refs #873, nullable interface for value objects

src/blackmisc/nullable.cpp

@@ -0,0 +1,69 @@
+/* Copyright (C) 2017
+ * swift project Community / Contributors
+ *
+ * This file is part of swift project. It is subject to the license terms in the LICENSE file found in the top-level
+ * directory of this distribution and at http://www.swift-project.org/license.html. No part of swift project,
+ * including this file, may be copied, modified, propagated, or distributed except according to the terms
+ * contained in the LICENSE file.
+ */
+
+#include "blackmisc/comparefunctions.h"
+#include "blackmisc/nullable.h"
+#include "blackmisc/verify.h"
+
+namespace BlackMisc
+{
+    INullable::INullable(std::nullptr_t null) : m_isNull(true)
+    {
+        Q_UNUSED(null);
+    }
+
+    bool INullable::canHandleIndex(const CPropertyIndex &index)
+    {
+        if (index.isEmpty()) { return false; }
+        int i = index.frontCasted<int>();
+        return (i >= static_cast<int>(IndexIsNull)) && (i <= static_cast<int>(IndexIsNull));
+    }
+
+    CVariant INullable::propertyByIndex(const CPropertyIndex &index) const
+    {
+        if (!index.isEmpty())
+        {
+            ColumnIndex i = index.frontCasted<ColumnIndex>();
+            switch (i)
+            {
+            case IndexIsNull:
+                return CVariant::fromValue(this->isNull());
+            default:
+                break;
+            }
+        }
+        const QString m = QString("Cannot handle index %1").arg(index.toQString());
+        BLACK_VERIFY_X(false, Q_FUNC_INFO, qUtf8Printable(m));
+        return CVariant::fromValue(m);
+    }
+
+    void INullable::setPropertyByIndex(const CPropertyIndex &index, const CVariant &variant)
+    {
+        if (!index.isEmpty())
+        {
+            ColumnIndex i = index.frontCasted<ColumnIndex>();
+            switch (i)
+            {
+            case IndexIsNull:
+                this->setNull(variant.toBool());
+                return;
+            default:
+                break;
+            }
+        }
+        const QString m = QString("Cannot handle index %1").arg(index.toQString());
+        BLACK_VERIFY_X(false, Q_FUNC_INFO, qUtf8Printable(m));
+    }
+
+    int INullable::comparePropertyByIndex(const CPropertyIndex &index, const INullable &compareValue) const
+    {
+        Q_UNUSED(index);
+        return Compare::compare(this->m_isNull, compareValue.m_isNull);
+    }
+} // namespace