Enable nested MapItemViews

This change allows MapItemView to use a MapItem, MapItemGroup or
MapItemView as delegate.
To achieve this, MapItemView base class also changes from QObject to
MapItemGroup, effectively making MapItemView a MapItemGroup.
Note, though, that MapItemGroup API in Map should be avoided, when
dealing with a MapItemView, and only MapItemView-specific API should be
used.

Tests and example coming after

[ChangeLog][QtLocation] Enabled nesting of MapItemView. This
required a behavioral change, as MapItemView is now a MapItemGroup,
not anymore a plain QObject.
Due to a bug, MapItemView was previously not a Qt Quick Item, making
it possible to create it as a child of any QObject. This has now been
fixed, so if you happen to have a MapItemView in your scene which is
not a child of a Qt Quick Item, you will get an error message.

Task-number: QTBUG-62683
Task-number: QTBUG-62397
Change-Id: Id97e480429e7f952a541fe88df5c01317afeac18
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

1 files changed, 81 insertions, 0 deletions

diff --git a/src/location/declarativemaps/qdeclarativegeomapitemtransitionmanager.cpp b/src/location/declarativemaps/qdeclarativegeomapitemtransitionmanager.cpp
new file mode 100644
index 00000000..549ab2cb
--- /dev/null
+++ b/src/location/declarativemaps/qdeclarativegeomapitemtransitionmanager.cpp
@@ -0,0 +1,81 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the QtLocation module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** 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 http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://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.LGPLv3 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.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 later 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 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qdeclarativegeomapitemtransitionmanager_p.h"
+#include "qdeclarativegeomapitemview_p.h"
+
+QT_BEGIN_NAMESPACE
+
+QDeclarativeGeoMapItemTransitionManager::QDeclarativeGeoMapItemTransitionManager(QObject *mapItem)
+    : QQuickTransitionManager(), m_mapItem(mapItem)
+{
+}
+
+void QDeclarativeGeoMapItemTransitionManager::transitionEnter()
+{
+    if (m_transitionState == ExitTransition)
+        cancel();
+
+    if (!prepareEnterTransition())
+        return;
+
+    if (m_view && m_view->m_enter)
+        transition(enterActions, m_view->m_enter, m_mapItem);
+    else
+        finished();
+}
+
+void QDeclarativeGeoMapItemTransitionManager::transitionExit()
+{
+    if (!prepareExitTransition())
+        return;
+
+    if (m_view && m_view->m_exit)
+        transition(exitActions, m_view->m_exit, m_mapItem);
+    else
+        finished();
+}
+
+void QDeclarativeGeoMapItemTransitionManager::finished()
+{
+    if (m_transitionState == EnterTransition)
+        finalizeEnterTransition();
+    else if (m_transitionState == ExitTransition)
+        finalizeExitTransition();
+}
+
+
+QT_END_NAMESPACE