/* This file contains parts of the KDE libraries
Copyright (C) 1999 Ian Zepp (icszepp@islc.net)
Copyright (C) 2006 by Dominic Battre <dominic@battre.de>
Copyright (C) 2006 by Martin Pool <mbp@canonical.com>
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.
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.
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.
*/
#include "qnaturalsorting.h"
//from KDE
/*
int naturalCompare(const QString &_a, const QString &_b, Qt::CaseSensitivity caseSensitivity)
{
// This method chops the input a and b into pieces of
// digits and non-digits (a1.05 becomes a | 1 | . | 05)
// and compares these pieces of a and b to each other
// (first with first, second with second, ...).
//
// This is based on the natural sort order code code by Martin Pool
// http://sourcefrog.net/projects/natsort/
// Martin Pool agreed to license this under LGPL or GPL.
// FIXME: Using toLower() to implement case insensitive comparison is
// sub-optimal, but is needed because we compare strings with
// localeAwareCompare(), which does not know about case sensitivity.
// A task has been filled for this in Qt Task Tracker with ID 205990.
// http://trolltech.com/developer/task-tracker/index_html?method=entry&id=205990
QString a;
QString b;
if (caseSensitivity == Qt::CaseSensitive) {
a = _a;
b = _b;
} else {
a = _a.toLower();
b = _b.toLower();
}
const QChar* currA = a.unicode(); // iterator over a
const QChar* currB = b.unicode(); // iterator over b
if (currA == currB) {
return 0;
}
const QChar* begSeqA = currA; // beginning of a new character sequence of a
const QChar* begSeqB = currB;
while (!currA->isNull() && !currB->isNull()) {
if (currA->unicode() == QChar::ObjectReplacementCharacter) {
return 1;
}
if (currB->unicode() == QChar::ObjectReplacementCharacter) {
return -1;
}
if (currA->unicode() == QChar::ReplacementCharacter) {
return 1;
}
if (currB->unicode() == QChar::ReplacementCharacter) {
return -1;
}
// find sequence of characters ending at the first non-character
while (!currA->isNull() && !currA->isDigit() && !currA->isPunct() && !currA->isSpace()) {
++currA;
}
while (!currB->isNull() && !currB->isDigit() && !currB->isPunct() && !currB->isSpace()) {
++currB;
}
// compare these sequences
const QStringRef& subA(a.midRef(begSeqA - a.unicode(), currA - begSeqA));
const QStringRef& subB(b.midRef(begSeqB - b.unicode(), currB - begSeqB));
const int cmp = QStringRef::localeAwareCompare(subA, subB);
if (cmp != 0) {
return cmp < 0 ? -1 : +1;
}
if (currA->isNull() || currB->isNull()) {
break;
}
// find sequence of characters ending at the first non-character
while (currA->isPunct() || currA->isSpace() || currB->isPunct() || currB->isSpace()) {
if (*currA != *currB) {
return (*currA < *currB) ? -1 : +1;
}
++currA;
++currB;
}
// now some digits follow...
if ((*currA == '0') || (*currB == '0')) {
// one digit-sequence starts with 0 -> assume we are in a fraction part
// do left aligned comparison (numbers are considered left aligned)
while (1) {
if (!currA->isDigit() && !currB->isDigit()) {
break;
} else if (!currA->isDigit()) {
return +1;
} else if (!currB->isDigit()) {
return -1;
} else if (*currA < *currB) {
return -1;
} else if (*currA > *currB) {
return + 1;
}
++currA;
++currB;
}
} else {
// No digit-sequence starts with 0 -> assume we are looking at some integer
// do right aligned comparison.
//
// The longest run of digits wins. That aside, the greatest
// value wins, but we can't know that it will until we've scanned
// both numbers to know that they have the same magnitude.
bool isFirstRun = true;
int weight = 0;
while (1) {
if (!currA->isDigit() && !currB->isDigit()) {
if (weight != 0) {
return weight;
}
break;
} else if (!currA->isDigit()) {
if (isFirstRun) {
return *currA < *currB ? -1 : +1;
} else {
return -1;
}
} else if (!currB->isDigit()) {
if (isFirstRun) {
return *currA < *currB ? -1 : +1;
} else {
return +1;
}
} else if ((*currA < *currB) && (weight == 0)) {
weight = -1;
} else if ((*currA > *currB) && (weight == 0)) {
weight = + 1;
}
++currA;
++currB;
isFirstRun = false;
}
}
begSeqA = currA;
begSeqB = currB;
}
if (currA->isNull() && currB->isNull()) {
return 0;
}
return currA->isNull() ? -1 : + 1;
}
*/
static inline QChar getNextChar(const QString &s, int location)
{
return (location < s.length()) ? s.at(location) : QChar();
}
int naturalCompare(const QString &s1, const QString &s2, Qt::CaseSensitivity cs)
{
for (int l1 = 0, l2 = 0; l1 <= s1.count() && l2 <= s2.count(); ++l1, ++l2) {
// skip spaces, tabs and 0's
QChar c1 = getNextChar(s1, l1);
while (c1.isSpace())
c1 = getNextChar(s1, ++l1);
QChar c2 = getNextChar(s2, l2);
while (c2.isSpace())
c2 = getNextChar(s2, ++l2);
if (c1.isDigit() && c2.isDigit()) {
while (c1.digitValue() == 0)
c1 = getNextChar(s1, ++l1);
while (c2.digitValue() == 0)
c2 = getNextChar(s2, ++l2);
int lookAheadLocation1 = l1;
int lookAheadLocation2 = l2;
int currentReturnValue = 0;
// find the last digit, setting currentReturnValue as we go if it isn't equal
for (
QChar lookAhead1 = c1, lookAhead2 = c2;
(lookAheadLocation1 <= s1.length() && lookAheadLocation2 <= s2.length());
lookAhead1 = getNextChar(s1, ++lookAheadLocation1),
lookAhead2 = getNextChar(s2, ++lookAheadLocation2)
) {
bool is1ADigit = !lookAhead1.isNull() && lookAhead1.isDigit();
bool is2ADigit = !lookAhead2.isNull() && lookAhead2.isDigit();
if (!is1ADigit && !is2ADigit)
break;
if (!is1ADigit)
return -1;
if (!is2ADigit)
return 1;
if (currentReturnValue == 0) {
if (lookAhead1 < lookAhead2) {
currentReturnValue = -1;
} else if (lookAhead1 > lookAhead2) {
currentReturnValue = 1;
}
}
}
if (currentReturnValue != 0)
return currentReturnValue;
}
if (cs == Qt::CaseInsensitive) {
if (!c1.isLower()) c1 = c1.toLower();
if (!c2.isLower()) c2 = c2.toLower();
}
int r = QString::localeAwareCompare(c1, c2);
if (r < 0)
return -1;
if (r > 0)
return 1;
}
// The two strings are the same (02 == 2) so fall back to the normal sort
return QString::compare(s1, s2, cs);
}
bool naturalSortLessThanCS( const QString &left, const QString &right )
{
return (naturalCompare( left, right, Qt::CaseSensitive ) < 0);
}
bool naturalSortLessThanCI( const QString &left, const QString &right )
{
return (naturalCompare( left, right, Qt::CaseInsensitive ) < 0);
}
bool naturalSortLessThanCIFileInfo(const QFileInfo & left,const QFileInfo & right)
{
return naturalSortLessThanCI(left.fileName(),right.fileName());
}