#[repr(C)]pub struct NSLayoutConstraint { /* private fields */ }
NSLayoutConstraint
only.Expand description
Implementations§
Source§impl NSLayoutConstraint
impl NSLayoutConstraint
pub unsafe fn constraintsWithVisualFormat_options_metrics_views( format: &NSString, opts: NSLayoutFormatOptions, metrics: Option<&NSDictionary<NSString, AnyObject>>, views: &NSDictionary<NSString, AnyObject>, ) -> Retained<NSArray<NSLayoutConstraint>>
objc2-core-foundation
only.pub unsafe fn priority(&self) -> NSLayoutPriority
Sourcepub unsafe fn setPriority(&self, priority: NSLayoutPriority)
pub unsafe fn setPriority(&self, priority: NSLayoutPriority)
Setter for priority
.
pub unsafe fn shouldBeArchived(&self) -> bool
Sourcepub unsafe fn setShouldBeArchived(&self, should_be_archived: bool)
pub unsafe fn setShouldBeArchived(&self, should_be_archived: bool)
Setter for shouldBeArchived
.
pub unsafe fn firstItem(&self) -> Option<Retained<AnyObject>>
pub unsafe fn secondItem(&self) -> Option<Retained<AnyObject>>
pub unsafe fn firstAttribute(&self) -> NSLayoutAttribute
pub unsafe fn secondAttribute(&self) -> NSLayoutAttribute
pub unsafe fn firstAnchor(&self) -> Retained<NSLayoutAnchor>
NSLayoutAnchor
only.pub unsafe fn secondAnchor(&self) -> Option<Retained<NSLayoutAnchor>>
NSLayoutAnchor
only.pub unsafe fn relation(&self) -> NSLayoutRelation
pub unsafe fn multiplier(&self) -> CGFloat
objc2-core-foundation
only.pub unsafe fn constant(&self) -> CGFloat
objc2-core-foundation
only.Sourcepub unsafe fn setConstant(&self, constant: CGFloat)
Available on crate feature objc2-core-foundation
only.
pub unsafe fn setConstant(&self, constant: CGFloat)
objc2-core-foundation
only.Setter for constant
.
pub unsafe fn isActive(&self) -> bool
pub unsafe fn activateConstraints(constraints: &NSArray<NSLayoutConstraint>)
pub unsafe fn deactivateConstraints(constraints: &NSArray<NSLayoutConstraint>)
Source§impl NSLayoutConstraint
Methods declared on superclass NSObject
.
impl NSLayoutConstraint
Methods declared on superclass NSObject
.
Source§impl NSLayoutConstraint
NSIdentifier.
impl NSLayoutConstraint
NSIdentifier.
pub unsafe fn identifier(&self) -> Option<Retained<NSString>>
Sourcepub unsafe fn setIdentifier(&self, identifier: Option<&NSString>)
pub unsafe fn setIdentifier(&self, identifier: Option<&NSString>)
Setter for identifier
.
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 NSLayoutConstraint
impl AsRef<AnyObject> for NSLayoutConstraint
Source§impl AsRef<NSLayoutConstraint> for NSLayoutConstraint
impl AsRef<NSLayoutConstraint> for NSLayoutConstraint
Source§impl AsRef<NSObject> for NSLayoutConstraint
impl AsRef<NSObject> for NSLayoutConstraint
Source§impl Borrow<AnyObject> for NSLayoutConstraint
impl Borrow<AnyObject> for NSLayoutConstraint
Source§impl Borrow<NSObject> for NSLayoutConstraint
impl Borrow<NSObject> for NSLayoutConstraint
Source§impl ClassType for NSLayoutConstraint
impl ClassType for NSLayoutConstraint
Source§const NAME: &'static str = "NSLayoutConstraint"
const NAME: &'static str = "NSLayoutConstraint"
Source§type ThreadKind = <<NSLayoutConstraint as ClassType>::Super as ClassType>::ThreadKind
type ThreadKind = <<NSLayoutConstraint as ClassType>::Super as ClassType>::ThreadKind
Source§impl Debug for NSLayoutConstraint
impl Debug for NSLayoutConstraint
Source§impl Deref for NSLayoutConstraint
impl Deref for NSLayoutConstraint
Source§impl Hash for NSLayoutConstraint
impl Hash for NSLayoutConstraint
Source§impl Message for NSLayoutConstraint
impl Message for NSLayoutConstraint
Source§impl NSAnimatablePropertyContainer for NSLayoutConstraint
impl NSAnimatablePropertyContainer for NSLayoutConstraint
Source§unsafe fn animations(
&self,
) -> Retained<NSDictionary<NSAnimatablePropertyKey, AnyObject>>
unsafe fn animations( &self, ) -> Retained<NSDictionary<NSAnimatablePropertyKey, AnyObject>>
NSAnimation
only.Source§unsafe fn setAnimations(
&self,
animations: &NSDictionary<NSAnimatablePropertyKey, AnyObject>,
)
unsafe fn setAnimations( &self, animations: &NSDictionary<NSAnimatablePropertyKey, AnyObject>, )
NSAnimation
only.animations
.Source§unsafe fn animationForKey(
&self,
key: &NSAnimatablePropertyKey,
) -> Option<Retained<AnyObject>>
unsafe fn animationForKey( &self, key: &NSAnimatablePropertyKey, ) -> Option<Retained<AnyObject>>
NSAnimation
only.Source§unsafe fn defaultAnimationForKey(
key: &NSAnimatablePropertyKey,
) -> Option<Retained<AnyObject>>
unsafe fn defaultAnimationForKey( key: &NSAnimatablePropertyKey, ) -> Option<Retained<AnyObject>>
NSAnimation
only.Source§impl NSObjectProtocol for NSLayoutConstraint
impl NSObjectProtocol for NSLayoutConstraint
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