Implement select listbox using shadow DOM

Source/core/html/HTMLOptGroupElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2010 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 10 matching lines @@
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #include "config.h"
 #include "core/html/HTMLOptGroupElement.h"
 
 #include "core/HTMLNames.h"
 #include "core/dom/Document.h"
 #include "core/dom/NodeRenderStyle.h"
+#include "core/dom/Text.h"
+#include "core/html/HTMLContentElement.h"
+#include "core/html/HTMLDivElement.h"
 #include "core/html/HTMLSelectElement.h"
 #include "wtf/StdLibExtras.h"
+#include "wtf/unicode/CharacterNames.h"
 
 namespace WebCore {
 
 using namespace HTMLNames;
 
+class GroupLabelElement : public HTMLDivElement {

[esprehn, 2014/06/23 21:59:56]

Put this in it's own file.

[keishi, 2014/07/01 04:53:32]

Removed this class.

+public:
+    static PassRefPtrWillBeRawPtr<GroupLabelElement> create(Document&);
+
+    void setText(const String& text)

[esprehn, 2014/06/23 21:59:55]

Not inline.

+    {
+        DEFINE_STATIC_LOCAL(String, nonBreakingSpaceString, (&noBreakSpace, 1));
+        const String& labelText = text.isEmpty() ? nonBreakingSpaceString : text;
+        if (!m_textNode) {
+            m_textNode = Text::create(document(), labelText);

[esprehn, 2014/06/23 21:59:55]

You should just setTextContent, don't rewrite it yourself. Always call it.

+            appendChild(m_textNode);
+        } else {
+            m_textNode->replaceWholeText(labelText);

[esprehn, 2014/06/23 21:59:56]

Use setTextContent.

+        }
+    }
+
+private:
+    explicit GroupLabelElement(Document& document)
+        : HTMLDivElement(document)
+        , m_textNode(nullptr)
+    {
+        setHasCustomStyleCallbacks();
+    }
+    virtual PassRefPtr<RenderStyle> customStyleForRenderer() OVERRIDE;
+
+    RefPtrWillBeMember<Text> m_textNode;
+};
+
+PassRefPtrWillBeRawPtr<GroupLabelElement> GroupLabelElement::create(Document& document)
+{
+    return adoptRefWillBeNoop(new GroupLabelElement(document));
+}
+
+PassRefPtr<RenderStyle> GroupLabelElement::customStyleForRenderer()
+{
+    RefPtr<RenderStyle> originalStyle = document().styleResolver()->styleForElement(this);

[esprehn, 2014/06/23 21:59:56]

originalStyleForRenderer()

+    RefPtr<RenderStyle> style = RenderStyle::clone(originalStyle.get());
+
+    style->setPaddingRight(Length(2, Fixed));
+    style->setPaddingLeft(Length(2, Fixed));
+
+    int paddingBottom = 1;
+    HTMLSelectElement* selectElement = toHTMLOptGroupElement(shadowHost())->ownerSelectElement();
+    if (selectElement) {
+        const WillBeHeapVector<RawPtrWillBeMember<HTMLElement> >& items = selectElement->listItems();
+        ASSERT(items.size() > 0);
+        if (items.last() == this)
+            paddingBottom = 0;
+    }

[esprehn, 2014/06/23 21:59:56]

Why do you need this custom styling hook, I'm not sure we should be adding more
of these.

[keishi, 2014/07/01 04:53:32]

Removed. The current implementation has a 1 pixel space between two lines so I
was trying to replicate that. We can just have 1px bottom padding on all rows.

+    style->setPaddingBottom(Length(paddingBottom, Fixed));
+
+    return style.release();
+}
+
+PassRefPtrWillBeRawPtr<HTMLOptGroupElement> HTMLOptGroupElement::create(Document& document)
+{
+    RefPtrWillBeRawPtr<HTMLOptGroupElement> optGroupElement = adoptRefWillBeNoop(new HTMLOptGroupElement(document));
+    optGroupElement->ensureUserAgentShadowRoot();
+    return optGroupElement.release();
+}
+
 inline HTMLOptGroupElement::HTMLOptGroupElement(Document& document)
     : HTMLElement(optgroupTag, document)
 {
     setHasCustomStyleCallbacks();
     ScriptWrappable::init(this);
 }
 
-DEFINE_NODE_FACTORY(HTMLOptGroupElement)
+void HTMLOptGroupElement::trace(Visitor* visitor)
+{
+    visitor->trace(m_groupLabelElement);
+    HTMLElement::trace(visitor);
+}
 
 bool HTMLOptGroupElement::isDisabledFormControl() const
 {
     return fastHasAttribute(disabledAttr);
 }
 
 bool HTMLOptGroupElement::rendererIsFocusable() const
 {
-    // Optgroup elements do not have a renderer so we check the renderStyle instead.
-    return renderStyle() && renderStyle()->display() != NONE;
+    HTMLSelectElement* selectElement = ownerSelectElement();
+    if (!selectElement || selectElement->usesMenuList()) {
+        return !isDisplayNone();
+    }
+    return HTMLElement::rendererIsFocusable();
 }
 
 void HTMLOptGroupElement::childrenChanged(bool changedByParser, Node* beforeChange, Node* afterChange, int childCountDelta)
 {
     recalcSelectOptions();
     HTMLElement::childrenChanged(changedByParser, beforeChange, afterChange, childCountDelta);
 }
 
+bool HTMLOptGroupElement::rendererIsNeeded(const RenderStyle&)
+{
+    HTMLSelectElement* select = ownerSelectElement();
+    return select && !select->usesMenuList() && !isDisplayNone();

[esprehn, 2014/06/23 21:59:55]

This is not correct, you should be calling the super class version to deal with
display none stuff.

[keishi, 2014/07/01 04:53:32]

Done.

+}
+
 void HTMLOptGroupElement::parseAttribute(const QualifiedName& name, const AtomicString& value)
 {
     HTMLElement::parseAttribute(name, value);
     recalcSelectOptions();
 
     if (name == disabledAttr)
         didAffectSelector(AffectedSelectorDisabled | AffectedSelectorEnabled);
+    else if (name == labelAttr)
+        updateGroupLabel();
 }
 
 void HTMLOptGroupElement::recalcSelectOptions()
 {
     if (HTMLSelectElement* select = Traversal<HTMLSelectElement>::firstAncestor(*this))
         select->setRecalcListItems();
 }
 
 void HTMLOptGroupElement::attach(const AttachContext& context)
 {
@@ skipping 24 matching lines @@
 {
     return m_style.get();
 }
 
 PassRefPtr<RenderStyle> HTMLOptGroupElement::customStyleForRenderer()
 {
     updateNonRenderStyle();
     return m_style;
 }
 
+
 String HTMLOptGroupElement::groupLabelText() const
 {
     String itemText = getAttribute(labelAttr);
 
     // In WinIE, leading and trailing whitespace is ignored in options and optgroups. We match this behavior.
     itemText = itemText.stripWhiteSpace();
     // We want to collapse our whitespace too.  This will match other browsers.
     itemText = itemText.simplifyWhiteSpace();
 
     return itemText;
 }
 
+LayoutUnit HTMLOptGroupElement::groupLabelHeight() const
+{
+    if (!m_groupLabelElement)
+        return 0;
+    RenderObject* labelRenderer = m_groupLabelElement->renderer();
+    if (!labelRenderer)
+        return 0;
+    return labelRenderer->absoluteBoundingBoxRect().height();

[esprehn, 2014/06/23 21:59:55]

This is wrong, you can't call int this when layout is dirty. This shouldn't be
in the DOM.

+}
+
 HTMLSelectElement* HTMLOptGroupElement::ownerSelectElement() const
 {
     return Traversal<HTMLSelectElement>::firstAncestor(*this);
 }
 
 void HTMLOptGroupElement::accessKeyAction(bool)
 {
     HTMLSelectElement* select = ownerSelectElement();
     // send to the parent to bring focus to the list box
     if (select && !select->focused())
         select->accessKeyAction(false);
 }
 
+void HTMLOptGroupElement::didAddUserAgentShadowRoot(ShadowRoot& root)
+{
+    RefPtr<GroupLabelElement> groupLabelElement = GroupLabelElement::create(document());
+    groupLabelElement->setText(String());

[esprehn, 2014/06/23 21:59:55]

I don't think yo need a custom GroupLabelElement at all, just use a <div> here
and do setTextContent. You can set an id on it to reference it later if you need
to update it.

[keishi, 2014/07/01 04:53:32]

Done.

+    root.appendChild(groupLabelElement);
+    m_groupLabelElement = groupLabelElement.get();

[esprehn, 2014/06/23 21:59:55]

Remove.

[keishi, 2014/07/01 04:53:32]

Done.

+
+    RefPtr<HTMLContentElement> content = HTMLContentElement::create(document());
+    content->setAttribute(selectAttr, "option");
+    root.appendChild(content);
+}
+
+void HTMLOptGroupElement::updateGroupLabel()
+{
+    static_cast<GroupLabelElement*>(ensureUserAgentShadowRoot().firstChild())->setText(groupLabelText());
+}
+
 bool HTMLOptGroupElement::isDisplayNone() const
 {
-    RenderStyle* style = nonRendererStyle();
-    return style && style->display() == NONE;
+    RenderStyle* style = renderStyle();
+    return !style || style->display() == NONE;

[esprehn, 2014/06/23 21:59:56]

We should just remove this method....

[keishi, 2014/07/01 04:53:32]

Done.

+}
+
+Node::InsertionNotificationRequest HTMLOptGroupElement::insertedInto(ContainerNode* insertionPoint)
+{
+    HTMLElement::insertedInto(insertionPoint);
+    return insertionPoint->inDocument() ? InsertionShouldCallDidNotifySubtreeInsertions : InsertionDone;

[esprehn, 2014/06/23 21:59:55]

You shouldn't be using InsertionShouldCallDidNotifySubtreeInsertions here...

[keishi, 2014/07/01 04:53:32]

Done.

+}
+
+void HTMLOptGroupElement::didNotifySubtreeInsertionsToDocument()
+{
+    updateView();
+}
+
+void HTMLOptGroupElement::updateView()
+{
+    HTMLSelectElement* select = ownerSelectElement();
+    if (select && !select->usesMenuList())
+        ensureUserAgentShadowRoot();

[esprehn, 2014/06/23 21:59:55]

You always have a UA ShadowRoot, you call it in ::create(). Remove this.

[keishi, 2014/07/01 04:53:32]

Done.

+    else if (userAgentShadowRoot() && document().lifecycle().stateAllowsDetach())

[esprehn, 2014/06/23 21:59:55]

Using stateAllowsDetach() is wrong, don't do that. That's only for assertions
and to keep you from doing something bad, checking it like this means you're
doing something bad.

+        userAgentShadowRoot()->detach();

[esprehn, 2014/06/23 21:59:55]

You should not be calling detach like this.

 }
 
 } // namespace