iOS: refactor usage of photos into optional plugin

Starting from iOS 10, apps that tries to access photos on the device
need to specify the reason for this up front by adding the key
'NSPhotoLibraryUsageDescription' into Info.plist. If the key is
missing, the app will be rejected from AppStore.

This causes problems for the iOS plugin as it stands since parts of it
already tries to access photos, e.g to show an image picker dialog
if a file dialog is set to open QStandardPaths::PicturesLocation.
This means that currently, all apps written with Qt will be rejected
from AppStore unless the developer adds this key, whether he tries
to access photos or not.

To solve this, we choose to split the plugin into two parts, one
that contains the core functionality, and one that contains
optional support. The latter will need to be enabled explicit
by the developer in the pro file, or in this case, indirectly
by adding the right key to the Info.plist.

This patch refactors the code in the plugin that gives access
to photos into a separate optional plugin called 'nsphotolibrarysupport'.

Change-Id: Ic4351eb0bbfffdf840fd88cd00bb29a25907798f
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Reviewed-by: Jake Petroules <jake.petroules@qt.io>

1 files changed, 55 insertions, 0 deletions

diff --git a/src/plugins/platforms/ios/optional/nsphotolibrarysupport/qiosfileenginefactory.h b/src/plugins/platforms/ios/optional/nsphotolibrarysupport/qiosfileenginefactory.h
new file mode 100644
index 0000000000..29f543caae
--- /dev/null
+++ b/src/plugins/platforms/ios/optional/nsphotolibrarysupport/qiosfileenginefactory.h
@@ -0,0 +1,55 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the plugins of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL21$
+** 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 2.1 or version 3 as published by the Free
+** Software Foundation and appearing in the file LICENSE.LGPLv21 and
+** LICENSE.LGPLv3 included in the packaging of this file. Please review the
+** following information to ensure the GNU Lesser General Public License
+** requirements will be met: https://www.gnu.org/licenses/lgpl.html and
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** As a special exception, The Qt Company gives you certain additional
+** rights. These rights are described in The Qt Company LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QIOSFILEENGINEFACTORY_H
+#define QIOSFILEENGINEFACTORY_H
+
+#include <QtCore/qstandardpaths.h>
+#include <QtCore/private/qabstractfileengine_p.h>
+#include "qiosfileengineassetslibrary.h"
+
+class QIOSFileEngineFactory : public QAbstractFileEngineHandler
+{
+public:
+    QAbstractFileEngine* create(const QString &fileName) const
+    {
+        static QLatin1String assetsScheme("assets-library:");
+
+        if (fileName.toLower().startsWith(assetsScheme))
+            return new QIOSFileEngineAssetsLibrary(fileName);
+
+        return 0;
+    }
+};
+
+#endif // QIOSFILEENGINEFACTORY_H