LibWeb: Send a beforeinput event for pasting

This allows us to paste text into Discord.

Libraries/LibWeb/Internals/Internals.cpp

@@ -155,6 +155,14 @@ void Internals::send_key(HTML::HTMLElement& target, String const& key_name, WebI
     page().handle_keydown(key_code, modifiers, 0, false);
 }
 
+void Internals::paste(HTML::HTMLElement& target, String const& text)
+{
+    auto& page = this->page();
+    target.focus();
+
+    page.focused_navigable().paste(text);
+}
+
 void Internals::commit_text()
 {
     page().handle_keydown(UIEvents::Key_Return, 0, 0x0d, false);

Libraries/LibWeb/Internals/Internals.h

@@ -31,6 +31,7 @@ public:
 
     void send_text(HTML::HTMLElement&, String const&, WebIDL::UnsignedShort modifiers);
     void send_key(HTML::HTMLElement&, String const&, WebIDL::UnsignedShort modifiers);
+    void paste(HTML::HTMLElement& target, String const& text);
     void commit_text();
 
     void click(double x, double y);

Libraries/LibWeb/Internals/Internals.idl

@@ -23,6 +23,7 @@ interface Internals {
 
     undefined sendText(HTMLElement target, DOMString text, optional unsigned short modifiers = 0);
     undefined sendKey(HTMLElement target, DOMString keyName, optional unsigned short modifiers = 0);
+    undefined paste(HTMLElement target, DOMString text);
     undefined commitText();
 
     undefined click(double x, double y);

Libraries/LibWeb/Page/EventHandler.cpp

@@ -1129,7 +1129,7 @@ static GC::RootVector<GC::Ref<DOM::StaticRange>> target_ranges_for_input_event(D
     return target_ranges;
 }
 
-EventResult EventHandler::input_event(FlyString const& event_name, FlyString const& input_type, HTML::Navigable& navigable, u32 code_point)
+EventResult EventHandler::input_event(FlyString const& event_name, FlyString const& input_type, HTML::Navigable& navigable, Variant<u32, String> code_point_or_string)
 {
     auto document = navigable.active_document();
     if (!document)
@@ -1138,16 +1138,23 @@ EventResult EventHandler::input_event(FlyString const& event_name, FlyString con
         return EventResult::Dropped;
 
     UIEvents::InputEventInit input_event_init;
+
+    if (code_point_or_string.has<u32>()) {
+        auto code_point = code_point_or_string.get<u32>();
         if (!is_unicode_control(code_point)) {
             input_event_init.data = String::from_code_point(code_point);
         }
+    } else {
+        input_event_init.data = code_point_or_string.get<String>();
+    }
+
     input_event_init.input_type = input_type;
 
     if (auto* focused_element = document->focused_element()) {
         if (is<HTML::NavigableContainer>(*focused_element)) {
             auto& navigable_container = as<HTML::NavigableContainer>(*focused_element);
             if (navigable_container.content_navigable())
-                return input_event(event_name, input_type, *navigable_container.content_navigable(), code_point);
+                return input_event(event_name, input_type, *navigable_container.content_navigable(), code_point_or_string);
         }
 
         auto event = UIEvents::InputEvent::create_from_platform_event(document->realm(), event_name, input_event_init, target_ranges_for_input_event(*document));
@@ -1366,18 +1373,21 @@ EventResult EventHandler::handle_keyup(UIEvents::KeyCode key, u32 modifiers, u32
     return fire_keyboard_event(UIEvents::EventNames::keyup, m_navigable, key, modifiers, code_point, false);
 }
 
-void EventHandler::handle_paste(String const& text)
+EventResult EventHandler::handle_paste(String const& text)
 {
     auto active_document = m_navigable->active_document();
     if (!active_document)
-        return;
+        return EventResult::Dropped;
     if (!active_document->is_fully_active())
-        return;
+        return EventResult::Dropped;
 
     auto* target = active_document->active_input_events_target();
     if (!target)
-        return;
+        return EventResult::Dropped;
+
+    FIRE(input_event(UIEvents::EventNames::beforeinput, UIEvents::InputTypes::insertFromPaste, m_navigable, text));
     target->handle_insert(text);
+    return EventResult::Handled;
 }
 
 void EventHandler::set_mouse_event_tracking_paintable(Painting::Paintable* paintable)

Libraries/LibWeb/Page/EventHandler.h

@@ -39,7 +39,7 @@ public:
 
     void set_mouse_event_tracking_paintable(Painting::Paintable*);
 
-    void handle_paste(String const& text);
+    EventResult handle_paste(String const& text);
 
     void visit_edges(JS::Cell::Visitor& visitor) const;
 
@@ -50,7 +50,7 @@ private:
     EventResult focus_previous_element();
 
     EventResult fire_keyboard_event(FlyString const& event_name, HTML::Navigable&, UIEvents::KeyCode, unsigned modifiers, u32 code_point, bool repeat);
-    [[nodiscard]] EventResult input_event(FlyString const& event_name, FlyString const& input_type, HTML::Navigable&, u32 code_point);
+    [[nodiscard]] EventResult input_event(FlyString const& event_name, FlyString const& input_type, HTML::Navigable&, Variant<u32, String> code_point_or_string);
     CSSPixelPoint compute_mouse_event_client_offset(CSSPixelPoint event_page_position) const;
     CSSPixelPoint compute_mouse_event_page_offset(CSSPixelPoint event_client_offset) const;
     CSSPixelPoint compute_mouse_event_movement(CSSPixelPoint event_client_offset) const;

Libraries/LibWeb/UIEvents/InputTypes.h

@@ -14,6 +14,7 @@ namespace Web::UIEvents::InputTypes {
 #define ENUMERATE_INPUT_TYPES                     \
     __ENUMERATE_INPUT_TYPE(deleteContentBackward) \
     __ENUMERATE_INPUT_TYPE(deleteContentForward)  \
+    __ENUMERATE_INPUT_TYPE(insertFromPaste)       \
     __ENUMERATE_INPUT_TYPE(insertLineBreak)       \
     __ENUMERATE_INPUT_TYPE(insertParagraph)       \
     __ENUMERATE_INPUT_TYPE(insertText)

Tests/LibWeb/Text/expected/Editing/beforeinput-event.txt

@@ -6,4 +6,10 @@ beforeinput data=(e) inputType=(insertText)
 beforeinput data=(c) inputType=(insertText)
 beforeinput data=(e) inputType=(insertText)
 beforeinput data=(null) inputType=(insertParagraph)
-Text in input: reee
+Text in input before any paste: reee
+beforeinput data=(non-cancelled paste) inputType=(insertFromPaste)
+beforeinput data=(null) inputType=(insertParagraph)
+Text in input after non-cancelled paste: reeenon-cancelled paste
+beforeinput data=(cancelled paste) inputType=(insertFromPaste)
+beforeinput data=(null) inputType=(insertParagraph)
+Text in input after cancelled paste: reeenon-cancelled paste

Tests/LibWeb/Text/input/Editing/beforeinput-event.html

@@ -13,13 +13,19 @@
         const input = document.getElementById("input");
         input.addEventListener("beforeinput", (e) => {
             println(`beforeinput data=(${e.data}) inputType=(${e.inputType})`);
-            if (e.data !== 'r' && e.data !== 'e') {
+            if (e.data !== 'r' && e.data !== 'e' && e.data !== "non-cancelled paste") {
                 e.preventDefault();
                 return;
             }
         });
         internals.sendText(input, "raebece");
         internals.commitText();
-        println(`Text in input: ${input.textContent}`);
+        println(`Text in input before any paste: ${input.textContent}`);
+        internals.paste(input, "non-cancelled paste");
+        internals.commitText();
+        println(`Text in input after non-cancelled paste: ${input.textContent}`);
+        internals.paste(input, "cancelled paste");
+        internals.commitText();
+        println(`Text in input after cancelled paste: ${input.textContent}`);
     });
 </script>