Add CSS parser support for break-after, break-before and break-inside.

third_party/WebKit/Source/core/css/parser/CSSPropertyParser.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/css/parser/CSSPropertyParser.h"
 
 #include "core/StylePropertyShorthand.h"
 #include "core/css/CSSBasicShapeValues.h"
 #include "core/css/CSSBorderImage.h"
 #include "core/css/CSSCalculationValue.h"
@@ skipping 4205 matching lines @@
             addProperty(CSSPropertyBorderImageRepeat, repeat ? repeat : cssValuePool().createImplicitInitialValue(), important);
             return true;
         default:
             ASSERT_NOT_REACHED();
             return false;
         }
     }
     return false;
 }
 
+static inline CSSValueID mapFromPageBreakBetween(CSSValueID value)
+{
+    if (value == CSSValueAlways)
+        return CSSValuePage;
+    // TODO(mstensho): "avoid" should just return "avoid", not "avoid-page", according to the spec.
+    if (value == CSSValueAvoid)
+        return CSSValueAvoidPage;
+    if (value == CSSValueAuto || value == CSSValueLeft || value == CSSValueRight)
+        return value;
+    return CSSValueInvalid;
+}
+
+static inline CSSValueID mapFromColumnBreakBetween(CSSValueID value)
+{
+    if (value == CSSValueAlways)
+        return CSSValueColumn;
+    // TODO(mstensho): "avoid" should just return "avoid", not "avoid-column".
+    if (value == CSSValueAvoid)
+        return CSSValueAvoidColumn;
+    // TODO(mstensho): column break properties shouldn't take 'left' and 'right' values (but
+    // allowing it for now, since that's what we've always done).
+    if (value == CSSValueAuto || value == CSSValueLeft || value == CSSValueRight)
+        return value;
+    return CSSValueInvalid;
+}
+
+static inline CSSValueID mapFromPageBreakInside(CSSValueID value)
+{
+    // TODO(mstensho): "avoid" should just return "avoid", not "avoid-page", according to the spec.
+    if (value == CSSValueAvoid)
+        return CSSValueAvoidPage;
+    if (value == CSSValueAuto)
+        return value;
+    return CSSValueInvalid;
+}
+
+static inline CSSValueID mapFromColumnBreakInside(CSSValueID value)
+{
+    // TODO(mstensho): "avoid" should just return "avoid", not "avoid-column".
+    if (value == CSSValueAvoid)
+        return CSSValueAvoidColumn;
+    if (value == CSSValueAuto)
+        return value;
+    return CSSValueInvalid;
+}
+
+static inline CSSPropertyID mapFromLegacyBreakProperty(CSSPropertyID property)
+{
+    if (property == CSSPropertyPageBreakAfter || property == CSSPropertyWebkitColumnBreakAfter)
+        return CSSPropertyBreakAfter;
+    if (property == CSSPropertyPageBreakBefore || property == CSSPropertyWebkitColumnBreakBefore)
+        return CSSPropertyBreakBefore;
+    if (property == CSSPropertyPageBreakInside || property == CSSPropertyWebkitColumnBreakInside)

[Timothy Loh, 2016/02/18 06:25:45]

I prefer the style of having the last if just be an ASSERT. But I don't feel
strongly about it, so do what you want.

[mstensho (USE GERRIT), 2016/02/18 09:05:26]

I like it!

Done.

+        return CSSPropertyBreakInside;
+    ASSERT_NOT_REACHED();
+    return property;
+}
+
+bool CSSPropertyParser::consumeLegacyBreakProperty(CSSPropertyID property, bool important)
+{
+    // The fragmentation spec says that page-break-(after|before|inside) are to be treated as
+    // shorthands for their break-(after|before|inside) counterparts. We'll do the same for the
+    // non-standard properties -webkit-column-break-(after|before|inside).
+    RefPtrWillBeRawPtr<CSSPrimitiveValue> keyword = consumeIdent(m_range);
+    if (!keyword)
+        return false;
+    if (!m_range.atEnd())
+        return false;
+    CSSValueID value = keyword->getValueID();
+    switch (property) {
+    case CSSPropertyPageBreakAfter:
+    case CSSPropertyPageBreakBefore:
+        value = mapFromPageBreakBetween(value);
+        break;
+    case CSSPropertyWebkitColumnBreakAfter:
+    case CSSPropertyWebkitColumnBreakBefore:
+        value = mapFromColumnBreakBetween(value);
+        break;
+    case CSSPropertyPageBreakInside:
+        value = mapFromPageBreakInside(value);
+        break;
+    case CSSPropertyWebkitColumnBreakInside:
+        value = mapFromColumnBreakInside(value);
+        break;
+    default:
+        ASSERT_NOT_REACHED();
+    }
+    if (value == CSSValueInvalid)
+        return false;
+
+    CSSPropertyID genericBreakProperty = mapFromLegacyBreakProperty(property);
+    addProperty(genericBreakProperty, cssValuePool().createIdentifierValue(value), important);
+    return true;
+}
+
 bool CSSPropertyParser::parseShorthand(CSSPropertyID unresolvedProperty, bool important)
 {
     CSSPropertyID property = resolveCSSPropertyID(unresolvedProperty);
 
     CSSPropertyID oldShorthand = m_currentShorthand;
     // TODO(rob.buis): Remove this when the legacy property parser is gone
     m_currentShorthand = property;
     switch (property) {
     case CSSPropertyWebkitMarginCollapse: {
         CSSValueID id = m_range.consumeIncludingWhitespace().id();
@@ skipping 114 matching lines @@
         return consumeShorthandGreedily(borderRightShorthand(), important);
     case CSSPropertyBorderBottom:
         return consumeShorthandGreedily(borderBottomShorthand(), important);
     case CSSPropertyBorderLeft:
         return consumeShorthandGreedily(borderLeftShorthand(), important);
     case CSSPropertyBorder:
         return consumeBorder(important);
     case CSSPropertyBorderImage:
     case CSSPropertyWebkitMaskBoxImage:
         return consumeBorderImage(property, important);
+    case CSSPropertyPageBreakAfter:
+    case CSSPropertyPageBreakBefore:
+    case CSSPropertyPageBreakInside:
+    case CSSPropertyWebkitColumnBreakAfter:
+    case CSSPropertyWebkitColumnBreakBefore:
+    case CSSPropertyWebkitColumnBreakInside:
+        return consumeLegacyBreakProperty(property, important);
     default:
         m_currentShorthand = oldShorthand;
         CSSParserValueList valueList(m_range);
         if (!valueList.size())
             return false;
         m_valueList = &valueList;
         return legacyParseShorthand(unresolvedProperty, important);
     }
 }
 
 } // namespace blink