De-ExceptionState-ify SVGLengthContext

Source/core/svg/SVGLengthTearOff.cpp

 /*
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * 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
@@ skipping 28 matching lines @@
 namespace blink {
 
 namespace {
 
 inline SVGLengthType toSVGLengthType(unsigned short type)
 {
     ASSERT(type >= LengthTypeUnknown && type <= LengthTypePC);
     return static_cast<SVGLengthType>(type);
 }
 
+inline bool canResolveRelativeUnits(const SVGElement* contextElement)
+{
+    return contextElement && contextElement->inDocument();
+}
+
 } // namespace
 
 SVGLengthType SVGLengthTearOff::unitType()
 {
     return target()->unitType();
 }
 
 SVGLengthMode SVGLengthTearOff::unitMode()
 {
     return target()->unitMode();
 }
 
-float SVGLengthTearOff::value(ExceptionState& es)
+float SVGLengthTearOff::value(ExceptionState& exceptionState)
 {
+    if (target()->isRelative() && !canResolveRelativeUnits(contextElement())) {
+        exceptionState.throwDOMException(NotSupportedError, "No context could be found.");
+        return 0;
+    }
+
     SVGLengthContext lengthContext(contextElement());
-    return target()->value(lengthContext, es);
+    return target()->value(lengthContext);
 }
 
-void SVGLengthTearOff::setValue(float value, ExceptionState& es)
+void SVGLengthTearOff::setValue(float value, ExceptionState& exceptionState)
 {
     if (isImmutable()) {
-        es.throwDOMException(NoModificationAllowedError, "The attribute is read-only.");
+        exceptionState.throwDOMException(NoModificationAllowedError, "The attribute is read-only.");
+        return;
+    }
+
+    if (target()->isRelative() && !canResolveRelativeUnits(contextElement())) {
+        exceptionState.throwDOMException(NotSupportedError, "No context could be found.");
         return;
     }
 
     SVGLengthContext lengthContext(contextElement());
-    target()->setValue(value, lengthContext, es);
+    target()->setValue(value, lengthContext);
     commitChange();
 }
 
 float SVGLengthTearOff::valueInSpecifiedUnits()
 {
     return target()->valueInSpecifiedUnits();
 }
 
 void SVGLengthTearOff::setValueInSpecifiedUnits(float value, ExceptionState& es)
 {
@@ skipping 42 matching lines @@
     if (isImmutable()) {
         exceptionState.throwDOMException(NoModificationAllowedError, "The object is read-only.");
         return;
     }
 
     if (unitType == LengthTypeUnknown || unitType > LengthTypePC) {
         exceptionState.throwDOMException(NotSupportedError, "Cannot convert to unknown or invalid units (" + String::number(unitType) + ").");
         return;
     }
 
+    if ((target()->isRelative() || SVGLength::isRelativeUnit(toSVGLengthType(unitType)))
+        && !canResolveRelativeUnits(contextElement())) {
+        exceptionState.throwDOMException(NotSupportedError, "No context could be found.");

[pdr., 2015/02/05 22:12:32]

Bikeshed: is the concept of a length context something users would know about?
We may just want to say "Could not resolve relative length".

[fs, 2015/02/06 12:26:04]

Funny you should say that, because that's pretty much what I intended to change
it too before I decided to be lazy... =P

+        return;
+    }
+
     SVGLengthContext lengthContext(contextElement());
-    target()->convertToSpecifiedUnits(toSVGLengthType(unitType), lengthContext, exceptionState);
+    target()->convertToSpecifiedUnits(toSVGLengthType(unitType), lengthContext);
     commitChange();
 }
 
 SVGLengthTearOff::SVGLengthTearOff(PassRefPtrWillBeRawPtr<SVGLength> target, SVGElement* contextElement, PropertyIsAnimValType propertyIsAnimVal, const QualifiedName& attributeName)
     : SVGPropertyTearOff<SVGLength>(target, contextElement, propertyIsAnimVal, attributeName)
 {
 }
 
 }