Introduce QItemDelegate::destroyEditor virtual invoked at editor close

This provides a stronger mechanism e.g when inheriting QItemDelegate.

It makes some things much easier e.g avoid delete of an editor
and maybe only delete depending on what the editor says itself.

This introduces a new virtual function.

Task-number: QTBUG-2299

Change-Id: I8410f8199775987dbacffd99e4c354fdadcdd21f
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>

2 files changed, 88 insertions, 0 deletions

diff --git a/tests/manual/widgets/itemviews/delegate/example.cpp b/tests/manual/widgets/itemviews/delegate/example.cpp
new file mode 100644
index 0000000000..20cff2663a
--- /dev/null
+++ b/tests/manual/widgets/itemviews/delegate/example.cpp
@@ -0,0 +1,86 @@
+/****************************************************************************
+**
+** Copyright (C) 2012 Thorbjørn Lund Martsum - tmartsum[at]gmail.com
+** Contact: http://www.qt-project.org/
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** GNU Lesser General Public License Usage
+** This file may be used under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation and
+** appearing in the file LICENSE.LGPL included in the packaging of this
+** file. Please review the following information to ensure the GNU Lesser
+** General Public License version 2.1 requirements will be met:
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU General
+** Public License version 3.0 as published by the Free Software Foundation
+** and appearing in the file LICENSE.GPL included in the packaging of this
+** file. Please review the following information to ensure the GNU General
+** Public License version 3.0 requirements will be met:
+** http://www.gnu.org/copyleft/gpl.html.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <QtWidgets/QtWidgets>
+
+class ExampleEditor : public QLineEdit
+{
+public:
+    ExampleEditor(QWidget *parent = 0):QLineEdit(parent) { qDebug() << "ctor"; }
+    ~ExampleEditor() { QApplication::instance()->quit(); }
+};
+
+class ExampleDelegate : public QItemDelegate
+{
+public:
+    ExampleDelegate():QItemDelegate() { m_editor = new ExampleEditor(0); }
+protected:
+    QWidget* createEditor(QWidget *p, const QStyleOptionViewItem &o, const QModelIndex &) const
+    {
+        m_editor->setParent(p);
+        m_editor->setGeometry(o.rect);
+        return m_editor;
+    }
+    void destroyEditor(QWidget *editor, const QModelIndex &) const
+    {
+        editor->setParent(0);
+        qDebug() << "intercepted destroy :)";
+    }
+
+    // Avoid setting data - and therefore show that the editor keeps its state.
+    void setEditorData(QWidget*, const QModelIndex &) const { }
+
+    ~ExampleDelegate() { delete m_editor; }
+    mutable ExampleEditor *m_editor;
+};
+
+int main(int argc, char *argv[])
+{
+    QApplication app(argc, argv);
+    QTableView tv;
+    QStandardItemModel m;
+    m.setRowCount(4);
+    m.setColumnCount(2);
+    tv.setModel(&m);
+    tv.show();
+    tv.setItemDelegate(new ExampleDelegate());
+    app.exec();
+}
diff --git a/tests/manual/widgets/itemviews/delegate/example.pro b/tests/manual/widgets/itemviews/delegate/example.pro
new file mode 100644
index 0000000000..e9f2189272
--- /dev/null
+++ b/tests/manual/widgets/itemviews/delegate/example.pro
@@ -0,0 +1,2 @@
+TEMPLATE = app
+SOURCES=example.cpp