ItemModel: Extract Method isVariantLessThan()

As noted in comments, QSortFilterProxyModel and QStandardItemModel
duplicate code to compare QVariant; extract this into a separate method
they can share.

Since there is only one common suitable header for both files,
the method was placed in qabstractitemmodel.cpp

Change-Id: I82bb4a2d6084059b8a70a8d556c16f1a29f4f686
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>

1 files changed, 38 insertions, 0 deletions

diff --git a/src/corelib/itemmodels/qabstractitemmodel.cpp b/src/corelib/itemmodels/qabstractitemmodel.cpp
index d645205155..54ea45782d 100644
--- a/src/corelib/itemmodels/qabstractitemmodel.cpp
+++ b/src/corelib/itemmodels/qabstractitemmodel.cpp
@@ -47,6 +47,7 @@
 #include <qvector.h>
 #include <qstack.h>
 #include <qbitarray.h>
+#include <qdatetime.h>
 
 #include <limits.h>
 
@@ -547,6 +548,43 @@ const QHash<int,QByteArray> &QAbstractItemModelPrivate::defaultRoleNames()
     return *qDefaultRoleNames();
 }
 
+bool QAbstractItemModelPrivate::isVariantLessThan(const QVariant &left, const QVariant &right,
+                                                  Qt::CaseSensitivity cs, bool isLocaleAware)
+{
+    if (left.userType() == QVariant::Invalid)
+        return false;
+    if (right.userType() == QVariant::Invalid)
+        return true;
+    switch (left.userType()) {
+    case QVariant::Int:
+        return left.toInt() < right.toInt();
+    case QVariant::UInt:
+        return left.toUInt() < right.toUInt();
+    case QVariant::LongLong:
+        return left.toLongLong() < right.toLongLong();
+    case QVariant::ULongLong:
+        return left.toULongLong() < right.toULongLong();
+    case QMetaType::Float:
+        return left.toFloat() < right.toFloat();
+    case QVariant::Double:
+        return left.toDouble() < right.toDouble();
+    case QVariant::Char:
+        return left.toChar() < right.toChar();
+    case QVariant::Date:
+        return left.toDate() < right.toDate();
+    case QVariant::Time:
+        return left.toTime() < right.toTime();
+    case QVariant::DateTime:
+        return left.toDateTime() < right.toDateTime();
+    case QVariant::String:
+    default:
+        if (isLocaleAware)
+            return left.toString().localeAwareCompare(right.toString()) < 0;
+        else
+            return left.toString().compare(right.toString(), cs) < 0;
+    }
+}
+
 
 static uint typeOfVariant(const QVariant &value)
 {