static String truncateString(const String& string, float maxWidth, const Font& font, TruncationFunction truncateToBuffer, bool disableRoundingHacks)
{
if (string.isEmpty())
return string;
ASSERT(maxWidth >= 0);
float currentEllipsisWidth = stringWidth(font, &horizontalEllipsis, 1, disableRoundingHacks);
UChar stringBuffer[STRING_BUFFER_SIZE];
unsigned truncatedLength;
unsigned keepCount;
unsigned length = string.length();
if (length > STRING_BUFFER_SIZE) {
keepCount = STRING_BUFFER_SIZE - 1; // need 1 character for the ellipsis
truncatedLength = centerTruncateToBuffer(string, length, keepCount, stringBuffer);
} else {
keepCount = length;
memcpy(stringBuffer, string.characters(), sizeof(UChar) * length);
truncatedLength = length;
}
float width = stringWidth(font, stringBuffer, truncatedLength, disableRoundingHacks);
if (width <= maxWidth)
return string;
unsigned keepCountForLargestKnownToFit = 0;
float widthForLargestKnownToFit = currentEllipsisWidth;
unsigned keepCountForSmallestKnownToNotFit = keepCount;
float widthForSmallestKnownToNotFit = width;
if (currentEllipsisWidth >= maxWidth) {
keepCountForLargestKnownToFit = 1;
keepCountForSmallestKnownToNotFit = 2;
}
while (keepCountForLargestKnownToFit + 1 < keepCountForSmallestKnownToNotFit) {
ASSERT(widthForLargestKnownToFit <= maxWidth);
ASSERT(widthForSmallestKnownToNotFit > maxWidth);
float ratio = (keepCountForSmallestKnownToNotFit - keepCountForLargestKnownToFit)
/ (widthForSmallestKnownToNotFit - widthForLargestKnownToFit);
keepCount = static_cast<unsigned>(maxWidth * ratio);
if (keepCount <= keepCountForLargestKnownToFit) {
keepCount = keepCountForLargestKnownToFit + 1;
} else if (keepCount >= keepCountForSmallestKnownToNotFit) {
keepCount = keepCountForSmallestKnownToNotFit - 1;
}
ASSERT(keepCount < length);
ASSERT(keepCount > 0);
ASSERT(keepCount < keepCountForSmallestKnownToNotFit);
ASSERT(keepCount > keepCountForLargestKnownToFit);
truncatedLength = truncateToBuffer(string, length, keepCount, stringBuffer);
width = stringWidth(font, stringBuffer, truncatedLength, disableRoundingHacks);
if (width <= maxWidth) {
keepCountForLargestKnownToFit = keepCount;
widthForLargestKnownToFit = width;
} else {
keepCountForSmallestKnownToNotFit = keepCount;
widthForSmallestKnownToNotFit = width;
}
}
if (keepCountForLargestKnownToFit == 0) {
keepCountForLargestKnownToFit = 1;
}
if (keepCount != keepCountForLargestKnownToFit) {
keepCount = keepCountForLargestKnownToFit;
truncatedLength = truncateToBuffer(string, length, keepCount, stringBuffer);
}
return String(stringBuffer, truncatedLength);
}
static String truncateString(const String& string, float maxWidth, const FontCascade& font, TruncationFunction truncateToBuffer, bool disableRoundingHacks, float* resultWidth = nullptr, bool shouldInsertEllipsis = true, float customTruncationElementWidth = 0, bool alwaysTruncate = false)
{
if (string.isEmpty())
return string;
if (resultWidth)
*resultWidth = 0;
ASSERT(maxWidth >= 0);
float currentEllipsisWidth = shouldInsertEllipsis ? stringWidth(font, &horizontalEllipsis, 1, disableRoundingHacks) : customTruncationElementWidth;
UChar stringBuffer[STRING_BUFFER_SIZE];
unsigned truncatedLength;
unsigned keepCount;
unsigned length = string.length();
if (length > STRING_BUFFER_SIZE) {
if (shouldInsertEllipsis)
keepCount = STRING_BUFFER_SIZE - 1; // need 1 character for the ellipsis
else
keepCount = 0;
truncatedLength = centerTruncateToBuffer(string, length, keepCount, stringBuffer, shouldInsertEllipsis);
} else {
keepCount = length;
StringView(string).getCharactersWithUpconvert(stringBuffer);
truncatedLength = length;
}
float width = stringWidth(font, stringBuffer, truncatedLength, disableRoundingHacks);
if (!shouldInsertEllipsis && alwaysTruncate)
width += customTruncationElementWidth;
if ((width - maxWidth) < 0.0001) { // Ignore rounding errors.
if (resultWidth)
*resultWidth = width;
return string;
}
unsigned keepCountForLargestKnownToFit = 0;
float widthForLargestKnownToFit = currentEllipsisWidth;
unsigned keepCountForSmallestKnownToNotFit = keepCount;
float widthForSmallestKnownToNotFit = width;
if (currentEllipsisWidth >= maxWidth) {
keepCountForLargestKnownToFit = 1;
keepCountForSmallestKnownToNotFit = 2;
}
while (keepCountForLargestKnownToFit + 1 < keepCountForSmallestKnownToNotFit) {
ASSERT_WITH_SECURITY_IMPLICATION(widthForLargestKnownToFit <= maxWidth);
ASSERT_WITH_SECURITY_IMPLICATION(widthForSmallestKnownToNotFit > maxWidth);
float ratio = (keepCountForSmallestKnownToNotFit - keepCountForLargestKnownToFit)
/ (widthForSmallestKnownToNotFit - widthForLargestKnownToFit);
keepCount = static_cast<unsigned>(maxWidth * ratio);
if (keepCount <= keepCountForLargestKnownToFit)
keepCount = keepCountForLargestKnownToFit + 1;
else if (keepCount >= keepCountForSmallestKnownToNotFit)
keepCount = keepCountForSmallestKnownToNotFit - 1;
ASSERT_WITH_SECURITY_IMPLICATION(keepCount < length);
ASSERT(keepCount > 0);
ASSERT_WITH_SECURITY_IMPLICATION(keepCount < keepCountForSmallestKnownToNotFit);
ASSERT_WITH_SECURITY_IMPLICATION(keepCount > keepCountForLargestKnownToFit);
truncatedLength = truncateToBuffer(string, length, keepCount, stringBuffer, shouldInsertEllipsis);
width = stringWidth(font, stringBuffer, truncatedLength, disableRoundingHacks);
if (!shouldInsertEllipsis)
width += customTruncationElementWidth;
if (width <= maxWidth) {
keepCountForLargestKnownToFit = keepCount;
widthForLargestKnownToFit = width;
if (resultWidth)
*resultWidth = width;
} else {
keepCountForSmallestKnownToNotFit = keepCount;
widthForSmallestKnownToNotFit = width;
}
}
if (keepCountForLargestKnownToFit == 0) {
keepCountForLargestKnownToFit = 1;
}
if (keepCount != keepCountForLargestKnownToFit) {
keepCount = keepCountForLargestKnownToFit;
truncatedLength = truncateToBuffer(string, length, keepCount, stringBuffer, shouldInsertEllipsis);
}
return String(stringBuffer, truncatedLength);
}
