async clipboard: implement readText (#36689)

part of #36084
Testing: Only idl harness tests will pass for now

---------

Signed-off-by: Gae24 <96017547+Gae24@users.noreply.github.com>

components/script/dom/clipboard.rs

@@ -3,24 +3,75 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 use std::rc::Rc;
+use std::str::FromStr;
 
 use constellation_traits::BlobImpl;
+use data_url::mime::Mime;
 use dom_struct::dom_struct;
 use embedder_traits::EmbedderMsg;
+use js::rust::HandleValue as SafeHandleValue;
 
 use crate::dom::bindings::codegen::Bindings::ClipboardBinding::{
     ClipboardMethods, PresentationStyle,
 };
+use crate::dom::bindings::error::Error;
 use crate::dom::bindings::refcounted::TrustedPromise;
 use crate::dom::bindings::reflector::{DomGlobal, reflect_dom_object};
 use crate::dom::bindings::root::DomRoot;
 use crate::dom::bindings::str::DOMString;
 use crate::dom::blob::Blob;
+use crate::dom::clipboarditem::Representation;
 use crate::dom::eventtarget::EventTarget;
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::promise::Promise;
+use crate::dom::promisenativehandler::{Callback, PromiseNativeHandler};
 use crate::dom::window::Window;
-use crate::script_runtime::CanGc;
+use crate::realms::{InRealm, enter_realm};
+use crate::routed_promise::{RoutedPromiseListener, route_promise};
+use crate::script_runtime::{CanGc, JSContext as SafeJSContext};
+
+/// The fulfillment handler for the reacting to representationDataPromise part of
+/// <https://w3c.github.io/clipboard-apis/#dom-clipboard-readtext>.
+#[derive(Clone, JSTraceable, MallocSizeOf)]
+struct RepresentationDataPromiseFulfillmentHandler {
+    #[ignore_malloc_size_of = "Rc are hard"]
+    promise: Rc<Promise>,
+}
+
+impl Callback for RepresentationDataPromiseFulfillmentHandler {
+    /// The fulfillment case of Step 3.4.1.1.4.3 of
+    /// <https://w3c.github.io/clipboard-apis/#dom-clipboard-readtext>.
+    fn callback(&self, cx: SafeJSContext, v: SafeHandleValue, _realm: InRealm, can_gc: CanGc) {
+        // If v is a DOMString, then follow the below steps:
+        // Resolve p with v.
+        // Return p.
+        self.promise.resolve(cx, v, can_gc);
+
+        // NOTE: Since we ask text from arboard, v can't be a Blob
+        // If v is a Blob, then follow the below steps:
+        // Let string be the result of UTF-8 decoding v’s underlying byte sequence.
+        // Resolve p with string.
+        // Return p.
+    }
+}
+
+/// The rejection handler for the reacting to representationDataPromise part of
+/// <https://w3c.github.io/clipboard-apis/#dom-clipboard-readtext>.
+#[derive(Clone, JSTraceable, MallocSizeOf)]
+struct RepresentationDataPromiseRejectionHandler {
+    #[ignore_malloc_size_of = "Rc are hard"]
+    promise: Rc<Promise>,
+}
+
+impl Callback for RepresentationDataPromiseRejectionHandler {
+    /// The rejection case of Step 3.4.1.1.4.3 of
+    /// <https://w3c.github.io/clipboard-apis/#dom-clipboard-readtext>.
+    fn callback(&self, _cx: SafeJSContext, _v: SafeHandleValue, _realm: InRealm, can_gc: CanGc) {
+        // Reject p with "NotFoundError" DOMException in realm.
+        // Return p.
+        self.promise.reject_error(Error::NotFound, can_gc);
+    }
+}
 
 #[dom_struct]
 pub(crate) struct Clipboard {
@@ -40,6 +91,34 @@ impl Clipboard {
 }
 
 impl ClipboardMethods<crate::DomTypeHolder> for Clipboard {
+    /// <https://w3c.github.io/clipboard-apis/#dom-clipboard-readtext>
+    fn ReadText(&self, can_gc: CanGc) -> Rc<Promise> {
+        // Step 1 Let realm be this's relevant realm.
+        let global = self.global();
+
+        // Step 2 Let p be a new promise in realm.
+        let p = Promise::new(&global, can_gc);
+
+        // Step 3 Run the following steps in parallel:
+
+        // TODO Step 3.1 Let r be the result of running check clipboard read permission.
+        // Step 3.2 If r is false, then:
+        // Step 3.2.1 Queue a global task on the permission task source, given realm’s global object,
+        // to reject p with "NotAllowedError" DOMException in realm.
+        // Step 3.2.2 Abort these steps.
+
+        // Step 3.3 Let data be a copy of the system clipboard data.
+        let window = global.as_window();
+        let sender = route_promise(&p, self, global.task_manager().clipboard_task_source());
+        window.send_to_embedder(EmbedderMsg::GetClipboardText(window.webview_id(), sender));
+
+        // Step 3.4 Queue a global task on the clipboard task source,
+        // given realm’s global object, to perform the below steps:
+        // NOTE: We queue the task inside route_promise and perform the steps inside handle_response
+
+        p
+    }
+
     /// <https://w3c.github.io/clipboard-apis/#dom-clipboard-writetext>
     fn WriteText(&self, data: DOMString, can_gc: CanGc) -> Rc<Promise> {
         // Step 1 Let realm be this's relevant realm.
@@ -95,6 +174,71 @@ impl ClipboardMethods<crate::DomTypeHolder> for Clipboard {
     }
 }
 
+impl RoutedPromiseListener<Result<String, String>> for Clipboard {
+    fn handle_response(
+        &self,
+        response: Result<String, String>,
+        promise: &Rc<Promise>,
+        can_gc: CanGc,
+    ) {
+        let global = self.global();
+        let text = response.unwrap_or_default();
+
+        // Step 3.4.1 For each systemClipboardItem in data:
+        // Step 3.4.1.1 For each systemClipboardRepresentation in systemClipboardItem:
+        // TODO: Arboard provide the first item that has a String representation
+
+        // Step 3.4.1.1.1 Let mimeType be the result of running the
+        // well-known mime type from os specific format algorithm given systemClipboardRepresentation’s name.
+        // Note: This is done by arboard, so we just convert the format to a MIME
+        let mime_type = Mime::from_str("text/plain").unwrap();
+
+        // Step 3.4.1.1.2 If mimeType is null, continue this loop.
+        // Note: Since the previous step is infallible, we don't need to handle this case
+
+        // Step 3.4.1.1.3 Let representation be a new representation.
+        let representation = Representation {
+            mime_type,
+            is_custom: false,
+            data: Promise::new_resolved(
+                &global,
+                GlobalScope::get_cx(),
+                DOMString::from(text),
+                can_gc,
+            ),
+        };
+
+        // Step 3.4.1.1.4 If representation’s MIME type essence is "text/plain", then:
+
+        // Step 3.4.1.1.4.1 Set representation’s MIME type to mimeType.
+        // Note: Done when creating a new representation
+
+        // Step 3.4.1.1.4.2 Let representationDataPromise be the representation’s data.
+        // Step 3.4.1.1.4.3 React to representationDataPromise:
+        let fulfillment_handler = Box::new(RepresentationDataPromiseFulfillmentHandler {
+            promise: promise.clone(),
+        });
+        let rejection_handler = Box::new(RepresentationDataPromiseRejectionHandler {
+            promise: promise.clone(),
+        });
+        let handler = PromiseNativeHandler::new(
+            &global,
+            Some(fulfillment_handler),
+            Some(rejection_handler),
+            can_gc,
+        );
+        let realm = enter_realm(&*global);
+        let comp = InRealm::Entered(&realm);
+        representation
+            .data
+            .append_native_handler(&handler, comp, can_gc);
+
+        // Step 3.4.2 Reject p with "NotFoundError" DOMException in realm.
+        // Step 3.4.3 Return p.
+        // NOTE: We follow the same behaviour of Gecko by doing nothing if no text is available instead of rejecting p
+    }
+}
+
 /// <https://w3c.github.io/clipboard-apis/#write-blobs-and-option-to-the-clipboard>
 fn write_blobs_and_option_to_the_clipboard(
     window: &Window,

components/script/dom/clipboarditem.rs

@@ -29,13 +29,13 @@ const CUSTOM_FORMAT_PREFIX: &str = "web ";
 
 /// <https://w3c.github.io/clipboard-apis/#representation>
 #[derive(JSTraceable, MallocSizeOf)]
-struct Representation {
+pub(super) struct Representation {
     #[no_trace]
     #[ignore_malloc_size_of = "Extern type"]
-    mime_type: Mime,
-    is_custom: bool,
+    pub mime_type: Mime,
+    pub is_custom: bool,
     #[ignore_malloc_size_of = "Rc is hard"]
-    data: Rc<Promise>,
+    pub data: Rc<Promise>,
 }
 
 #[dom_struct]

components/script_bindings/codegen/Bindings.conf

@@ -88,7 +88,7 @@ DOMInterfaces = {
 },
 
 'Clipboard': {
-    'canGc': ['WriteText']
+    'canGc': ['ReadText', 'WriteText']
 },
 
 'ClipboardItem': {

components/script_bindings/webidls/Clipboard.webidl

@@ -9,7 +9,7 @@ typedef sequence<ClipboardItem> ClipboardItems;
 [SecureContext, Exposed=Window, Pref="dom_async_clipboard_enabled"]
 interface Clipboard : EventTarget {
   // Promise<ClipboardItems> read();
-  // Promise<DOMString> readText();
+  Promise<DOMString> readText();
   // Promise<undefined> write(ClipboardItems data);
   Promise<undefined> writeText(DOMString data);
 };

tests/wpt/meta/clipboard-apis/idlharness.https.window.js.ini

@@ -8,9 +8,6 @@
   [Clipboard interface: operation read(optional ClipboardUnsanitizedFormats)]
     expected: FAIL
 
-  [Clipboard interface: operation readText()]
-    expected: FAIL
-
   [Clipboard interface: operation write(ClipboardItems)]
     expected: FAIL
 
@@ -20,9 +17,6 @@
   [Clipboard interface: calling read(optional ClipboardUnsanitizedFormats) on navigator.clipboard with too few arguments must throw TypeError]
     expected: FAIL
 
-  [Clipboard interface: navigator.clipboard must inherit property "readText()" with the proper type]
-    expected: FAIL
-
   [Clipboard interface: navigator.clipboard must inherit property "write(ClipboardItems)" with the proper type]
     expected: FAIL