Sort labels in RSS Downloader dialog, closes #3140.

src/core/utils/string.cpp

@@ -45,7 +45,7 @@ std::string Utils::String::toStdString(const QString &str)
 }
 
 // uses lessThan comparison
-bool Utils::String::naturalSort(QString left, QString right, bool &result)
+bool Utils::String::naturalSort(const QString &left, const QString &right, bool &result)
 {
     // Return value indicates if functions was successful
     // result argument will contain actual comparison result if function was successful
@@ -106,6 +106,83 @@ bool Utils::String::naturalSort(QString left, QString right, bool &result)
     return false;
 }
 
+Utils::String::NaturalCompare::NaturalCompare()
+{
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 2, 0))
+#if defined(Q_OS_WIN)
+    // Without ICU library, QCollator doesn't support `setNumericMode(true)` on OS older than Win7
+    if(SysInfo::windowsVersion() < QSysInfo::WV_WINDOWS7)
+        return;
+#endif
+    m_collator.setNumericMode(true);
+    m_collator.setCaseSensitivity(Qt::CaseInsensitive);
+#endif
+}
+
+bool Utils::String::NaturalCompare::operator()(const QString &l, const QString &r)
+{
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 2, 0))
+#if defined(Q_OS_WIN)
+    // Without ICU library, QCollator doesn't support `setNumericMode(true)` on OS older than Win7
+    if(SysInfo::windowsVersion() < QSysInfo::WV_WINDOWS7)
+        return lessThan(l, r);
+#endif
+    return (m_collator.compare(l, r) < 0);
+#else
+    return lessThan(l, r);
+#endif
+}
+
+bool Utils::String::NaturalCompare::lessThan(const QString &left, const QString &right)
+{
+    // Return value `false` indicates `right` should go before `left`, otherwise, after
+    int posL = 0;
+    int posR = 0;
+    while (true) {
+        while (true) {
+            if (posL == left.size() || posR == right.size())
+                return (left.size() < right.size());  // when a shorter string is another string's prefix, shorter string place before longer string
+
+            QChar leftChar = left[posL].toLower();
+            QChar rightChar = right[posR].toLower();
+            if (leftChar == rightChar)
+                ;  // compare next character
+            else if (leftChar.isDigit() && rightChar.isDigit())
+                break; // Both are digits, break this loop and compare numbers
+            else
+                return leftChar < rightChar;
+
+            ++posL;
+            ++posR;
+        }
+
+        int startL = posL;
+        while ((posL < left.size()) && left[posL].isDigit())
+            ++posL;
+#if QT_VERSION >= QT_VERSION_CHECK(5, 1, 0)
+        int numL = left.midRef(startL, posL - startL).toInt();
+#else
+        int numL = left.mid(startL, posL - startL).toInt();
+#endif
+
+        int startR = posR;
+        while ((posR < right.size()) && right[posR].isDigit())
+            ++posR;
+#if QT_VERSION >= QT_VERSION_CHECK(5, 1, 0)
+        int numR = right.midRef(startR, posR - startR).toInt();
+#else
+        int numR = right.mid(startR, posR - startR).toInt();
+#endif
+
+        if (numL != numR)
+            return (numL < numR);
+
+        // Strings + digits do match and we haven't hit string end
+        // Do another round
+    }
+    return false;
+}
+
 // to send numbers instead of strings with suffixes
 QString Utils::String::fromDouble(double n, int precision)
 {

src/core/utils/string.h

@@ -31,6 +31,10 @@
 #define UTILS_STRING_H
 
 #include <string>
+#include <QtGlobal>
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 2, 0))
+#include <QCollator>
+#endif
 
 class QString;
 class QByteArray;
@@ -41,12 +45,25 @@ namespace Utils
     {
         QString fromStdString(const std::string &str);
         std::string toStdString(const QString &str);
-        bool naturalSort(QString left, QString right, bool &result);
         QString fromDouble(double n, int precision);
 
         // Implements constant-time comparison to protect against timing attacks
         // Taken from https://crackstation.net/hashing-security.htm
         bool slowEquals(const QByteArray &a, const QByteArray &b);
+
+        bool naturalSort(const QString &left, const QString &right, bool &result);
+
+        class NaturalCompare
+        {
+        public:
+            NaturalCompare();
+            bool operator()(const QString &l, const QString &r);
+            bool lessThan(const QString &left, const QString &right);
+#if (QT_VERSION >= QT_VERSION_CHECK(5, 2, 0))
+        private:
+            QCollator m_collator;
+#endif
+        };
     }
 }
 

src/gui/rss/automatedrssdownloader.cpp

@@ -43,6 +43,7 @@
 #include "guiiconprovider.h"
 #include "autoexpandabledialog.h"
 #include "core/utils/fs.h"
+#include "core/utils/string.h"
 
 AutomatedRssDownloader::AutomatedRssDownloader(const QWeakPointer<RssManager>& manager, QWidget *parent) :
   QDialog(parent),
@@ -308,10 +309,10 @@ RssDownloadRulePtr AutomatedRssDownloader::getCurrentRule() const
 void AutomatedRssDownloader::initLabelCombobox()
 {
   // Load custom labels
-  const QStringList customLabels = Preferences::instance()->getTorrentLabels();
-  foreach (const QString& label, customLabels) {
-    ui->comboLabel->addItem(label);
-  }
+  QStringList customLabels = Preferences::instance()->getTorrentLabels();
+  std::sort(customLabels.begin(), customLabels.end(), Utils::String::NaturalCompare());
+  foreach (const QString& l, customLabels)
+    ui->comboLabel->addItem(l);
 }
 
 void AutomatedRssDownloader::saveEditedRule()