Struct UICellAccessory

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

Available on crate feature UICellAccessory only.

Expand description

Abstract base class. Do not instantiate directly.

Implementations§

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impl UICellAccessory

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pub unsafe fn displayedState(&self) -> UICellAccessoryDisplayedState

The state(s) for which the accessory should be displayed.

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pub unsafe fn setDisplayedState( &self, displayed_state: UICellAccessoryDisplayedState, )

Setter for displayedState.

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pub unsafe fn isHidden(&self) -> bool

Hidden accessories take up space in the layout, but are not visible and do not provide any behaviors. Use this property to achieve a consistent layout across cells when some show the accessory and others do not.

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pub unsafe fn setHidden(&self, hidden: bool)

Setter for isHidden.

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pub unsafe fn reservedLayoutWidth(&self) -> CGFloat

Available on crate feature objc2-core-foundation only.

The layout width that is reserved for the accessory, inside which the accessory will be centered. This is used to ensure horizontal alignment of different accessories in adjacent cells, even when the actual accessory view width varies slightly. A value of 0 means the actual width of the accessory will be used. Use UICellAccessoryStandardDimension to request the standard width.

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pub unsafe fn setReservedLayoutWidth(&self, reserved_layout_width: CGFloat)

Available on crate feature objc2-core-foundation only.

Setter for reservedLayoutWidth.

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pub unsafe fn tintColor(&self) -> Option<Retained<UIColor>>

Available on crate feature UIColor only.

The tint color to apply to the accessory. Default value is nil, which uses the system default.

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pub unsafe fn setTintColor(&self, tint_color: Option<&UIColor>)

Available on crate feature UIColor only.

Setter for tintColor.

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

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

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impl UICellAccessory

Methods declared on superclass NSObject.

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pub unsafe fn new(mtm: MainThreadMarker) -> Retained<Self>

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impl UICellAccessory

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pub unsafe fn position_before_accessory_of_class( accessory_class: &AnyClass, ) -> UICellAccessoryPosition

Available on crate feature block2 only.

Positions the accessory before the accessory matching the class specified, or at the beginning if not found.

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pub unsafe fn position_after_accessory_of_class( accessory_class: &AnyClass, ) -> UICellAccessoryPosition

Available on crate feature block2 only.

Positions the accessory after the accessory matching the class specified, or at the end if not found.

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

Available on crate feature UIIndirectScribbleInteraction only.

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.

Available on crate feature UIIndirectScribbleInteraction only.

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,

Available on crate feature UIIndirectScribbleInteraction only.

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`
    }
}