gecko/content/smil/nsSMILParserUtils.cpp

903 lines
24 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is the Mozilla SMIL module.
*
* The Initial Developer of the Original Code is Brian Birtles.
* Portions created by the Initial Developer are Copyright (C) 2005
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Brian Birtles <birtles@gmail.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#include "nsSMILParserUtils.h"
#include "nsISMILAttr.h"
#include "nsSMILValue.h"
#include "nsSMILTimeValue.h"
#include "nsSMILTimeValueSpecParams.h"
#include "nsSMILTypes.h"
#include "nsSMILRepeatCount.h"
#include "nsContentUtils.h"
#include "nsString.h"
#include "prdtoa.h"
#include "nsCRT.h"
#include "nsCOMPtr.h"
#include "prlong.h"
#include "nsCharSeparatedTokenizer.h"
//------------------------------------------------------------------------------
// Helper functions and Constants
namespace {
const PRUint32 MSEC_PER_SEC = 1000;
const PRUint32 MSEC_PER_MIN = 1000 * 60;
const PRUint32 MSEC_PER_HOUR = 1000 * 60 * 60;
const PRInt32 DECIMAL_BASE = 10;
#define ACCESSKEY_PREFIX_LC NS_LITERAL_STRING("accesskey(") // SMIL2+
#define ACCESSKEY_PREFIX_CC NS_LITERAL_STRING("accessKey(") // SVG/SMIL ANIM
#define REPEAT_PREFIX NS_LITERAL_STRING("repeat(")
#define WALLCLOCK_PREFIX NS_LITERAL_STRING("wallclock(")
// NS_IS_SPACE relies on isspace which may return true for \xB and \xC but
// SMILANIM does not consider these characters to be whitespace.
inline bool
IsSpace(const PRUnichar c)
{
return (c == 0x9 || c == 0xA || c == 0xD || c == 0x20);
}
template<class T>
inline void
SkipBeginWsp(T& aStart, T aEnd)
{
while (aStart != aEnd && IsSpace(*aStart)) {
++aStart;
}
}
inline void
SkipBeginEndWsp(const PRUnichar*& aStart, const PRUnichar*& aEnd)
{
SkipBeginWsp(aStart, aEnd);
while (aEnd != aStart && IsSpace(*(aEnd - 1))) {
--aEnd;
}
}
double
GetFloat(const char*& aStart, const char* aEnd, nsresult* aErrorCode)
{
char* floatEnd;
double value = PR_strtod(aStart, &floatEnd);
nsresult rv;
if (floatEnd == aStart || floatEnd > aEnd) {
rv = NS_ERROR_FAILURE;
} else {
aStart = floatEnd;
rv = NS_OK;
}
if (aErrorCode) {
*aErrorCode = rv;
}
return value;
}
size_t
GetUnsignedInt(const nsAString& aStr, PRUint32& aResult)
{
NS_ConvertUTF16toUTF8 cstr(aStr);
const char* str = cstr.get();
char* rest;
PRInt32 value = strtol(str, &rest, DECIMAL_BASE);
if (rest == str || value < 0)
return 0;
aResult = static_cast<PRUint32>(value);
return rest - str;
}
bool
GetUnsignedIntAndEndParen(const nsAString& aStr, PRUint32& aResult)
{
size_t intLen = GetUnsignedInt(aStr, aResult);
const PRUnichar* start = aStr.BeginReading();
const PRUnichar* end = aStr.EndReading();
// Make sure the string is only digit+')'
if (intLen == 0 || start + intLen + 1 != end || *(start + intLen) != ')')
return false;
return true;
}
inline bool
ConsumeSubstring(const char*& aStart, const char* aEnd, const char* aSubstring)
{
size_t substrLen = PL_strlen(aSubstring);
if (static_cast<size_t>(aEnd - aStart) < substrLen)
return false;
bool result = false;
if (PL_strstr(aStart, aSubstring) == aStart) {
aStart += substrLen;
result = true;
}
return result;
}
bool
ParseClockComponent(const char*& aStart,
const char* aEnd,
double& aResult,
bool& aIsReal,
bool& aCouldBeMin,
bool& aCouldBeSec)
{
nsresult rv;
const char* begin = aStart;
double value = GetFloat(aStart, aEnd, &rv);
// Check a number was found
if (NS_FAILED(rv))
return false;
// Check that it's not expressed in exponential form
size_t len = aStart - begin;
bool isExp = (PL_strnpbrk(begin, "eE", len) != nsnull);
if (isExp)
return false;
// Don't allow real numbers of the form "23."
if (*(aStart - 1) == '.')
return false;
// Number looks good
aResult = value;
// Set some flags so we can check this number is valid once we know
// whether it's an hour, minute string etc.
aIsReal = (PL_strnchr(begin, '.', len) != nsnull);
aCouldBeMin = (value < 60.0 && (len == 2));
aCouldBeSec = (value < 60.0 ||
(value == 60.0 && begin[0] == '5')); // Take care of rounding error
aCouldBeSec &= (len >= 2 &&
(begin[2] == '\0' || begin[2] == '.' || IsSpace(begin[2])));
return true;
}
bool
ParseMetricMultiplicand(const char*& aStart,
const char* aEnd,
PRInt32& multiplicand)
{
bool result = false;
size_t len = aEnd - aStart;
const char* cur = aStart;
if (len) {
switch (*cur++)
{
case 'h':
multiplicand = MSEC_PER_HOUR;
result = true;
break;
case 'm':
if (len >= 2) {
if (*cur == 's') {
++cur;
multiplicand = 1;
result = true;
} else if (len >= 3 && *cur++ == 'i' && *cur++ == 'n') {
multiplicand = MSEC_PER_MIN;
result = true;
}
}
break;
case 's':
multiplicand = MSEC_PER_SEC;
result = true;
break;
}
}
if (result) {
aStart = cur;
}
return result;
}
nsresult
ParseOptionalOffset(const nsAString& aSpec, nsSMILTimeValueSpecParams& aResult)
{
if (aSpec.IsEmpty()) {
aResult.mOffset.SetMillis(0);
return NS_OK;
}
if (aSpec.First() != '+' && aSpec.First() != '-')
return NS_ERROR_FAILURE;
return nsSMILParserUtils::ParseClockValue(aSpec, &aResult.mOffset,
nsSMILParserUtils::kClockValueAllowSign);
}
nsresult
ParseAccessKey(const nsAString& aSpec, nsSMILTimeValueSpecParams& aResult)
{
NS_ABORT_IF_FALSE(StringBeginsWith(aSpec, ACCESSKEY_PREFIX_CC) ||
StringBeginsWith(aSpec, ACCESSKEY_PREFIX_LC),
"Calling ParseAccessKey on non-accesskey-type spec");
nsSMILTimeValueSpecParams result;
result.mType = nsSMILTimeValueSpecParams::ACCESSKEY;
NS_ABORT_IF_FALSE(
ACCESSKEY_PREFIX_LC.Length() == ACCESSKEY_PREFIX_CC.Length(),
"Case variations for accesskey prefix differ in length");
const PRUnichar* start = aSpec.BeginReading() + ACCESSKEY_PREFIX_LC.Length();
const PRUnichar* end = aSpec.EndReading();
// Expecting at least <accesskey> + ')'
if (end - start < 2)
return NS_ERROR_FAILURE;
PRUint32 c = *start++;
// Process 32-bit codepoints
if (NS_IS_HIGH_SURROGATE(c)) {
if (end - start < 2) // Expecting at least low-surrogate + ')'
return NS_ERROR_FAILURE;
PRUint32 lo = *start++;
if (!NS_IS_LOW_SURROGATE(lo))
return NS_ERROR_FAILURE;
c = SURROGATE_TO_UCS4(c, lo);
// XML 1.1 says that 0xFFFE and 0xFFFF are not valid characters
} else if (NS_IS_LOW_SURROGATE(c) || c == 0xFFFE || c == 0xFFFF) {
return NS_ERROR_FAILURE;
}
result.mRepeatIterationOrAccessKey = c;
if (*start++ != ')')
return NS_ERROR_FAILURE;
SkipBeginWsp(start, end);
nsresult rv = ParseOptionalOffset(Substring(start, end), result);
if (NS_FAILED(rv))
return rv;
aResult = result;
return NS_OK;
}
const PRUnichar*
GetTokenEnd(const nsAString& aStr, bool aBreakOnDot)
{
const PRUnichar* tokenEnd = aStr.BeginReading();
const PRUnichar* const end = aStr.EndReading();
bool escape = false;
while (tokenEnd != end) {
PRUnichar c = *tokenEnd;
if (IsSpace(c) ||
(!escape && (c == '+' || c == '-' || (aBreakOnDot && c == '.')))) {
break;
}
escape = (!escape && c == '\\');
++tokenEnd;
}
return tokenEnd;
}
void
Unescape(nsAString& aStr)
{
const PRUnichar* read = aStr.BeginReading();
const PRUnichar* const end = aStr.EndReading();
PRUnichar* write = aStr.BeginWriting();
bool escape = false;
while (read != end) {
NS_ABORT_IF_FALSE(write <= read, "Writing past where we've read");
if (!escape && *read == '\\') {
escape = true;
++read;
} else {
*write++ = *read++;
escape = false;
}
}
aStr.SetLength(write - aStr.BeginReading());
}
nsresult
ParseElementBaseTimeValueSpec(const nsAString& aSpec,
nsSMILTimeValueSpecParams& aResult)
{
nsSMILTimeValueSpecParams result;
//
// The spec will probably look something like one of these
//
// element-name.begin
// element-name.event-name
// event-name
// element-name.repeat(3)
// event\.name
//
// Technically `repeat(3)' is permitted but the behaviour in this case is not
// defined (for SMIL Animation) so we don't support it here.
//
const PRUnichar* tokenStart = aSpec.BeginReading();
const PRUnichar* tokenEnd = GetTokenEnd(aSpec, true);
nsAutoString token(Substring(tokenStart, tokenEnd));
Unescape(token);
if (token.IsEmpty())
return NS_ERROR_FAILURE;
// Whether the token is an id-ref or event-symbol it should be a valid NCName
if (NS_FAILED(nsContentUtils::CheckQName(token, false)))
return NS_ERROR_FAILURE;
// Parse the second token if there is one
if (tokenEnd != aSpec.EndReading() && *tokenEnd == '.') {
result.mDependentElemID = do_GetAtom(token);
tokenStart = ++tokenEnd;
tokenEnd = GetTokenEnd(Substring(tokenStart, aSpec.EndReading()), false);
// Don't unescape the token unless we need to and not until after we've
// tested it
const nsAString& rawToken2 = Substring(tokenStart, tokenEnd);
// element-name.begin
if (rawToken2.Equals(NS_LITERAL_STRING("begin"))) {
result.mType = nsSMILTimeValueSpecParams::SYNCBASE;
result.mSyncBegin = true;
// element-name.end
} else if (rawToken2.Equals(NS_LITERAL_STRING("end"))) {
result.mType = nsSMILTimeValueSpecParams::SYNCBASE;
result.mSyncBegin = false;
// element-name.repeat(digit+)
} else if (StringBeginsWith(rawToken2, REPEAT_PREFIX)) {
result.mType = nsSMILTimeValueSpecParams::REPEAT;
if (!GetUnsignedIntAndEndParen(
Substring(tokenStart + REPEAT_PREFIX.Length(), tokenEnd),
result.mRepeatIterationOrAccessKey))
return NS_ERROR_FAILURE;
// element-name.event-symbol
} else {
nsAutoString token2(rawToken2);
Unescape(token2);
result.mType = nsSMILTimeValueSpecParams::EVENT;
if (token2.IsEmpty() ||
NS_FAILED(nsContentUtils::CheckQName(token2, false)))
return NS_ERROR_FAILURE;
result.mEventSymbol = do_GetAtom(token2);
}
} else {
// event-symbol
result.mType = nsSMILTimeValueSpecParams::EVENT;
result.mEventSymbol = do_GetAtom(token);
}
// We've reached the end of the token, so we should now be either looking at
// a '+', '-', or the end.
const PRUnichar* specEnd = aSpec.EndReading();
SkipBeginWsp(tokenEnd, specEnd);
nsresult rv = ParseOptionalOffset(Substring(tokenEnd, specEnd), result);
if (NS_SUCCEEDED(rv)) {
aResult = result;
}
return rv;
}
} // end anonymous namespace block
//------------------------------------------------------------------------------
// Implementation
nsresult
nsSMILParserUtils::ParseKeySplines(const nsAString& aSpec,
nsTArray<double>& aSplineArray)
{
nsresult rv = NS_OK;
NS_ConvertUTF16toUTF8 spec(aSpec);
const char* start = spec.BeginReading();
const char* end = spec.EndReading();
SkipBeginWsp(start, end);
int i = 0;
while (start != end)
{
double value = GetFloat(start, end, &rv);
if (NS_FAILED(rv))
break;
if (value > 1.0 || value < 0.0) {
rv = NS_ERROR_FAILURE;
break;
}
if (!aSplineArray.AppendElement(value)) {
rv = NS_ERROR_OUT_OF_MEMORY;
break;
}
++i;
SkipBeginWsp(start, end);
if (start == end)
break;
if (i % 4) {
if (*start == ',') {
++start;
}
} else {
if (*start != ';') {
rv = NS_ERROR_FAILURE;
break;
}
++start;
}
SkipBeginWsp(start, end);
}
if (i % 4) {
rv = NS_ERROR_FAILURE; // wrong number of points
}
return rv;
}
nsresult
nsSMILParserUtils::ParseSemicolonDelimitedProgressList(const nsAString& aSpec,
bool aNonDecreasing,
nsTArray<double>& aArray)
{
nsresult rv = NS_OK;
NS_ConvertUTF16toUTF8 spec(aSpec);
const char* start = spec.BeginReading();
const char* end = spec.EndReading();
SkipBeginWsp(start, end);
double previousValue = -1.0;
while (start != end) {
double value = GetFloat(start, end, &rv);
if (NS_FAILED(rv))
break;
if (value > 1.0 || value < 0.0 ||
(aNonDecreasing && value < previousValue)) {
rv = NS_ERROR_FAILURE;
break;
}
if (!aArray.AppendElement(value)) {
rv = NS_ERROR_OUT_OF_MEMORY;
break;
}
previousValue = value;
SkipBeginWsp(start, end);
if (start == end)
break;
if (*start++ != ';') {
rv = NS_ERROR_FAILURE;
break;
}
SkipBeginWsp(start, end);
}
return rv;
}
// Helper class for ParseValues
class SMILValueParser : public nsSMILParserUtils::GenericValueParser
{
public:
SMILValueParser(const nsISMILAnimationElement* aSrcElement,
const nsISMILAttr* aSMILAttr,
nsTArray<nsSMILValue>* aValuesArray,
bool* aPreventCachingOfSandwich) :
mSrcElement(aSrcElement),
mSMILAttr(aSMILAttr),
mValuesArray(aValuesArray),
mPreventCachingOfSandwich(aPreventCachingOfSandwich)
{}
virtual nsresult Parse(const nsAString& aValueStr) {
nsSMILValue newValue;
bool tmpPreventCachingOfSandwich;
nsresult rv = mSMILAttr->ValueFromString(aValueStr, mSrcElement, newValue,
tmpPreventCachingOfSandwich);
if (NS_FAILED(rv))
return rv;
if (!mValuesArray->AppendElement(newValue)) {
return NS_ERROR_OUT_OF_MEMORY;
}
if (tmpPreventCachingOfSandwich) {
*mPreventCachingOfSandwich = true;
}
return NS_OK;
}
protected:
const nsISMILAnimationElement* mSrcElement;
const nsISMILAttr* mSMILAttr;
nsTArray<nsSMILValue>* mValuesArray;
bool* mPreventCachingOfSandwich;
};
nsresult
nsSMILParserUtils::ParseValues(const nsAString& aSpec,
const nsISMILAnimationElement* aSrcElement,
const nsISMILAttr& aAttribute,
nsTArray<nsSMILValue>& aValuesArray,
bool& aPreventCachingOfSandwich)
{
// Assume all results can be cached, until we find one that can't.
aPreventCachingOfSandwich = false;
SMILValueParser valueParser(aSrcElement, &aAttribute,
&aValuesArray, &aPreventCachingOfSandwich);
return ParseValuesGeneric(aSpec, valueParser);
}
nsresult
nsSMILParserUtils::ParseValuesGeneric(const nsAString& aSpec,
GenericValueParser& aParser)
{
nsCharSeparatedTokenizer tokenizer(aSpec, ';');
if (!tokenizer.hasMoreTokens()) { // Empty list
return NS_ERROR_FAILURE;
}
while (tokenizer.hasMoreTokens()) {
nsresult rv = aParser.Parse(tokenizer.nextToken());
if (NS_FAILED(rv)) {
return NS_ERROR_FAILURE;
}
}
// Disallow ;-terminated values lists.
if (tokenizer.lastTokenEndedWithSeparator()) {
return NS_ERROR_FAILURE;
}
return NS_OK;
}
nsresult
nsSMILParserUtils::ParseRepeatCount(const nsAString& aSpec,
nsSMILRepeatCount& aResult)
{
nsresult rv = NS_OK;
NS_ConvertUTF16toUTF8 spec(aSpec);
const char* start = spec.BeginReading();
const char* end = spec.EndReading();
SkipBeginWsp(start, end);
if (start != end)
{
if (ConsumeSubstring(start, end, "indefinite")) {
aResult.SetIndefinite();
} else {
double value = GetFloat(start, end, &rv);
if (NS_SUCCEEDED(rv))
{
/* Repeat counts must be > 0 */
if (value <= 0.0) {
rv = NS_ERROR_FAILURE;
} else {
aResult = value;
}
}
}
/* Check for trailing junk */
SkipBeginWsp(start, end);
if (start != end) {
rv = NS_ERROR_FAILURE;
}
} else {
/* Empty spec */
rv = NS_ERROR_FAILURE;
}
if (NS_FAILED(rv)) {
aResult.Unset();
}
return rv;
}
nsresult
nsSMILParserUtils::ParseTimeValueSpecParams(const nsAString& aSpec,
nsSMILTimeValueSpecParams& aResult)
{
nsresult rv = NS_ERROR_FAILURE;
const PRUnichar* start = aSpec.BeginReading();
const PRUnichar* end = aSpec.EndReading();
SkipBeginEndWsp(start, end);
if (start == end)
return rv;
const nsAString &spec = Substring(start, end);
// offset type
if (*start == '+' || *start == '-' || NS_IsAsciiDigit(*start)) {
rv = ParseClockValue(spec, &aResult.mOffset,
nsSMILParserUtils::kClockValueAllowSign);
if (NS_SUCCEEDED(rv)) {
aResult.mType = nsSMILTimeValueSpecParams::OFFSET;
}
}
// indefinite
else if (spec.Equals(NS_LITERAL_STRING("indefinite"))) {
aResult.mType = nsSMILTimeValueSpecParams::INDEFINITE;
rv = NS_OK;
}
// wallclock type
else if (StringBeginsWith(spec, WALLCLOCK_PREFIX)) {
rv = NS_ERROR_NOT_IMPLEMENTED;
}
// accesskey type
else if (StringBeginsWith(spec, ACCESSKEY_PREFIX_LC) ||
StringBeginsWith(spec, ACCESSKEY_PREFIX_CC)) {
rv = ParseAccessKey(spec, aResult);
}
// event, syncbase, or repeat
else {
rv = ParseElementBaseTimeValueSpec(spec, aResult);
}
return rv;
}
nsresult
nsSMILParserUtils::ParseClockValue(const nsAString& aSpec,
nsSMILTimeValue* aResult,
PRUint32 aFlags, // = 0
bool* aIsMedia) // = nsnull
{
nsSMILTime offset = 0L;
double component = 0.0;
PRInt8 sign = 0;
PRUint8 colonCount = 0;
// Indicates we have started parsing a clock-value (not including the optional
// +/- that precedes the clock-value) or keyword ("media", "indefinite")
bool started = false;
PRInt32 metricMultiplicand = MSEC_PER_SEC;
bool numIsReal = false;
bool prevNumCouldBeMin = false;
bool numCouldBeMin = false;
bool numCouldBeSec = false;
bool isIndefinite = false;
if (aIsMedia) {
*aIsMedia = false;
}
NS_ConvertUTF16toUTF8 spec(aSpec);
const char* start = spec.BeginReading();
const char* end = spec.EndReading();
while (start != end) {
if (IsSpace(*start)) {
++start;
if (started) {
break;
}
} else if (!started && (aFlags & kClockValueAllowSign) &&
(*start == '+' || *start == '-')) {
// check sign has not already been set (e.g. ++10s)
if (sign != 0) {
return NS_ERROR_FAILURE;
}
sign = (*start == '+') ? 1 : -1;
++start;
// The NS_IS_DIGIT etc. macros are not locale-specific
} else if (NS_IS_DIGIT(*start)) {
prevNumCouldBeMin = numCouldBeMin;
if (!ParseClockComponent(start, end, component, numIsReal, numCouldBeMin,
numCouldBeSec)) {
return NS_ERROR_FAILURE;
}
started = true;
} else if (started && *start == ':') {
++colonCount;
// Neither minutes nor hours can be reals
if (numIsReal) {
return NS_ERROR_FAILURE;
}
// Can't have more than two colons
if (colonCount > 2) {
return NS_ERROR_FAILURE;
}
// Multiply the offset by 60 and add the last accumulated component
offset = offset * 60 + nsSMILTime(component);
component = 0.0;
++start;
} else if (NS_IS_ALPHA(*start)) {
if (colonCount > 0) {
return NS_ERROR_FAILURE;
}
if (!started && (aFlags & kClockValueAllowIndefinite) &&
ConsumeSubstring(start, end, "indefinite")) {
// We set a separate flag because we don't know what the state of the
// passed in time value is and we shouldn't change it in the case of a
// bad input string (so we can't initialise it to 0ms for example).
isIndefinite = true;
if (aResult) {
aResult->SetIndefinite();
}
started = true;
} else if (!started && aIsMedia &&
ConsumeSubstring(start, end, "media")) {
*aIsMedia = true;
started = true;
} else if (!ParseMetricMultiplicand(start, end, metricMultiplicand)) {
return NS_ERROR_FAILURE;
}
// Nothing must come after the string except whitespace
break;
} else {
return NS_ERROR_FAILURE;
}
}
// Whitespace/empty string
if (!started) {
return NS_ERROR_FAILURE;
}
// Process remainder of string (if any) to ensure it is only trailing
// whitespace (embedded whitespace is not allowed)
SkipBeginWsp(start, end);
if (start != end) {
return NS_ERROR_FAILURE;
}
// No more processing required if the value was "indefinite" or "media".
if (isIndefinite || (aIsMedia && *aIsMedia)) {
return NS_OK;
}
// If there is more than one colon then the previous component must be a
// correctly formatted minute (i.e. two digits between 00 and 59) and the
// latest component must be a correctly formatted second (i.e. two digits
// before the .)
if (colonCount > 0 && (!prevNumCouldBeMin || !numCouldBeSec)) {
return NS_ERROR_FAILURE;
}
// Tack on the last component
if (colonCount > 0) {
offset *= 60 * 1000;
component *= 1000;
// rounding
component = (component >= 0) ? component + 0.5 : component - 0.5;
offset += nsSMILTime(component);
} else {
component *= metricMultiplicand;
// rounding
component = (component >= 0) ? component + 0.5 : component - 0.5;
offset = nsSMILTime(component);
}
// we haven't applied the sign yet so if the result is negative we must have
// overflowed
if (offset < 0) {
return NS_ERROR_FAILURE;
}
if (aResult) {
if (sign == -1) {
offset = -offset;
}
aResult->SetMillis(offset);
}
return NS_OK;
}
PRInt32
nsSMILParserUtils::CheckForNegativeNumber(const nsAString& aStr)
{
PRInt32 absValLocation = -1;
nsAString::const_iterator start, end;
aStr.BeginReading(start);
aStr.EndReading(end);
// Skip initial whitespace
SkipBeginWsp(start, end);
// Check for dash
if (start != end && *start == '-') {
++start;
// Check for numeric character
if (start != end && NS_IS_DIGIT(*start)) {
absValLocation = start.get() - start.start();
}
}
return absValLocation;
}