Implement select listbox using shadow DOM

Source/core/html/HTMLSelectElement.cpp

 /*
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
  * 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, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
@@ skipping 21 matching lines @@
 #include "bindings/v8/ExceptionState.h"
 #include "bindings/v8/ExceptionStatePlaceholder.h"
 #include "core/HTMLNames.h"
 #include "core/accessibility/AXObjectCache.h"
 #include "core/dom/Attribute.h"
 #include "core/dom/ElementTraversal.h"
 #include "core/dom/NodeTraversal.h"
 #include "core/events/GestureEvent.h"
 #include "core/events/KeyboardEvent.h"
 #include "core/events/MouseEvent.h"
+#include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/html/FormDataList.h"
 #include "core/html/HTMLFormElement.h"
+#include "core/html/HTMLOptGroupElement.h"
 #include "core/html/HTMLOptionElement.h"
 #include "core/html/forms/FormController.h"
+#include "core/page/AutoscrollController.h"
 #include "core/page/EventHandler.h"
+#include "core/page/Page.h"
 #include "core/page/SpatialNavigation.h"
+#include "core/rendering/HitTestRequest.h"
+#include "core/rendering/HitTestResult.h"
 #include "core/rendering/RenderListBox.h"
 #include "core/rendering/RenderMenuList.h"
 #include "core/rendering/RenderTheme.h"
+#include "core/rendering/RenderView.h"
 #include "platform/PlatformMouseEvent.h"
 #include "platform/text/PlatformLocale.h"
 
 using namespace WTF::Unicode;
 
 namespace WebCore {
 
 using namespace HTMLNames;
 
 // Upper limit agreed upon with representatives of Opera and Mozilla.
 static const unsigned maxSelectItems = 10000;
 
 HTMLSelectElement::HTMLSelectElement(Document& document, HTMLFormElement* form)
     : HTMLFormControlElementWithState(selectTag, document, form)
     , m_typeAhead(this)
     , m_size(0)
     , m_lastOnChangeIndex(-1)
     , m_activeSelectionAnchorIndex(-1)
     , m_activeSelectionEndIndex(-1)
     , m_isProcessingUserDrivenChange(false)
     , m_multiple(false)
     , m_activeSelectionState(false)
     , m_shouldRecalcListItems(false)
     , m_suggestedIndex(-1)
+    , m_capturing(false)
 {
     ScriptWrappable::init(this);
     setHasCustomStyleCallbacks();
 }
 
 PassRefPtrWillBeRawPtr<HTMLSelectElement> HTMLSelectElement::create(Document& document)
 {
     return adoptRefWillBeNoop(new HTMLSelectElement(document, 0));
 }
 
@@ skipping 241 matching lines @@
                 sizeAttribute->setValue(attrSize);
         }
         size = std::max(size, 1);
 
         // Ensure that we've determined selectedness of the items at least once prior to changing the size.
         if (oldSize != size)
             updateListItemSelectedStates();
 
         m_size = size;
         setNeedsValidityCheck();
-        if (m_size != oldSize && inActiveDocument()) {
-            lazyReattachIfAttached();
-            setRecalcListItems();
+        if (m_size != oldSize && document().isActive()) {
+            // ensureShadowDOM needs to be run even when !inDocument().

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

ensureUserAgentShadowRoot should be run by ::create()

+            updateView();
+            if (inDocument())
+                setRecalcListItems();
         }
     } else if (name == multipleAttr)
         parseMultipleAttribute(value);
     else if (name == accesskeyAttr) {
         // FIXME: ignore for the moment.
         //
     } else if (name == disabledAttr) {
         HTMLFormControlElementWithState::parseAttribute(name, value);
         if (renderer() && renderer()->isMenuList()) {
             if (RenderMenuList* menuList = toRenderMenuList(renderer())) {
                 if (menuList->popupIsVisible())
                     menuList->hidePopup();
             }
         }
 
     } else
         HTMLFormControlElementWithState::parseAttribute(name, value);
 }
 
 bool HTMLSelectElement::shouldShowFocusRingOnMouseFocus() const
 {
     return true;
 }
 
 bool HTMLSelectElement::canSelectAll() const
 {
     return !usesMenuList();
 }
 
-RenderObject* HTMLSelectElement::createRenderer(RenderStyle*)
+RenderObject* HTMLSelectElement::createRenderer(RenderStyle* style)
 {
     if (usesMenuList())
         return new RenderMenuList(this);
     return new RenderListBox(this);
 }
 
 PassRefPtrWillBeRawPtr<HTMLCollection> HTMLSelectElement::selectedOptions()
 {
     updateListItemSelectedStates();
     return ensureCachedHTMLCollection(SelectedOptions);
@@ skipping 316 matching lines @@
         m_lastOnChangeIndex = selected;
         m_isProcessingUserDrivenChange = false;
         RefPtrWillBeRawPtr<HTMLSelectElement> protector(this);
         dispatchInputEvent();
         dispatchFormControlChangeEvent();
     }
 }
 
 void HTMLSelectElement::scrollToSelection()
 {
+    if (!isFinishedParsingChildren())
+        return;
     if (usesMenuList())
         return;
-
-    if (RenderObject* renderer = this->renderer())
-        toRenderListBox(renderer)->selectionChanged();
+    scrollTo(activeSelectionEndListIndex());
+    if (AXObjectCache* cache = document().existingAXObjectCache())
+        cache->selectedChildrenChanged(this);
 }
 
 void HTMLSelectElement::setOptionsChangedOnRenderer()
 {
     if (RenderObject* renderer = this->renderer()) {
         if (usesMenuList())
             toRenderMenuList(renderer)->setOptionsChanged(true);
-        else
-            toRenderListBox(renderer)->setOptionsChanged(true);
     }
 }
 
 const WillBeHeapVector<RawPtrWillBeMember<HTMLElement> >& HTMLSelectElement::listItems() const
 {
     if (m_shouldRecalcListItems)
         recalcListItems();
     else {
 #if ASSERT_ENABLED
         WillBeHeapVector<RawPtrWillBeMember<HTMLElement> > items = m_listItems;
@@ skipping 121 matching lines @@
 {
     return m_suggestedIndex;
 }
 
 void HTMLSelectElement::setSuggestedIndex(int suggestedIndex)
 {
     m_suggestedIndex = suggestedIndex;
 
     if (RenderObject* renderer = this->renderer())  {
         renderer->updateFromElement();
-        if (renderer->isListBox())
-            toRenderListBox(renderer)->scrollToRevealElementAtListIndex(suggestedIndex);
+        scrollTo(suggestedIndex);
     }
 }
 
+void HTMLSelectElement::scrollTo(int listIndex)
+{
+    if (listIndex < 0)
+        return;
+    const WillBeHeapVector<RawPtrWillBeMember<HTMLElement> >& items = listItems();
+    int listSize = static_cast<int>(items.size());
+    if (listIndex >= listSize)
+        return;
+    items[listIndex]->scrollIntoViewIfNeeded(false);
+}
+
 void HTMLSelectElement::optionSelectionStateChanged(HTMLOptionElement* option, bool optionIsSelected)
 {
     ASSERT(option->ownerSelectElement() == this);
     if (optionIsSelected)
         selectOption(option->index());
     else if (!usesMenuList() || multiple())
         selectOption(-1);
     else
         selectOption(nextSelectableListIndex(-1));
 }
 
+void HTMLSelectElement::optionRemoved(HTMLOptionElement* option)
+{
+    if (m_activeSelectionAnchorIndex < 0 && m_activeSelectionEndIndex < 0)
+        return;
+    int listIndex = optionToListIndex(option->index());

[keishi, 2014/06/23 20:42:01]

fast/forms/select-max-length.html was slow because this line causes
recalcListItems to be called for every option removed. Adding the if statement
before this made the test pass but it will still be slow for other websites.

+    if (listIndex <= m_activeSelectionAnchorIndex)
+        m_activeSelectionAnchorIndex--;
+    if (listIndex <= m_activeSelectionEndIndex)
+        m_activeSelectionEndIndex--;
+}
+
 void HTMLSelectElement::selectOption(int optionIndex, SelectOptionFlags flags)
 {
     bool shouldDeselect = !m_multiple || (flags & DeselectOtherOptions);
 
     const WillBeHeapVector<RawPtrWillBeMember<HTMLElement> >& items = listItems();
     int listIndex = optionToListIndex(optionIndex);
 
     HTMLElement* element = 0;
     if (listIndex >= 0) {
         element = items[listIndex];
@@ skipping 15 matching lines @@
 
     scrollToSelection();
 
     setNeedsValidityCheck();
 
     if (usesMenuList()) {
         m_isProcessingUserDrivenChange = flags & UserDriven;
         if (flags & DispatchInputAndChangeEvent)
             dispatchInputAndChangeEventForMenuList();
         if (RenderObject* renderer = this->renderer()) {
-            if (usesMenuList())
+            if (usesMenuList()) {
                 toRenderMenuList(renderer)->didSetSelectedIndex(listIndex);
-            else if (renderer->isListBox())
-                toRenderListBox(renderer)->selectionChanged();
+            } else if (renderer->isListBox()) {
+                if (AXObjectCache* cache = document().existingAXObjectCache())
+                    cache->selectedChildrenChanged(this);
+            }
         }
     }
 
     notifyFormStateChanged();
 }
 
 int HTMLSelectElement::optionToListIndex(int optionIndex) const
 {
     const WillBeHeapVector<RawPtrWillBeMember<HTMLElement> >& items = listItems();
     int listSize = static_cast<int>(items.size());
@@ skipping 120 matching lines @@
             startIndex = foundIndex + 1;
         }
     }
 
     setOptionsChangedOnRenderer();
     setNeedsValidityCheck();
 }
 
 void HTMLSelectElement::parseMultipleAttribute(const AtomicString& value)
 {
-    bool oldUsesMenuList = usesMenuList();
     m_multiple = !value.isNull();
     setNeedsValidityCheck();
-    if (oldUsesMenuList != usesMenuList())
-        lazyReattachIfAttached();
+
+    updateView();
+}
+
+void HTMLSelectElement::updateView()
+{
+    if (!usesMenuList())
+        ensureUserAgentShadowRoot();
+    else if (userAgentShadowRoot() && document().lifecycle().stateAllowsDetach())

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

This is wrong, you should not be manually interacting with detach() or
ensureUserAgentShadowRoot like this.

+        userAgentShadowRoot()->detach();
+    const WillBeHeapVector<RawPtrWillBeMember<HTMLElement> >& items = listItems();
+    unsigned optionCount = 0;
+    for (unsigned i = 0; i < items.size(); ++i) {
+        HTMLElement* element = items[i];
+        if (isHTMLOptionElement(*element)) {
+            toHTMLOptionElement(*element).updateView();
+            optionCount++;
+        } else if (isHTMLOptGroupElement(*element)) {
+            toHTMLOptGroupElement(*element).updateView();
+        }
+        if (optionCount >= maxSelectItems)
+            break;
+    }
+    lazyReattachIfAttached();

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

If you're going to reattach anyway, then there's no reason for the detach above
anyway.

 }
 
 bool HTMLSelectElement::appendFormData(FormDataList& list, bool)
 {
     const AtomicString& name = this->name();
     if (name.isEmpty())
         return false;
 
     bool successful = false;
     const WillBeHeapVector<RawPtrWillBeMember<HTMLElement> >& items = listItems();
@@ skipping 257 matching lines @@
     // we're doing a single selection, or a multiple selection (using cmd or
     // ctrl), then initialize the anchor index to the listIndex that just got
     // clicked.
     if (m_activeSelectionAnchorIndex < 0 || !shiftSelect)
         setActiveSelectionAnchorIndex(listIndex);
 
     setActiveSelectionEndIndex(listIndex);
     updateListBoxSelection(!multiSelect);
 }
 
+int HTMLSelectElement::listIndexForMouseEvent(const MouseEvent& event)
+{
+    Node* targetNode = event.target()->toNode();
+    if (targetNode != this)
+        return listIndexForEvent(event);
+    HitTestRequest request(HitTestRequest::ReadOnly | HitTestRequest::Active | HitTestRequest::Move | HitTestRequest::ConfusingAndOftenMisusedDisallowShadowContent);

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

Why are you using HitTestRequest::ConfusingAndOftenMisusedDisallowShadowContent?
This is going to be broken if you put a <select> inside a SHadowRoot like
polymer does.

[keishi, 2014/07/01 04:53:33]

I was able to remove this hit test.

+    HitTestResult result(event.absoluteLocation());
+    document().renderView()->hitTest(request, result);

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

What makes sure the layout/style is updated before you call this?

+    Node* hitNode = result.targetNode();
+    if (!hitNode)
+        return -1;
+    return listIndexForNode(*hitNode);
+}
+
+int HTMLSelectElement::listIndexForEvent(const Event& event)
+{
+    Node* targetNode = event.target()->toNode();
+    if (!targetNode)
+        return -1;
+    return listIndexForNode(*targetNode);
+}
+
+int HTMLSelectElement::listIndexForNode(const Node& targetNode)

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

Can you scope this to a more specific type?

[keishi, 2014/07/01 04:53:33]

Done.

+{
+    const WillBeHeapVector<RawPtrWillBeMember<HTMLElement> >& items = this->listItems();
+    for (const Node* node = &targetNode; node; node = node->parentOrShadowHostNode()) {

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

This walks all the way up to root of the document, why is that correct?

+        if (node->isElementNode() && (toElement(node)->hasTagName(optionTag) || toElement(node)->hasTagName(optgroupTag))) {
+            size_t length = items.size();
+            for (size_t i = 0; i < length; ++i) {
+                if (items[i] == node) {
+                    return i;
+                }
+            }
+        }
+    }
+    return -1;
+}
+
+AutoscrollController* HTMLSelectElement::autoscrollController() const
+{
+    if (Page* page = document().page())
+        return &page->autoscrollController();
+    return 0;
+}
+
 void HTMLSelectElement::listBoxDefaultEventHandler(Event* event)
 {
     const WillBeHeapVector<RawPtrWillBeMember<HTMLElement> >& listItems = this->listItems();
     if (event->type() == EventTypeNames::gesturetap && event->isGestureEvent()) {
         focus();
         // Calling focus() may cause us to lose our renderer or change the render type, in which case do not want to handle the event.
         if (!renderer() || !renderer()->isListBox())
             return;
 
         // Convert to coords relative to the list box if needed.
         GestureEvent& gestureEvent = toGestureEvent(*event);
-        IntPoint localOffset = roundedIntPoint(renderer()->absoluteToLocal(gestureEvent.absoluteLocation(), UseTransforms));
-        int listIndex = toRenderListBox(renderer())->listIndexAtOffset(toIntSize(localOffset));
+        int listIndex = listIndexForEvent(gestureEvent);
         if (listIndex >= 0) {
             if (!isDisabledFormControl())
                 updateSelectedState(listIndex, true, gestureEvent.shiftKey());
             event->setDefaultHandled();
         }
     } else if (event->type() == EventTypeNames::mousedown && event->isMouseEvent() && toMouseEvent(event)->button() == LeftButton) {
         focus();
         // Calling focus() may cause us to lose our renderer, in which case do not want to handle the event.
         if (!renderer() || !renderer()->isListBox() || isDisabledFormControl())
             return;
 
+        if (Page* page = document().page())
+            page->autoscrollController().startAutoscrollForSelection(renderer());
+
+        if (LocalFrame* frame = document().frame()) {
+            frame->eventHandler().setCapturingMouseEventsNode(this);
+            m_capturing = true;
+        }
+
         // Convert to coords relative to the list box if needed.
         MouseEvent* mouseEvent = toMouseEvent(event);
-        IntPoint localOffset = roundedIntPoint(renderer()->absoluteToLocal(mouseEvent->absoluteLocation(), UseTransforms));
-        int listIndex = toRenderListBox(renderer())->listIndexAtOffset(toIntSize(localOffset));
+        int listIndex = listIndexForMouseEvent(*mouseEvent);
         if (listIndex >= 0) {
             if (!isDisabledFormControl()) {
 #if OS(MACOSX)
                 updateSelectedState(listIndex, mouseEvent->metaKey(), mouseEvent->shiftKey());
 #else
                 updateSelectedState(listIndex, mouseEvent->ctrlKey(), mouseEvent->shiftKey());
 #endif
             }
             if (LocalFrame* frame = document().frame())
                 frame->eventHandler().setMouseDownMayStartAutoscroll();
 
             event->setDefaultHandled();
         }
-    } else if (event->type() == EventTypeNames::mousemove && event->isMouseEvent() && !toRenderBox(renderer())->canBeScrolledAndHasScrollableArea()) {
+    } else if (event->type() == EventTypeNames::mousemove && event->isMouseEvent()) {
         MouseEvent* mouseEvent = toMouseEvent(event);
         if (mouseEvent->button() != LeftButton || !mouseEvent->buttonDown())
             return;
-
-        IntPoint localOffset = roundedIntPoint(renderer()->absoluteToLocal(mouseEvent->absoluteLocation(), UseTransforms));
-        int listIndex = toRenderListBox(renderer())->listIndexAtOffset(toIntSize(localOffset));
+        int listIndex = listIndexForMouseEvent(*mouseEvent);
         if (listIndex >= 0) {
             if (!isDisabledFormControl()) {
                 if (m_multiple) {
                     // Only extend selection if there is something selected.
                     if (m_activeSelectionAnchorIndex < 0)
                         return;
 
                     setActiveSelectionEndIndex(listIndex);
                     updateListBoxSelection(false);
                 } else {
                     setActiveSelectionAnchorIndex(listIndex);
                     setActiveSelectionEndIndex(listIndex);
                     updateListBoxSelection(true);
                 }
             }
         }
-    } else if (event->type() == EventTypeNames::mouseup && event->isMouseEvent() && toMouseEvent(event)->button() == LeftButton && renderer() && !toRenderBox(renderer())->autoscrollInProgress()) {
+    } else if (event->type() == EventTypeNames::mouseup && event->isMouseEvent() && toMouseEvent(event)->button() == LeftButton && renderer()) {
+        LocalFrame* frame = document().frame();
+        if (m_capturing && frame) {
+            frame->eventHandler().setCapturingMouseEventsNode(nullptr);
+            m_capturing = false;
+        }
         // We didn't start this click/drag on any options.
         if (m_lastOnChangeSelection.isEmpty())
             return;
         listBoxOnChange();
     } else if (event->type() == EventTypeNames::keydown) {
         if (!event->isKeyboardEvent())
             return;
         const String& keyIdentifier = toKeyboardEvent(event)->keyIdentifier();
 
         bool handled = false;
@@ skipping 58 matching lines @@
                 m_activeSelectionState = true;
             // If the anchor is unitialized, or if we're going to deselect all
             // other options, then set the anchor index equal to the end index.
             bool deselectOthers = !m_multiple || (!toKeyboardEvent(event)->shiftKey() && selectNewItem);
             if (m_activeSelectionAnchorIndex < 0 || deselectOthers) {
                 if (deselectOthers)
                     deselectItemsWithoutValidation();
                 setActiveSelectionAnchorIndex(m_activeSelectionEndIndex);
             }
 
-            toRenderListBox(renderer())->scrollToRevealElementAtListIndex(endIndex);
+            scrollTo(endIndex);
             if (selectNewItem) {
                 updateListBoxSelection(deselectOthers);
                 listBoxOnChange();
             } else
                 scrollToSelection();
 
             event->setDefaultHandled();
         }
     } else if (event->type() == EventTypeNames::keypress) {
         if (!event->isKeyboardEvent())
@@ skipping 130 matching lines @@
             ++options;
     }
 
     return options;
 }
 
 void HTMLSelectElement::finishParsingChildren()
 {
     HTMLFormControlElementWithState::finishParsingChildren();
     updateListItemSelectedStates();
+    scrollToSelection();
 }
 
 bool HTMLSelectElement::anonymousIndexedSetter(unsigned index, PassRefPtrWillBeRawPtr<HTMLOptionElement> value, ExceptionState& exceptionState)
 {
     if (!value) { // undefined or null
         remove(index);
         return true;
     }
     setOption(index, value.get(), exceptionState);
     return true;
@@ skipping 15 matching lines @@
 }
 
 void HTMLSelectElement::trace(Visitor* visitor)
 {
 #if ENABLE(OILPAN)
     visitor->trace(m_listItems);
 #endif
     HTMLFormControlElementWithState::trace(visitor);
 }
 
+void HTMLSelectElement::didAddUserAgentShadowRoot(ShadowRoot& root)
+{
+    RefPtrWillBeRawPtr<HTMLContentElement> content = HTMLContentElement::create(document());
+    content->setAttribute(selectAttr, "option,optgroup");
+    root.appendChild(content);
+}
+
 } // namespace