#[repr(C)]pub struct UIDragItem { /* private fields */ }
UIDragItem
only.Expand description
Implementations§
Source§impl UIDragItem
impl UIDragItem
pub unsafe fn initWithItemProvider( this: Allocated<Self>, item_provider: &NSItemProvider, ) -> Retained<Self>
pub unsafe fn init(this: Allocated<Self>) -> Retained<Self>
pub unsafe fn new(mtm: MainThreadMarker) -> Retained<Self>
pub unsafe fn itemProvider(&self) -> Retained<NSItemProvider>
Sourcepub unsafe fn localObject(&self) -> Option<Retained<AnyObject>>
pub unsafe fn localObject(&self) -> Option<Retained<AnyObject>>
Use localObject
to attach additional information to
this drag item, visible only inside the app that started the drag.
Sourcepub unsafe fn setLocalObject(&self, local_object: Option<&AnyObject>)
pub unsafe fn setLocalObject(&self, local_object: Option<&AnyObject>)
Setter for localObject
.
Sourcepub unsafe fn previewProvider(
&self,
) -> *mut DynBlock<dyn Fn() -> *mut UIDragPreview>
Available on crate features UIDragPreview
and block2
only.
pub unsafe fn previewProvider( &self, ) -> *mut DynBlock<dyn Fn() -> *mut UIDragPreview>
UIDragPreview
and block2
only.Use previewProvider
to change the preview for an item.
Each item is usually given a preview when the drag begins,
either by the UIDragInteractionDelegate’s -dragInteraction:previewForLiftingItem:session:
method, or by creating a preview from the dragging view.
During the drag, applications may attempt to change the item’s preview,
by setting previewProvider
to a block that returns a preview.
It will be called when and if the system requests it.
To use the default preview, set previewProvider
to nil.
To hide the preview, set previewProvider
to a block that returns nil.
Sourcepub unsafe fn setPreviewProvider(
&self,
preview_provider: Option<&DynBlock<dyn Fn() -> *mut UIDragPreview>>,
)
Available on crate features UIDragPreview
and block2
only.
pub unsafe fn setPreviewProvider( &self, preview_provider: Option<&DynBlock<dyn Fn() -> *mut UIDragPreview>>, )
UIDragPreview
and block2
only.Setter for previewProvider
.
Sourcepub unsafe fn setNeedsDropPreviewUpdate(&self)
pub unsafe fn setNeedsDropPreviewUpdate(&self)
Requests for the drop preview to be updated if an active drop animation is in progress, and can handle updates. If no active drop animation is in progress for the specified item, then nothing happens.
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 UIIndirectScribbleInteraction
only.
pub fn class(&self) -> &'static AnyClass
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());
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 UIIndirectScribbleInteraction
only.
pub unsafe fn get_ivar<T>(&self, name: &str) -> &Twhere
T: Encode,
Ivar::load
instead.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.
Sourcepub fn downcast_ref<T>(&self) -> Option<&T>where
T: DowncastTarget,
Available on crate feature UIIndirectScribbleInteraction
only.
pub fn downcast_ref<T>(&self) -> Option<&T>where
T: DowncastTarget,
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`
}
}
Trait Implementations§
Source§impl AsRef<AnyObject> for UIDragItem
impl AsRef<AnyObject> for UIDragItem
Source§impl AsRef<NSObject> for UIDragItem
impl AsRef<NSObject> for UIDragItem
Source§impl AsRef<UIDragItem> for UIDragItem
impl AsRef<UIDragItem> for UIDragItem
Source§impl Borrow<AnyObject> for UIDragItem
impl Borrow<AnyObject> for UIDragItem
Source§impl Borrow<NSObject> for UIDragItem
impl Borrow<NSObject> for UIDragItem
Source§impl ClassType for UIDragItem
impl ClassType for UIDragItem
Source§const NAME: &'static str = "UIDragItem"
const NAME: &'static str = "UIDragItem"
Source§type ThreadKind = dyn MainThreadOnly
type ThreadKind = dyn MainThreadOnly
Source§impl Debug for UIDragItem
impl Debug for UIDragItem
Source§impl Deref for UIDragItem
impl Deref for UIDragItem
Source§impl Hash for UIDragItem
impl Hash for UIDragItem
Source§impl Message for UIDragItem
impl Message for UIDragItem
Source§impl NSObjectProtocol for UIDragItem
impl NSObjectProtocol for UIDragItem
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
Source§fn isMemberOfClass(&self, cls: &AnyClass) -> bool
fn isMemberOfClass(&self, cls: &AnyClass) -> bool
Source§fn respondsToSelector(&self, aSelector: Sel) -> bool
fn respondsToSelector(&self, aSelector: Sel) -> bool
Source§fn conformsToProtocol(&self, aProtocol: &AnyProtocol) -> bool
fn conformsToProtocol(&self, aProtocol: &AnyProtocol) -> bool
Source§fn debugDescription(&self) -> Retained<NSObject>
fn debugDescription(&self) -> Retained<NSObject>
Source§impl PartialEq for UIDragItem
impl PartialEq for UIDragItem
Source§impl RefEncode for UIDragItem
impl RefEncode for UIDragItem
Source§const ENCODING_REF: Encoding = <NSObject as ::objc2::RefEncode>::ENCODING_REF
const ENCODING_REF: Encoding = <NSObject as ::objc2::RefEncode>::ENCODING_REF
impl DowncastTarget for UIDragItem
impl Eq for UIDragItem
Auto Trait Implementations§
impl !Freeze for UIDragItem
impl !RefUnwindSafe for UIDragItem
impl !Send for UIDragItem
impl !Sync for UIDragItem
impl !Unpin for UIDragItem
impl !UnwindSafe for UIDragItem
Blanket Implementations§
Source§impl<T> BorrowMut<T> for Twhere
T: ?Sized,
impl<T> BorrowMut<T> for Twhere
T: ?Sized,
Source§fn borrow_mut(&mut self) -> &mut T
fn borrow_mut(&mut self) -> &mut T
Source§impl<'a, T> MainThreadOnly for T
impl<'a, T> MainThreadOnly for T
Source§fn mtm(&self) -> MainThreadMarker
fn mtm(&self) -> MainThreadMarker
MainThreadMarker
from the main-thread-only object. Read more