iOS: add a file engine to support loading assets/photos

This patch will add a new file engine that lets the
app load images from the asset library using QFile.
The engine will recognize file names with the scheme
'assets-library', which is the same scheme returned
by UIImagePickerController.

This patch will be the first of a set of patches
that lets the user open a native image picker dialog
by using a QFileDialog with directory set to
QStandardPaths::PictureLocation. This patch will
ensure that the url returned from the dialog can
be loaded using QFile.

AssetsLibrary, which is used in this patch, is actually
deprecated in favor of the new Photos framework. But
since the latter is only supported from iOS8, we
choose to use the former framework for now.

Change-Id: If2a6eb394ae4df55fb4e9e1dc245a1574d38618a
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@theqtcompany.com>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 63 insertions, 0 deletions

diff --git a/src/plugins/platforms/ios/qiosfileenginefactory.h b/src/plugins/platforms/ios/qiosfileenginefactory.h
new file mode 100644
index 0000000000..cba5818e51
--- /dev/null
+++ b/src/plugins/platforms/ios/qiosfileenginefactory.h
@@ -0,0 +1,63 @@
+/****************************************************************************
+**
+** Copyright (C) 2015 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the plugins of the Qt Toolkit.
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+** 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 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
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+** rights.  These rights are described in the Digia Qt LGPL Exception
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+** 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
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+****************************************************************************/
+
+#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