Cleanup: QPlaceContent and subclasses (1/3)

QPlaceContent and subclasses are value types, and subclassing value
is a bad idea, for many reasons. Great care had been taken to work
around the slicing problem, resulting in lot of code and complexity.

Instead of the slicing problem, we now have the problem that we can
assign a QPlaceContent item to a QPlaceImage and back, but that same
QPlaceContent object can also be assigned to a QPlaceReview and a
QPlaceEditorial item. Those then end up as empty items. So while it
seems convenient to have C++ types, we replaced compile errors or
explicitly dynamic APIs, like QVariant, with implicit conversions that
require explicit type checks before, with the risk of silently losing
data.

Ironcially, applications access those different values then through
various QAbstractItemModel implementations - which return QVariants
anyway, requiring explicit type checking and coertion. And the C++
convenience is exclusively interesting for backend implementors, who
anyway need to parse data and identify types dynamically.

What we really need is a map of QVariants, and some information about
what kind of data we can get out of the map.

So as a first step in cleaning, replace the data storage with such a map
and remove all the subclass specific privates, together with all the
complexity (virtual functions, QSharedDataPointer::clone template
specializations, macros).

The subclasses themselves become very thin API wrappers. Their only
special feature is that they all can still be constructed from a
QPlaceContent instance. We need this for compatibility. With all the
convenience C++ APIs marked as deprecated, people can still use
those when using Qt 6.2-compatible Qt Location, and use the warnings
to prepare for Qt 6.5 where we can then remove those APIs entirely.

Change-Id: Id75f55d784fbe214a0db93d3c1f786209ef0a690
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

1 files changed, 0 insertions, 75 deletions

diff --git a/src/location/places/qplaceeditorial_p.h b/src/location/places/qplaceeditorial_p.h
deleted file mode 100644
index afcab4d9..00000000
--- a/src/location/places/qplaceeditorial_p.h
+++ /dev/null
@@ -1,75 +0,0 @@
-/****************************************************************************
-**
-** Copyright (C) 2022 The Qt Company Ltd.
-** Contact: https://www.qt.io/licensing/
-**
-** This file is part of the QtLocation module of the Qt Toolkit.
-**
-** $QT_BEGIN_LICENSE:LGPL$
-** Commercial License Usage
-** Licensees holding valid commercial Qt licenses may use this file in
-** accordance with the commercial license agreement provided with the
-** Software or, alternatively, in accordance with the terms contained in
-** a written agreement between you and The Qt Company. For licensing terms
-** and conditions see https://www.qt.io/terms-conditions. For further
-** information use the contact form at https://www.qt.io/contact-us.
-**
-** GNU Lesser General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU Lesser
-** General Public License version 3 as published by the Free Software
-** Foundation and appearing in the file LICENSE.LGPL3 included in the
-** packaging of this file. Please review the following information to
-** ensure the GNU Lesser General Public License version 3 requirements
-** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
-**
-** GNU General Public License Usage
-** Alternatively, this file may be used under the terms of the GNU
-** General Public License version 2.0 or (at your option) the GNU General
-** Public license version 3 or any later version approved by the KDE Free
-** Qt Foundation. The licenses are as published by the Free Software
-** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
-** included in the packaging of this file. Please review the following
-** information to ensure the GNU General Public License requirements will
-** be met: https://www.gnu.org/licenses/gpl-2.0.html and
-** https://www.gnu.org/licenses/gpl-3.0.html.
-**
-** $QT_END_LICENSE$
-**
-****************************************************************************/
-
-#ifndef QPLACEDESCRIPTION_P_H
-#define QPLACEDESCRIPTION_P_H
-
-//
-//  W A R N I N G
-//  -------------
-//
-// This file is not part of the Qt API.  It exists purely as an
-// implementation detail.  This header file may change from version to
-// version without notice, or even be removed.
-//
-// We mean it.
-//
-
-#include <QtCore/QUrl>
-#include <QtLocation/QPlaceSupplier>
-
-#include "qplacecontent_p.h"
-
-QT_BEGIN_NAMESPACE
-
-class QPlaceEditorialPrivate : public QPlaceContentPrivate
-{
-public:
-    bool compare(const QPlaceContentPrivate *other) const override;
-
-    Q_DEFINE_CONTENT_PRIVATE_HELPER(QPlaceEditorial, QPlaceContent::EditorialType)
-
-    QString text;
-    QString contentTitle;
-    QString language;
-};
-
-QT_END_NAMESPACE
-
-#endif // QPLACEDESCRIPTION_P_H