1 files changed, 76 insertions, 0 deletions
diff --git a/chromium/third_party/blink/renderer/core/html/forms/menu_list_inner_element.cc b/chromium/third_party/blink/renderer/core/html/forms/menu_list_inner_element.cc
new file mode 100644
index 00000000000..abd197d33c8
--- /dev/null
+++ b/chromium/third_party/blink/renderer/core/html/forms/menu_list_inner_element.cc
@@ -0,0 +1,76 @@
+// Copyright 2020 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "third_party/blink/renderer/core/html/forms/menu_list_inner_element.h"
+
+#include "third_party/blink/renderer/core/dom/node_computed_style.h"
+#include "third_party/blink/renderer/core/html/forms/html_select_element.h"
+#include "third_party/blink/renderer/core/layout/layout_theme.h"
+#include "third_party/blink/renderer/core/style/computed_style.h"
+
+namespace blink {
+
+MenuListInnerElement::MenuListInnerElement(Document& document)
+    : HTMLDivElement(document) {
+  SetHasCustomStyleCallbacks();
+}
+
+scoped_refptr<ComputedStyle>
+MenuListInnerElement::CustomStyleForLayoutObject() {
+  const ComputedStyle& parent_style = OwnerShadowHost()->ComputedStyleRef();
+  scoped_refptr<ComputedStyle> style =
+      ComputedStyle::CreateAnonymousStyleWithDisplay(parent_style,
+                                                     EDisplay::kBlock);
+  style->SetFlexGrow(1);
+  style->SetFlexShrink(1);
+  // min-width: 0; is needed for correct shrinking.
+  style->SetMinWidth(Length::Fixed(0));
+  style->SetHasLineIfEmpty(true);
+  style->SetOverflowX(EOverflow::kHidden);
+  style->SetOverflowY(EOverflow::kHidden);
+  style->SetShouldIgnoreOverflowPropertyForInlineBlockBaseline();
+  style->SetTextOverflow(parent_style.TextOverflow());
+  style->SetUserModify(EUserModify::kReadOnly);
+
+  // Use margin:auto instead of align-items:center to get safe centering, i.e.
+  // when the content overflows, treat it the same as align-items: flex-start.
+  // But we only do that for the cases where html.css would otherwise use
+  // center.
+  if (parent_style.AlignItemsPosition() == ItemPosition::kCenter) {
+    style->SetMarginTop(Length());
+    style->SetMarginBottom(Length());
+    style->SetAlignSelfPosition(ItemPosition::kFlexStart);
+  }
+
+  // We set margin-left/right instead of padding-left/right to clip text by
+  // 'overflow: hidden'.
+  LayoutTheme& theme = LayoutTheme::GetTheme();
+  Length margin_start =
+      Length::Fixed(theme.PopupInternalPaddingStart(parent_style));
+  Length margin_end = Length::Fixed(
+      theme.PopupInternalPaddingEnd(GetDocument().GetFrame(), parent_style));
+  if (parent_style.IsLeftToRightDirection()) {
+    style->SetTextAlign(ETextAlign::kLeft);
+    style->SetMarginLeft(margin_start);
+    style->SetMarginRight(margin_end);
+  } else {
+    style->SetTextAlign(ETextAlign::kRight);
+    style->SetMarginLeft(margin_end);
+    style->SetMarginRight(margin_start);
+  }
+  style->SetPaddingTop(
+      Length::Fixed(theme.PopupInternalPaddingTop(parent_style)));
+  style->SetPaddingBottom(
+      Length::Fixed(theme.PopupInternalPaddingBottom(parent_style)));
+
+  if (const ComputedStyle* option_style =
+          To<HTMLSelectElement>(OwnerShadowHost())->OptionStyle()) {
+    style->SetDirection(option_style->Direction());
+    style->SetUnicodeBidi(option_style->GetUnicodeBidi());
+  }
+
+  return style;
+}
+
+}  // namespace blink