New SessionItemData class to extract data handling from SessionItem

GUI/coregui/Models/SessionItemData.cpp

+// ************************************************************************** //
+//
+//  BornAgain: simulate and fit scattering at grazing incidence
+//
+//! @file      GUI/coregui/Models/SessionItemData.cpp
+//! @brief     Implements class SessionItemData
+//!
+//! @homepage  http://www.bornagainproject.org
+//! @license   GNU General Public License v3 or higher (see COPYING)
+//! @copyright Forschungszentrum Jülich GmbH 2016
+//! @authors   Scientific Computing Group at MLZ Garching
+//! @authors   Céline Durniak, Marina Ganeva, David Li, Gennady Pospelov
+//! @authors   Walter Van Herck, Joachim Wuttke
+//
+// ************************************************************************** //
+
+#include "SessionItemData.h"
+#include "SessionItemUtils.h"
+
+SessionItemData::ItemData::ItemData(int r, const QVariant& v)
+    : role(r)
+    , data(v)
+{
+
+}
+
+bool SessionItemData::ItemData::operator==(const SessionItemData::ItemData& other) const
+{
+    return role == other.role && SessionItemUtils::IsTheSame(data, other.data);
+}
+
+QVector<int> SessionItemData::roles() const
+{
+    QVector<int> result;
+    for (const auto& value : m_values)
+        result.push_back(value.role);
+    return result;
+}
+
+QVariant SessionItemData::data(int role) const
+{
+    role = (role == Qt::EditRole) ? Qt::DisplayRole : role;
+    for (const auto& value : m_values) {
+        if (value.role == role)
+            return value.data;
+    }
+    return QVariant();
+}
+
+//! Sets the data for given role. Returns true if data was changed.
+
+bool SessionItemData::setData(int role, const QVariant& value)
+{
+    role = (role == Qt::EditRole) ? Qt::DisplayRole : role;
+    for (auto it = m_values.begin(); it != m_values.end(); ++it) {
+        if (it->role == role) {
+            if (value.isValid()) {
+                if (SessionItemUtils::IsTheSame(it->data, value))
+                    return false;
+                it->data = value;
+            } else {
+                m_values.erase(it);
+            }
+            return true;
+        }
+    }
+    m_values.push_back(ItemData(role, value));
+    return true;
+}

GUI/coregui/Models/SessionItemData.h

+// ************************************************************************** //
+//
+//  BornAgain: simulate and fit scattering at grazing incidence
+//
+//! @file      GUI/coregui/Models/SessionItemData.h
+//! @brief     Defines class SessionItemData
+//!
+//! @homepage  http://www.bornagainproject.org
+//! @license   GNU General Public License v3 or higher (see COPYING)
+//! @copyright Forschungszentrum Jülich GmbH 2016
+//! @authors   Scientific Computing Group at MLZ Garching
+//! @authors   Céline Durniak, Marina Ganeva, David Li, Gennady Pospelov
+//! @authors   Walter Van Herck, Joachim Wuttke
+//
+// ************************************************************************** //
+
+#ifndef SESSIONITEMDATA_H
+#define SESSIONITEMDATA_H
+
+#include "WinDllMacros.h"
+#include <QVector>
+#include <QVariant>
+
+//! Handles all data roles for SessionItem.
+
+class BA_CORE_API_ SessionItemData
+{
+public:
+
+    QVector<int> roles() const;
+
+    QVariant data(int role) const;
+
+    bool setData(int role, const QVariant& value);
+
+private:
+    class ItemData
+    {
+    public:
+        ItemData(int r = -1, const QVariant& v = QVariant());
+        int role;
+        QVariant data;
+        bool operator==(const ItemData& other) const;
+    };
+
+    QVector<ItemData> m_values;
+};
+
+#endif //   SESSIONITEMDATA_H

Tests/UnitTests/GUI/TestGUI.cpp

@@ -41,6 +41,7 @@
 #include "TestSessionXML.h"
 #include "TestTranslations.h"
 #include "TestUpdateTimer.h"
+#include "TestSessionItemData.h"
 
 int main(int argc, char** argv) {
     QCoreApplication app(argc, argv);

Tests/UnitTests/GUI/TestSessionItemData.h

+#include "google_test.h"
+#include "SessionItemData.h"
+#include "ExternalProperty.h"
+#include "SessionFlags.h"
+
+class TestSessionItemData : public ::testing::Test
+{
+public:
+    ~TestSessionItemData();
+};
+
+TestSessionItemData::~TestSessionItemData() = default;
+
+TEST_F(TestSessionItemData, initialState)
+{
+    SessionItemData itemData;
+    EXPECT_TRUE(itemData.roles().isEmpty());
+    EXPECT_FALSE(itemData.data(Qt::DisplayRole).isValid());
+}
+
+TEST_F(TestSessionItemData, setData)
+{
+    SessionItemData itemData;
+
+    // setting DisplayRole
+    QVariant v(42.0);
+    EXPECT_TRUE(itemData.setData(Qt::DisplayRole, v));
+    QVector<int> expected {Qt::DisplayRole};
+    EXPECT_EQ(itemData.roles(), expected);
+    EXPECT_TRUE(itemData.data(Qt::DisplayRole) == v);
+
+    // setting same data twice
+    EXPECT_FALSE(itemData.setData(Qt::DisplayRole, v));
+    EXPECT_EQ(itemData.roles(), expected);
+
+    // changing the data
+    v.setValue(43.0);
+    EXPECT_TRUE(itemData.setData(Qt::DisplayRole, v));
+    EXPECT_EQ(itemData.roles(), expected);
+    EXPECT_TRUE(itemData.data(Qt::DisplayRole) == QVariant(43.0));
+
+    // setting invalid variant for the role
+    EXPECT_TRUE(itemData.setData(Qt::DisplayRole, QVariant()));
+    EXPECT_TRUE(itemData.roles().isEmpty());
+    EXPECT_FALSE(itemData.data(Qt::DisplayRole).isValid());
+
+    // Setting custom variant
+    ExternalProperty ep;
+    ep.setIdentifier("abc");
+
+    EXPECT_TRUE(itemData.setData(Qt::DisplayRole, ep.variant()));
+    EXPECT_TRUE(itemData.setData(SessionFlags::CustomEditorRole, QVariant::fromValue(QString("abc"))));
+
+    expected = {Qt::DisplayRole, SessionFlags::CustomEditorRole};
+    EXPECT_EQ(itemData.roles(), expected);
+
+    EXPECT_EQ(itemData.data(Qt::DisplayRole).value<ExternalProperty>(), ep);
+    EXPECT_EQ(itemData.data(SessionFlags::CustomEditorRole).toString(), QString("abc"));
+}