[CSSMQ] Implemented support for the scan media feature.

Source/core/css/MediaQueryEvaluator.cpp

 /*
  * CSS Media Query Evaluator
  *
  * Copyright (C) 2006 Kimmo Kinnunen <kimmo.t.kinnunen@nokia.com>.
  * Copyright (C) 2013 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ skipping 49 matching lines @@
 namespace WebCore {
 
 using namespace MediaFeatureNames;
 
 enum MediaFeaturePrefix { MinPrefix, MaxPrefix, NoPrefix };
 
 typedef bool (*EvalFunc)(CSSValue*, RenderStyle*, Frame*, MediaFeaturePrefix);
 typedef HashMap<AtomicStringImpl*, EvalFunc> FunctionMap;
 static FunctionMap* gFunctionMap;
 
-/*
- * FIXME: following media features are not implemented:  scan
- *
- * scan: The "scan" media feature describes the scanning process of
- * tv output devices. It's unknown how to retrieve this information from
- * the platform
- */
-
 MediaQueryEvaluator::MediaQueryEvaluator(bool mediaFeatureResult)
     : m_frame(0)
     , m_style(0)
     , m_expResult(mediaFeatureResult)
 {
 }
 
 MediaQueryEvaluator::MediaQueryEvaluator(const String& acceptedMediaType, bool mediaFeatureResult)
     : m_mediaType(acceptedMediaType)
     , m_frame(0)
@@ skipping 565 matching lines @@
 
     if (!value->isPrimitiveValue())
         return false;
 
     const int id = toCSSPrimitiveValue(value)->getIdent();
     return (pointer == NoPointer && id == CSSValueNone)
         || (pointer == TouchPointer && id == CSSValueCoarse)
         || (pointer == MousePointer && id == CSSValueFine);
 }
 
+static bool scanMediaFeatureEval(CSSValue* value, RenderStyle*, Frame* frame, MediaFeaturePrefix)
+{
+    // Scan only applies to tv media.
+    if (!equalIgnoringCase(frame->view()->mediaType(), "tv"))
+        return false;
+
+    if (!value)
+        return true;
+
+    if (!value->isPrimitiveValue())
+        return false;
+
+    // If a platform interface supplies progressive/interlace info for TVs in the
+    // future, it needs to be handled here. For now, assume a modern TV with
+    // progressive display.
+    const int id = toCSSPrimitiveValue(value)->getIdent();
+    return id == CSSValueProgressive;
+}
+
 static void createFunctionMap()
 {
     // Create the table.
     gFunctionMap = new FunctionMap;
 #define ADD_TO_FUNCTIONMAP(name, str)  \
     gFunctionMap->set(name##MediaFeature.impl(), name##MediaFeatureEval);
     CSS_MEDIAQUERY_NAMES_FOR_EACH_MEDIAFEATURE(ADD_TO_FUNCTIONMAP);
 #undef ADD_TO_FUNCTIONMAP
 }
 
@@ skipping 12 matching lines @@
     // and let trampoline functions override the prefix if prefix is
     // used
     EvalFunc func = gFunctionMap->get(expr->mediaFeature().impl());
     if (func)
         return func(expr->value(), m_style.get(), m_frame, NoPrefix);
 
     return false;
 }
 
 } // namespace