Struct ItemProvider 

pub struct ItemProvider(/* private fields */);

An NSItemProvider SwiftUI handed to a callback, or one built to hand back.

Reading what a provider carries is asynchronous — that is the whole point of the class — so what a synchronous Rust callback can see is which type identifiers it offers, which is a plain property.

Implementations

impl ItemProvider

pub fn as_ptr(&self) -> *mut c_void

The underlying NSItemProvider.

pub fn type_identifiers(&self) -> Vec<String>

The uniform type identifiers this provider can produce.

pub fn load_plain_text(&self, then: impl FnOnce(Option<String>) + 'static)

Ask for the item’s text. The answer arrives later, on the main queue.

A drop handler could see how many items were dropped and what type identifiers they carried, and nothing about what they actually were — which is most of the way to not having a drop handler.

Asynchronous because it has to be, not as a matter of taste: measured with a probe that waited a full second without turning the run loop, the completion never came, and the same load with the loop running returned immediately. NSItemProvider delivers on the main queue, so a synchronous read from a drop handler — which is already running on the main thread inside AppKit’s own dispatch — would wait for a block that cannot run until it returns. Swift’s loadItem is async for the same reason.

let drop = text("drop here").on_drop(&[ContentType::PlainText], |providers| {
    for p in providers {
        p.load_plain_text(|text| println!("dropped {text:?}"));
    }
    true
});

pub fn plain_text(text: &str) -> Self

Build a provider carrying text as plain text.

Trait Implementations

impl Clone for ItemProvider

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for ItemProvider

impl Debug for ItemProvider

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Send for ItemProvider

impl Sync for ItemProvider