@Christian-Ehrlicher
ahh, you are right. Good catch.
http://doc.qt.io/qt-5/qjsonvalue.html#toDouble
converts the QJsonValue to double if its that type().
in this case it will return defaultValue (0)

so its something like

QJsonValue bid1 = jsonObj.value("bid_1"); QString asStr=bid1.toString(); double n = asStr.toDouble(); qDebug() << n;

Hi and welcome to devnet,

There's no ready made "console widget", you can use QPlainTextEdit or depending on the amount of data a QListView with a custom QStyledItemDelegate for fancy rendering.

For getting the output of your cli application, you can use QProcess.

Hi
You did read ?
http://doc.qt.io/qt-5/stylesheet-examples.html#customizing-qscrollbar

@GhostWolf
Sounds like it crash.
Does the samples also crash ?

@jsulm Oh. I haven't considered that. I'm definitely going to try that. I don't know why it didn't came to my mind. Thank you very much. I really appreciate your advice. I have been stuck at this problem for a week. I am glad there are people who are willing to help beginners.

@moffa13 said in Slot called multiple times to a blocking function in the same thread:

One question : Is it bad to lock and unlock a mutex multiple times ?

No, that's exactly what they are deigned for

Hi,
sadly, I do not now. It looks like it can be a pain to integrate OpenGL with qtquick2, but it is possible. Widget-base approach is much more straightforward, but you loose "qtquickness" :P

Sorry for the delay, I had a long brake from work.

Here is a possible solution for solving this "missing check/mark" issue.

I implemented the CSS "indicator" solution I got from this qt form post which is problematic.

Sources of solution:

Doc page: here Implementation: here QPalette p = ui->checkBox->palette(); p.setColor(QPalette::Active, QPalette::Base, QColor(255, 255, 255)); p.setColor(QPalette::Button, QColor(255, 255, 255)); ui->checkBox->setAutoFillBackground(true); ui->checkBox->setPalette(p); QColor(255, 255, 255)

refers to your desired background color, possibly the same color as your window background, etc.

QPallete::Active, QPalette::base

refers to the active checkbox's background (the white box background)

QPalette::Button

refers to the "actual background" (behind the checkbox and the checkbox text)

Hope this helps!

@Onikouzou What is this checkbox used for?
If you only want to use a combobox then do:

QInputDialog showSounds; QStringList soundList; soundList << "Sound 1" << "Sound 2"; showSounds.setOptions(QInputDialog::UseListViewForComboBoxItems); // Remove this if you want a combobox instead of a list showSounds.setComboBoxItems(soundList); showSounds.setWindowTitle("Select sounds"); showSounds.exec();

Anreads I sent you my CV I am Sujan from India, if you give work visa I can relocate

@SGaist Thank you, I will try it!

@raven-worx Thank you for pointing me to the proper documentation pages – I'll have a look at them asap.
If the project actually takes off, I'll be a regular in the forums :-)

Best regards,
– Davide

if instead of checking the property you use the pseudo-state it should work

qwidget->setStyleSheet( "QWidget:disabled{color: #64B2D1;}" "QWidget{color: blue;}");

Hey @Wieland . Thanks for the help . It is working fine . ( i will customize it now to my needs )

Actually, my idea is to have a storage of different wooden blocks in user interface and drag them one-by-one to working area to design a house model and then generate a txt file containing the stream of the coordinates (including some other attributes like color, shape) of building blocks.

@Wieland, this float number is represent the speed Value of DC motor in RPM, may you mean I it should be in double type or something else!!.
in fact I don't know obviously whit's the type I should use this is the GUI I built
link text
you can see in Stack-overflow here:
link text
may you get what I need, I'am sory to be annoying but I spent alot of time in this problem :(

By the way, in QApplication's detailed documentation, you have an example of how start an application in "no-gui" mode.

Understood. Thank you.

Then you should take a look at this to get started.

See also Qt::AA_EnableHighDpiScaling in Qt's Application Attributes enumeration

Thank you for your depth explanations. I am able to understand a lot of things now. Its time to tweak around and learn as I go further :)

@JohanSolo

Ah ok, so it is due to the organization of C++ not Qt, and like you said, the difference of a class instances and pointers.

It has been long time since I've had to use C++ and I never did anything too advance with it other than a text-based adventure game. I generally am more focused on hardware oriented programing such as with C and Verilog, and MATLAB is the only more software (excluding Arduino interaction) oriented language I have decent experience with.

Thank you for pointing out why there needs to be a difference. I wasn't familar with pointer usage in C++.

@sush what if the Python app "publish" the values it reads from the sensor by some communication mechanism and you poll those values from the C++ displaying the GUI?

Could you provide more details about what sensor you're using, and how the Python app is interfacing with the sensor? I bet that's a very likley chance a C equivalent program can be written instead...

@alex_malyu
The original post is some 2 months old. So I wrote a whole lot of a post in reply to the original question ... well didn't my ears burn, when I noticed the post time ... I felt like a complete idiot. :)

Hi
Its sounds like the classic
worker - processing - display design with the twist of
caching signals in processing.

In my opinion is a very good design. :)

Got it to work. The only way I got it to work is to launch from command line. ex: gammaray --probe PROBE_OF_CHOICE PATH_TO_QT_EXE\qt_app.exe.

And of course the probe config must be the same as the app's build config. For reference, my environment is Windows 10. GammaRay on Qt 5.6 QtQuick 2.0 apps.

@SGaist
Ok. Thank you!

@kshegunov
Yap, Thanks, Thanks. :-)
Now It's generate all the required files, I also need to add QWidgets in Select Required Models.

Best Regards,
IL

I don't understand what you mean, Qt is a GUI library by design.

@aney
Yeah when meta compiler doesn't run, it all get a bit strange. :)

In first post , under it. to the right. is Topic Tools button. It can mark as solved.

I solved this.
I moved everything related to the serial port into a separate class SerialWorker and moved it to a separate thread.

QThread* serialthread = new QThread; SerialWorker* serialworker = new SerialWorker(); serialworker->moveToThread(serialthread); connect(serialthread, SIGNAL(started()), serialworker, SLOT(InitSerialPort())); serialthread->start(); connect(serialworker, SIGNAL(NewProto(QByteArray)), this, SLOT(ProtocolInterpreter(QByteArray))); connect(this, SIGNAL(SendRS(QByteArray)) , serialworker, SLOT(writeData(QByteArray)));

This works as supposed. Serial port is now more or less very responsive.
WebKit is still blocking the GUI thread sometimes but thats not as much an issue as the serial port not responding.

@KaranBehar
Well agile is not different with Qt.
Just make sure project is under code revision control and go ahead :)

This is a quick and dirty example from the top of my head. It could have been made simpler by using a lambda but so you'll see that QStackedWidget is working the way you want it.

class MyDialog : public QDialog { Q_OBJECT public: explicit MyDialog(QWidget *parent=0); private slots: void gotToPage2(); private: QStackedWidget *_stackedWidget; }; MyDialog::MyDialog(QWidget *parent) : QDialog(parent) { // Create first widget QWidget *firstPage = new QWidget; QLabel *instructionLabel = new QLabel(tr("Instruction for user")); QLineEdit *userNameLineEdit = new QLineEdit; QPushButton *page2PushButton = new QPushButton(tr("Page 2")); QVBoxLayout *firstPageLayout = new QVBoxLayout(firstPage); // automatically set the layout on the widget firstPageLayout->addWidget(instructionLabel); firstPageLayout->addWidget(userNameLineEdit); firstPageLayout->addWidget(page2PushButton); // Create second widget QWidget *secondPage = new QWIdget; QLineEdit *firstNameLineEdit = new QLineEdit; QLineEdit *lastNameLineEdit = new QLineEdit; QPushButton *endPushButton = new QPushButton(tr("End")); QVBoxLayout *secondPageLayout = new QVBoxLayout(secondPage); secondPageLayout->addWidget(firstName); secondPageLayout->addWidget(lastNameLineEdit); secondPageLayout->addWidget(endPushButton); _stackedWidget = new QStackedWidget; stackedWidget->addWidget(firstPage); stackedWidget->addWidget(secondPage); connect(page2PushButton, &QPushButton::clicked, this, &MyDialog::goToPage2); } void MyDialog::gotToPage2() { stackedWidget->setCurrentIndex(1); }

Note that you could also be interested by QWizard

I'm not sure anyone cares about this anymore, but I believe I know what the problem is.

When the plugin class is created, it is actually created outside the currently executing QApplication (via dlopen) and the code is running in a different thread. By reading up a bit on dlopen, it seems that the memory where the library is created comes from a different pool and that all libraries (used like this at least), should make sure to implement a function to destroy themselves.

Not sure if this makes any sense for someone, but it does for me.

Now, I just need to figure a way to get the libraries thread to join with the man QApplication that is already running.

Yes, you are correct. There is more information here for anyone else interested:

https://bugreports.qt.io/browse/QTBUG-47701