Allow exposing QItemSelectionModel to QML

This requires being able to create a QItemSelectionModel
without specifiying its model, and also setting the model
later. Also, several classes, like QPersistentModelIndex,
need to be declared as meta-type.

Finally, and in order to introduce the 'model' property,
we need to have a type compatible getter. Hence the new,
non-const model() function.

Where needed, meta-type declarations have been removed from
auto-tests.

[ChangeLog][QtCore][Item Models] QItemSelectionModel
can now be created without a model and have one set later.

Change-Id: If49bed061a5d1012331f335ca7f6e3959ecd3f1c
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@theqtcompany.com>
Reviewed-by: J-P Nurmi <jpnurmi@theqtcompany.com>

src/corelib/itemmodels/qabstractitemmodel.h

@@ -481,4 +481,7 @@ inline uint qHash(const QModelIndex &index) Q_DECL_NOTHROW
 
 QT_END_NAMESPACE
 
+Q_DECLARE_METATYPE(QModelIndexList)
+Q_DECLARE_METATYPE(QPersistentModelIndex)
+
 #endif // QABSTRACTITEMMODEL_H

src/corelib/itemmodels/qitemselectionmodel.cpp

@@ -589,33 +589,51 @@ void QItemSelection::split(const QItemSelectionRange &range,
 }
 
 
-void QItemSelectionModelPrivate::initModel(QAbstractItemModel *model)
+void QItemSelectionModelPrivate::initModel(QAbstractItemModel *m)
 {
-    this->model = model;
+    struct Cx {
+        const char *signal;
+        const char *slot;
+    };
+    static const Cx connections[] = {
+        { SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)),
+          SLOT(_q_rowsAboutToBeRemoved(QModelIndex,int,int)) },
+        { SIGNAL(columnsAboutToBeRemoved(QModelIndex,int,int)),
+          SLOT(_q_columnsAboutToBeRemoved(QModelIndex,int,int)) },
+        { SIGNAL(rowsAboutToBeInserted(QModelIndex,int,int)),
+          SLOT(_q_rowsAboutToBeInserted(QModelIndex,int,int)) },
+        { SIGNAL(columnsAboutToBeInserted(QModelIndex,int,int)),
+          SLOT(_q_columnsAboutToBeInserted(QModelIndex,int,int)) },
+        { SIGNAL(rowsAboutToBeMoved(QModelIndex,int,int,QModelIndex,int)),
+          SLOT(_q_layoutAboutToBeChanged()) },
+        { SIGNAL(columnsAboutToBeMoved(QModelIndex,int,int,QModelIndex,int)),
+          SLOT(_q_layoutAboutToBeChanged()) },
+        { SIGNAL(rowsMoved(QModelIndex,int,int,QModelIndex,int)),
+          SLOT(_q_layoutChanged()) },
+        { SIGNAL(columnsMoved(QModelIndex,int,int,QModelIndex,int)),
+          SLOT(_q_layoutChanged()) },
+        { SIGNAL(layoutAboutToBeChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)),
+          SLOT(_q_layoutAboutToBeChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)) },
+        { SIGNAL(layoutChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)),
+          SLOT(_q_layoutChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)) },
+        { SIGNAL(modelReset()),
+          SLOT(reset()) },
+        { 0, 0 }
+    };
+
+    if (model == m)
+        return;
+
+    Q_Q(QItemSelectionModel);
     if (model) {
-        Q_Q(QItemSelectionModel);
-        QObject::connect(model, SIGNAL(rowsAboutToBeRemoved(QModelIndex,int,int)),
-                q, SLOT(_q_rowsAboutToBeRemoved(QModelIndex,int,int)));
-        QObject::connect(model, SIGNAL(columnsAboutToBeRemoved(QModelIndex,int,int)),
-                q, SLOT(_q_columnsAboutToBeRemoved(QModelIndex,int,int)));
-        QObject::connect(model, SIGNAL(rowsAboutToBeInserted(QModelIndex,int,int)),
-                q, SLOT(_q_rowsAboutToBeInserted(QModelIndex,int,int)));
-        QObject::connect(model, SIGNAL(columnsAboutToBeInserted(QModelIndex,int,int)),
-                q, SLOT(_q_columnsAboutToBeInserted(QModelIndex,int,int)));
-        QObject::connect(model, SIGNAL(rowsAboutToBeMoved(QModelIndex,int,int,QModelIndex,int)),
-                q, SLOT(_q_layoutAboutToBeChanged()));
-        QObject::connect(model, SIGNAL(columnsAboutToBeMoved(QModelIndex,int,int,QModelIndex,int)),
-                q, SLOT(_q_layoutAboutToBeChanged()));
-        QObject::connect(model, SIGNAL(rowsMoved(QModelIndex,int,int,QModelIndex,int)),
-                q, SLOT(_q_layoutChanged()));
-        QObject::connect(model, SIGNAL(columnsMoved(QModelIndex,int,int,QModelIndex,int)),
-                q, SLOT(_q_layoutChanged()));
-        QObject::connect(model, SIGNAL(layoutAboutToBeChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)),
-                q, SLOT(_q_layoutAboutToBeChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)));
-        QObject::connect(model, SIGNAL(layoutChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)),
-                q, SLOT(_q_layoutChanged(QList<QPersistentModelIndex>,QAbstractItemModel::LayoutChangeHint)));
-        QObject::connect(model, SIGNAL(modelReset()),
-                q, SLOT(reset()));
+        for (const Cx *cx = &connections[0]; cx->signal; cx++)
+            QObject::disconnect(model, cx->signal, q, cx->slot);
+        q->reset();
+    }
+    model = m;
+    if (model) {
+        for (const Cx *cx = &connections[0]; cx->signal; cx++)
+            QObject::connect(model, cx->signal, q, cx->slot);
     }
 }
 
@@ -1078,6 +1096,10 @@ void QItemSelectionModelPrivate::_q_layoutChanged(const QList<QPersistentModelIn
     selection. All functions operate on both layers; for example,
     \l {QTableWidget::selectedItems()}{selecteditems()} will return items from both layers.
 
+    \note Since 5.5, \l{QItemSelectionModel::model()}{model},
+    \l{QItemSelectionModel::hasSelection()}{hasSelection}, and
+    \l{QItemSelectionModel::currentIndex()}{currentIndex} are meta-object properties.
+
     \sa {Model/View Programming}, QAbstractItemModel, {Chart Example}
 */
 
@@ -1174,6 +1196,16 @@ void QItemSelectionModel::select(const QModelIndex &index, QItemSelectionModel::
     \sa select(), currentChanged()
 */
 
+/*!
+    \fn void QItemSelectionModel::modelChanged(QAbstractItemModel *model)
+    \since 5.5
+
+    This signal is emitted when the model is successfully set with setModel().
+
+    \sa model(), setModel()
+*/
+
+
 /*!
     \enum QItemSelectionModel::SelectionFlag
 
@@ -1205,6 +1237,10 @@ void QItemSelectionModel::select(const QModelIndex &index, QItemSelectionModel::
 void QItemSelectionModel::select(const QItemSelection &selection, QItemSelectionModel::SelectionFlags command)
 {
     Q_D(QItemSelectionModel);
+    if (!d->model) {
+        qWarning("QItemSelectionModel: Selecting when no model has been set will result in a no-op.");
+        return;
+    }
     if (command == NoUpdate)
         return;
 
@@ -1312,6 +1348,10 @@ void QItemSelectionModel::clearSelection()
 void QItemSelectionModel::setCurrentIndex(const QModelIndex &index, QItemSelectionModel::SelectionFlags command)
 {
     Q_D(QItemSelectionModel);
+    if (!d->model) {
+        qWarning("QItemSelectionModel: Setting the current index when no model has been set will result in a no-op.");
+        return;
+    }
     if (index == d->currentIndex) {
         if (command != NoUpdate)
             select(index, command); // select item
@@ -1387,6 +1427,8 @@ bool QItemSelectionModel::isSelected(const QModelIndex &index) const
 bool QItemSelectionModel::isRowSelected(int row, const QModelIndex &parent) const
 {
     Q_D(const QItemSelectionModel);
+    if (!d->model)
+        return false;
     if (parent.isValid() && d->model != parent.model())
         return false;
 
@@ -1447,6 +1489,8 @@ bool QItemSelectionModel::isRowSelected(int row, const QModelIndex &parent) cons
 bool QItemSelectionModel::isColumnSelected(int column, const QModelIndex &parent) const
 {
     Q_D(const QItemSelectionModel);
+    if (!d->model)
+        return false;
     if (parent.isValid() && d->model != parent.model())
         return false;
 
@@ -1503,6 +1547,8 @@ bool QItemSelectionModel::isColumnSelected(int column, const QModelIndex &parent
 bool QItemSelectionModel::rowIntersectsSelection(int row, const QModelIndex &parent) const
 {
     Q_D(const QItemSelectionModel);
+    if (!d->model)
+        return false;
     if (parent.isValid() && d->model != parent.model())
          return false;
 
@@ -1535,6 +1581,8 @@ bool QItemSelectionModel::rowIntersectsSelection(int row, const QModelIndex &par
 bool QItemSelectionModel::columnIntersectsSelection(int column, const QModelIndex &parent) const
 {
     Q_D(const QItemSelectionModel);
+    if (!d->model)
+        return false;
     if (parent.isValid() && d->model != parent.model())
         return false;
 
@@ -1671,6 +1719,35 @@ const QItemSelection QItemSelectionModel::selection() const
     return selected;
 }
 
+/*!
+    \since 5.5
+
+    \property QItemSelectionModel::hasSelection
+    \internal
+*/
+/*!
+    \since 5.5
+
+    \property QItemSelectionModel::currentIndex
+    \internal
+*/
+/*!
+    \since 5.5
+
+    \property QItemSelectionModel::model
+    \internal
+*/
+
+/*!
+    \since 5.5
+
+    Returns the item model operated on by the selection model.
+*/
+QAbstractItemModel *QItemSelectionModel::model()
+{
+    return d_func()->model;
+}
+
 /*!
     Returns the item model operated on by the selection model.
 */
@@ -1679,6 +1756,23 @@ const QAbstractItemModel *QItemSelectionModel::model() const
     return d_func()->model;
 }
 
+/*!
+    \since 5.5
+
+    Sets the model. The modelChanged() signal will be emitted.
+
+    \sa model(), modelChanged()
+*/
+void QItemSelectionModel::setModel(QAbstractItemModel *model)
+{
+    Q_D(QItemSelectionModel);
+    if (d->model == model)
+        return;
+
+    d->initModel(model);
+    emit modelChanged(model);
+}
+
 /*!
     Compares the two selections \a newSelection and \a oldSelection
     and emits selectionChanged() with the deselected and selected items.

src/corelib/itemmodels/qitemselectionmodel.h

@@ -143,6 +143,10 @@ class QItemSelectionModelPrivate;
 class Q_CORE_EXPORT QItemSelectionModel : public QObject
 {
     Q_OBJECT
+    Q_PROPERTY(QAbstractItemModel *model READ model WRITE setModel NOTIFY modelChanged)
+    Q_PROPERTY(bool hasSelection READ hasSelection NOTIFY selectionChanged STORED false DESIGNABLE false)
+    Q_PROPERTY(QModelIndex currentIndex READ currentIndex NOTIFY currentChanged STORED false DESIGNABLE false)
+
     Q_DECLARE_PRIVATE(QItemSelectionModel)
     Q_FLAGS(SelectionFlags)
 
@@ -164,27 +168,31 @@ public:
 
     Q_DECLARE_FLAGS(SelectionFlags, SelectionFlag)
 
-    explicit QItemSelectionModel(QAbstractItemModel *model);
+    explicit QItemSelectionModel(QAbstractItemModel *model = 0);
     explicit QItemSelectionModel(QAbstractItemModel *model, QObject *parent);
     virtual ~QItemSelectionModel();
 
     QModelIndex currentIndex() const;
 
-    bool isSelected(const QModelIndex &index) const;
-    bool isRowSelected(int row, const QModelIndex &parent) const;
-    bool isColumnSelected(int column, const QModelIndex &parent) const;
+    Q_INVOKABLE bool isSelected(const QModelIndex &index) const;
+    Q_INVOKABLE bool isRowSelected(int row, const QModelIndex &parent) const;
+    Q_INVOKABLE bool isColumnSelected(int column, const QModelIndex &parent) const;
 
-    bool rowIntersectsSelection(int row, const QModelIndex &parent) const;
-    bool columnIntersectsSelection(int column, const QModelIndex &parent) const;
+    Q_INVOKABLE bool rowIntersectsSelection(int row, const QModelIndex &parent) const;
+    Q_INVOKABLE bool columnIntersectsSelection(int column, const QModelIndex &parent) const;
 
     bool hasSelection() const;
 
-    QModelIndexList selectedIndexes() const;
-    QModelIndexList selectedRows(int column = 0) const;
-    QModelIndexList selectedColumns(int row = 0) const;
-    const QItemSelection selection() const;
+    Q_INVOKABLE QModelIndexList selectedIndexes() const;
+    Q_INVOKABLE QModelIndexList selectedRows(int column = 0) const;
+    Q_INVOKABLE QModelIndexList selectedColumns(int row = 0) const;
+    Q_INVOKABLE const QItemSelection selection() const;
 
+    // ### Qt 6: Merge these two as "QAbstractItemModel *model() const"
     const QAbstractItemModel *model() const;
+    QAbstractItemModel *model();
+
+    void setModel(QAbstractItemModel *model);
 
 public Q_SLOTS:
     virtual void setCurrentIndex(const QModelIndex &index, QItemSelectionModel::SelectionFlags command);
@@ -201,6 +209,7 @@ Q_SIGNALS:
     void currentChanged(const QModelIndex &current, const QModelIndex &previous);
     void currentRowChanged(const QModelIndex &current, const QModelIndex &previous);
     void currentColumnChanged(const QModelIndex &current, const QModelIndex &previous);
+    void modelChanged(QAbstractItemModel *model);
 
 protected:
     QItemSelectionModel(QItemSelectionModelPrivate &dd, QAbstractItemModel *model);
@@ -243,4 +252,7 @@ Q_CORE_EXPORT QDebug operator<<(QDebug, const QItemSelectionRange &);
 
 QT_END_NAMESPACE
 
+Q_DECLARE_METATYPE(QItemSelectionRange)
+Q_DECLARE_METATYPE(QItemSelection)
+
 #endif // QITEMSELECTIONMODEL_H

tests/auto/corelib/itemmodels/qabstractproxymodel/tst_qabstractproxymodel.cpp

@@ -211,7 +211,6 @@ void tst_QAbstractProxyModel::mapFromSource()
     QCOMPARE(model.mapFromSource(sourceIndex), mapFromSource);
 }
 
-Q_DECLARE_METATYPE(QItemSelection)
 void tst_QAbstractProxyModel::mapSelectionFromSource_data()
 {
     QTest::addColumn<QItemSelection>("selection");

tests/auto/corelib/itemmodels/qitemselectionmodel/tst_qitemselectionmodel.cpp

@@ -86,6 +86,7 @@ private slots:
     void deselectRemovedMiddleRange();
     void rangeOperatorLessThan_data();
     void rangeOperatorLessThan();
+    void setModel();
 
     void testDifferentModels();
 
@@ -107,8 +108,6 @@ typedef QList<int> IntList;
 typedef QPair<int, int> IntPair;
 typedef QList<IntPair> PairList;
 
-Q_DECLARE_METATYPE(QItemSelection)
-
 class QStreamHelper: public QAbstractItemModel
 {
 public:
@@ -2561,6 +2560,21 @@ void tst_QItemSelectionModel::rangeOperatorLessThan()
         QVERIFY(r4 < r2);
 }
 
+void tst_QItemSelectionModel::setModel()
+{
+    QItemSelectionModel sel;
+    QVERIFY(!sel.model());
+    QSignalSpy modelChangedSpy(&sel, SIGNAL(modelChanged(QAbstractItemModel*)));
+    QStringListModel model(QStringList() << "Blah" << "Blah" << "Blah");
+    sel.setModel(&model);
+    QCOMPARE(sel.model(), &model);
+    QCOMPARE(modelChangedSpy.count(), 1);
+    sel.select(model.index(0), QItemSelectionModel::Select);
+    QVERIFY(!sel.selection().isEmpty());
+    sel.setModel(0);
+    QVERIFY(sel.selection().isEmpty());
+}
+
 void tst_QItemSelectionModel::testDifferentModels()
 {
     QStandardItemModel model1;

tests/auto/widgets/itemviews/qabstractitemview/tst_qabstractitemview.cpp

@@ -1827,7 +1827,6 @@ void tst_QAbstractItemView::testFocusPolicy()
     QVERIFY(!qApp->focusWidget());
 }
 
-Q_DECLARE_METATYPE(QItemSelection)
 void tst_QAbstractItemView::QTBUG31411_noSelection()
 {
     QWidget window;