Implement `DataTransfer` and related interfaces (#34205)

* add datatransfer interfaces

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

* implement DataTransfer interface

implemented Constructor, setter and getter for drop_effect and effect_allowed, Items and SetDragImage

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

* implement DataTransferItem interface

Implemented Kind, Type, GetAsString, GetAsFile.
Marked DataTransfer as weakReferenceable to access its field
inside DataTransferItemList and DataTransferItem.
Signed-off-by: Gae24 <96017547+Gae24@users.noreply.github.com>

* implement DataTransferItemList interface

implemented Lenght, Getter, Add, Remove, Clear
Signed-off-by: Gae24 <96017547+Gae24@users.noreply.github.com>

* added DataTransfer's old interface

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

* DataTransfer: implemented GetData, SetData, SetData

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

* set Weakref to DataTransfer in DataTransferItemList and DataTransferItem

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

* DataTransfer: implemented Types and Files

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

* cleanup get_data, set_data, clear_data

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

* fix clippy warning

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

* add drag data store

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

* fix DataTransfer's Types() behaviour

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

* DataTransferItem: use the underlying drag data store

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

* fix DataTransferItemList's getter and remove

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

* fix clippy warnings

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

* update test expectations

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

---------

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

1 files changed, 282 insertions, 0 deletions

diff --git a/components/script/drag_data_store.rs b/components/script/drag_data_store.rs
new file mode 100644
index 00000000000..8cc893dd73c
--- /dev/null
+++ b/components/script/drag_data_store.rs
@@ -0,0 +1,282 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use std::sync::Arc;
+
+use pixels::Image;
+use script_traits::serializable::BlobImpl;
+
+use crate::dom::bindings::error::{Error, Fallible};
+use crate::dom::bindings::root::DomRoot;
+use crate::dom::bindings::str::DOMString;
+use crate::dom::file::File;
+use crate::dom::globalscope::GlobalScope;
+use crate::script_runtime::CanGc;
+
+/// <https://html.spec.whatwg.org/multipage/#the-drag-data-item-kind>
+#[derive(Clone)]
+pub enum Kind {
+    Text(PlainString),
+    File(Binary),
+}
+
+#[derive(Clone)]
+pub struct PlainString {
+    data: DOMString,
+    type_: DOMString,
+}
+
+impl PlainString {
+    pub fn new(data: DOMString, type_: DOMString) -> Self {
+        Self { data, type_ }
+    }
+}
+
+#[derive(Clone)]
+pub struct Binary {
+    bytes: Vec<u8>,
+    name: DOMString,
+    type_: String,
+}
+
+impl Binary {
+    pub fn new(bytes: Vec<u8>, name: DOMString, type_: String) -> Self {
+        Self { bytes, name, type_ }
+    }
+}
+
+impl Kind {
+    pub fn type_(&self) -> DOMString {
+        match self {
+            Kind::Text(string) => string.type_.clone(),
+            Kind::File(binary) => DOMString::from(binary.type_.clone()),
+        }
+    }
+
+    pub fn as_string(&self) -> Option<DOMString> {
+        match self {
+            Kind::Text(string) => Some(string.data.clone()),
+            Kind::File(_) => None,
+        }
+    }
+
+    // TODO for now we create a new BlobImpl
+    // since File constructor requires moving it.
+    pub fn as_file(&self, global: &GlobalScope) -> Option<DomRoot<File>> {
+        match self {
+            Kind::Text(_) => None,
+            Kind::File(binary) => Some(File::new(
+                global,
+                BlobImpl::new_from_bytes(binary.bytes.clone(), binary.type_.clone()),
+                binary.name.clone(),
+                None,
+                CanGc::note(),
+            )),
+        }
+    }
+
+    fn text_type_matches(&self, type_: &str) -> bool {
+        matches!(self, Kind::Text(string) if string.type_.eq(type_))
+    }
+
+    fn is_file(&self) -> bool {
+        matches!(self, Kind::File(_))
+    }
+}
+
+/// <https://html.spec.whatwg.org/multipage/#drag-data-store-bitmap>
+#[allow(dead_code)] // TODO this used by DragEvent.
+struct Bitmap {
+    image: Option<Arc<Image>>,
+    x: i32,
+    y: i32,
+}
+
+/// Control the behaviour of the drag data store
+#[derive(Clone, Copy, Eq, PartialEq)]
+pub enum Mode {
+    /// <https://html.spec.whatwg.org/multipage/#concept-dnd-rw>
+    ReadWrite,
+    /// <https://html.spec.whatwg.org/multipage/#concept-dnd-ro>
+    #[allow(dead_code)] // TODO this used by ClipboardEvent.
+    ReadOnly,
+    /// <https://html.spec.whatwg.org/multipage/#concept-dnd-p>
+    Protected,
+}
+
+#[allow(dead_code)] // TODO some fields are used by DragEvent.
+pub struct DragDataStore {
+    /// <https://html.spec.whatwg.org/multipage/#drag-data-store-item-list>
+    item_list: Vec<Kind>,
+    /// <https://html.spec.whatwg.org/multipage/#drag-data-store-default-feedback>
+    default_feedback: Option<String>,
+    bitmap: Option<Bitmap>,
+    mode: Mode,
+    /// <https://html.spec.whatwg.org/multipage/#drag-data-store-allowed-effects-state>
+    allowed_effects_state: String,
+}
+
+impl DragDataStore {
+    /// <https://html.spec.whatwg.org/multipage/#create-a-drag-data-store>
+    // We don't really need it since it's only instantiated by DataTransfer.
+    #[allow(clippy::new_without_default)]
+    pub fn new() -> DragDataStore {
+        DragDataStore {
+            item_list: Vec::new(),
+            default_feedback: None,
+            bitmap: None,
+            mode: Mode::Protected,
+            allowed_effects_state: String::from("uninitialized"),
+        }
+    }
+
+    /// Get the drag data store mode
+    pub fn mode(&self) -> Mode {
+        self.mode
+    }
+
+    /// Set the drag data store mode
+    pub fn set_mode(&mut self, mode: Mode) {
+        self.mode = mode;
+    }
+
+    pub fn set_bitmap(&mut self, image: Option<Arc<Image>>, x: i32, y: i32) {
+        self.bitmap = Some(Bitmap { image, x, y });
+    }
+
+    /// <https://html.spec.whatwg.org/multipage/#concept-datatransfer-types>
+    pub fn types(&self) -> Vec<DOMString> {
+        let mut types = Vec::new();
+
+        let has_files = self.item_list.iter().fold(false, |has_files, item| {
+            // Step 2.1 For each item in the item list whose kind is text,
+            // add an entry to L consisting of the item's type string.
+            match item {
+                Kind::Text(string) => types.push(string.type_.clone()),
+                Kind::File(_) => return true,
+            }
+
+            has_files
+        });
+
+        // Step 2.2 If there are any items in the item list whose kind is File,
+        // add an entry to L consisting of the string "Files".
+        if has_files {
+            types.push(DOMString::from("Files"));
+        }
+        types
+    }
+
+    pub fn find_matching_text(&self, type_: &str) -> Option<DOMString> {
+        self.item_list
+            .iter()
+            .find(|item| item.text_type_matches(type_))
+            .and_then(|item| item.as_string())
+    }
+
+    pub fn add(&mut self, kind: Kind) -> Fallible<()> {
+        if let Kind::Text(ref string) = kind {
+            // Step 2.1 If there is already an item in the item list whose kind is text
+            // and whose type string is equal to the method's second argument, throw "NotSupportedError".
+            if self
+                .item_list
+                .iter()
+                .any(|item| item.text_type_matches(&string.type_))
+            {
+                return Err(Error::NotSupported);
+            }
+        }
+
+        // Step 2.2
+        self.item_list.push(kind);
+
+        Ok(())
+    }
+
+    pub fn set_data(&mut self, format: DOMString, data: DOMString) {
+        // Step 3-4
+        let type_ = normalize_mime(format);
+
+        // Step 5 Remove the item in the drag data store item list whose kind is text
+        // and whose type string is equal to format, if there is one.
+        self.item_list
+            .retain(|item| !item.text_type_matches(&type_));
+
+        // Step 6 Add an item whose kind is text, whose type is format, and whose data is the method's second argument.
+        self.item_list.push(Kind::Text(PlainString { data, type_ }));
+    }
+
+    pub fn clear_data(&mut self, format: Option<DOMString>) -> bool {
+        let mut was_modified = false;
+
+        if let Some(format) = format {
+            // Step 4-5
+            let type_ = normalize_mime(format);
+
+            // Step 6 Remove the item in the item list whose kind is text and whose type is format.
+            self.item_list.retain(|item| {
+                let matches = item.text_type_matches(&type_);
+
+                if matches {
+                    was_modified = true;
+                }
+                !matches
+            });
+        } else {
+            // Step 3 Remove each item in the item list whose kind is text.
+            self.item_list.retain(|item| {
+                let matches = item.is_file();
+
+                if !matches {
+                    was_modified = true;
+                }
+                matches
+            });
+        }
+
+        was_modified
+    }
+
+    pub fn files(&self, global: &GlobalScope, file_list: &mut Vec<DomRoot<File>>) {
+        // Step 3 If the data store is in the protected mode return the empty list.
+        if self.mode == Mode::Protected {
+            return;
+        }
+
+        // Step 4 For each item in the drag data store item list whose kind is File, add the item's data to the list L.
+        self.item_list
+            .iter()
+            .filter_map(|item| item.as_file(global))
+            .for_each(|file| file_list.push(file));
+    }
+
+    pub fn list_len(&self) -> usize {
+        self.item_list.len()
+    }
+
+    pub fn get_item(&self, index: usize) -> Option<Kind> {
+        self.item_list.get(index).cloned()
+    }
+
+    pub fn remove(&mut self, index: usize) {
+        self.item_list.remove(index);
+    }
+
+    pub fn clear_list(&mut self) {
+        self.item_list.clear();
+    }
+}
+
+fn normalize_mime(mut format: DOMString) -> DOMString {
+    // Convert format to ASCII lowercase.
+    format.make_ascii_lowercase();
+
+    match format.as_ref() {
+        // If format equals "text", change it to "text/plain".
+        "text" => DOMString::from("text/plain"),
+        // If format equals "url", change it to "text/uri-list".
+        "url" => DOMString::from("text/uri-list"),
+        s => DOMString::from(s),
+    }
+}