TextControl NG: Implement LayoutNGTextControlMultiLine::NodeAtPoint() override

Port LayoutTextControlMultiLine::NodeAtPoint() to
LayoutNGTextControlMultiLine.

- Make LayoutTextControl::HitInnerEditorElement() public and static
  in order to share it with LayoutNGTextControl*.


This CL fixes the following web tests with LayoutNGTextArea flag:
- fast/events/inputevents/inputevent-drag-drop.html
- fast/forms/input-readonly-select.html
- fast/forms/textarea/drag-into-textarea.html
- fast/forms/textarea/drag-out-of-textarea.html

This CL has no behavior changes.  The flag is not enabled yet.

Bug: 1040826
Change-Id: Ia369377659d78476302f8c4b7e32532d60f938f7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2463007
Auto-Submit: Kent Tamura <tkent@chromium.org>
Reviewed-by: Koji Ishii <kojii@chromium.org>
Commit-Queue: Koji Ishii <kojii@chromium.org>
Commit-Queue: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#815563}

third_party/blink/renderer/core/layout/layout_text_control.cc

@@ -90,19 +90,20 @@ int LayoutTextControl::ScrollbarThickness(const LayoutBox& box) {
 }
 
 void LayoutTextControl::HitInnerEditorElement(
+    const LayoutBox& box,
+    HTMLElement& inner_editor,
     HitTestResult& result,
     const HitTestLocation& hit_test_location,
     const PhysicalOffset& accumulated_offset) {
   NOT_DESTROYED();
-  HTMLElement* inner_editor = InnerEditorElement();
-  if (!inner_editor->GetLayoutObject())
+  if (!inner_editor.GetLayoutObject())
     return;
 
   PhysicalOffset local_point =
       hit_test_location.Point() - accumulated_offset -
-      inner_editor->GetLayoutObject()->LocalToAncestorPoint(PhysicalOffset(),
-                                                            this);
-  result.SetNodeAndPosition(inner_editor, local_point);
+      inner_editor.GetLayoutObject()->LocalToAncestorPoint(PhysicalOffset(),
+                                                           &box);
+  result.SetNodeAndPosition(&inner_editor, local_point);
 }
 
 static const char* const kFontFamiliesWithInvalidCharWidth[] = {

third_party/blink/renderer/core/layout/layout_text_control.h

@@ -53,6 +53,12 @@ class CORE_EXPORT LayoutTextControl : public LayoutBlockFlow {
   static float GetAvgCharWidth(const ComputedStyle& style);
   static bool HasValidAvgCharWidth(const Font& font);
 
+  static void HitInnerEditorElement(const LayoutBox& box,
+                                    HTMLElement& inner_editor,
+                                    HitTestResult&,
+                                    const HitTestLocation&,
+                                    const PhysicalOffset& accumulated_offset);
+
  protected:
   LayoutTextControl(TextControlElement*);
 
@@ -62,10 +68,6 @@ class CORE_EXPORT LayoutTextControl : public LayoutBlockFlow {
 
   void StyleDidChange(StyleDifference, const ComputedStyle* old_style) override;
 
-  void HitInnerEditorElement(HitTestResult&,
-                             const HitTestLocation&,
-                             const PhysicalOffset& accumulated_offset);
-
   LayoutObject* LayoutSpecialExcludedChild(bool relayout_children,
                                            SubtreeLayoutScope&) override;
 

third_party/blink/renderer/core/layout/layout_text_control_multi_line.cc

@@ -50,9 +50,10 @@ bool LayoutTextControlMultiLine::NodeAtPoint(
     return true;
 
   if (result.InnerNode() == GetNode() ||
-      result.InnerNode() == InnerEditorElement())
-    HitInnerEditorElement(result, hit_test_location, accumulated_offset);
-
+      result.InnerNode() == InnerEditorElement()) {
+    HitInnerEditorElement(*this, *InnerEditorElement(), result,
+                          hit_test_location, accumulated_offset);
+  }
   return true;
 }
 

third_party/blink/renderer/core/layout/layout_text_control_single_line.cc

@@ -171,7 +171,8 @@ bool LayoutTextControlSingleLine::NodeAtPoint(
             container->GetLayoutBox()->PhysicalLocation();
       }
     }
-    HitInnerEditorElement(result, hit_test_location, accumulated_offset);
+    HitInnerEditorElement(*this, *InnerEditorElement(), result,
+                          hit_test_location, accumulated_offset);
   }
   return true;
 }

third_party/blink/renderer/core/layout/ng/layout_ng_block_flow_mixin.h

@@ -46,7 +46,7 @@ class LayoutNGBlockFlowMixin : public LayoutNGMixin<Base> {
   bool NodeAtPoint(HitTestResult&,
                    const HitTestLocation&,
                    const PhysicalOffset& accumulated_offset,
-                   HitTestAction) final;
+                   HitTestAction) override;
 
   PositionWithAffinity PositionForPoint(const PhysicalOffset&) const override;
 

third_party/blink/renderer/core/layout/ng/layout_ng_text_control_multi_line.cc

@@ -4,6 +4,9 @@
 
 #include "third_party/blink/renderer/core/layout/ng/layout_ng_text_control_multi_line.h"
 
+#include "third_party/blink/renderer/core/html/forms/text_control_element.h"
+#include "third_party/blink/renderer/core/layout/layout_text_control.h"
+
 namespace blink {
 
 LayoutNGTextControlMultiLine::LayoutNGTextControlMultiLine(Element* element)
@@ -14,4 +17,26 @@ bool LayoutNGTextControlMultiLine::IsOfType(LayoutObjectType type) const {
          LayoutNGBlockFlow::IsOfType(type);
 }
 
+bool LayoutNGTextControlMultiLine::NodeAtPoint(
+    HitTestResult& result,
+    const HitTestLocation& hit_test_location,
+    const PhysicalOffset& accumulated_offset,
+    HitTestAction hit_test_action) {
+  if (!LayoutNGBlockFlow::NodeAtPoint(result, hit_test_location,
+                                      accumulated_offset, hit_test_action))
+    return false;
+
+  const LayoutObject* stop_node = result.GetHitTestRequest().GetStopNode();
+  if (stop_node && stop_node->NodeForHitTest() == result.InnerNode())
+    return true;
+
+  HTMLElement* inner_editor =
+      To<TextControlElement>(GetNode())->InnerEditorElement();
+  if (result.InnerNode() == GetNode() || result.InnerNode() == inner_editor) {
+    LayoutTextControl::HitInnerEditorElement(
+        *this, *inner_editor, result, hit_test_location, accumulated_offset);
+  }
+  return true;
+}
+
 }  // namespace blink

third_party/blink/renderer/core/layout/ng/layout_ng_text_control_multi_line.h

@@ -26,6 +26,11 @@ class LayoutNGTextControlMultiLine final : public LayoutNGBlockFlow {
     NOT_DESTROYED();
     return true;
   }
+
+  bool NodeAtPoint(HitTestResult& result,
+                   const HitTestLocation& hit_test_location,
+                   const PhysicalOffset& accumulated_offset,
+                   HitTestAction hit_test_action) override;
 };
 
 }  // namespace blink