add pan-x and pan-y support to CSS touch-action parsing.

Source/core/css/CSSParser-in.cpp

Index: Source/core/css/CSSParser-in.cpp
diff --git a/Source/core/css/CSSParser-in.cpp b/Source/core/css/CSSParser-in.cpp
old mode 100644
new mode 100755
index 376f7c4e8f25bd71a537be28fa788a08f5492cb9..662ac381b38770bda4a3c48056a6bd1cdb3734af
--- a/Source/core/css/CSSParser-in.cpp
+++ b/Source/core/css/CSSParser-in.cpp
@@ -621,10 +621,6 @@ static inline bool isValidKeywordPropertyAndValue(CSSPropertyID propertyId, int
         if ((valueID >= CSSValueCapitalize && valueID <= CSSValueLowercase) || valueID == CSSValueNone)
             return true;
         break;
-    case CSSPropertyTouchAction: // auto | none
-        if (RuntimeEnabledFeatures::cssTouchActionEnabled() && (valueID == CSSValueAuto || valueID == CSSValueNone))
-            return true;
-        break;
     case CSSPropertyTouchActionDelay: // none | script
         if (RuntimeEnabledFeatures::cssTouchActionEnabled() && (valueID == CSSValueScript || valueID == CSSValueNone))
             return true;
@@ -882,7 +878,6 @@ static inline bool isKeywordPropertyID(CSSPropertyID propertyId)
     case CSSPropertyTextTransform:
     case CSSPropertyTextUnderlineMode:
     case CSSPropertyTextUnderlineStyle:
-    case CSSPropertyTouchAction:
     case CSSPropertyTouchActionDelay:
     case CSSPropertyVisibility:
     case CSSPropertyWebkitAppearance:
@@ -2706,6 +2701,11 @@ bool CSSParser::parseValue(CSSPropertyID propId, bool important)
     case CSSPropertyShapeImageThreshold:
         validPrimitive = (RuntimeEnabledFeatures::cssShapesEnabled() && !id && validUnit(value, FNumber));
         break;
+
+    case CSSPropertyTouchAction:
+    // auto | none | (panX || panY)

[Rick Byers, 2013/12/06 21:44:04]

indent comment

[gnana, 2013/12/10 18:24:37]

Done.

+        return parseTouchAction(propId, important);
+
     case CSSPropertyBorderBottomStyle:
     case CSSPropertyBorderCollapse:
     case CSSPropertyBorderLeftStyle:
@@ -2746,7 +2746,6 @@ bool CSSParser::parseValue(CSSPropertyID propId, bool important)
     case CSSPropertyTextTransform:
     case CSSPropertyTextUnderlineMode:
     case CSSPropertyTextUnderlineStyle:
-    case CSSPropertyTouchAction:
     case CSSPropertyTouchActionDelay:
     case CSSPropertyVariable:
     case CSSPropertyVisibility:
@@ -9014,6 +9013,56 @@ bool CSSParser::parsePerspectiveOrigin(CSSPropertyID propId, CSSPropertyID& prop
     return value;
 }
 
+void CSSParser::addTouchActionProperty(CSSPropertyID propId, PassRefPtr<CSSValue> value, bool important)

[Rick Byers, 2013/12/06 21:44:04]

this looks like it's copied from a function dealing with shorthand properties
(like 'background' which is a shorthand for the combination of a bunch of
background-* properties).  You don't need any of this shorthand logic for
touch-action.  Instead of this function, I believe you can call addProperty
directly.

In fact you may just want to return the parsedValue and rely on the common
addProperty call at the end of parseValue (slightly simpler I think).

[gnana, 2013/12/10 18:24:37]

Done.
Removed this function and called addProperty directly.

+{
+    if (propId == CSSPropertyTouchAction && !important && !inShorthand()) {
+        for (unsigned i = 0; i < m_parsedProperties.size(); ++i) {
+            if (m_parsedProperties[i].id() == CSSPropertyTouchAction)
+                return;
+        }
+    }
+    addProperty(propId, value, important);
+}
+
+bool CSSParser::parseTouchAction(CSSPropertyID propId, bool important)
+{
+    if (propId == CSSPropertyTouchAction
+        && !RuntimeEnabledFeatures::cssTouchActionEnabled())
+        return false;
+
+    CSSParserValue* value = m_valueList->current();
+    RefPtr<CSSValueList> list = CSSValueList::createSpaceSeparated();
+    if (m_valueList->size() == 1 && value && (value->id == CSSValueAuto || value->id == CSSValueNone)) {
+        list->append(cssValuePool().createIdentifierValue(value->id));
+        addTouchActionProperty(propId, list.release(), important);
+        m_valueList->next();
+        return true;
+    }
+
+    bool isValid = true;
+    while (isValid && value) {
+        switch (value->id) {
+        case CSSValuePanX:
+        case CSSValuePanY:
+            list->append(cssValuePool().createIdentifierValue(value->id));

[Rick Byers, 2013/12/06 21:44:04]

You should check that a given value never occurs more than once, and then add a
test for, eg. 'touch-action: pan-x pan-x' and verify that it fails to parse.  I
double checked that IE11 rejects this too.

[gnana, 2013/12/10 18:24:37]

Done.

+            break;
+        default:
+            isValid = false;
+            break;
+        }
+        if (isValid)
+            value = m_valueList->next();
+    }
+
+    // Values are either valid or in shorthand scope.
+    if (list->length() && isValid) {
+        addTouchActionProperty(propId, list.release(), important);
+        return true;
+    }
+
+    return false;
+}
+
 void CSSParser::addTextDecorationProperty(CSSPropertyID propId, PassRefPtr<CSSValue> value, bool important)
 {
     // The text-decoration-line property takes priority over text-decoration, unless the latter has important priority set.