[CSS Grid Layout] Implement 'justify-items' parsing

Source/core/css/parser/CSSPropertyParser.cpp

 /*
  * Copyright (C) 2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2012 Adobe Systems Incorporated. All rights reserved.
  * Copyright (C) 2012 Intel Corporation. All rights reserved.
  *
@@ skipping 1181 matching lines @@
             return true;
         }
         return false;
     }
 
     case CSSPropertyJustifySelf:
         if (!RuntimeEnabledFeatures::cssGridLayoutEnabled())
             return false;
 
         return parseItemPositionOverflowPosition(propId, important);
+
+    case CSSPropertyJustifyItems:
+        if (!RuntimeEnabledFeatures::cssGridLayoutEnabled())
+            return false;
+
+        if (!parseLegacyPosition(propId, important)) {

[Julien - ping for review, 2014/06/24 19:04:56]

I would avoid the negative branch as it confused me here (maybe it's just me
though). It also avoids nesting:

if (parseLegacyPosition(propId, important))
    return true;

// Rewind and try the <item-position> && <overflow-position> | auto | stretch.
m_valueList->setCurrentIndex(0);
return parseItemPositionOverflowPosition(propId, important);

[jfernandez, 2014/06/26 12:58:44]

Done.

+            m_valueList->setCurrentIndex(0);
+            return parseItemPositionOverflowPosition(propId, important);
+        }
+
+        return true;
+
     case CSSPropertyGridAutoColumns:
     case CSSPropertyGridAutoRows:
         if (!RuntimeEnabledFeatures::cssGridLayoutEnabled())
             return false;
         parsedValue = parseGridTrackSize(*m_valueList);
         break;
 
     case CSSPropertyGridTemplateColumns:
     case CSSPropertyGridTemplateRows:
         if (!RuntimeEnabledFeatures::cssGridLayoutEnabled())
@@ skipping 2914 matching lines @@
     return shape;
 }
 
 static bool isItemPositionKeyword(CSSValueID id)
 {
     return id == CSSValueStart || id == CSSValueEnd || id == CSSValueCenter
         || id == CSSValueSelfStart || id == CSSValueSelfEnd || id == CSSValueFlexStart
         || id == CSSValueFlexEnd || id == CSSValueLeft || id == CSSValueRight;
 }
 
+bool CSSPropertyParser::parseLegacyPosition(CSSPropertyID propId, bool important)
+{
+    // [ legacy && [ left | right | center ]
+
+    CSSParserValue* value = m_valueList->current();
+    if (!value || value->id != CSSValueLegacy || !(value = m_valueList->next()))

[Julien - ping for review, 2014/06/24 19:04:56]

Per the grammar: legacy && [ left | right | center ]

That means legacy can appear before *and after* the other keywords. Btw your
test coverage doesn't handle this case.

[jfernandez, 2014/06/26 12:58:44]

Done.

+        return false;
+
+    if (value->id == CSSValueCenter || value->id == CSSValueLeft || value->id == CSSValueRight) {
+        if (m_valueList->next())
+            return false;
+
+        addProperty(propId, createPrimitiveValuePair(cssValuePool().createIdentifierValue(CSSValueLegacy), cssValuePool().createIdentifierValue(value->id)), important);
+        return true;
+    }
+
+    return false;
+}
+
 bool CSSPropertyParser::parseItemPositionOverflowPosition(CSSPropertyID propId, bool important)
 {
     // auto | baseline | stretch | [<item-position> && <overflow-position>? ]
     // <item-position> = center | start | end | self-start | self-end | flex-start | flex-end | left | right;
     // <overflow-position> = true | safe
 
     CSSParserValue* value = m_valueList->current();
+    if (!value)
+        return false;
 
     if (value->id == CSSValueAuto || value->id == CSSValueBaseline || value->id == CSSValueStretch) {
         if (m_valueList->next())
             return false;
 
         addProperty(propId, cssValuePool().createIdentifierValue(value->id), important);
         return true;
     }
 
     RefPtrWillBeRawPtr<CSSPrimitiveValue> position = nullptr;
@@ skipping 4264 matching lines @@
         parsedValues->append(CSSPrimitiveValue::createIdentifier(CSSValueFill));
     if (!seenStroke)
         parsedValues->append(CSSPrimitiveValue::createIdentifier(CSSValueStroke));
     if (!seenMarkers)
         parsedValues->append(CSSPrimitiveValue::createIdentifier(CSSValueMarkers));
 
     return parsedValues.release();
 }
 
 } // namespace WebCore