LibWeb: Move code for finding the parent element into a helper function

This exact same loop is repeated a couple of times.

Userland/Libraries/LibWeb/Page/EventHandler.cpp

@@ -34,6 +34,16 @@ static JS::GCPtr<DOM::Node> dom_node_for_event_dispatch(Painting::Paintable cons
  return nullptr;
 }
 
+static bool parent_element_for_event_dispatch(Painting::Paintable const& paintable, JS::GCPtr<DOM::Node>& node, Layout::Node const*& layout_node)
+{
+ layout_node = &paintable.layout_node();
+ while (layout_node && node && !node->is_element() && layout_node->parent()) {
+ layout_node = layout_node->parent();
+ node = layout_node->dom_node();
+ }
+ return node && layout_node;
+}
+
 static Gfx::StandardCursor cursor_css_to_gfx(Optional<CSS::Cursor> cursor)
 {
  if (!cursor.has_value()) {
@@ -167,14 +177,9 @@ bool EventHandler::handle_mousewheel(Gfx::IntPoint const& position, unsigned but
  }
 
  // Search for the first parent of the hit target that's an element.
- auto* layout_node = &paintable->layout_node();
- while (layout_node && node && !node->is_element() && layout_node->parent()) {
- layout_node = layout_node->parent();
- node = layout_node->dom_node();
- }
- if (!node || !layout_node) {
+ Layout::Node const* layout_node;
+ if (!parent_element_for_event_dispatch(*paintable, node, layout_node))
  return false;
- }
 
  auto offset = compute_mouse_event_offset(position, *layout_node);
  if (node->dispatch_event(*UIEvents::WheelEvent::create_from_platform_event(node->realm(), UIEvents::EventNames::wheel, offset.x(), offset.y(), position.x(), position.y(), wheel_delta_x, wheel_delta_y, buttons, button))) {
@@ -232,12 +237,8 @@ bool EventHandler::handle_mouseup(Gfx::IntPoint const& position, unsigned button
  // Search for the first parent of the hit target that's an element.
  // "The click event type MUST be dispatched on the topmost event target indicated by the pointer." (https://www.w3.org/TR/uievents/#event-type-click)
  // "The topmost event target MUST be the element highest in the rendering order which is capable of being an event target." (https://www.w3.org/TR/uievents/#topmost-event-target)
- auto* layout_node = &paintable->layout_node();
- while (layout_node && node && !node->is_element() && layout_node->parent()) {
- layout_node = layout_node->parent();
- node = layout_node->dom_node();
- }
- if (!node || !layout_node) {
+ Layout::Node const* layout_node;
+ if (!parent_element_for_event_dispatch(*paintable, node, layout_node)) {
  // FIXME: This is pretty ugly but we need to bail out here.
  goto after_node_use;
  }
@@ -358,12 +359,8 @@ bool EventHandler::handle_mousedown(Gfx::IntPoint const& position, unsigned butt
  // Search for the first parent of the hit target that's an element.
  // "The click event type MUST be dispatched on the topmost event target indicated by the pointer." (https://www.w3.org/TR/uievents/#event-type-click)
  // "The topmost event target MUST be the element highest in the rendering order which is capable of being an event target." (https://www.w3.org/TR/uievents/#topmost-event-target)
- auto* layout_node = &paintable->layout_node();
- while (layout_node && node && !node->is_element() && layout_node->parent()) {
- layout_node = layout_node->parent();
- node = layout_node->dom_node();
- }
- if (!node || !layout_node)
+ Layout::Node const* layout_node;
+ if (!parent_element_for_event_dispatch(*paintable, node, layout_node))
  return false;
 
  m_mousedown_target = node.ptr();
@@ -475,12 +472,8 @@ bool EventHandler::handle_mousemove(Gfx::IntPoint const& position, unsigned butt
  // Search for the first parent of the hit target that's an element.
  // "The click event type MUST be dispatched on the topmost event target indicated by the pointer." (https://www.w3.org/TR/uievents/#event-type-click)
  // "The topmost event target MUST be the element highest in the rendering order which is capable of being an event target." (https://www.w3.org/TR/uievents/#topmost-event-target)
- auto* layout_node = &paintable->layout_node();
- while (layout_node && node && !node->is_element() && layout_node->parent()) {
- layout_node = layout_node->parent();
- node = layout_node->dom_node();
- }
- if (!node || !layout_node) {
+ Layout::Node const* layout_node;
+ if (!parent_element_for_event_dispatch(*paintable, node, layout_node)) {
  // FIXME: This is pretty ugly but we need to bail out here.
  goto after_node_use;
  }
@@ -563,12 +556,8 @@ bool EventHandler::handle_doubleclick(Gfx::IntPoint const& position, unsigned bu
 
  // Search for the first parent of the hit target that's an element.
  // "The topmost event target MUST be the element highest in the rendering order which is capable of being an event target." (https://www.w3.org/TR/uievents/#topmost-event-target)
- auto* layout_node = &paintable->layout_node();
- while (layout_node && node && !node->is_element() && layout_node->parent()) {
- layout_node = layout_node->parent();
- node = layout_node->dom_node();
- }
- if (!node || !layout_node)
+ Layout::Node const* layout_node;
+ if (!parent_element_for_event_dispatch(*paintable, node, layout_node))
  return false;
 
  auto offset = compute_mouse_event_offset(position, *layout_node);