ItemWidgets: add supportedDragActions()/setSupportedDragActions()

In Qt6 the deprecated function QAIM::setSupportedDragActions() was
removed so the itemwidgets had no possibility to specify the drag
actions anymore. Fix this by adding it to the itemwidgets themselves.

Done-with: David Faure <david.faure@kdab.com>
Fixes: QTBUG-87465
Change-Id: Ib10fa30c5b2c9e8e5cd3f0e1c2664f7a12fb249b
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>

src/widgets/itemviews/qlistwidget.cpp

@@ -431,6 +431,11 @@ Qt::DropActions QListModel::supportedDropActions() const
 }
 #endif // QT_CONFIG(draganddrop)
 
+Qt::DropActions QListModel::supportedDragActions() const
+{
+    return view()->supportedDragActions();
+}
+
 /*!
     \class QListWidgetItem
     \brief The QListWidgetItem class provides an item for use with the
@@ -1804,7 +1809,7 @@ QMimeData *QListWidget::mimeData(const QList<QListWidgetItem *> &items) const
     with the given \a action in the given \a index. Returns \c true if \a data and
     \a action can be handled by the model; otherwise returns \c false.
 
-    \sa supportedDropActions()
+    \sa supportedDropActions(), supportedDragActions()
 */
 bool QListWidget::dropMimeData(int index, const QMimeData *data, Qt::DropAction action)
 {
@@ -1829,7 +1834,7 @@ void QListWidget::dropEvent(QDropEvent *event)
 /*!
     Returns the drop actions supported by this view.
 
-    \sa Qt::DropActions
+    \sa Qt::DropActions, supportedDragActions(), dropMimeData()
 */
 Qt::DropActions QListWidget::supportedDropActions() const
 {
@@ -1838,6 +1843,31 @@ Qt::DropActions QListWidget::supportedDropActions() const
 }
 #endif // QT_CONFIG(draganddrop)
 
+/*!
+    Returns the drag actions supported by this view.
+
+    \since 6.10
+    \sa Qt::DropActions, setSupportedDragActions(), supportedDropActions()
+*/
+Qt::DropActions QListWidget::supportedDragActions() const
+{
+    Q_D(const QListWidget);
+    return d->supportedDragActions.value_or(supportedDropActions());
+}
+
+/*!
+    Sets the drag \a actions supported by this view.
+
+    \since 6.10
+    \sa Qt::DropActions, supportedDragActions()
+*/
+
+void QListWidget::setSupportedDragActions(Qt::DropActions actions)
+{
+    Q_D(QListWidget);
+    d->supportedDragActions = actions;
+}
+
 /*!
     Returns a list of pointers to the items contained in the \a data object. If
     the object was not created by a QListWidget in the same process, the list

src/widgets/itemviews/qlistwidget.h

@@ -221,6 +221,9 @@ public:
     QModelIndex indexFromItem(const QListWidgetItem *item) const;
     QListWidgetItem *itemFromIndex(const QModelIndex &index) const;
 
+    void setSupportedDragActions(Qt::DropActions actions);
+    Qt::DropActions supportedDragActions() const;
+
 protected:
 #if QT_CONFIG(draganddrop)
     void dropEvent(QDropEvent *event) override;

src/widgets/itemviews/qlistwidget_p.h

@@ -98,6 +98,7 @@ public:
                       int row, int column, const QModelIndex &parent) override;
     Qt::DropActions supportedDropActions() const override;
 #endif
+    Qt::DropActions supportedDragActions() const override;
 
     QMimeData *internalMimeData()  const;
 private:
@@ -126,9 +127,10 @@ public:
     void emitCurrentItemChanged(const QModelIndex &current, const QModelIndex &previous);
     void sort();
     void dataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight);
+
     Qt::SortOrder sortOrder;
     bool sortingEnabled;
-
+    std::optional<Qt::DropActions> supportedDragActions;
     std::array<QMetaObject::Connection, 8> connections;
     std::array<QMetaObject::Connection, 2> selectionModelConnections;
 };

src/widgets/itemviews/qtablewidget.cpp

@@ -869,6 +869,12 @@ Qt::DropActions QTableModel::supportedDropActions() const
     return (view ? view->supportedDropActions() : Qt::DropActions(Qt::IgnoreAction));
 }
 
+Qt::DropActions QTableModel::supportedDragActions() const
+{
+    const QTableWidget *view = this->view();
+    return (view ? view->supportedDragActions() : Qt::DropActions(Qt::IgnoreAction));
+}
+
 /*!
     \class QTableWidgetSelectionRange
 
@@ -2605,7 +2611,7 @@ QMimeData *QTableWidget::mimeData(const QList<QTableWidgetItem *> &items) const
     Returns \c true if the data and action can be handled by the model;
     otherwise returns \c false.
 
-    \sa supportedDropActions()
+    \sa supportedDropActions(), supportedDragActions()
 */
 bool QTableWidget::dropMimeData(int row, int column, const QMimeData *data, Qt::DropAction action)
 {
@@ -2624,13 +2630,38 @@ bool QTableWidget::dropMimeData(int row, int column, const QMimeData *data, Qt::
 /*!
   Returns the drop actions supported by this view.
 
-  \sa Qt::DropActions
+  \sa Qt::DropActions, supportedDragActions(), dropMimeData()
 */
 Qt::DropActions QTableWidget::supportedDropActions() const
 {
     return d_func()->tableModel()->QAbstractTableModel::supportedDropActions() | Qt::MoveAction;
 }
 
+/*!
+  Returns the drag actions supported by this view.
+
+  \since 6.10
+  \sa Qt::DropActions, setSupportedDragActions(), supportedDropActions()
+*/
+Qt::DropActions QTableWidget::supportedDragActions() const
+{
+    Q_D(const QTableWidget);
+    return d->supportedDragActions.value_or(supportedDropActions());
+}
+
+/*!
+  Sets the drag \a actions supported by this view.
+
+  \since 6.10
+  \sa Qt::DropActions, supportedDragActions()
+*/
+
+void QTableWidget::setSupportedDragActions(Qt::DropActions actions)
+{
+    Q_D(QTableWidget);
+    d->supportedDragActions = actions;
+}
+
 /*!
   Returns a list of pointers to the items contained in the \a data object.
   If the object was not created by a QTreeWidget in the same process, the list

src/widgets/itemviews/qtablewidget.h

@@ -265,6 +265,9 @@ public:
     const QTableWidgetItem *itemPrototype() const;
     void setItemPrototype(const QTableWidgetItem *item);
 
+    Qt::DropActions supportedDragActions() const;
+    void setSupportedDragActions(Qt::DropActions actions);
+
 public Q_SLOTS:
     void scrollToItem(const QTableWidgetItem *item, QAbstractItemView::ScrollHint hint = EnsureVisible);
     void insertRow(int row);

src/widgets/itemviews/qtablewidget_p.h

@@ -136,6 +136,7 @@ public:
     bool dropMimeData(const QMimeData *data, Qt::DropAction action,
             int row, int column, const QModelIndex &parent) override;
     Qt::DropActions supportedDropActions() const override;
+    Qt::DropActions supportedDragActions() const override;
 
     QMimeData *internalMimeData()  const;
 
@@ -173,6 +174,7 @@ public:
     void dataChanged(const QModelIndex &topLeft, const QModelIndex &bottomRight);
 
     std::array<QMetaObject::Connection, 10> connections;
+    std::optional<Qt::DropActions> supportedDragActions;
 };
 
 class QTableWidgetItemPrivate

src/widgets/itemviews/qtreewidget.cpp

@@ -737,6 +737,11 @@ Qt::DropActions QTreeModel::supportedDropActions() const
     return view()->supportedDropActions();
 }
 
+Qt::DropActions QTreeModel::supportedDragActions() const
+{
+    return view()->supportedDragActions();
+}
+
 void QTreeModel::itemChanged(QTreeWidgetItem *item)
 {
     if (item->columnCount() <= 0)
@@ -3193,7 +3198,7 @@ QMimeData *QTreeWidget::mimeData(const QList<QTreeWidgetItem *> &items) const
     successfully handled by decoding the mime data and inserting it
     into the model; otherwise it returns \c false.
 
-    \sa supportedDropActions()
+    \sa supportedDropActions(), supportedDragActions()
 */
 bool QTreeWidget::dropMimeData(QTreeWidgetItem *parent, int index,
                                const QMimeData *data, Qt::DropAction action)
@@ -3206,13 +3211,38 @@ bool QTreeWidget::dropMimeData(QTreeWidgetItem *parent, int index,
 /*!
   Returns the drop actions supported by this view.
 
-  \sa Qt::DropActions
+  \sa Qt::DropActions, supportedDragActions(), dropMimeData()
 */
 Qt::DropActions QTreeWidget::supportedDropActions() const
 {
     return model()->QAbstractItemModel::supportedDropActions() | Qt::MoveAction;
 }
 
+/*!
+    Returns the drag actions supported by this view.
+
+    \since 6.10
+    \sa Qt::DropActions, setSupportedDragActions(), supportedDropActions()
+*/
+Qt::DropActions QTreeWidget::supportedDragActions() const
+{
+    Q_D(const QTreeWidget);
+    return d->supportedDragActions.value_or(supportedDropActions());
+}
+
+/*!
+    Sets the drag \a actions supported by this view.
+
+    \since 6.10
+    \sa Qt::DropActions, supportedDragActions()
+*/
+
+void QTreeWidget::setSupportedDragActions(Qt::DropActions actions)
+{
+    Q_D(QTreeWidget);
+    d->supportedDragActions = actions;
+}
+
 /*!
     Returns the QModelIndex associated with the given \a item in the given \a column.
 

src/widgets/itemviews/qtreewidget.h

@@ -288,6 +288,9 @@ public:
 
     void setSelectionModel(QItemSelectionModel *selectionModel) override;
 
+    Qt::DropActions supportedDragActions() const;
+    void setSupportedDragActions(Qt::DropActions actions);
+
 public Q_SLOTS:
     void scrollToItem(const QTreeWidgetItem *item,
                       QAbstractItemView::ScrollHint hint = EnsureVisible);

src/widgets/itemviews/qtreewidget_p.h

@@ -96,6 +96,7 @@ public:
     bool dropMimeData(const QMimeData *data, Qt::DropAction action,
                       int row, int column, const QModelIndex &parent) override;
     Qt::DropActions supportedDropActions() const override;
+    Qt::DropActions supportedDragActions() const override;
 
     QMimeData *internalMimeData() const;
 
@@ -210,6 +211,7 @@ public:
     int explicitSortColumn;
 
     std::array<QMetaObject::Connection, 12> connections;
+    std::optional<Qt::DropActions> supportedDragActions;
 };
 
 QT_END_NAMESPACE

tests/auto/widgets/itemviews/qlistwidget/tst_qlistwidget.cpp

@@ -100,15 +100,14 @@ private slots:
     void QTBUG50891_ensureSelectionModelSignalConnectionsAreSet();
     void createPersistentOnLayoutAboutToBeChanged();
     void createPersistentOnLayoutAboutToBeChangedAutoSort();
-#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
     void clearItemData();
-#endif
 
     void moveRows_data();
     void moveRows();
     void moveRowsInvalid_data();
     void moveRowsInvalid();
     void noopDragDrop();
+    void supportedDragActions();
 
 protected slots:
     void rowsAboutToBeInserted(const QModelIndex &parent, int first, int last)
@@ -2002,7 +2001,6 @@ void tst_QListWidget::noopDragDrop() // QTBUG-100128
     CHECK_ITEM;
 }
 
-#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
 void tst_QListWidget::clearItemData()
 {
     QListWidget list;
@@ -2022,7 +2020,25 @@ void tst_QListWidget::clearItemData()
     QVERIFY(list.model()->clearItemData(list.model()->index(0, 0)));
     QCOMPARE(dataChangeSpy.size(), 0);
 }
-#endif
+
+class MoveOnlyListWidget : public QListWidget
+{
+    Q_OBJECT
+public:
+    using QListWidget::QListWidget;
+    Qt::DropActions supportedDropActions() const override { return Qt::MoveAction; }
+};
+
+void tst_QListWidget::supportedDragActions()
+{
+    MoveOnlyListWidget listWidget;
+    QCOMPARE(listWidget.model()->supportedDropActions(), Qt::MoveAction);
+    // For Qt < 6.8 compatibility reasons, supportedDragActions defaults to supportedDropActions
+    QCOMPARE(listWidget.model()->supportedDragActions(), Qt::MoveAction);
+
+    listWidget.setSupportedDragActions(Qt::CopyAction);
+    QCOMPARE(listWidget.model()->supportedDragActions(), Qt::CopyAction);
+}
 
 QTEST_MAIN(tst_QListWidget)
 #include "tst_qlistwidget.moc"

tests/auto/widgets/itemviews/qtablewidget/tst_qtablewidget.cpp

@@ -87,6 +87,7 @@ private slots:
     void moveRows();
     void moveRowsInvalid_data();
     void moveRowsInvalid();
+    void supportedDragActions();
 
 private:
     std::unique_ptr<QTableWidget> testWidget;
@@ -2047,5 +2048,24 @@ void tst_QTableWidget::moveRowsInvalid()
     delete baseWidget;
 }
 
+class MoveOnlyTableWidget : public QTableWidget
+{
+    Q_OBJECT
+public:
+    using QTableWidget::QTableWidget;
+    Qt::DropActions supportedDropActions() const override { return Qt::MoveAction; }
+};
+
+void tst_QTableWidget::supportedDragActions()
+{
+    MoveOnlyTableWidget tableWidget;
+    QCOMPARE(tableWidget.model()->supportedDropActions(), Qt::MoveAction);
+    // For Qt < 6.8 compatibility reasons, supportedDragActions defaults to supportedDropActions
+    QCOMPARE(tableWidget.model()->supportedDragActions(), Qt::MoveAction);
+
+    tableWidget.setSupportedDragActions(Qt::CopyAction);
+    QCOMPARE(tableWidget.model()->supportedDragActions(), Qt::CopyAction);
+}
+
 QTEST_MAIN(tst_QTableWidget)
 #include "tst_qtablewidget.moc"

tests/auto/widgets/itemviews/qtreewidget/tst_qtreewidget.cpp

@@ -130,9 +130,8 @@ private slots:
     void persistentChildIndex();
     void createPersistentOnLayoutAboutToBeChanged();
     void createPersistentOnLayoutAboutToBeChangedAutoSort();
-#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
     void clearItemData();
-#endif
+    void supportedDragActions();
 
 public slots:
     void itemSelectionChanged();
@@ -3589,7 +3588,6 @@ void tst_QTreeWidget::persistentChildIndex() // QTBUG-90030
     QCOMPARE(persistentIdx.data().toString(), QStringLiteral("child2"));
 }
 
-#if QT_VERSION >= QT_VERSION_CHECK(6, 0, 0)
 void tst_QTreeWidget::clearItemData()
 {
     QTreeWidget tree;
@@ -3625,7 +3623,6 @@ void tst_QTreeWidget::clearItemData()
     QCOMPARE(dataChangeArgs.at(1).value<QModelIndex>(), childIdx);
     QVERIFY(dataChangeArgs.at(2).value<QList<int>>().isEmpty());
 }
-#endif
 
 void tst_QTreeWidget::createPersistentOnLayoutAboutToBeChanged() // QTBUG-93466
 {
@@ -3694,5 +3691,24 @@ void tst_QTreeWidget::createPersistentOnLayoutAboutToBeChangedAutoSort() // QTBU
     QCOMPARE(layoutChangedSpy.size(), 1);
 }
 
+class MoveOnlyTreeWidget : public QTreeWidget
+{
+    Q_OBJECT
+public:
+    using QTreeWidget::QTreeWidget;
+    Qt::DropActions supportedDropActions() const override { return Qt::MoveAction; }
+};
+
+void tst_QTreeWidget::supportedDragActions()
+{
+    MoveOnlyTreeWidget treeWidget;
+    QCOMPARE(treeWidget.model()->supportedDropActions(), Qt::MoveAction);
+    // For Qt < 6.8 compatibility reasons, supportedDragActions defaults to supportedDropActions
+    QCOMPARE(treeWidget.model()->supportedDragActions(), Qt::MoveAction);
+
+    treeWidget.setSupportedDragActions(Qt::CopyAction);
+    QCOMPARE(treeWidget.model()->supportedDragActions(), Qt::CopyAction);
+}
+
 QTEST_MAIN(tst_QTreeWidget)
 #include "tst_qtreewidget.moc"