Add native iOS file dialog

This patch adds native iOS file open and directory picking support for
the QFileDialog using the iOS UIDocumentPickerViewController class.

Change-Id: Ia724a59742650a01c62067aed3477f82ab1fd546
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>

src/plugins/platforms/ios/kernel.pro

@@ -57,13 +57,15 @@ HEADERS = \
         qiosmenu.mm \
         qiosfiledialog.mm \
         qiosmessagedialog.mm \
-        qiostextinputoverlay.mm
+        qiostextinputoverlay.mm \
+        qiosdocumentpickercontroller.mm
     HEADERS += \
         qiosclipboard.h \
         qiosmenu.h \
         qiosfiledialog.h \
         qiosmessagedialog.h \
-        qiostextinputoverlay.h
+        qiostextinputoverlay.h \
+        qiosdocumentpickercontroller.h
 }
 
 OTHER_FILES = \

src/plugins/platforms/ios/qiosdocumentpickercontroller.h

@@ -0,0 +1,46 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 Harald Meyer.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the plugins 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#import <UIKit/UIKit.h>
+
+#include "qiosfiledialog.h"
+
+@interface QIOSDocumentPickerController : UIDocumentPickerViewController <UIDocumentPickerDelegate, UINavigationControllerDelegate>
+- (instancetype)initWithQIOSFileDialog:(QIOSFileDialog *)fileDialog;
+@end

src/plugins/platforms/ios/qiosdocumentpickercontroller.mm

@@ -0,0 +1,103 @@
+/****************************************************************************
+**
+** Copyright (C) 2020 Harald Meyer.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the plugins 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.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#import <UIKit/UIKit.h>
+#import <MobileCoreServices/MobileCoreServices.h>
+
+#include "qiosdocumentpickercontroller.h"
+
+@implementation QIOSDocumentPickerController {
+    QIOSFileDialog *m_fileDialog;
+}
+
+- (instancetype)initWithQIOSFileDialog:(QIOSFileDialog *)fileDialog
+{
+    NSMutableArray <NSString *> *docTypes = [[[NSMutableArray alloc] init] autorelease];
+    UIDocumentPickerMode importMode;
+    switch (fileDialog->options()->fileMode()) {
+    case QFileDialogOptions::AnyFile:
+    case QFileDialogOptions::ExistingFile:
+    case QFileDialogOptions::ExistingFiles:
+        [docTypes addObject:(__bridge NSString *)kUTTypeContent];
+        [docTypes addObject:(__bridge NSString *)kUTTypeItem];
+        [docTypes addObject:(__bridge NSString *)kUTTypeData];
+        importMode = UIDocumentPickerModeImport;
+        break;
+    case QFileDialogOptions::Directory:
+    case QFileDialogOptions::DirectoryOnly:
+        // Directory picking is not supported because it requires
+        // special handling not possible with the current QFilePicker
+        // implementation.
+
+        Q_UNREACHABLE();
+    }
+
+    if (self = [super initWithDocumentTypes:docTypes inMode:importMode]) {
+        m_fileDialog = fileDialog;
+        self.modalPresentationStyle = UIModalPresentationFormSheet;
+        self.delegate = self;
+
+        if (m_fileDialog->options()->fileMode() == QFileDialogOptions::ExistingFiles)
+            self.allowsMultipleSelection = YES;
+
+        if (@available(ios 13.0, *))
+            self.directoryURL = m_fileDialog->options()->initialDirectory().toNSURL();
+    }
+    return self;
+}
+
+- (void)documentPicker:(UIDocumentPickerViewController *)controller didPickDocumentsAtURLs:(NSArray <NSURL *>*)urls
+{
+    Q_UNUSED(controller);
+
+    QList<QUrl> files;
+    for (NSURL* url in urls)
+        files.append(QUrl::fromNSURL(url));
+
+    m_fileDialog->selectedFilesChanged(files);
+    emit m_fileDialog->accept();
+}
+
+- (void)documentPickerWasCancelled:(UIDocumentPickerViewController *)controller
+{
+    Q_UNUSED(controller)
+    emit m_fileDialog->reject();
+}
+
+@end

src/plugins/platforms/ios/qiosfiledialog.h

@@ -65,7 +65,7 @@ public:
     void selectNameFilter(const QString &) override {}
     QString selectedNameFilter() const override { return QString(); }
 
-    void selectedFilesChanged(QList<QUrl> selection);
+    void selectedFilesChanged(const QList<QUrl> &selection);
 
 private:
     QUrl m_directory;
@@ -74,6 +74,7 @@ private:
     UIViewController *m_viewController;
 
     bool showImagePickerDialog(QWindow *parent);
+    bool showNativeDocumentPickerDialog(QWindow *parent);
 };
 
 QT_END_NAMESPACE

src/plugins/platforms/ios/qiosfiledialog.mm

@@ -48,6 +48,7 @@
 #include "qiosfiledialog.h"
 #include "qiosintegration.h"
 #include "qiosoptionalplugininterface.h"
+#include "qiosdocumentpickercontroller.h"
 
 QIOSFileDialog::QIOSFileDialog()
     : m_viewController(nullptr)
@@ -72,8 +73,12 @@ bool QIOSFileDialog::show(Qt::WindowFlags windowFlags, Qt::WindowModality window
     bool acceptOpen = options()->acceptMode() == QFileDialogOptions::AcceptOpen;
     QString directory = options()->initialDirectory().toLocalFile();
 
-    if (acceptOpen && directory.startsWith(QLatin1String("assets-library:")))
-        return showImagePickerDialog(parent);
+    if (acceptOpen) {
+        if (directory.startsWith(QLatin1String("assets-library:")))
+            return showImagePickerDialog(parent);
+        else
+            return showNativeDocumentPickerDialog(parent);
+    }
 
     return false;
 }
@@ -102,6 +107,25 @@ bool QIOSFileDialog::showImagePickerDialog(QWindow *parent)
     return true;
 }
 
+bool QIOSFileDialog::showNativeDocumentPickerDialog(QWindow *parent)
+{
+#ifndef Q_OS_TVOS
+    if (options()->fileMode() == QFileDialogOptions::Directory ||
+        options()->fileMode() == QFileDialogOptions::DirectoryOnly)
+        return false;
+
+    m_viewController = [[QIOSDocumentPickerController alloc] initWithQIOSFileDialog:this];
+
+    UIWindow *window = parent ? reinterpret_cast<UIView *>(parent->winId()).window
+        : qt_apple_sharedApplication().keyWindow;
+    [window.rootViewController presentViewController:m_viewController animated:YES completion:nil];
+
+    return true;
+#else
+    return false;
+#endif
+}
+
 void QIOSFileDialog::hide()
 {
     // QFileDialog will remember the last directory set, and open subsequent dialogs in the same
@@ -123,7 +147,7 @@ QList<QUrl> QIOSFileDialog::selectedFiles() const
     return m_selection;
 }
 
-void QIOSFileDialog::selectedFilesChanged(QList<QUrl> selection)
+void QIOSFileDialog::selectedFilesChanged(const QList<QUrl> &selection)
 {
     m_selection = selection;
     emit filesSelected(m_selection);