#[repr(C)]pub struct NSLayoutYAxisAnchor { /* private fields */ }
NSLayoutAnchor
only.Expand description
Implementations§
Source§impl NSLayoutYAxisAnchor
impl NSLayoutYAxisAnchor
pub unsafe fn anchorWithOffsetToAnchor( &self, other_anchor: &NSLayoutYAxisAnchor, ) -> Retained<NSLayoutDimension>
pub unsafe fn constraintEqualToSystemSpacingBelowAnchor_multiplier( &self, anchor: &NSLayoutYAxisAnchor, multiplier: CGFloat, ) -> Retained<NSLayoutConstraint>
NSLayoutConstraint
and objc2-core-foundation
only.pub unsafe fn constraintGreaterThanOrEqualToSystemSpacingBelowAnchor_multiplier( &self, anchor: &NSLayoutYAxisAnchor, multiplier: CGFloat, ) -> Retained<NSLayoutConstraint>
NSLayoutConstraint
and objc2-core-foundation
only.pub unsafe fn constraintLessThanOrEqualToSystemSpacingBelowAnchor_multiplier( &self, anchor: &NSLayoutYAxisAnchor, multiplier: CGFloat, ) -> Retained<NSLayoutConstraint>
NSLayoutConstraint
and objc2-core-foundation
only.Methods from Deref<Target = NSLayoutAnchor>§
pub unsafe fn constraintEqualToAnchor( &self, anchor: &NSLayoutAnchor<AnchorType>, ) -> Retained<NSLayoutConstraint>
NSLayoutConstraint
only.pub unsafe fn constraintGreaterThanOrEqualToAnchor( &self, anchor: &NSLayoutAnchor<AnchorType>, ) -> Retained<NSLayoutConstraint>
NSLayoutConstraint
only.pub unsafe fn constraintLessThanOrEqualToAnchor( &self, anchor: &NSLayoutAnchor<AnchorType>, ) -> Retained<NSLayoutConstraint>
NSLayoutConstraint
only.pub unsafe fn constraintEqualToAnchor_constant( &self, anchor: &NSLayoutAnchor<AnchorType>, c: CGFloat, ) -> Retained<NSLayoutConstraint>
NSLayoutConstraint
and objc2-core-foundation
only.pub unsafe fn constraintGreaterThanOrEqualToAnchor_constant( &self, anchor: &NSLayoutAnchor<AnchorType>, c: CGFloat, ) -> Retained<NSLayoutConstraint>
NSLayoutConstraint
and objc2-core-foundation
only.pub unsafe fn constraintLessThanOrEqualToAnchor_constant( &self, anchor: &NSLayoutAnchor<AnchorType>, c: CGFloat, ) -> Retained<NSLayoutConstraint>
NSLayoutConstraint
and objc2-core-foundation
only.pub unsafe fn name(&self) -> Retained<NSString>
pub unsafe fn item(&self) -> Option<Retained<AnyObject>>
pub unsafe fn hasAmbiguousLayout(&self) -> bool
pub unsafe fn constraintsAffectingLayout( &self, ) -> Retained<NSArray<NSLayoutConstraint>>
NSLayoutConstraint
only.Methods from Deref<Target = NSObject>§
Sourcepub fn doesNotRecognizeSelector(&self, sel: Sel) -> !
pub fn doesNotRecognizeSelector(&self, sel: Sel) -> !
Handle messages the object doesn’t recognize.
See Apple’s documentation for details.
Methods from Deref<Target = AnyObject>§
Sourcepub fn class(&self) -> &'static AnyClass
Available on crate feature NSAccessibilityConstants
only.
pub fn class(&self) -> &'static AnyClass
NSAccessibilityConstants
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());
Sourcepub unsafe fn get_ivar<T>(&self, name: &str) -> &Twhere
T: Encode,
👎Deprecated: this is difficult to use correctly, use Ivar::load
instead.Available on crate feature NSAccessibilityConstants
only.
pub unsafe fn get_ivar<T>(&self, name: &str) -> &Twhere
T: Encode,
Ivar::load
instead.NSAccessibilityConstants
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.
Sourcepub fn downcast_ref<T>(&self) -> Option<&T>where
T: DowncastTarget,
Available on crate feature NSAccessibilityConstants
only.
pub fn downcast_ref<T>(&self) -> Option<&T>where
T: DowncastTarget,
NSAccessibilityConstants
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`
}
}
Trait Implementations§
Source§impl AsRef<AnyObject> for NSLayoutYAxisAnchor
impl AsRef<AnyObject> for NSLayoutYAxisAnchor
Source§impl AsRef<NSLayoutAnchor> for NSLayoutYAxisAnchor
impl AsRef<NSLayoutAnchor> for NSLayoutYAxisAnchor
Source§fn as_ref(&self) -> &NSLayoutAnchor
fn as_ref(&self) -> &NSLayoutAnchor
Source§impl AsRef<NSObject> for NSLayoutYAxisAnchor
impl AsRef<NSObject> for NSLayoutYAxisAnchor
Source§impl Borrow<AnyObject> for NSLayoutYAxisAnchor
impl Borrow<AnyObject> for NSLayoutYAxisAnchor
Source§impl Borrow<NSLayoutAnchor> for NSLayoutYAxisAnchor
impl Borrow<NSLayoutAnchor> for NSLayoutYAxisAnchor
Source§fn borrow(&self) -> &NSLayoutAnchor
fn borrow(&self) -> &NSLayoutAnchor
Source§impl Borrow<NSObject> for NSLayoutYAxisAnchor
impl Borrow<NSObject> for NSLayoutYAxisAnchor
Source§impl ClassType for NSLayoutYAxisAnchor
impl ClassType for NSLayoutYAxisAnchor
Source§const NAME: &'static str = "NSLayoutYAxisAnchor"
const NAME: &'static str = "NSLayoutYAxisAnchor"
Source§type Super = NSLayoutAnchor
type Super = NSLayoutAnchor
Source§type ThreadKind = <<NSLayoutYAxisAnchor as ClassType>::Super as ClassType>::ThreadKind
type ThreadKind = <<NSLayoutYAxisAnchor as ClassType>::Super as ClassType>::ThreadKind
Source§impl CopyingHelper for NSLayoutYAxisAnchor
impl CopyingHelper for NSLayoutYAxisAnchor
Source§type Result = NSLayoutYAxisAnchor
type Result = NSLayoutYAxisAnchor
Self
if the type has no
immutable counterpart. Read moreSource§impl Debug for NSLayoutYAxisAnchor
impl Debug for NSLayoutYAxisAnchor
Source§impl Deref for NSLayoutYAxisAnchor
impl Deref for NSLayoutYAxisAnchor
Source§impl Message for NSLayoutYAxisAnchor
impl Message for NSLayoutYAxisAnchor
Source§impl NSCoding for NSLayoutYAxisAnchor
impl NSCoding for NSLayoutYAxisAnchor
Source§impl NSCopying for NSLayoutYAxisAnchor
impl NSCopying for NSLayoutYAxisAnchor
Source§impl NSObjectProtocol for NSLayoutYAxisAnchor
impl NSObjectProtocol for NSLayoutYAxisAnchor
Source§fn isEqual(&self, other: Option<&AnyObject>) -> bool
fn isEqual(&self, other: Option<&AnyObject>) -> bool
Source§fn hash(&self) -> usize
fn hash(&self) -> usize
Source§fn isKindOfClass(&self, cls: &AnyClass) -> bool
fn isKindOfClass(&self, cls: &AnyClass) -> bool
Source§fn is_kind_of<T>(&self) -> bool
fn is_kind_of<T>(&self) -> bool
isKindOfClass
directly, or cast your objects with AnyObject::downcast_ref