LibWeb: Implement InputEvent.getTargetRanges()

This returns a list of ranges that would be affected by a change to the
DOM if the input event is not cancelled.

Libraries/LibWeb/Editing/ExecCommand.cpp

@@ -127,7 +127,7 @@ WebIDL::ExceptionOr<bool> Document::exec_command(FlyString const& command, [[may
         if (command == Editing::CommandNames::insertText)
             event_init.data = value;
 
-        auto event = realm().create<UIEvents::InputEvent>(realm(), HTML::EventNames::input, event_init);
+        auto event = UIEvents::InputEvent::create_from_platform_event(realm(), HTML::EventNames::input, event_init);
         event->set_is_trusted(true);
         affected_editing_host->dispatch_event(event);
     }

Libraries/LibWeb/Page/EventHandler.cpp

@@ -1117,6 +1117,18 @@ static bool is_enter_key_or_interoperable_enter_key_combo(UIEvents::KeyCode key,
     return false;
 }
 
+static GC::RootVector<GC::Ref<DOM::StaticRange>> target_ranges_for_input_event(DOM::Document const& document)
+{
+    GC::RootVector<GC::Ref<DOM::StaticRange>> target_ranges { document.heap() };
+    if (auto selection = document.get_selection(); selection && !selection->is_collapsed()) {
+        if (auto range = selection->range()) {
+            auto static_range = document.realm().create<DOM::StaticRange>(range->start_container(), range->start_offset(), range->end_container(), range->end_offset());
+            target_ranges.append(static_range);
+        }
+    }
+    return target_ranges;
+}
+
 EventResult EventHandler::input_event(FlyString const& event_name, FlyString const& input_type, HTML::Navigable& navigable, u32 code_point)
 {
     auto document = navigable.active_document();
@@ -1138,11 +1150,11 @@ EventResult EventHandler::input_event(FlyString const& event_name, FlyString con
                 return input_event(event_name, input_type, *navigable_container.content_navigable(), code_point);
         }
 
-        auto event = UIEvents::InputEvent::create_from_platform_event(document->realm(), event_name, input_event_init);
+        auto event = UIEvents::InputEvent::create_from_platform_event(document->realm(), event_name, input_event_init, target_ranges_for_input_event(*document));
         return focused_element->dispatch_event(event) ? EventResult::Accepted : EventResult::Cancelled;
     }
 
-    auto event = UIEvents::InputEvent::create_from_platform_event(document->realm(), event_name, input_event_init);
+    auto event = UIEvents::InputEvent::create_from_platform_event(document->realm(), event_name, input_event_init, target_ranges_for_input_event(*document));
 
     if (auto* body = document->body())
         return body->dispatch_event(event) ? EventResult::Accepted : EventResult::Cancelled;

Libraries/LibWeb/UIEvents/InputEvent.cpp

@@ -12,9 +12,9 @@ namespace Web::UIEvents {
 
 GC_DEFINE_ALLOCATOR(InputEvent);
 
-GC::Ref<InputEvent> InputEvent::create_from_platform_event(JS::Realm& realm, FlyString const& event_name, InputEventInit const& event_init)
+GC::Ref<InputEvent> InputEvent::create_from_platform_event(JS::Realm& realm, FlyString const& event_name, InputEventInit const& event_init, Vector<GC::Ref<DOM::StaticRange>> const& target_ranges)
 {
-    auto event = realm.create<InputEvent>(realm, event_name, event_init);
+    auto event = realm.create<InputEvent>(realm, event_name, event_init, target_ranges);
     event->set_bubbles(true);
     if (event_name == "beforeinput"_fly_string) {
         event->set_cancelable(true);
@@ -27,11 +27,12 @@ WebIDL::ExceptionOr<GC::Ref<InputEvent>> InputEvent::construct_impl(JS::Realm& r
     return realm.create<InputEvent>(realm, event_name, event_init);
 }
 
-InputEvent::InputEvent(JS::Realm& realm, FlyString const& event_name, InputEventInit const& event_init)
+InputEvent::InputEvent(JS::Realm& realm, FlyString const& event_name, InputEventInit const& event_init, Vector<GC::Ref<DOM::StaticRange>> const& target_ranges)
     : UIEvent(realm, event_name, event_init)
     , m_data(event_init.data)
     , m_is_composing(event_init.is_composing)
     , m_input_type(event_init.input_type)
+    , m_target_ranges(target_ranges)
 {
 }
 
@@ -43,10 +44,19 @@ void InputEvent::initialize(JS::Realm& realm)
     Base::initialize(realm);
 }
 
-Vector<DOM::StaticRange> InputEvent::get_target_ranges() const
+void InputEvent::visit_edges(Visitor& visitor)
 {
-    dbgln("FIXME: Implement InputEvent::get_target_ranges()");
+    Base::visit_edges(visitor);
-    return {};
+    visitor.visit(m_target_ranges);
+}
+
+// https://w3c.github.io/input-events/#dom-inputevent-gettargetranges
+ReadonlySpan<GC::Ref<DOM::StaticRange>> InputEvent::get_target_ranges() const
+{
+    // getTargetRanges() returns an array of StaticRanges representing the content that the event will modify if it is
+    // not canceled. The returned StaticRanges MUST cover only the code points that the browser would normally replace,
+    // even if they are only part of a grapheme cluster.
+    return m_target_ranges;
 }
 
 }

Libraries/LibWeb/UIEvents/InputEvent.h

@@ -22,7 +22,7 @@ class InputEvent final : public UIEvent {
     GC_DECLARE_ALLOCATOR(InputEvent);
 
 public:
-    [[nodiscard]] static GC::Ref<InputEvent> create_from_platform_event(JS::Realm&, FlyString const& type, InputEventInit const& event_init);
+    [[nodiscard]] static GC::Ref<InputEvent> create_from_platform_event(JS::Realm&, FlyString const& type, InputEventInit const& event_init, Vector<GC::Ref<DOM::StaticRange>> const& target_ranges = {});
     static WebIDL::ExceptionOr<GC::Ref<InputEvent>> construct_impl(JS::Realm&, FlyString const& event_name, InputEventInit const& event_init);
 
     virtual ~InputEvent() override;
@@ -36,16 +36,18 @@ public:
     // https://w3c.github.io/uievents/#dom-inputevent-inputtype
     FlyString input_type() const { return m_input_type; }
 
-    Vector<DOM::StaticRange> get_target_ranges() const;
+    ReadonlySpan<GC::Ref<DOM::StaticRange>> get_target_ranges() const;
 
 private:
-    InputEvent(JS::Realm&, FlyString const& event_name, InputEventInit const&);
+    InputEvent(JS::Realm&, FlyString const& event_name, InputEventInit const&, Vector<GC::Ref<DOM::StaticRange>> const& target_ranges = {});
 
     virtual void initialize(JS::Realm&) override;
+    virtual void visit_edges(Visitor&) override;
 
     Optional<String> m_data;
     bool m_is_composing;
     FlyString m_input_type;
+    Vector<GC::Ref<DOM::StaticRange>> m_target_ranges;
 };
 
 }

Tests/LibWeb/Text/expected/UIEvents/inputevent-gettargetranges.txt

@@ -0,0 +1,2 @@
+Target range count: 1. Start offset: 1, End offset: 3
+No target ranges

Tests/LibWeb/Text/input/UIEvents/inputevent-gettargetranges.html

@@ -0,0 +1,29 @@
+<!DOCTYPE html>
+<div contenteditable>text</div>
+<script src="../include.js"></script>
+<script>
+    test(() => {
+        const editableElement = document.querySelector("div");
+        editableElement.addEventListener("beforeinput", e => {
+            const targetRanges = e.getTargetRanges();
+            if (targetRanges.length === 0) {
+                println("No target ranges");
+            } else {
+                println(`Target range count: ${targetRanges.length}. Start offset: ${targetRanges[0].startOffset}, End offset: ${targetRanges[0].endOffset}`);
+            }
+        });
+        editableElement.focus();
+        const range = document.createRange();
+        range.setStart(editableElement.firstChild, 1);
+        range.setEnd(editableElement.firstChild, 3);
+        const selection = window.getSelection();
+        selection.removeAllRanges();
+        selection.addRange(range);
+        // GetTargetRanges should return a single range representing the selection.
+        internals.sendKey(editableElement, "Backspace");
+        // An input event shouldn't be dispatched for events that wouldn't affect the DOM.
+        internals.sendKey(editableElement, "End");
+        // GetTargetRanges should be empty because there are no ranges.
+        internals.sendKey(editableElement, "Backspace");
+    });
+</script>