[SVG] SVGLength{,List} migration to new SVG property impl.

Source/core/svg/SVGLength.cpp

 /*
- * Copyright (C) 2004, 2005, 2006 Nikolas Zimmermann <zimmermann@kde.org>
- * Copyright (C) 2004, 2005, 2006, 2007 Rob Buis <buis@kde.org>
- * Copyright (C) 2007 Apple Inc. All rights reserved.
+ * Copyright (C) 2013 Google Inc. All rights reserved.
  *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Library General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
  *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Library General Public License for more details.
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
  *
- * You should have received a copy of the GNU Library General Public License
- * along with this library; see the file COPYING.LIB.  If not, write to
- * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
- * Boston, MA 02110-1301, USA.
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 
 #include "core/svg/SVGLength.h"
 
 #include "SVGNames.h"
-#include "bindings/v8/ExceptionStatePlaceholder.h"
+#include "bindings/v8/ExceptionState.h"
 #include "core/css/CSSPrimitiveValue.h"
 #include "core/dom/ExceptionCode.h"
+#include "core/svg/SVGAnimationElement.h"
 #include "core/svg/SVGParserUtilities.h"
+#include "platform/animation/AnimationUtilities.h"
 #include "wtf/MathExtras.h"
 #include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
-static inline SVGLengthMode toSVGLengthMode(unsigned short mode)
+namespace {
+
+inline SVGLengthMode toSVGLengthMode(unsigned short mode)
 {
     ASSERT(mode >= LengthModeWidth && mode <= LengthModeOther);
     return static_cast<SVGLengthMode>(mode);
 }
 
-static inline SVGLengthType toSVGLengthType(unsigned short type)
+inline SVGLengthType toSVGLengthType(unsigned short type)
 {
     ASSERT(type >= LengthTypeUnknown && type <= LengthTypePC);
     return static_cast<SVGLengthType>(type);
 }
 
-static inline unsigned int storeUnit(SVGLengthMode mode, SVGLengthType type)
-{
-    return (mode << 4) | type;
-}
-
-static inline SVGLengthMode extractMode(unsigned int unit)
-{
-    unsigned int mode = unit >> 4;
-    return toSVGLengthMode(mode);
-}
-
-static inline SVGLengthType extractType(unsigned int unit)
-{
-    unsigned int mode = unit >> 4;
-    unsigned int type = unit ^ (mode << 4);
-    return toSVGLengthType(type);
-}
-
-static inline String lengthTypeToString(SVGLengthType type)
+inline String lengthTypeToString(SVGLengthType type)
 {
     switch (type) {
     case LengthTypeUnknown:
     case LengthTypeNumber:
         return "";
     case LengthTypePercentage:
         return "%";
     case LengthTypeEMS:
         return "em";
     case LengthTypeEXS:
@@ skipping 10 matching lines @@
         return "pt";
     case LengthTypePC:
         return "pc";
     }
 
     ASSERT_NOT_REACHED();
     return String();
 }
 
 template<typename CharType>
-static SVGLengthType stringToLengthType(const CharType*& ptr, const CharType* end)
+SVGLengthType stringToLengthType(const CharType*& ptr, const CharType* end)
 {
     if (ptr == end)
         return LengthTypeNumber;
 
     const UChar firstChar = *ptr;
 
     if (++ptr == end)
         return firstChar == '%' ? LengthTypePercentage : LengthTypeUnknown;
 
     const UChar secondChar = *ptr;
@@ skipping 14 matching lines @@
     if (firstChar == 'i' && secondChar == 'n')
         return LengthTypeIN;
     if (firstChar == 'p' && secondChar == 't')
         return LengthTypePT;
     if (firstChar == 'p' && secondChar == 'c')
         return LengthTypePC;
 
     return LengthTypeUnknown;
 }
 
-SVGLength::SVGLength(SVGLengthMode mode, const String& valueAsString)
+} // namespace
+
+SVGLength::SVGLength(SVGLengthMode mode)
     : m_valueInSpecifiedUnits(0)
-    , m_unit(storeUnit(mode, LengthTypeNumber))
-{
-    setValueAsString(valueAsString, IGNORE_EXCEPTION);
-}
-
-SVGLength::SVGLength(const SVGLengthContext& context, float value, SVGLengthMode mode, SVGLengthType unitType)
-    : m_valueInSpecifiedUnits(0)
-    , m_unit(storeUnit(mode, unitType))
-{
-    setValue(value, context, ASSERT_NO_EXCEPTION);
-}
-
-SVGLength::SVGLength(const SVGLength& other)
-    : m_valueInSpecifiedUnits(other.m_valueInSpecifiedUnits)
-    , m_unit(other.m_unit)
+    , m_unitMode(mode)
+    , m_unitType(LengthTypeNumber)
 {
 }
 
-void SVGLength::setValueAsString(const String& valueAsString, SVGLengthMode mode, ExceptionState& exceptionState)
+PassRefPtr<SVGLength> SVGLength::clone() const
 {
-    m_valueInSpecifiedUnits = 0;
-    m_unit = storeUnit(mode, LengthTypeNumber);
-    setValueAsString(valueAsString, exceptionState);
+    RefPtr<SVGLength> length = create();

[pdr., 2014/01/07 06:42:53]

This function may be hot on performance. It could be useful to add a private
constructor that takes an SVGLength reference (to avoid setting the member
variables in the ctor), but I'm not completely sure.

[kouhei (in TOK), 2014/01/08 08:12:07]

Done.

+
+    length->m_valueInSpecifiedUnits = m_valueInSpecifiedUnits;
+    length->m_unitMode = m_unitMode;
+    length->m_unitType = m_unitType;
+
+    return length.release();
+}
+
+PassRefPtr<NewSVGPropertyBase> SVGLength::cloneForAnimation(const String& value) const
+{
+    RefPtr<SVGLength> length = create();
+
+    length->m_unitMode = m_unitMode;
+    length->m_unitType = m_unitType;
+    length->setValueAsString(value, IGNORE_EXCEPTION);
+
+    return length.release();
 }
 
 bool SVGLength::operator==(const SVGLength& other) const
 {
-    return m_unit == other.m_unit
+    return m_unitMode == other.m_unitMode
+        && m_unitType == other.m_unitType
         && m_valueInSpecifiedUnits == other.m_valueInSpecifiedUnits;
 }
 
-bool SVGLength::operator!=(const SVGLength& other) const
+void SVGLength::setUnitType(SVGLengthType unitType)
 {
-    return !operator==(other);
+    ASSERT(unitType != LengthTypeUnknown && unitType <= LengthTypePC);
+    m_unitType = unitType;
 }
 
-SVGLength SVGLength::construct(SVGLengthMode mode, const String& valueAsString, SVGParsingError& parseError, SVGLengthNegativeValuesMode negativeValuesMode)
+float SVGLength::value(const SVGLengthContext& context, ExceptionState& es) const
 {
-    TrackExceptionState exceptionState;
-    SVGLength length(mode);
-
-    length.setValueAsString(valueAsString, exceptionState);
-
-    if (exceptionState.hadException())
-        parseError = ParsingAttributeFailedError;
-    else if (negativeValuesMode == ForbidNegativeLengths && length.valueInSpecifiedUnits() < 0)
-        parseError = NegativeValueForbiddenError;
-
-    return length;
+    return context.convertValueToUserUnits(m_valueInSpecifiedUnits, unitMode(), unitType(), es);
 }
 
-SVGLengthType SVGLength::unitType() const
+void SVGLength::setValue(float value, const SVGLengthContext& context, ExceptionState& es)
 {
-    return extractType(m_unit);
+    // 100% = 100.0 instead of 1.0 for historical reasons, this could eventually be changed
+    if (m_unitType == LengthTypePercentage)
+        value = value / 100;
+
+    float convertedValue = context.convertValueFromUserUnits(value, unitMode(), unitType(), es);
+    if (es.hadException())
+        return;
+
+    m_valueInSpecifiedUnits = convertedValue;
 }
 
-SVGLengthMode SVGLength::unitMode() const
-{
-    return extractMode(m_unit);
-}
-
-float SVGLength::value(const SVGLengthContext& context) const
-{
-    return value(context, IGNORE_EXCEPTION);
-}
-
-float SVGLength::value(const SVGLengthContext& context, ExceptionState& exceptionState) const
-{
-    return context.convertValueToUserUnits(m_valueInSpecifiedUnits, extractMode(m_unit), extractType(m_unit), exceptionState);
-}
-
-void SVGLength::setValue(const SVGLengthContext& context, float value, SVGLengthMode mode, SVGLengthType unitType, ExceptionState& exceptionState)
-{
-    m_unit = storeUnit(mode, unitType);
-    setValue(value, context, exceptionState);
-}
-
-void SVGLength::setValue(float value, const SVGLengthContext& context, ExceptionState& exceptionState)
-{
-    // 100% = 100.0 instead of 1.0 for historical reasons, this could eventually be changed
-    if (extractType(m_unit) == LengthTypePercentage)
-        value = value / 100;
-
-    float convertedValue = context.convertValueFromUserUnits(value, extractMode(m_unit), extractType(m_unit), exceptionState);
-    if (!exceptionState.hadException())
-        m_valueInSpecifiedUnits = convertedValue;
-}
 float SVGLength::valueAsPercentage() const
 {
     // 100% = 100.0 instead of 1.0 for historical reasons, this could eventually be changed
-    if (extractType(m_unit) == LengthTypePercentage)
+    if (m_unitType == LengthTypePercentage)
         return m_valueInSpecifiedUnits / 100;
 
     return m_valueInSpecifiedUnits;
 }
 
 template<typename CharType>
 static bool parseValueInternal(const String& string, float& convertedNumber, SVGLengthType& type)
 {
     const CharType* ptr = string.getCharacters<CharType>();
     const CharType* end = ptr + string.length();
 
     if (!parseNumber(ptr, end, convertedNumber, false))
         return false;
 
     type = stringToLengthType(ptr, end);
     ASSERT(ptr <= end);
     if (type == LengthTypeUnknown)
         return false;
 
     return true;
 }
 
-void SVGLength::setValueAsString(const String& string, ExceptionState& exceptionState)
+void SVGLength::setValueAsString(const String& string, ExceptionState& es)
 {
-    if (string.isEmpty())
+    if (string.isEmpty()) {
+        m_unitType = LengthTypeUnknown;
+        m_valueInSpecifiedUnits = 0;
         return;
+    }
 
     float convertedNumber = 0;
     SVGLengthType type = LengthTypeUnknown;
 
     bool success = string.is8Bit() ?
         parseValueInternal<LChar>(string, convertedNumber, type) :
         parseValueInternal<UChar>(string, convertedNumber, type);
 
     if (!success) {
-        exceptionState.throwUninformativeAndGenericDOMException(SyntaxError);
+        m_valueInSpecifiedUnits = 0;
+        es.throwDOMException(SyntaxError, "Invalid value");
         return;
     }
 
-    m_unit = storeUnit(extractMode(m_unit), type);
+    m_unitType = type;
     m_valueInSpecifiedUnits = convertedNumber;
 }
 
 String SVGLength::valueAsString() const
 {
-    return String::number(m_valueInSpecifiedUnits) + lengthTypeToString(extractType(m_unit));
+    return String::number(m_valueInSpecifiedUnits) + lengthTypeToString(unitType());
 }
 
-void SVGLength::newValueSpecifiedUnits(unsigned short type, float value, ExceptionState& exceptionState)
+void SVGLength::newValueSpecifiedUnits(SVGLengthType type, float value)
 {
-    if (type == LengthTypeUnknown || type > LengthTypePC) {
-        exceptionState.throwUninformativeAndGenericDOMException(NotSupportedError);
-        return;
-    }
-
-    m_unit = storeUnit(extractMode(m_unit), toSVGLengthType(type));
+    m_unitType = type;
     m_valueInSpecifiedUnits = value;
 }
 
-void SVGLength::convertToSpecifiedUnits(unsigned short type, const SVGLengthContext& context, ExceptionState& exceptionState)
+void SVGLength::convertToSpecifiedUnits(SVGLengthType type, const SVGLengthContext& context, ExceptionState& es)
 {
-    if (type == LengthTypeUnknown || type > LengthTypePC) {
-        exceptionState.throwUninformativeAndGenericDOMException(NotSupportedError);
-        return;
-    }
-
-    float valueInUserUnits = value(context, exceptionState);
-    if (exceptionState.hadException())
+    float valueInUserUnits = value(context, es);
+    if (es.hadException())
         return;
 
-    unsigned int originalUnitAndType = m_unit;
-    m_unit = storeUnit(extractMode(m_unit), toSVGLengthType(type));
-    setValue(valueInUserUnits, context, exceptionState);
-    if (!exceptionState.hadException())
+    SVGLengthType originalType = unitType();
+    m_unitType = toSVGLengthType(type);
+    setValue(valueInUserUnits, context, es);
+    if (!es.hadException())
         return;
 
-    // Eventually restore old unit and type
-    m_unit = originalUnitAndType;
+    // Eventually restore old type
+    m_unitType = originalType;
 }
 
-SVGLength SVGLength::fromCSSPrimitiveValue(CSSPrimitiveValue* value)
+PassRefPtr<SVGLength> SVGLength::fromCSSPrimitiveValue(CSSPrimitiveValue* value)
 {
     ASSERT(value);
 
     SVGLengthType svgType;
     switch (value->primitiveType()) {
     case CSSPrimitiveValue::CSS_NUMBER:
         svgType = LengthTypeNumber;
         break;
     case CSSPrimitiveValue::CSS_PERCENTAGE:
         svgType = LengthTypePercentage;
@@ skipping 22 matching lines @@
     case CSSPrimitiveValue::CSS_PC:
         svgType = LengthTypePC;
         break;
     case CSSPrimitiveValue::CSS_UNKNOWN:
     default:
         svgType = LengthTypeUnknown;
         break;
     };
 
     if (svgType == LengthTypeUnknown)
-        return SVGLength();
+        return SVGLength::create();
 
-    TrackExceptionState exceptionState;
-    SVGLength length;
-    length.newValueSpecifiedUnits(svgType, value->getFloatValue(), exceptionState);
-    if (exceptionState.hadException())
-        return SVGLength();
-
+    RefPtr<SVGLength> length = SVGLength::create();
+    length->newValueSpecifiedUnits(svgType, value->getFloatValue());
     return length;
 }
 
-PassRefPtr<CSSPrimitiveValue> SVGLength::toCSSPrimitiveValue(const SVGLength& length)
+PassRefPtr<CSSPrimitiveValue> SVGLength::toCSSPrimitiveValue(PassRefPtr<SVGLength> passLength)
 {
+    RefPtr<SVGLength> length = passLength;
+
     CSSPrimitiveValue::UnitTypes cssType = CSSPrimitiveValue::CSS_UNKNOWN;
-    switch (length.unitType()) {
+    switch (length->unitType()) {
     case LengthTypeUnknown:
         break;
     case LengthTypeNumber:
         cssType = CSSPrimitiveValue::CSS_NUMBER;
         break;
     case LengthTypePercentage:
         cssType = CSSPrimitiveValue::CSS_PERCENTAGE;
         break;
     case LengthTypeEMS:
         cssType = CSSPrimitiveValue::CSS_EMS;
@@ skipping 14 matching lines @@
         cssType = CSSPrimitiveValue::CSS_IN;
         break;
     case LengthTypePT:
         cssType = CSSPrimitiveValue::CSS_PT;
         break;
     case LengthTypePC:
         cssType = CSSPrimitiveValue::CSS_PC;
         break;
     };
 
-    return CSSPrimitiveValue::create(length.valueInSpecifiedUnits(), cssType);
+    return CSSPrimitiveValue::create(length->valueInSpecifiedUnits(), cssType);
 }
 
 SVGLengthMode SVGLength::lengthModeForAnimatedLengthAttribute(const QualifiedName& attrName)
 {
     typedef HashMap<QualifiedName, SVGLengthMode> LengthModeForLengthAttributeMap;
     DEFINE_STATIC_LOCAL(LengthModeForLengthAttributeMap, s_lengthModeMap, ());
 
     if (s_lengthModeMap.isEmpty()) {
         s_lengthModeMap.set(SVGNames::xAttr, LengthModeWidth);
         s_lengthModeMap.set(SVGNames::yAttr, LengthModeHeight);
         s_lengthModeMap.set(SVGNames::cxAttr, LengthModeWidth);
         s_lengthModeMap.set(SVGNames::cyAttr, LengthModeHeight);
         s_lengthModeMap.set(SVGNames::dxAttr, LengthModeWidth);
         s_lengthModeMap.set(SVGNames::dyAttr, LengthModeHeight);
         s_lengthModeMap.set(SVGNames::fxAttr, LengthModeWidth);
         s_lengthModeMap.set(SVGNames::fyAttr, LengthModeHeight);
         s_lengthModeMap.set(SVGNames::rAttr, LengthModeOther);
+        s_lengthModeMap.set(SVGNames::rxAttr, LengthModeWidth);
+        s_lengthModeMap.set(SVGNames::ryAttr, LengthModeHeight);
         s_lengthModeMap.set(SVGNames::widthAttr, LengthModeWidth);
         s_lengthModeMap.set(SVGNames::heightAttr, LengthModeHeight);
         s_lengthModeMap.set(SVGNames::x1Attr, LengthModeWidth);
         s_lengthModeMap.set(SVGNames::x2Attr, LengthModeWidth);
         s_lengthModeMap.set(SVGNames::y1Attr, LengthModeHeight);
         s_lengthModeMap.set(SVGNames::y2Attr, LengthModeHeight);
         s_lengthModeMap.set(SVGNames::refXAttr, LengthModeWidth);
         s_lengthModeMap.set(SVGNames::refYAttr, LengthModeHeight);
         s_lengthModeMap.set(SVGNames::markerWidthAttr, LengthModeWidth);
         s_lengthModeMap.set(SVGNames::markerHeightAttr, LengthModeHeight);
         s_lengthModeMap.set(SVGNames::textLengthAttr, LengthModeWidth);
         s_lengthModeMap.set(SVGNames::startOffsetAttr, LengthModeWidth);
     }
 
     if (s_lengthModeMap.contains(attrName))
         return s_lengthModeMap.get(attrName);
 
     return LengthModeOther;
 }
 
+PassRefPtr<SVGLength> SVGLength::blend(const SVGLength* from, float progress) const
+{
+    SVGLengthType toType = unitType();
+    SVGLengthType fromType = from->unitType();
+    if ((from->isZero() && isZero())
+        || fromType == LengthTypeUnknown
+        || toType == LengthTypeUnknown
+        || (!from->isZero() && fromType != LengthTypePercentage && toType == LengthTypePercentage)
+        || (!isZero() && fromType == LengthTypePercentage && toType != LengthTypePercentage)
+        || (!from->isZero() && !isZero() && (fromType == LengthTypeEMS || fromType == LengthTypeEXS) && fromType != toType))
+        return clone();
+
+    RefPtr<SVGLength> length = create();
+
+    if (fromType == LengthTypePercentage || toType == LengthTypePercentage) {
+        float fromPercent = from->valueAsPercentage() * 100;
+        float toPercent = valueAsPercentage() * 100;
+        length->newValueSpecifiedUnits(LengthTypePercentage, WebCore::blend(fromPercent, toPercent, progress));
+        return length;
+    }
+
+    if (fromType == toType || from->isZero() || isZero() || fromType == LengthTypeEMS || fromType == LengthTypeEXS) {
+        float fromValue = from->valueInSpecifiedUnits();
+        float toValue = valueInSpecifiedUnits();
+        if (isZero())
+            length->newValueSpecifiedUnits(fromType, WebCore::blend(fromValue, toValue, progress));
+        else
+            length->newValueSpecifiedUnits(toType, WebCore::blend(fromValue, toValue, progress));
+        return length;
+    }
+
+    ASSERT(!isRelative());
+    ASSERT(!from->isRelative());
+
+    TrackExceptionState es;
+    SVGLengthContext nonRelativeLengthContext(0);
+    float fromValueInUserUnits = nonRelativeLengthContext.convertValueToUserUnits(from->valueInSpecifiedUnits(), from->unitMode(), fromType, es);
+    if (es.hadException())
+        return create();
+
+    float fromValue = nonRelativeLengthContext.convertValueFromUserUnits(fromValueInUserUnits, unitMode(), toType, es);
+    if (es.hadException())
+        return create();
+
+    float toValue = valueInSpecifiedUnits();
+    length->newValueSpecifiedUnits(toType, WebCore::blend(fromValue, toValue, progress));
+    return length;
 }
+
+void SVGLength::add(PassRefPtr<NewSVGPropertyBase> other, SVGElement* contextElement)
+{
+    SVGLengthContext lengthContext(contextElement);
+
+    SVGLength* otherLength = toSVGLength(other.get());
+
+    setValue(value(lengthContext) + otherLength->value(lengthContext), lengthContext, ASSERT_NO_EXCEPTION);
+}
+
+void SVGLength::calculateAnimatedValue(SVGAnimationElement* animationElement, float percentage, unsigned repeatCount, PassRefPtr<NewSVGPropertyBase> fromValue, PassRefPtr<NewSVGPropertyBase> toValue, PassRefPtr<NewSVGPropertyBase> toAtEndOfDurationValue, SVGElement* contextElement)
+{
+    SVGLengthContext lengthContext(contextElement);
+    const SVGLength* fromLength = toSVGLength(fromValue.get());
+    const SVGLength* toLength = toSVGLength(toValue.get());
+    const SVGLength* toAtEndOfDurationLength = toSVGLength(toAtEndOfDurationValue.get());
+    float animatedNumber = value(lengthContext, IGNORE_EXCEPTION);
+    SVGLengthType unitType = percentage < 0.5 ? fromLength->unitType() : toLength->unitType();
+    animationElement->animateAdditiveNumber(percentage, repeatCount, fromLength->value(lengthContext, IGNORE_EXCEPTION), toLength->value(lengthContext, IGNORE_EXCEPTION), toAtEndOfDurationLength->value(lengthContext, IGNORE_EXCEPTION), animatedNumber);
+    ASSERT(unitMode() == SVGLength::lengthModeForAnimatedLengthAttribute(animationElement->attributeName()));
+
+    setUnitType(unitType);
+    setValue(animatedNumber, lengthContext, ASSERT_NO_EXCEPTION);
+}
+
+float SVGLength::calculateDistance(PassRefPtr<NewSVGPropertyBase> to, SVGElement* contextElement)
+{
+    SVGLengthContext lengthContext(contextElement);
+    const SVGLength* toLength = toSVGLength(to.get());
+
+    return fabsf(toLength->value(lengthContext, IGNORE_EXCEPTION) - value(lengthContext, IGNORE_EXCEPTION));
+}
+
+SVGLengthType SVGLengthTearOff::unitType()
+{
+    return target()->unitType();
+}
+
+SVGLengthMode SVGLengthTearOff::unitMode()
+{
+    return target()->unitMode();
+}
+
+float SVGLengthTearOff::value(ExceptionState& es)
+{
+    SVGLengthContext lengthContext(contextElement());
+    return target()->value(lengthContext, es);
+}
+
+void SVGLengthTearOff::setValue(float value, ExceptionState& es)
+{
+    if (isImmutable()) {
+        es.throwDOMException(NoModificationAllowedError, ExceptionMessages::failedToSet("value", "SVGLength", "The attribute is read-only."));
+        return;
+    }
+
+    SVGLengthContext lengthContext(contextElement());
+    target()->setValue(value, lengthContext, es);
+    commitChange();
+}
+
+float SVGLengthTearOff::valueInSpecifiedUnits()
+{
+    return target()->valueInSpecifiedUnits();
+}
+
+void SVGLengthTearOff::setValueInSpecifiedUnits(float value, ExceptionState& es)
+{
+    if (isImmutable()) {
+        es.throwDOMException(NoModificationAllowedError, ExceptionMessages::failedToSet("valueInSpecifiedUnits", "SVGLength", "The attribute is read-only."));
+        return;
+    }
+    target()->setValueInSpecifiedUnits(value);
+    commitChange();
+}
+
+String SVGLengthTearOff::valueAsString()
+{
+    return target()->valueAsString();
+}
+
+void SVGLengthTearOff::setValueAsString(const String& str, ExceptionState& es)
+{
+    if (isImmutable()) {
+        es.throwDOMException(NoModificationAllowedError, ExceptionMessages::failedToSet("valueAsString", "SVGLength", "The attribute is read-only."));
+        return;
+    }
+
+    target()->setValueAsString(str, es);
+    commitChange();
+}
+
+void SVGLengthTearOff::newValueSpecifiedUnits(unsigned short unitType, float valueInSpecifiedUnits, ExceptionState& es)
+{
+    if (isImmutable()) {
+        es.throwDOMException(NoModificationAllowedError, ExceptionMessages::failedToSet("newValueSpecifiedUnits", "SVGLength", "The object is read-only."));
+        return;
+    }
+
+    if (unitType == LengthTypeUnknown || unitType > LengthTypePC) {
+        es.throwDOMException(NoModificationAllowedError, ExceptionMessages::failedToSet("newValueSpecifiedUnits", "SVGLength", "The specified SVGLengthMode is invalid."));
+        return;
+    }
+
+    target()->newValueSpecifiedUnits(toSVGLengthType(unitType), valueInSpecifiedUnits);
+    commitChange();
+}
+
+void SVGLengthTearOff::convertToSpecifiedUnits(unsigned short unitType, ExceptionState& es)
+{
+    if (isImmutable()) {
+        es.throwDOMException(NoModificationAllowedError, ExceptionMessages::failedToSet("convertToSpecifiedUnits", "SVGLength", "The object is read-only."));
+        return;
+    }
+
+    if (unitType == LengthTypeUnknown || unitType > LengthTypePC) {
+        es.throwDOMException(NoModificationAllowedError, ExceptionMessages::failedToSet("convertToSpecifiedUnits", "SVGLength", "The specified SVGLengthMode is invalid."));
+        return;
+    }
+
+    SVGLengthContext lengthContext(contextElement());
+    target()->convertToSpecifiedUnits(toSVGLengthType(unitType), lengthContext, es);
+    commitChange();
+}
+
+SVGLengthTearOff::SVGLengthTearOff(PassRefPtr<SVGLength> target, SVGElement* contextElement, PropertyIsAnimValType propertyIsAnimVal, const QualifiedName& attributeName)
+    : NewSVGPropertyTearOff<SVGLength>(target, contextElement, propertyIsAnimVal, attributeName)
+{
+    ScriptWrappable::init(this);
+}
+
+}