Simulate left mouse button unclick (release button)

mrjj

@Andrey-Shmelew
well, i would dig a bit deeper into what is going on.
I never seen combo not work like that.
Seems something else than missing events.

But yes, you can most likely work around using event filters but there might surface other stuff
like broken drag and drop or something as its not a bug in combobox ( no other reports) as such so
something else is not as expected with the touch.

I tried at work with touch screen and could not reproduce it so Im a bit lost why
its not just closing its dropdown.

I think it will/might be a mess with eventfilter
but if you only have one combobox you
need to fix it should be ok
but if you use combos all over program i would
go for better solution.

Andrey Shmelew

@mrjj
Unfortunately, i use combos all over program. I want to use comboboxes for configure my device. if you could not reproduce it, maybe it happens because of my touch's non-correct work. If i could make any help for you for help me ...

mrjj

@Andrey-Shmelew

Hmm, I asked another mod here for some input (later) as there is something
funky here. Maybe im overlooking something.
If your touch acts as pure touch or is faulty then other controls should also have issues.

But since we do not have any event trace is very unclear what is happening.
Also as far as I know, the drop down part of the combobox is already using event filter.
So its not sure event filters are a good/easy fix.

I think i would still dig deeper to find real reason. ( look in Qt source)

Alternatively, make my own combo box and control the dropdown with lost focus if possible.
Didnt check the code so not sure how it handles the dropdown.

raven-worx

@Andrey-Shmelew
whats your touch screen model?
Whats your input mode (evdev, tslib, libinput) used?
What is your used Qt platform (X, LinuxFB, EGLFS)?

Just to make sure: you are using QtWidgets right, not QML?

btw. VLC also uses Qt for it's GUI. But i currently don't know which version.
Can you also try to use Qt 5.8 RC if you encounter the same issues?

Also you could log all events like the following. Start the application from the console and you should see the output in stdout.

qApp->installEventFilter( this );
...
bool eventFilter( QObject* watched, QEvent* event )
{
     switch( event->type() )
     {
               case QEvent::MousePressEvent:
               case QEvent::MouseReleaseEvent:
               case QEvent::TouchBegin:
               case QEvent::TouchCancel:
               case QEvent::TouchEnd:
                        qDebug() << int(event->type()) << watched;
              break;
     }

     return BaseClass::eventFilter(watched,event);
}

Andrey Shmelew

@raven-worx
This is my display : http://www.waveshare.com/10.1inch-hdmi-lcd-b-with-case.htm
i dont know inpute mode (maybe this is a reason of a bug)
i also dont know qt platform (maybe Qt Creator 4.1.0
Основан на Qt 5.7.0 (MSVC 2013, 32 бита) is answer), and i built qt everywere with gcc arm none eabi compiler.
I use QtWidgets, not QML, i am sure.
OK I think i can try QT 5.8 RC
Ok i will log all events following your code

here is video demonstrates how combo works https://drive.google.com/file/d/0ByPoVqOCWO2IVERuMkMzTmZsMjA/view

raven-worx

@Andrey-Shmelew
in the video the mouse cursor changes it's shape (to Qt::IBeamCursor), from then on your widgets do not react anymore.
You can also log the focus changes by connecting to QApplication::focusChanged() signal. It would be interesting what's the focus widget is in that case.

Maybe you use QWidget::grabMouse() in this widget?

Can you also please set QT_DEBUG_PLUGINS=1 environment variable and post the output from the console. Maybe before/after you try the other debug output.
This shows what plugins are being loaded.

Andrey Shmelew

@raven-worx
i added QApplication::focusChanged() signal:

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    QObject::connect(&a, SIGNAL(focusChanged(QWidget*,QWidget*)), &w, SLOT(textupdate()));
    w.show();
    return a.exec();
}

then added a slot:

void MainWindow::textupdate()
{
QWidget * fw = qApp->focusWidget();
ui->textEdit_3->setText(ui->textEdit_3->toPlainText() + " | " + fw->objectName());
}

accordingly, i can see focused widget name, right?
After it, i noticed strange behaviour:
after some clicks on comboboxes, it becomes impossible to control all of widgets besides textEdit widgets (and sometimes... dial). Thats all. All other widgets (sliders, combos) are dead. And strange that when i click on textEdit, mouse cursor is always at the begin.

And the following video : https://drive.google.com/open?id=0ByPoVqOCWO2IMmdlMk8xTEVoa0U

PS, sometimes when bug happens, i can select text in textEdit by my finger (as if I hold down the left mouse button), so i made a conclusion that "touch mouse button" didnt released properly. And the video:
https://drive.google.com/open?id=0ByPoVqOCWO2IS2lIQUpBSlNPWDA

trying QT 5.8 RC did not bring good results

case QEvent::MousePressEvent:
case QEvent::MouseReleaseEvent:

MousePressEvent and MouseReleaseEvent are not exsist

PPS: After i connect regular mouse and click left button, all becomes normal.

Andrey Shmelew

@raven-worx said in Simulate left mouse button unclick (release button):

Also you could log all events like the following. Start the application from the console and you should see the output in stdout.

this is code to see events in event filter:

bool MainWindow::eventFilter(QObject *obj, QEvent *event)
{
    switch( event->type() ){
    case QEvent::MouseButtonDblClick:
        //        qDebug() << "Mouse Button Double Clicked";
        ui->textEdit_3->setText("Mouse Double Clicked");
        break;
    case QEvent::MouseButtonPress:
        //        qDebug() << "Mouse Button Pressed";
        ui->textEdit_3->setText("Mouse Button Pressed");
        break;
    case QEvent::MouseButtonRelease:
        //        qDebug() << "Mouse Button Released";
        ui->textEdit_3->setText("Mouse Button Released");
        break;

    case QEvent::TouchBegin:
        //        qDebug() << "TouchBegin";
        ui->textEdit_3->setText("TouchBegin");
        break;

    case QEvent::TouchEnd:
        //        qDebug() << "TouchEnd";
        ui->textEdit_3->setText("TouchEnd");
        break;

    case QEvent::TouchCancel:
        //        qDebug() << "TouchCancel";
        ui->textEdit_3->setText("TouchCancel");
        break;

    case QEvent::TouchUpdate:
        //qDebug() << "TouchUpdate";
        ui->textEdit_3->setText("TouchUpdate");
        break;

    default:
        break;
    }
    // pass the event on to the parent class
    return QMainWindow::eventFilter(obj, event);
}

So, i noticed that mouse when i touch widgets, release event is called but... not always...
but if i connect mouse instead of touch screen, and press left button, it becomes OK.

Andrey Shmelew

Ok, the problem is solved,

i have recieved a new touch-panel, and it is working fine, mouse released lert button after i release my finger.

Thanks for help

mrjj

@Andrey-Shmelew
So it was just a faulty driver or something?

Andrey Shmelew

@mrjj

it was faulty Touch Hardware Driver IMHO

mrjj

@Andrey-Shmelew

yep I suspected that
But HW is hard to debug remotely :)

Happy programming