Android 13 Devices – API 30+ - SelectFiles – CreateFiles – Qt 5.15

[ekkescorner]

In one of my apps the user must be able to select one or more files from shared data and also to create a new file in a selected directory.
Up to API 29 I did this using QStandardPathes, per ex. for PicturesLocation and DocumentsLocation and have built my own CustomFileDialog.

With API30 QStandardPathes only work with AppDataLocation, but not with external shared data because of ScopedStorage.

Qt support for ScopedStorage is still work-in-progress (https://bugreports.qt.io/browse/QTBUG-98974)

Tried to use MANAGE_EXTERNAL_STORAGE, because the app is a DropBox-like app to manage files from shared network drives or SharePoints.

cpp:

#define PACKAGE_NAME "package:org.company.package_name"
jboolean value = QAndroidJniObject::callStaticMethod<jboolean>("android/os/Environment", "isExternalStorageManager");
if( value == false )
{ 
QAndroidJniObject ACTION_MANAGE_APP_ALL_FILES_ACCESS_PERMISSION = QAndroidJniObject::getStaticObjectField( "android/provider/Settings", "ACTION_MANAGE_APP_ALL_FILES_ACCESS_PERMISSION","Ljava/lang/String;" ); 
QAndroidJniObject intent("android/content/Intent", "(Ljava/lang/String;)V", ACTION_MANAGE_APP_ALL_FILES_ACCESS_PERMISSION.object()); 
QAndroidJniObject jniPath = QAndroidJniObject::fromString(PACKAGE_NAME); 
QAdroidJniObject jniUri = QAndroidJniObject::callStaticObjectMethod("android/net/Uri", "parse", "(Ljava/lang/String;)Landroid/net/Uri;", jniPath.object<jstring>());
QAndroidJniObject jniResult = intent.callObjectMethod("setData", "(Landroid/net/Uri;)Landroid/content/Intent;", jniUri.object<jobject>() );
QtAndroid::startActivity(intent, 0); 
}

Manifest:

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.MANAGE_EXTERNAL_STORAGE"/>

App asks for permission and sets permission – controlled at settings-apps-special apps-apps with all files access.

But nothing changed – QStandardPathes still gives no access to files – only for internal AppDataLocation.

Any idea what could be missed to get the “old” behaviour back using MANAGE_EXTERNAL_STORAGE permission ?

Looked for workarounds and tried KDAB SharedStorage Library:
https://www.kdab.com/android-shared-storage-qt-wrapper/
https://github.com/KDAB/android/tree/master/shared_storage
YEP - it works, but there’s a drawback:
selecting files only selects one file – haven’t found a way to select multiple files using KDABs SharedStorage library and this is essential for users.
Selecting a folder and then creating a file inside the folder works great.

Then I found out, that QDir and QFile not only support file pathes, but also Content URIs (https://developer.android.com/reference/android/content/ContentUris).

This is not documented yet, because full ScopedStorage support not ready yet (https://bugreports.qt.io/browse/QTBUG-99664)

But the current implementation helps if using the QML FileDialog on Android :)

Select multi files: Using the QML FileDialog I can see the files from different external locations and I can select multi files, what was missing from KDABs SharedStorage. I’m getting a list of ContentUris and can then use QFile directly using the ContentUris :)

Create File in folder: I can select a folder, was asked for permission, but then trying to create a file inside the selected folder, I’m getting errors:

E Qt JAVA : openFdForContentUrl(): No permissions to open Uri

and “Unknown error” from QFile, per ex. using
"content://com.android.externalstorage.documents/tree/primary%3ADocuments/ekke.txt"

Unfortunately using the QML FileDialog I’m getting some warnings:

W libenbwDOCS_x_arm64-v8a.so: qrc:/android_rcc_bundle/qml/QtQuick/Controls/Styles/Android/LabelStyle.qml:94: TypeError: Cannot read property 'ENABLED_SELECTED_STATE_SET' of undefined
W libenbwDOCS_x_arm64-v8a.so: qrc:/android_rcc_bundle/qml/QtQuick/Controls/Styles/Android/LabelStyle.qml:89: TypeError: Cannot read property 'ENABLED_STATE_SET' of undefined

Conclusion:
Selecting a folder and creating a file I can do using KDABs SharedStorage,
Selecting multiple files I can do using QML FileDialog and have to live with the warnings.

Any better ideas?
Thx
ekke

[JoeCFD]

call the following code at start-up. You add read as well. Try it out.

    bool ok{ true };
    auto write_permission = QtAndroid::checkPermission( "android.permission.WRITE_EXTERNAL_STORAGE" );
    if ( write_permission == QtAndroid::PermissionResult::Denied) {
        QtAndroid::requestPermissionsSync( QStringList() << "android.permission.WRITE_EXTERNAL_STORAGE" );
        write_permission = QtAndroid::checkPermission("android.permission.WRITE_EXTERNAL_STORAGE");
        if ( write_permission == QtAndroid::PermissionResult::Denied ) {
             ok = false;
        }
    }

Note that any permission has to be approved by users, not your code. This seems to be the policies of Android.

[ekkescorner]

@JoeCFD thx. checked again my customer app, where I also got MANAGE_EXTERNAL_STORAGE and I'm already doing this:

#if defined(Q_OS_ANDROID)
bool DataUtil::checkPermission() {
    QtAndroid::PermissionResult r = QtAndroid::checkPermission("android.permission.WRITE_EXTERNAL_STORAGE");
    if(r == QtAndroid::PermissionResult::Denied) {
        QtAndroid::requestPermissionsSync( QStringList() << "android.permission.WRITE_EXTERNAL_STORAGE" );
        r = QtAndroid::checkPermission("android.permission.WRITE_EXTERNAL_STORAGE");
        if(r == QtAndroid::PermissionResult::Denied) {
            qDebug() << "Permission denied";
            return false;
        }
    }
    qDebug() << "YEP: Permission WRITE_EXTERNAL_STORAGE OK";
    return true;
}
#endif

this worked until API 29, but not for API 30+

also verified my test app for QFileDialog - and there I'm also checking permission

[ekkescorner]

@ekkescorner as written I was able to get Content URIs from FileDialog using a small test app:

content://com.android.externalstorage.documents/document/primary%3ADocuments%2Fekke.txt

now I wanted to implement this in my customer app. unfortunately now the Content URIs from FileDialog look different:

content://com.android.providers.media.documents/document/document%3A1000000020

this URI also gives me access to the file content, but I'm missing the name and suffix
any idea what could cause this different behavior ?

same environment, same QML FileDialog from QtQuick.Dialogs1.3 inside a QQC2 app
only difference: customer app is using user 10 (Business app)

thx
ekke

[JoeCFD]

can you try QStandardPaths for write and read? I remember I used them. When I get a chance, I will test for you. I built my app for Android 11(API 30) and 12(API 31).

[ekkescorner]

@JoeCFD this is what I did before: used a custom FileDialog based on QStandardPathes. But with API30 only QStandardPath for 'internal' data with AppDataLocation is working - all others like PicturesLocation, DocumentsLocation are empty.
Up to API 29 all works well.
I'm using Qt 5.15.7 - will update to 5.15.11 next week

[ekkescorner]

@ekkescorner Assam Boudjelthia has done a great work on this and now prepared cherry-picks for 5.15 🙂
see QTBUG-98974
can someone help and test ?