Add the Qt::ItemNeverHasChildren flag and use it in QTreeView.

It can be used to determine whether expand() should really expand.

Change-Id: If79d8c295a4ca1356e60051682b227524a065126
Reviewed-by: David Faure (KDE) <faure@kde.org>
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Reviewed-by: Thorbjørn Lund Martsum <tmartsum@gmail.com>

4 files changed, 28 insertions, 1 deletions

diff --git a/src/corelib/global/qnamespace.h b/src/corelib/global/qnamespace.h
index ebbfc9ca83..a60743d3df 100644
--- a/src/corelib/global/qnamespace.h
+++ b/src/corelib/global/qnamespace.h
@@ -1395,7 +1395,8 @@ public:
         ItemIsDropEnabled = 8,
         ItemIsUserCheckable = 16,
         ItemIsEnabled = 32,
-        ItemIsTristate = 64
+        ItemIsTristate = 64,
+        ItemNeverHasChildren = 128
     };
     Q_DECLARE_FLAGS(ItemFlags, ItemFlag)
 
diff --git a/src/corelib/global/qnamespace.qdoc b/src/corelib/global/qnamespace.qdoc
index f157190591..b271620ee0 100644
--- a/src/corelib/global/qnamespace.qdoc
+++ b/src/corelib/global/qnamespace.qdoc
@@ -2441,6 +2441,7 @@
     \value ItemIsUserCheckable It can be checked or unchecked by the user.
     \value ItemIsEnabled The user can interact with the item.
     \value ItemIsTristate The item is checkable with three separate states.
+    \value ItemNeverHasChildren The item never has child items.
 
     Note that checkable items need to be given both a suitable set of flags
     and an initial state, indicating whether the item is checked or not.
diff --git a/src/corelib/itemmodels/qabstractitemmodel.cpp b/src/corelib/itemmodels/qabstractitemmodel.cpp
index ebe38a97cd..ad9be5419b 100644
--- a/src/corelib/itemmodels/qabstractitemmodel.cpp
+++ b/src/corelib/itemmodels/qabstractitemmodel.cpp
@@ -3272,6 +3272,17 @@ bool QAbstractTableModel::hasChildren(const QModelIndex &parent) const
 }
 
 /*!
+    \reimp
+ */
+Qt::ItemFlags QAbstractTableModel::flags(const QModelIndex &index) const
+{
+    Qt::ItemFlags f = QAbstractItemModel::flags(index);
+    if (index.isValid())
+        f |= Qt::ItemNeverHasChildren;
+    return f;
+}
+
+/*!
     \class QAbstractListModel
     \inmodule QtCore
     \brief The QAbstractListModel class provides an abstract model that can be
@@ -3392,6 +3403,17 @@ QModelIndex QAbstractListModel::parent(const QModelIndex & /* index */) const
 }
 
 /*!
+    \reimp
+ */
+Qt::ItemFlags QAbstractListModel::flags(const QModelIndex &index) const
+{
+    Qt::ItemFlags f = QAbstractItemModel::flags(index);
+    if (index.isValid())
+        f |= Qt::ItemNeverHasChildren;
+    return f;
+}
+
+/*!
     \internal
 
     Returns the number of columns in the list with the given \a parent.
diff --git a/src/corelib/itemmodels/qabstractitemmodel.h b/src/corelib/itemmodels/qabstractitemmodel.h
index f138f53487..8e4f12e9ea 100644
--- a/src/corelib/itemmodels/qabstractitemmodel.h
+++ b/src/corelib/itemmodels/qabstractitemmodel.h
@@ -419,6 +419,7 @@ public:
     bool dropMimeData(const QMimeData *data, Qt::DropAction action,
                       int row, int column, const QModelIndex &parent);
 
+    Qt::ItemFlags flags(const QModelIndex &index) const Q_DECL_OVERRIDE;
 protected:
     QAbstractTableModel(QAbstractItemModelPrivate &dd, QObject *parent);
 
@@ -439,6 +440,8 @@ public:
     QModelIndex index(int row, int column = 0, const QModelIndex &parent = QModelIndex()) const;
     bool dropMimeData(const QMimeData *data, Qt::DropAction action,
                       int row, int column, const QModelIndex &parent);
+
+    Qt::ItemFlags flags(const QModelIndex &index) const Q_DECL_OVERRIDE;
 protected:
     QAbstractListModel(QAbstractItemModelPrivate &dd, QObject *parent);