Mobile and Embedded

SOLVED: I had to type this command:
sudo chmod $USER:$USER $ANDROID_SDK_ROOT
I hope this will help unfortunate people like me, who couldn't figure this out for days or even months.

@jsulm , Thank you so much. Now I understood. You got a new follower now.

I have resolved the issue, as the /usr/share directory was not included in the sysroot.

Here is the same code using appDataLocation

void DatabaseManager::OpenConnection() { // Configure the database connection parameters for SQLite m_db = QSqlDatabase::addDatabase("QSQLITE"); // Use QStandardPaths to get the application data location QString dbName = "identifier.sqlite"; QString dbLocation = QStandardPaths::writableLocation(QStandardPaths::AppDataLocation); QString fullDbPath = dbLocation + "/" + dbName; QDir dbDir(dbLocation); if (!dbDir.exists()) { if (dbDir.mkpath(dbLocation)) { qDebug() << "Created application data directory:" << dbLocation; } else { qDebug() << "Failed to create application data directory:" << dbLocation; return; // Exit if the directory cannot be created } } // Set the SQLite database file location m_db.setDatabaseName(fullDbPath); // Check if the database file exists in the application data location if (!QFile::exists(fullDbPath)) { qDebug() << "Database does not exist in AppDataLocation, copying from resources."; // Path to the resource database file QString resourceDbPath = ":/resources/identifier.sqlite"; // Adjust the path to your resource file // Attempt to copy the database from resources to the writable location if (QFile::copy(resourceDbPath, fullDbPath)) { qDebug() << "Database copied successfully to AppDataLocation."; // Set file permissions to writable (necessary for some platforms) QFile::setPermissions(fullDbPath, QFileDevice::ReadOwner | QFileDevice::WriteOwner); } else { qDebug() << "Failed to copy database from resources."; return; // Exit if the database cannot be copied } } // Open the database connection and handle success or failure if (m_db.open()) { qDebug() << "Database opened successfully."; // Sample query to verify the database contents } else { // Handle connection error qDebug() << "Database failed to open."; qDebug() << m_db.lastError().text(); } }

My workaround for the time being is as follows:

Construct the Java class when the related C++ class is constructed Set Activity for the class Call static methods like before

Java:

private static Activity m_activity = null; public void setActivity(Activity activity) { m_activity = activity; return; }

also change all methods that previously called QtNative.activity() to now check for and use m_activity instead.

C++:

mJNIInstance = QJniObject("the/qualified/ClassPath"); if (mJNIInstance.isValid()) { mJNIInstance.callMethod<void>("setActivity", "(Landroid/app/Activity;)V", QNativeInterface::QAndroidApplication::context().object()); } else { // output a warning or error }

I needed to add developer mode and trust the developer on my iphone

@Qreator35 Are you aware of Qt's CAN support?

Hi, jsulm,

Thanks for your reply.

Yeap, I want the app to always stay on top.
Because the Android system have a Activate Window always on the top of the screen.
My program app must be in front of the Activate Window. And I must.
I implemented a demo in Android Studio by using TYPE_SYSTEM_ALERT to on the top.
But my full program is implemented using Qt.

Need your advice.
Daniel

Hi, AnQuter,

Is your question solved?
// setContentView(R.layout.dream); - how to use Qt app layout?

How can I load Qt mainwindow.ui in java code?
Thanks a lot.

Hi and welcome to devnet,

From the looks of it, no there's nothing directly in Qt for that.
You should take a look at the bug report system to see if there's something related to that.

I am now facing a problem with NetworkAuth and WebAssembly. I opened another request but got left behind
https://forum.qt.io/topic/159704/how-to-install-qtnetworkauth-for-webassemby/8?_=1732390034893

Just as I posted that I found a workaround, but I would still like to know how to correct this.

For those that are having the same issue and just "want it done" here's what I did: On a fresh bitbake run, when gn-native failed, it showed me the command-line that it ran, which looked something like this:

cd /home/aaron/yocto/build-raspberrypi-armv8/tmp/work/x86_64-linux/gn-native/6.8.0/build && /home/aaron/yocto/build-raspberrypi-armv8/tmp/work/x86_64-linux/gn-native/6.8.0/recipe-sysroot-native/usr/bin/python3-native/python3 /home/aaron/yocto/build-raspberrypi-armv8/tmp/work/x86_64-linux/gn-native/6.8.0/git/src/3rdparty/gn/build/gen.py --no-last-commit-position --out-path /home/aaron/yocto/build-raspberrypi-armv8/tmp/work/x86_64-linux/gn-native/6.8.0/build/ --cc /home/aaron/yocto/build-raspberrypi-armv8/tmp/hosttools/gcc --cxx /home/aaron/yocto/build-raspberrypi-armv8/tmp/hosttools/g++ --ld /home/aaron/yocto/build-raspberrypi-armv8/tmp/hosttools/g++ --platform linux --ar /home/aaron/yocto/sources/poky/scripts/native-intercept/ar --qt-version 6.8.0.qtwebengine.qt.io && /home/aaron/yocto/build-raspberrypi-armv8/tmp/work/x86_64-linux/gn-native/6.8.0/recipe-sysroot-native/usr/bin/ninja -C /home/aaron/yocto/build-raspberrypi-armv8/tmp/work/x86_64-linux/gn-native/6.8.0/build/ gn

Right around where it says gen.py notice there's a bunch of flags: --no-commit-position --out-path etc. Somewhere in those flags, add --allow-warnings and re-run that command. gn-native will (hopefully) build successfully, with warnings, and you will be able to proceed with your Yocto build.

Here is my Solve:

class AndroidItemModel : public QStandardItemModel {
Q_OBJECT
public:
AndroidItemModel(QObject *parent = nullptr): QStandardItemModel(parent) {}
Qt::ItemFlags flags(const QModelIndex &index) const override {
if (!index.isValid()) {return Qt::NoItemFlags;}
return Qt::ItemIsSelectable | Qt::ItemIsEnabled;
}
};

QComboBox * cb = new QComboBox();
cb ->setModel(new AndroidItemModel());

I'm very sorry that I've been busy before.,So I didn't come back to reply.,Then I've found the problem.,Now I'm back to answer the question I hope it can help you.,The main reason is that the default frame rate of my device's camera is the lowest, resulting in the number of frames being too low to cause Caton.,So I increased the number of frames to get it solved.

void ThreadGetCamPic::run() { bool ret = stVideoCaptrue.open(0); //The code in the horizontal line is currently known to be only valid for the RK35xx series cameras, if there is a problem with the camera turned on, it should be here, just comment it out, and it is also the reason to solve the freeze of the camera acquisition screen /*---------------------------------------------------------------------------------*/ // stVideoCaptrue.set(cv::CAP_PROP_FRAME_WIDTH, 800); // stVideoCaptrue.set(cv::CAP_PROP_FRAME_HEIGHT, 600); // stVideoCaptrue.set(cv::CAP_PROP_FPS, 20); /*---------------------------------------------------------------------------------*/ Mat matTemp; // QImage img; m_bStop = false; while(!m_bStop){ stVideoCaptrue&gt;&gt;matTemp; if(matTemp.empty()){ msleep(50); continue; } img = QImage(matTemp.data,matTemp.cols,matTemp.rows,matTemp.step,QImage::Format_RGB888).copy(); img = convertRGB888toBGR888UsingOpenCV(img); emit sigSendCurImg(img); } }

@jsulm ,

Got it,
I will check it first
Very Appreciate your help

This is not legal advice. But I can tell you an anecdotal story from my previous company I worked for.

The company produced heavy duty machines that could, for a better user experience, be equipped with a of the shelf android tablet and a custom app made in Qt.

We used to own a normal commercial licence there and developed that app with that licence. After some years during a renewal process, the QtC decided that this was an embedded device since the tablet was sold/shipped with the app preinstalled and would like money for each sold unit.

The end of the story is, the mechanic setting the machine up now has to do the extra step of connecting the tablet to the internet, getting the app from the Appstore and than placing it back into the machine.

Oh, and the company startet to transition away from Qt.

It compiles for me, too, but it doesn’t run.