[CSS Grid Layout] Implementation of the grid shorthand.

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 1259 matching lines @@
         if (!RuntimeEnabledFeatures::cssGridLayoutEnabled())
             return false;
         parsedValue = parseGridTemplateAreas();
         break;
 
     case CSSPropertyGridTemplate:
         if (!RuntimeEnabledFeatures::cssGridLayoutEnabled())
             return false;
         return parseGridTemplateShorthand(important);
 
+    case CSSPropertyGrid:
+        if (!RuntimeEnabledFeatures::cssGridLayoutEnabled())
+            return false;
+        return parseGridShorthand(important);
+
     case CSSPropertyWebkitMarginCollapse: {
         if (num == 1) {
             ShorthandScope scope(this, CSSPropertyWebkitMarginCollapse);
             if (!parseValue(webkitMarginCollapseShorthand().properties()[0], important))
                 return false;
             CSSValue* value = m_parsedProperties.last().value();
             addProperty(webkitMarginCollapseShorthand().properties()[1], value, important);
             return true;
         }
         else if (num == 2) {
@@ skipping 2302 matching lines @@
 
     // 3- [<track-list> /]? [<line-names>? <string> [<track-size> <line-names>]? ]+ syntax.
     // The template-columns <track-list> can't be 'none'.
     if (firstValueIsNone)
         return false;
     // It requires to rewind parsing due to previous syntax failures.
     m_valueList->setCurrentIndex(index);
     return parseGridTemplateRowsAndAreas(columnsValue, important);
 }
 
+bool CSSPropertyParser::parseGridShorthand(bool important)
+{
+    ShorthandScope scope(this, CSSPropertyGrid);
+    const StylePropertyShorthand& shorthand = shorthandForProperty(CSSPropertyGrid);
+    ASSERT_UNUSED(shorthand, shorthand.length() == 4);

[Julien - ping for review, 2014/04/03 21:14:30]

Can't we just do:

ASSERT(shorthandForProperty(CSSPropertyGrid).lenght() == 4);

[jfernandez, 2014/04/04 15:09:35]

Done.

+
+    // 1- <grid-template>
+    if (parseGridTemplateShorthand(important)) {
+        // Default values for the implicit grid properties.
+        addProperty(CSSPropertyGridAutoFlow, cssValuePool().createIdentifierValue(CSSValueNone), important);
+        addProperty(CSSPropertyGridAutoColumns, cssValuePool().createIdentifierValue(CSSValueAuto), important);
+        addProperty(CSSPropertyGridAutoRows, cssValuePool().createIdentifierValue(CSSValueAuto), important);
+        return true;
+    }
+
+    // Need to rewind parsing to explore the alternative syntax of this shorthand.
+    m_valueList->setCurrentIndex(0);
+
+    // 2- <grid-auto-flow> [ <grid-auto-columns> [ / <grid-auto-rows> ]? ]
+    CSSValueID id = m_valueList->current()->id;
+    if (id != CSSValueRow && id != CSSValueColumn && id != CSSValueNone)
+        return false;
+
+    RefPtrWillBeRawPtr<CSSValue> autoFlowValue = cssValuePool().createIdentifierValue(id);
+    RefPtrWillBeRawPtr<CSSValue> autoColumnsValue = cssValuePool().createIdentifierValue(CSSValueAuto);

[Julien - ping for review, 2014/04/03 21:14:30]

I would rather leave both auto*Value to nullptr and initialize them in the
'else' branches below (if (m_valueList->next())).

Also the specification prose mentions to set them up to the *initial* value, for
which we have a keyword: CSSValueInitial.

[jfernandez, 2014/04/04 15:09:35]

Done.
Well, I think what is has to be done is to use the
"createExplicitInitialValue()" method to set the corresponding "initial" values
for each property; right ? 

+    RefPtrWillBeRawPtr<CSSValue> autoRowsValue = nullptr;
+
+    if (m_valueList->next()) {
+        autoColumnsValue = parseGridTrackSize(*m_valueList);
+        if (!autoColumnsValue)
+            return false;
+        if (m_valueList->current()) {
+            if (!(isForwardSlashOperator(m_valueList->current()) && m_valueList->next()))

[Julien - ping for review, 2014/04/03 21:14:30]

Let's avoid !(... && ...) by expanding it.

[jfernandez, 2014/04/04 15:09:35]

Done.

+                return false;
+            autoRowsValue = parseGridTrackSize(*m_valueList);
+            if (!autoRowsValue)
+                return false;
+        }
+        if (m_valueList->current())
+            return false;
+    }
+    addProperty(CSSPropertyGridAutoFlow, autoFlowValue, important);
+    addProperty(CSSPropertyGridAutoColumns, autoColumnsValue, important);
+    if (autoRowsValue)
+        addProperty(CSSPropertyGridAutoRows, autoRowsValue, important);
+    else
+        addProperty(CSSPropertyGridAutoRows, autoColumnsValue, important);
+
+    // Default values for the explicit grid properties.

[Julien - ping for review, 2014/04/03 21:14:30]

You should quote the specification here or give a more precise comment as this
looks really suspicious until you read the specification prose.

[jfernandez, 2014/04/04 15:09:35]

Done.

+    addProperty(CSSPropertyGridTemplateColumns, cssValuePool().createIdentifierValue(CSSValueNone), important);
+    addProperty(CSSPropertyGridTemplateRows, cssValuePool().createIdentifierValue(CSSValueNone), important);
+    addProperty(CSSPropertyGridTemplateAreas, cssValuePool().createIdentifierValue(CSSValueNone), important);
+
+    return true;
+}
+
 bool CSSPropertyParser::parseGridAreaShorthand(bool important)
 {
     ASSERT(RuntimeEnabledFeatures::cssGridLayoutEnabled());
 
     ShorthandScope scope(this, CSSPropertyGridArea);
     const StylePropertyShorthand& shorthand = gridAreaShorthand();
     ASSERT_UNUSED(shorthand, shorthand.length() == 4);
 
     RefPtrWillBeRawPtr<CSSValue> rowStartValue = parseGridPosition();
     if (!rowStartValue)
@@ skipping 4844 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