentException is thrown.

Returns: An AVCaptureIndexPicker instance that picks between localizedIndexTitles.count values.

Suitable when you already have an array containing a title for each picked value.

Source

pub unsafe fn selectedIndex(&self) -> NSInteger

The currently selected index.

Because the camera system may be independent from the main thread or MainThreadOnly, selectedIndex must be changed on actionQueue – the queue provided to setActionQueue:action:. The default value is 0. An index may only be set if it is greater than 0 or less than numberOfIndexes, otherwise an NSInvalidArgumentException is thrown.

Source

pub unsafe fn setSelectedIndex(&self, selected_index: NSInteger)

Setter for selectedIndex.

Source

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

A localized string that describes the picker’s action.

Source

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

The name of a symbol to represent the picker.

Source

pub unsafe fn numberOfIndexes(&self) -> NSInteger

The number of indexes to pick between.

Source

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

The titles used for each index.

Source

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

A string that identifies the picker.

Source

pub unsafe fn setAccessibilityIdentifier( &self, accessibility_identifier: Option<&NSString>, )

Setter for accessibilityIdentifier.

This is copied when set.

Source

pub unsafe fn setActionQueue_action( &self, action_queue: &DispatchQueue, action: &DynBlock<dyn Fn(NSInteger)>, )

Available on crate features block2 and dispatch2 only.

Configures the picker’s action which is called on actionQueue whenever the index of the picker is changed.

Parameter actionQueue: A queue for the action to be called.

Parameter action: An action called on actionQueue whenever the selected index of the picker is changed.

Because the camera system may be independent from the main thread or MainThreadOnly, action is always called on an internal DispatchSerialQueue targeted at actionQueue.

If action modifies a property of the camera system, actionQueue must represent the same exclusive execution context as the camera system (see isSameExclusiveExecutionContext).

§Safety

action_queue possibly has additional threading requirements.

Source §

impl AVCaptureIndexPicker

Methods declared on superclass AVCaptureControl.

Source

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

Source

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

Methods from Deref<Target = AVCaptureControl>§

Source

pub unsafe fn isEnabled(&self) -> bool

Indicates whether the control should be enabled for user interaction.

The value of this property is a BOOL that determines whether the control should be enabled for user interaction. Clients can set this property to keep a control added to an AVCaptureSession but prevent it from being interacted with by the user. A control’s value may still be changed while it is disabled. The default value is YES.

Source

pub unsafe fn setEnabled(&self, enabled: bool)

Setter for isEnabled.

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`
    }
}