Implement select element list box with shadow DOM.

Source/WebCore/html/HTMLOptionElement.cpp

Index: Source/WebCore/html/HTMLOptionElement.cpp
diff --git a/Source/WebCore/html/HTMLOptionElement.cpp b/Source/WebCore/html/HTMLOptionElement.cpp
index ac0bb7ff1422d2562de922317d6eba4ddfac1f8f..6836ef0db301ce16e6a24e404d6140ded7ed00d8 100644
--- a/Source/WebCore/html/HTMLOptionElement.cpp
+++ b/Source/WebCore/html/HTMLOptionElement.cpp
@@ -34,12 +34,11 @@
 #include "HTMLNames.h"
 #include "HTMLParserIdioms.h"
 #include "HTMLSelectElement.h"
-#include "NodeRenderStyle.h"
-#include "NodeRenderingContext.h"
 #include "NodeTraversal.h"
 #include "RenderMenuList.h"
 #include "RenderTheme.h"
 #include "ScriptElement.h"
+#include "ShadowRoot.h"
 #include "StyleResolver.h"
 #include "Text.h"
 #include <wtf/StdLibExtras.h>
@@ -62,18 +61,20 @@ HTMLOptionElement::HTMLOptionElement(const QualifiedName& tagName, Document* doc
 
 PassRefPtr<HTMLOptionElement> HTMLOptionElement::create(Document* document)
 {
-    return adoptRef(new HTMLOptionElement(optionTag, document));
+  return HTMLOptionElement::create(optionTag, document);
 }
 
 PassRefPtr<HTMLOptionElement> HTMLOptionElement::create(const QualifiedName& tagName, Document* document)
 {
-    return adoptRef(new HTMLOptionElement(tagName, document));
+    RefPtr<HTMLOptionElement> option = adoptRef(new HTMLOptionElement(tagName, document));
+    option->ensureUserAgentShadowRoot();

[yosin_UTC9, 2013/05/01 01:38:21]

Can we postpone creating shadow root until this option element  in listbox? We
may not want to have shadow root for datalist/option.

+    return option.release();
 }
 
 PassRefPtr<HTMLOptionElement> HTMLOptionElement::createForJSConstructor(Document* document, const String& data, const String& value,
         bool defaultSelected, bool selected, ExceptionCode& ec)
 {
-    RefPtr<HTMLOptionElement> element = adoptRef(new HTMLOptionElement(optionTag, document));
+    RefPtr<HTMLOptionElement> element = HTMLOptionElement::create(optionTag, document);
 
     RefPtr<Text> text = Text::create(document, data.isNull() ? "" : data);
 
@@ -91,22 +92,6 @@ PassRefPtr<HTMLOptionElement> HTMLOptionElement::createForJSConstructor(Document
     return element.release();
 }
 
-void HTMLOptionElement::attach()
-{
-    HTMLElement::attach();
-    // If after attaching nothing called styleForRenderer() on this node we
-    // manually cache the value. This happens if our parent doesn't have a
-    // renderer like <optgroup> or if it doesn't allow children like <select>.
-    if (!m_style && parentNode()->renderStyle())
-        updateNonRenderStyle();
-}
-
-void HTMLOptionElement::detach()
-{
-    m_style.clear();
-    HTMLElement::detach();
-}
-
 bool HTMLOptionElement::supportsFocus() const
 {
     return HTMLElement::supportsFocus();
@@ -216,6 +201,8 @@ void HTMLOptionElement::parseAttribute(const QualifiedName& name, const AtomicSt
         // that we need to do more than just set m_isSelected to select in that
         // case; we'd need to do the other work from the setSelected function.
         m_isSelected = !value.isNull();
+    } else if (name == labelAttr) {
+        updateLabel();
     } else
         HTMLElement::parseAttribute(name, value);
 }
@@ -272,6 +259,7 @@ void HTMLOptionElement::childrenChanged(bool changedByParser, Node* beforeChange
 #endif
     if (HTMLSelectElement* select = ownerSelectElement())
         select->optionElementChildrenChanged();
+    updateLabel();
     HTMLElement::childrenChanged(changedByParser, beforeChange, afterChange, childCountDelta);
 }
 
@@ -311,34 +299,6 @@ void HTMLOptionElement::setLabel(const String& label)
     setAttribute(labelAttr, label);
 }
 
-void HTMLOptionElement::updateNonRenderStyle()
-{
-    m_style = document()->styleResolver()->styleForElement(this);
-}
-
-RenderStyle* HTMLOptionElement::nonRendererStyle() const
-{
-    return m_style.get();
-}
-
-PassRefPtr<RenderStyle> HTMLOptionElement::customStyleForRenderer()
-{
-    // styleForRenderer is called whenever a new style should be associated
-    // with an Element so now is a good time to update our cached style.
-    updateNonRenderStyle();
-    return m_style;
-}
-
-void HTMLOptionElement::didRecalcStyle(StyleChange)
-{
-    // FIXME: This is nasty, we ask our owner select to repaint even if the new
-    // style is exactly the same.
-    if (HTMLSelectElement* select = ownerSelectElement()) {
-        if (RenderObject* renderer = select->renderer())
-            renderer->repaint();
-    }
-}
-
 String HTMLOptionElement::textIndentedToRespectGroupLabel() const
 {
     ContainerNode* parent = parentNode();
@@ -390,6 +350,30 @@ String HTMLOptionElement::collectOptionInnerText() const
     return text.toString();
 }
 
+void HTMLOptionElement::updateLabel()
+{
+    Text* const textNode = toText(userAgentShadowRoot()->firstChild());
+    if (textNode)
+        textNode->replaceWholeText(text(), ASSERT_NO_EXCEPTION);
+    else
+        userAgentShadowRoot()->appendChild(Text::create(document(), text()), ASSERT_NO_EXCEPTION);
+}
+
+PassRefPtr<RenderStyle> HTMLOptionElement::customStyleForRenderer()
+{
+    RefPtr<RenderStyle> originalStyle = document()->styleResolver()->styleForElement(this);
+    RefPtr<RenderStyle> style = RenderStyle::clone(originalStyle.get());
+
+    HTMLSelectElement* selectElement = ownerSelectElement();
+    if (selectElement) {
+        const Vector<HTMLElement*>& items = selectElement->listItems();
+        if (items[items.size() - 1] == this)

[yosin_UTC9, 2013/05/01 01:38:21]

nit: We should check item.size() > 0.

+            style->setPaddingBottom(Length(0, Fixed));
+    }
+
+    return style.release();
+}
+
 #ifndef NDEBUG
 
 HTMLOptionElement* toHTMLOptionElement(Node* node)