CSS Custom Properties (Variables)

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 16 matching lines @@
 #include "config.h"
 #include "core/css/parser/CSSPropertyParser.h"
 
 #include "core/StylePropertyShorthand.h"
 #include "core/css/CSSBasicShapes.h"
 #include "core/css/CSSBorderImage.h"
 #include "core/css/CSSCanvasValue.h"
 #include "core/css/CSSContentDistributionValue.h"
 #include "core/css/CSSCrossfadeValue.h"
 #include "core/css/CSSCursorImageValue.h"
+#include "core/css/CSSCustomVariableValue.h"
 #include "core/css/CSSFontFaceSrcValue.h"
 #include "core/css/CSSFontFeatureValue.h"
 #include "core/css/CSSFunctionValue.h"
 #include "core/css/CSSGridLineNamesValue.h"
 #include "core/css/CSSImageSetValue.h"
 #include "core/css/CSSImageValue.h"
 #include "core/css/CSSLineBoxContainValue.h"
 #include "core/css/CSSPathValue.h"
 #include "core/css/CSSPrimitiveValueMappings.h"
 #include "core/css/CSSProperty.h"
@@ skipping 392 matching lines @@
             return false;
         addExpandedPropertyForValue(propId, cssValuePool().createExplicitInitialValue(), important);
         return true;
     } else if (id == CSSValueUnset) {
         if (m_valueList->size() != 1)
             return false;
         addExpandedPropertyForValue(propId, cssValuePool().createUnsetValue(), important);
         return true;
     }
 
+
     int num = inShorthand() ? 1 : m_valueList->size();
 
+    if (RuntimeEnabledFeatures::cssVariablesEnabled() && value->unit() == CSSPrimitiveValue::UnitType::VariableReference) {
+        // We don't expand the shorthand here because crazypants.
+        m_parsedProperties.append(CSSProperty(propId, CSSPrimitiveValue::create(value->variableData), important, false, 0, m_implicitShorthand));
+        m_valueList->next();
+        return true;
+    }
+
     if (CSSParserFastPaths::isKeywordPropertyID(propId)) {
         if (!CSSParserFastPaths::isValidKeywordPropertyAndValue(propId, id))
             return false;
         if (m_valueList->next() && !inShorthand())
             return false;
         addProperty(propId, cssValuePool().createIdentifierValue(id), important);
         return true;
     }
 
     bool validPrimitive = false;
@@ skipping 7114 matching lines @@
 
     // If just one value is supplied, the second value
     // is implicitly initialized with the first value.
     if (numValues == 1)
         m_valueList->previous();
 
     return parseViewportProperty(second, important);
 }
 
 template <typename CharacterType>
+static bool isVariableDefinition(const CharacterType* propertyName, unsigned length)
+{
+    return (length >= 2 && propertyName[0] == '-' && propertyName[1] == '-');
+}
+
+template <typename CharacterType>
 static CSSPropertyID unresolvedCSSPropertyID(const CharacterType* propertyName, unsigned length)

[alancutter (OOO until 2018), 2015/08/05 08:01:43]

I'm not sure that we should be returning CSSPropertyVariable from this function.
Existing calls to it are unlikely going to handle the custom property case
correctly since it's not a real property identifier.
It's probably better to continue returning CSSPropertyInvalid and at the call
site just call isVariableDefinition() on the original string. I suspect existing
call sites like transition-property parsing will not want to treat them any
differently from CSSPropertyInvalid.

 {
     char buffer[maxCSSPropertyNameLength + 1]; // 1 for null character
 
     for (unsigned i = 0; i != length; ++i) {
         CharacterType c = propertyName[i];
-        if (c == 0 || c >= 0x7F)
+        if (c == 0 || c >= 0x7F) {
+            if (isVariableDefinition(propertyName, length))
+                return CSSPropertyVariable;
             return CSSPropertyInvalid; // illegal character
+        }
         buffer[i] = toASCIILower(c);
     }
     buffer[length] = '\0';
 
     const char* name = buffer;
     const Property* hashTableEntry = findProperty(name, length);
-    if (!hashTableEntry)
+    if (!hashTableEntry) {
+        if (isVariableDefinition(propertyName, length))
+            return CSSPropertyVariable;
         return CSSPropertyInvalid;
+    }
     CSSPropertyID property = static_cast<CSSPropertyID>(hashTableEntry->id);
     if (!CSSPropertyMetadata::isEnabledProperty(property))
         return CSSPropertyInvalid;
     return property;
 }
 
 CSSPropertyID unresolvedCSSPropertyID(const String& string)
 {
     unsigned length = string.length();
 
     if (!length)
         return CSSPropertyInvalid;
-    if (length > maxCSSPropertyNameLength)
+    if (length > maxCSSPropertyNameLength) {
+        if (string.is8Bit() ? isVariableDefinition(string.characters8(), length) : isVariableDefinition(string.characters16(), length))
+            return CSSPropertyVariable;
         return CSSPropertyInvalid;
+    }
 
     return string.is8Bit() ? unresolvedCSSPropertyID(string.characters8(), length) : unresolvedCSSPropertyID(string.characters16(), length);
 }
 
 CSSPropertyID unresolvedCSSPropertyID(const CSSParserString& string)
 {
     unsigned length = string.length();
 
     if (!length)
         return CSSPropertyInvalid;
-    if (length > maxCSSPropertyNameLength)
+    if (length > maxCSSPropertyNameLength) {
+        if (string.is8Bit() ? isVariableDefinition(string.characters8(), length) : isVariableDefinition(string.characters16(), length))
+            return CSSPropertyVariable;
         return CSSPropertyInvalid;
+    }
 
     return string.is8Bit() ? unresolvedCSSPropertyID(string.characters8(), length) : unresolvedCSSPropertyID(string.characters16(), length);
 }
 
 template <typename CharacterType>
 static CSSValueID cssValueKeywordID(const CharacterType* valueKeyword, unsigned length)
 {
     char buffer[maxCSSValueKeywordLength + 1]; // 1 for null character
 
     for (unsigned i = 0; i != length; ++i) {
@@ skipping 523 matching lines @@
         }
     }
 
     if (!list->length())
         return nullptr;
 
     return list.release();
 }
 
 } // namespace blink