LibWeb: Implement DataTransferItemList.remove()

Author: https://github.com/tcl3
Commit: d9341adb1e
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/6088
Reviewed-by: https://github.com/gmta

Libraries/LibWeb/HTML/DataTransfer.cpp

@@ -248,6 +248,22 @@ GC::Ref<DataTransferItem> DataTransfer::add_item(DragDataStoreItem item)
     return data_transfer_item;
 }
 
+void DataTransfer::remove_item(size_t index)
+{
+    VERIFY(m_associated_drag_data_store);
+    VERIFY(index < m_item_list.size());
+
+    m_associated_drag_data_store->remove_item_at(index);
+    auto& item = m_item_list.at(index);
+    item->set_item_index({}, OptionalNone {});
+    m_item_list.remove(index);
+    for (size_t i = index; i < m_item_list.size(); ++i) {
+        m_item_list.at(i)->set_item_index({}, i);
+    }
+
+    update_data_transfer_types_list();
+}
+
 bool DataTransfer::contains_item_with_type(DragDataStoreItem::Kind kind, String const& type) const
 {
     VERIFY(m_associated_drag_data_store);

Libraries/LibWeb/HTML/DataTransfer.h

@@ -60,6 +60,7 @@ public:
     void disassociate_with_drag_data_store();
 
     GC::Ref<DataTransferItem> add_item(DragDataStoreItem item);
+    void remove_item(size_t index);
     bool contains_item_with_type(DragDataStoreItem::Kind, String const& type) const;
     GC::Ref<DataTransferItem> item(size_t index) const;
     DragDataStoreItem const& drag_data(size_t index) const;

Libraries/LibWeb/HTML/DataTransferItem.h

@@ -25,6 +25,7 @@ public:
 
     String kind() const;
     String type() const;
+    void set_item_index(Badge<DataTransfer>, Optional<size_t> index) { m_item_index = move(index); }
 
     void get_as_string(GC::Ptr<WebIDL::CallbackType>) const;
     GC::Ptr<FileAPI::File> get_as_file() const;

Libraries/LibWeb/HTML/DataTransferItemList.cpp

@@ -108,6 +108,23 @@ GC::Ptr<DataTransferItem> DataTransferItemList::add(GC::Ref<FileAPI::File> file)
     return item;
 }
 
+// https://html.spec.whatwg.org/multipage/dnd.html#dom-datatransferitemlist-remove
+WebIDL::ExceptionOr<void> DataTransferItemList::remove(WebIDL::UnsignedLong index)
+{
+    // 1. If the DataTransferItemList object is not in the read/write mode, throw an "InvalidStateError" DOMException.
+    if (m_data_transfer->mode() != DragDataStore::Mode::ReadWrite)
+        return WebIDL::InvalidStateError::create(realm(), "DataTransferItemList is not in read/write mode"_utf16);
+
+    // 2. If the drag data store does not contain an indexth item, then return.
+    if (index >= m_data_transfer->length())
+        return {};
+
+    // 3. Remove the indexth item from the drag data store
+    m_data_transfer->remove_item(index);
+
+    return {};
+}
+
 // https://html.spec.whatwg.org/multipage/dnd.html#dom-datatransferitemlist-item
 Optional<JS::Value> DataTransferItemList::item_value(size_t index) const
 {

Libraries/LibWeb/HTML/DataTransferItemList.h

@@ -26,6 +26,7 @@ public:
 
     WebIDL::ExceptionOr<GC::Ptr<DataTransferItem>> add(String const& data, String const& type);
     GC::Ptr<DataTransferItem> add(GC::Ref<FileAPI::File>);
+    WebIDL::ExceptionOr<void> remove(WebIDL::UnsignedLong index);
 
 private:
     DataTransferItemList(JS::Realm&, GC::Ref<DataTransfer>);

Libraries/LibWeb/HTML/DataTransferItemList.idl

@@ -8,6 +8,6 @@ interface DataTransferItemList {
     getter DataTransferItem (unsigned long index);
     DataTransferItem? add(DOMString data, DOMString type);
     DataTransferItem? add(File data);
-    [FIXME] undefined remove(unsigned long index);
+    undefined remove(unsigned long index);
     [FIXME] undefined clear();
 };

Libraries/LibWeb/HTML/DragDataStore.h

@@ -47,6 +47,7 @@ public:
     ~DragDataStore();
 
     void add_item(DragDataStoreItem item) { m_item_list.append(move(item)); }
+    void remove_item_at(size_t const& index) { m_item_list.remove(index); }
     ReadonlySpan<DragDataStoreItem> item_list() const { return m_item_list; }
     size_t size() const { return m_item_list.size(); }
     bool has_text_item() const;