C++ nsString::CompressWhitespace方法代码示例

ENameValueFlag
HTMLButtonAccessible::NativeName(nsString& aName)
{
  ENameValueFlag nameFlag = Accessible::NativeName(aName);
  if (!aName.IsEmpty() || mContent->Tag() != nsGkAtoms::input)
    return nameFlag;

  // Note: No need to check @value attribute since it results in anonymous text
  // node. The name is calculated from subtree in this case.
  if (!mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::alt, aName)) {
    // Use the button's (default) label if nothing else works
    nsIFrame* frame = GetFrame();
    if (frame) {
      nsIFormControlFrame* fcFrame = do_QueryFrame(frame);
      if (fcFrame)
        fcFrame->GetFormProperty(nsGkAtoms::defaultLabel, aName);
    }
  }

  if (aName.IsEmpty() &&
      !mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::src, aName)) {
    mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::data, aName);
  }

  aName.CompressWhitespace();
  return eNameOK;
}

ENameValueFlag
XULToolbarAccessible::NativeName(nsString& aName)
{
  if (mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::toolbarname, aName))
    aName.CompressWhitespace();

  return eNameOK;
}

void
nsTextEquivUtils::GetTextEquivFromSubtree(Accessible* aAccessible,
                                          nsString& aTextEquiv)
{
  aTextEquiv.Truncate();

  uint32_t nameRule = GetRoleRule(aAccessible->Role());
  if (nameRule & eNameFromSubtreeIfReqRule) {
    AppendFromAccessibleChildren(aAccessible, &aTextEquiv);
    aTextEquiv.CompressWhitespace();
  }
}

ENameValueFlag
HTMLSelectOptionAccessible::NativeName(nsString& aName)
{
  // CASE #1 -- great majority of the cases
  // find the label attribute - this is what the W3C says we should use
  mContent->GetAttr(kNameSpaceID_None, nsGkAtoms::label, aName);
  if (!aName.IsEmpty())
    return eNameOK;

  // CASE #2 -- no label parameter, get the first child, 
  // use it if it is a text node
  nsIContent* text = mContent->GetFirstChild();
  if (text && text->IsNodeOfType(nsINode::eTEXT)) {
    nsTextEquivUtils::AppendTextEquivFromTextContent(text, &aName);
    aName.CompressWhitespace();
    return aName.IsEmpty() ? eNameOK : eNameFromSubtree;
  }

  return eNameOK;
}

static void
ParseAlignAttribute(nsString& aValue, eAlign& aAlign, int32_t& aRowIndex)
{
  // by default, the table is centered about the axis
  aRowIndex = 0;
  aAlign = eAlign_axis;
  int32_t len = 0;

  // we only have to remove the leading spaces because 
  // ToInteger ignores the whitespaces around the number
  aValue.CompressWhitespace(true, false);

  if (0 == aValue.Find("top")) {
    len = 3; // 3 is the length of 'top'
    aAlign = eAlign_top;
  }
  else if (0 == aValue.Find("bottom")) {
    len = 6; // 6 is the length of 'bottom'
    aAlign = eAlign_bottom;
  }
  else if (0 == aValue.Find("center")) {
    len = 6; // 6 is the length of 'center'
    aAlign = eAlign_center;
  }
  else if (0 == aValue.Find("baseline")) {
    len = 8; // 8 is the length of 'baseline'
    aAlign = eAlign_baseline;
  }
  else if (0 == aValue.Find("axis")) {
    len = 4; // 4 is the length of 'axis'
    aAlign = eAlign_axis;
  }
  if (len) {
    nsresult error;
    aValue.Cut(0, len); // aValue is not a const here
    aRowIndex = aValue.ToInteger(&error);
    if (NS_FAILED(error))
      aRowIndex = 0;
  }
}

ENameValueFlag HTMLButtonAccessible::NativeName(nsString& aName) const {
  // No need to check @value attribute for buttons since this attribute results
  // in native anonymous text node and the name is calculated from subtree.
  // The same magic works for @alt and @value attributes in case of type="image"
  // element that has no valid @src (note if [email protected]="image" has an image
  // then neither @alt nor @value attributes are used to generate a visual label
  // and thus we need to obtain the accessible name directly from attribute
  // value). Also the same algorithm works in case of default labels for
  // type="submit"/"reset"/"image" elements.

  ENameValueFlag nameFlag = Accessible::NativeName(aName);
  if (!aName.IsEmpty() || !mContent->IsHTMLElement(nsGkAtoms::input) ||
      !mContent->AsElement()->AttrValueIs(kNameSpaceID_None, nsGkAtoms::type,
                                          nsGkAtoms::image, eCaseMatters))
    return nameFlag;

  if (!mContent->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::alt, aName))
    mContent->AsElement()->GetAttr(kNameSpaceID_None, nsGkAtoms::value, aName);

  aName.CompressWhitespace();
  return eNameOK;
}

// parse an input string in the following format (see bug 148326 for testcases):
// [+|-] unsigned-number (% [pseudo-unit] | pseudo-unit | css-unit | namedspace)
bool
nsMathMLmpaddedFrame::ParseAttribute(nsString&   aString,
                                     int32_t&    aSign,
                                     nsCSSValue& aCSSValue,
                                     int32_t&    aPseudoUnit)
{
  aCSSValue.Reset();
  aSign = NS_MATHML_SIGN_INVALID;
  aPseudoUnit = NS_MATHML_PSEUDO_UNIT_UNSPECIFIED;
  aString.CompressWhitespace(); // aString is not a const in this code

  int32_t stringLength = aString.Length();
  if (!stringLength)
    return false;

  nsAutoString number, unit;

  //////////////////////
  // see if the sign is there

  int32_t i = 0;

  if (aString[0] == '+') {
    aSign = NS_MATHML_SIGN_PLUS;
    i++;
  }
  else if (aString[0] == '-') {
    aSign = NS_MATHML_SIGN_MINUS;
    i++;
  }
  else
    aSign = NS_MATHML_SIGN_UNSPECIFIED;

  // get the number
  bool gotDot = false, gotPercent = false;
  for (; i < stringLength; i++) {
    PRUnichar c = aString[i];
    if (gotDot && c == '.') {
      // error - two dots encountered
      aSign = NS_MATHML_SIGN_INVALID;
      return false;
    }

    if (c == '.')
      gotDot = true;
    else if (!nsCRT::IsAsciiDigit(c)) {
      break;
    }
    number.Append(c);
  }

  // catch error if we didn't enter the loop above... we could simply initialize
  // floatValue = 1, to cater for cases such as width="height", but that wouldn't
  // be in line with the spec which requires an explicit number
  if (number.IsEmpty()) {
    aSign = NS_MATHML_SIGN_INVALID;
    return false;
  }

  nsresult errorCode;
  float floatValue = number.ToFloat(&errorCode);
  if (NS_FAILED(errorCode)) {
    aSign = NS_MATHML_SIGN_INVALID;
    return false;
  }

  // see if this is a percentage-based value
  if (i < stringLength && aString[i] == '%') {
    i++;
    gotPercent = true;
  }

  // the remainder now should be a css-unit, or a pseudo-unit, or a named-space
  aString.Right(unit, stringLength - i);

  if (unit.IsEmpty()) {
    if (gotPercent) {
      // case ["+"|"-"] unsigned-number "%" 
      aCSSValue.SetPercentValue(floatValue / 100.0f);
      aPseudoUnit = NS_MATHML_PSEUDO_UNIT_ITSELF;
      return true;
    } else {
      // case ["+"|"-"] unsigned-number
      // XXXfredw: should we allow non-zero unitless values? See bug 757703.
      if (!floatValue) {
        aCSSValue.SetFloatValue(floatValue, eCSSUnit_Number);
        aPseudoUnit = NS_MATHML_PSEUDO_UNIT_ITSELF;
        return true;
      }
    }
  }
  else if (unit.EqualsLiteral("width"))  aPseudoUnit = NS_MATHML_PSEUDO_UNIT_WIDTH;
  else if (unit.EqualsLiteral("height")) aPseudoUnit = NS_MATHML_PSEUDO_UNIT_HEIGHT;
  else if (unit.EqualsLiteral("depth"))  aPseudoUnit = NS_MATHML_PSEUDO_UNIT_DEPTH;
  else if (!gotPercent) { // percentage can only apply to a pseudo-unit

    // see if the unit is a named-space
    if (nsMathMLElement::ParseNamedSpaceValue(unit, aCSSValue,
//.........这里部分代码省略.........

// parse an input string in the following format (see bug 148326 for testcases):
// [+|-] unsigned-number (% [pseudo-unit] | pseudo-unit | css-unit | namedspace)
PRBool
nsMathMLmpaddedFrame::ParseAttribute(nsString&   aString,
                                     PRInt32&    aSign,
                                     nsCSSValue& aCSSValue,
                                     PRInt32&    aPseudoUnit)
{
  aCSSValue.Reset();
  aSign = NS_MATHML_SIGN_INVALID;
  aPseudoUnit = NS_MATHML_PSEUDO_UNIT_UNSPECIFIED;
  aString.CompressWhitespace(); // aString is not a const in this code

  PRInt32 stringLength = aString.Length();
  if (!stringLength)
    return PR_FALSE;

  nsAutoString number, unit;

  //////////////////////
  // see if the sign is there

  PRInt32 i = 0;

  if (aString[0] == '+') {
    aSign = NS_MATHML_SIGN_PLUS;
    i++;
  }
  else if (aString[0] == '-') {
    aSign = NS_MATHML_SIGN_MINUS;
    i++;
  }
  else
    aSign = NS_MATHML_SIGN_UNSPECIFIED;

  // skip any space after the sign
  if (i < stringLength && nsCRT::IsAsciiSpace(aString[i]))
    i++;

  // get the number
  PRBool gotDot = PR_FALSE, gotPercent = PR_FALSE;
  for (; i < stringLength; i++) {
    PRUnichar c = aString[i];
    if (gotDot && c == '.') {
      // error - two dots encountered
      aSign = NS_MATHML_SIGN_INVALID;
      return PR_FALSE;
    }

    if (c == '.')
      gotDot = PR_TRUE;
    else if (!nsCRT::IsAsciiDigit(c)) {
      break;
    }
    number.Append(c);
  }

  // catch error if we didn't enter the loop above... we could simply initialize
  // floatValue = 1, to cater for cases such as width="height", but that wouldn't
  // be in line with the spec which requires an explicit number
  if (number.IsEmpty()) {
#ifdef NS_DEBUG
    printf("mpadded: attribute with bad numeric value: %s\n",
            NS_LossyConvertUTF16toASCII(aString).get());
#endif
    aSign = NS_MATHML_SIGN_INVALID;
    return PR_FALSE;
  }

  PRInt32 errorCode;
  float floatValue = number.ToFloat(&errorCode);
  if (errorCode) {
    aSign = NS_MATHML_SIGN_INVALID;
    return PR_FALSE;
  }

  // skip any space after the number
  if (i < stringLength && nsCRT::IsAsciiSpace(aString[i]))
    i++;

  // see if this is a percentage-based value
  if (i < stringLength && aString[i] == '%') {
    i++;
    gotPercent = PR_TRUE;

    // skip any space after the '%' sign
    if (i < stringLength && nsCRT::IsAsciiSpace(aString[i]))
      i++;
  }

  // the remainder now should be a css-unit, or a pseudo-unit, or a named-space
  aString.Right(unit, stringLength - i);

  if (unit.IsEmpty()) {
    // also cater for the edge case of "0" for which the unit is optional
    if (gotPercent || !floatValue) {
      aCSSValue.SetPercentValue(floatValue / 100.0f);
      aPseudoUnit = NS_MATHML_PSEUDO_UNIT_ITSELF;
      return PR_TRUE;
    }
//.........这里部分代码省略.........

/* static */ PRBool
nsMathMLFrame::ParseNamedSpaceValue(nsIFrame*   aMathMLmstyleFrame,
                                    nsString&   aString,
                                    nsCSSValue& aCSSValue)
{
  aCSSValue.Reset();
  aString.CompressWhitespace(); //  aString is not a const in this code...
  if (!aString.Length()) return PR_FALSE;

  // See if it is one of the 'namedspace' (ranging 1/18em...7/18em)
  PRInt32 i = 0;
  nsIAtom* namedspaceAtom = nsnull;
  if (aString.EqualsLiteral("veryverythinmathspace")) {
    i = 1;
    namedspaceAtom = nsMathMLAtoms::veryverythinmathspace_;
  }
  else if (aString.EqualsLiteral("verythinmathspace")) {
    i = 2;
    namedspaceAtom = nsMathMLAtoms::verythinmathspace_;
  }
  else if (aString.EqualsLiteral("thinmathspace")) {
    i = 3;
    namedspaceAtom = nsMathMLAtoms::thinmathspace_;
  }
  else if (aString.EqualsLiteral("mediummathspace")) {
    i = 4;
    namedspaceAtom = nsMathMLAtoms::mediummathspace_;
  }
  else if (aString.EqualsLiteral("thickmathspace")) {
    i = 5;
    namedspaceAtom = nsMathMLAtoms::thickmathspace_;
  }
  else if (aString.EqualsLiteral("verythickmathspace")) {
    i = 6;
    namedspaceAtom = nsMathMLAtoms::verythickmathspace_;
  }
  else if (aString.EqualsLiteral("veryverythickmathspace")) {
    i = 7;
    namedspaceAtom = nsMathMLAtoms::veryverythickmathspace_;
  }

  if (0 != i) {
    if (aMathMLmstyleFrame) {
      // see if there is a <mstyle> that has overriden the default value
      // GetAttribute() will recurse all the way up into the <mstyle> hierarchy
      nsAutoString value;
      if (NS_CONTENT_ATTR_HAS_VALUE ==
          GetAttribute(nsnull, aMathMLmstyleFrame, namedspaceAtom, value)) {
        if (ParseNumericValue(value, aCSSValue) &&
            aCSSValue.IsLengthUnit()) {
          return PR_TRUE;
        }
      }
    }

    // fall back to the default value
    aCSSValue.SetFloatValue(float(i)/float(18), eCSSUnit_EM);
    return PR_TRUE;
  }

  return PR_FALSE;
}