Test signal emission on selection changes

This commit adds a unit test that changes the selection in various
ways, verifies the result and checks that the selection manager's
selectionChanged signal has been emitted correctly. The test is
data-driven, so I hope that most further testing needs can be
fulfilled by adding new test data.

Moreover, I changed selectedItems() such that the anchored
selection is only taken into account if anchor and current item
are different. The reason is that in some situation the anchor
should not be selected initially (i.e., if an already selected
item is Control-clicked). If the anchor should be selected from
the beginning, it must be selected manually.

2 files changed, 137 insertions, 2 deletions

diff --git a/src/kitemviews/kitemlistselectionmanager.cpp b/src/kitemviews/kitemlistselectionmanager.cpp
index cfe847b69..e0ec4060c 100644
--- a/src/kitemviews/kitemlistselectionmanager.cpp
+++ b/src/kitemviews/kitemlistselectionmanager.cpp
@@ -81,7 +81,7 @@ QSet<int> KItemListSelectionManager::selectedItems() const
 {
     QSet<int> selectedItems = m_selectedItems;
 
-    if (m_isAnchoredSelectionActive) {
+    if (m_isAnchoredSelectionActive && (m_anchorItem != m_currentItem)) {
         const int from = qMin(m_anchorItem, m_currentItem);
         const int to = qMax(m_anchorItem, m_currentItem);
 
@@ -95,7 +95,7 @@ QSet<int> KItemListSelectionManager::selectedItems() const
 
 bool KItemListSelectionManager::hasSelection() const
 {
-    return !m_selectedItems.isEmpty() || m_isAnchoredSelectionActive;
+    return !m_selectedItems.isEmpty() || (m_isAnchoredSelectionActive && (m_anchorItem != m_currentItem));
 }
 
 void KItemListSelectionManager::setSelected(int index, int count, SelectionMode mode)
diff --git a/src/tests/kitemlistselectionmanagertest.cpp b/src/tests/kitemlistselectionmanagertest.cpp
index a79b9e6f3..3174a8b4d 100644
--- a/src/tests/kitemlistselectionmanagertest.cpp
+++ b/src/tests/kitemlistselectionmanagertest.cpp
@@ -65,6 +65,8 @@ private slots:
     void testItemsInserted();
     void testItemsRemoved();
     void testAnchoredSelection();
+    void testChangeSelection_data();
+    void testChangeSelection();
 
 private:
     KItemListSelectionManager* m_selectionManager;
@@ -308,6 +310,139 @@ void KItemListSelectionManagerTest::testAnchoredSelection()
     QCOMPARE(m_selectionManager->selectedItems(), QSet<int>() << 5 << 6 << 7 << 9 << 10);
 }
 
+namespace {
+    enum ModelChangeType {
+        NoChange,
+        InsertItems,
+        RemoveItems
+    };
+}
+
+Q_DECLARE_METATYPE(QSet<int>);
+Q_DECLARE_METATYPE(ModelChangeType);
+Q_DECLARE_METATYPE(KItemRangeList);
+
+void KItemListSelectionManagerTest::testChangeSelection_data()
+{
+    QTest::addColumn<QSet<int> >("initialSelection");
+    QTest::addColumn<int>("anchor");
+    QTest::addColumn<int>("current");
+    QTest::addColumn<QSet<int> >("expectedSelection");
+    QTest::addColumn<ModelChangeType>("changeType");
+    QTest::addColumn<KItemRangeList>("changedItems");
+    QTest::addColumn<QSet<int> >("finalSelection");
+
+    QTest::newRow("No change")
+        << (QSet<int>() << 5 << 6)
+        << 2 << 3
+        << (QSet<int>() << 2 << 3 << 5 << 6)
+        << NoChange << KItemRangeList()
+        << (QSet<int>() << 2 << 3 << 5 << 6);    
+
+    QTest::newRow("Insert Items")
+        << (QSet<int>() << 5 << 6)
+        << 2 << 3
+        << (QSet<int>() << 2 << 3 << 5 << 6)
+        << InsertItems << (KItemRangeList() << KItemRange(1, 1) << KItemRange(5, 2) << KItemRange(10, 5))
+        << (QSet<int>() << 3 << 4 << 8 << 9);
+
+    QTest::newRow("Remove Items")
+        << (QSet<int>() << 5 << 6)
+        << 2 << 3
+        << (QSet<int>() << 2 << 3 << 5 << 6)
+        << RemoveItems << (KItemRangeList() << KItemRange(1, 1) << KItemRange(3, 1) << KItemRange(10, 5))
+        << (QSet<int>() << 1 << 2 << 3 << 4);
+}
+
+void KItemListSelectionManagerTest::testChangeSelection()
+{
+    QFETCH(QSet<int>, initialSelection);
+    QFETCH(int, anchor);
+    QFETCH(int, current);
+    QFETCH(QSet<int> , expectedSelection);
+    QFETCH(ModelChangeType, changeType);
+    QFETCH(KItemRangeList, changedItems);
+    QFETCH(QSet<int> , finalSelection);
+
+    QSignalSpy spySelectionChanged(m_selectionManager, SIGNAL(selectionChanged(QSet<int>,QSet<int>)));
+
+    // Initial selection should be empty
+    QVERIFY(!m_selectionManager->hasSelection());
+    QVERIFY(m_selectionManager->selectedItems().isEmpty());
+
+    // Perform the initial selectiion
+    m_selectionManager->setSelectedItems(initialSelection);
+    QCOMPARE(m_selectionManager->selectedItems(), initialSelection);
+    if (initialSelection.isEmpty()) {
+        QVERIFY(!m_selectionManager->hasSelection());
+        QCOMPARE(spySelectionChanged.count(), 0);
+    }
+    else {
+        QVERIFY(m_selectionManager->hasSelection());
+        QCOMPARE(spySelectionChanged.count(), 1);
+        QList<QVariant> arguments = spySelectionChanged.takeFirst();
+        QCOMPARE(qvariant_cast<QSet<int> >(arguments.at(0)), initialSelection);
+        QCOMPARE(qvariant_cast<QSet<int> >(arguments.at(1)), QSet<int>());
+    }
+
+    // Perform an anchored selection.
+    // Note that current and anchor index are equal first because this is the case in typical uses of the
+    // selection manager, and because this makes it easier to test the correctness of the signal's arguments.
+    m_selectionManager->setCurrentItem(anchor);
+    m_selectionManager->beginAnchoredSelection(anchor);
+    m_selectionManager->setCurrentItem(current);
+    QCOMPARE(m_selectionManager->selectedItems(), expectedSelection);
+    QCOMPARE(m_selectionManager->hasSelection(), !expectedSelection.isEmpty());
+    if (expectedSelection == initialSelection) {
+        QCOMPARE(spySelectionChanged.count(), 0);
+    }
+    else {
+        QCOMPARE(spySelectionChanged.count(), 1);
+        QList<QVariant> arguments = spySelectionChanged.takeFirst();
+        QCOMPARE(qvariant_cast<QSet<int> >(arguments.at(0)), expectedSelection);
+        QCOMPARE(qvariant_cast<QSet<int> >(arguments.at(1)), initialSelection);
+    }
+
+    // Change the model by inserting or removing items.
+    switch (changeType) {
+    case InsertItems:
+        m_selectionManager->itemsInserted(changedItems);
+        break;
+    case RemoveItems:
+        m_selectionManager->itemsRemoved(changedItems);
+        break;
+    case NoChange:
+        break;
+    }
+
+    QCOMPARE(m_selectionManager->selectedItems(), finalSelection);
+    QCOMPARE(m_selectionManager->hasSelection(), !finalSelection.isEmpty());
+    if (finalSelection == expectedSelection) {
+        QCOMPARE(spySelectionChanged.count(), 0);
+    }
+    else {
+        QCOMPARE(spySelectionChanged.count(), 1);
+        QList<QVariant> arguments = spySelectionChanged.takeFirst();
+        QCOMPARE(qvariant_cast<QSet<int> >(arguments.at(0)), finalSelection);
+        QCOMPARE(qvariant_cast<QSet<int> >(arguments.at(1)), expectedSelection);
+    }
+
+    // Finally, clear the selection
+    m_selectionManager->clearSelection();
+    QCOMPARE(m_selectionManager->selectedItems(), QSet<int>());
+    QVERIFY(!m_selectionManager->hasSelection());
+    if (finalSelection.isEmpty()) {
+        // Selection has been empty already
+        QCOMPARE(spySelectionChanged.count(), 0);
+    }
+    else {
+        QCOMPARE(spySelectionChanged.count(), 1);
+        QList<QVariant> arguments = spySelectionChanged.takeFirst();
+        QCOMPARE(qvariant_cast<QSet<int> >(arguments.at(0)), QSet<int>());
+        QCOMPARE(qvariant_cast<QSet<int> >(arguments.at(1)), finalSelection);
+    }
+}
+
 QTEST_KDEMAIN(KItemListSelectionManagerTest, NoGUI)
 
 #include "kitemlistselectionmanagertest.moc"