Simulate left mouse button unclick (release button)



  • Hi all!
    i have an applcation on qt 5.7.0 for my beaglebone board.
    I need to ... how to say... need to clear mouse button pressed flag, or make mouse button to become unpressed. That happend with me because i use 10 inch lcd with capacitive touch screen, and when i click any combobox with my finger, and then click on any other place on the screen, mouse button state is still stays as pressed and i do not can press any other controls.


  • Qt Champions 2016

    Hi
    Something else is wrong I think.
    Maybe the touch controller only sends MouseDown event or the up event get eaten somehow.

    Does touch work correctly with buttons?
    Click and hold the button. It should stay down. Then release and it go up.

    You can construct a Mouse Event yourself and send it but i would look for other reason before trying that.



  • @mrjj
    Hi! if we are talking about buttons, all works fine, when i hold finger on the button it stays down.
    When i click on combobox, it opens and shows all submenus. When i release my finger, combobox becomes normal. After it i touch on any other area, and for somehow this combobox becomes opened again, as if I pressed it again (but i did not). At this moment we have button pressed event and i can not press other buttons.


  • Qt Champions 2016

    Hi, sounds like the combobox eats the events after.

    Is this a std combo box?

    When you click outside, it should not stay open.



  • @mrjj
    i think it is std combobox

    the problem exsists if only i use touch screen (connected by USB). if i click outside it stays open for a while, and then when i clicked outside second time - combobox closes (and "finger" click becomes pressed forewer),

    If i manipulate by regular USB mouse, comboboxes are working fine!

    So, i want to try to generate mous unclick event


  • Qt Champions 2016

    well
    the drop down part of a combo box is using an event filter. I think its related to this but
    not sure. If it works with a real mouse, why not with touch ?

    Do you use real touch events or did you tell it to act like a mouse? ( the touch controller)

    Well, no harm in trying but I guess it will just be eaten too
    QMouseEvent *mEvnRelease = new QMouseEvent(QEvent::MouseButtonRelease, pos, Qt::LeftButton, Qt::LeftButton, Qt::NoModifier);
    QCoreApplication::sendEvent(QWidget::focusWidget(),mEvnRelease);

    Did you try with other applications?
    Anything with a combobox should do the same. :)



  • @mrjj
    hmmm...

    i use yours code:

    void MainWindow::mousePressEvent(QMouseEvent* event)
    {
        if(event->buttons() == Qt::RightButton)
            ui->label_7->setText("Only right button");
        if(event->buttons() == Qt::LeftButton)
            ui->label_7->setText("Only left button");
        QMouseEvent *mEvnRelease = new QMouseEvent(QEvent::MouseButtonRelease, QCursor::pos(), Qt::LeftButton, Qt::LeftButton, Qt::NoModifier);
        QCoreApplication::sendEvent(QWidget::focusWidget(),mEvnRelease);
    }
    

    , it works now better, but even if MouseButtonRelease event exsists, buttons somehow becomes untouchable.

    "Do you use real touch events or did you tell it to act like a mouse? ( the touch controller)"

    it acts like a mouse (touch controller presents)!

    I have uploaded example project with combobox to the device, and there is exactly the same problem.


  • Qt Champions 2016

    @Andrey-Shmelew
    Hmm really sounds like the touch controller is not acting as a mouse and only
    sends touch events.

    You could set a event filter and watch what events you get.
    http://www.informit.com/articles/article.aspx?p=1405544&seqNum=2

    also note with the code its sends m up to the focused control so if it was not the
    same control that got Mouse Press, it will not work.

    Ps. to get names and not ints for the events, you can use
    https://www.dropbox.com/s/rujoldiax0cql3z/names.txt?dl=0



  • @mrjj

    thank you for the link, sir!

    i have event handler:

    void MainWindow::mouseReleaseEvent(QMouseEvent* event)
    {
        ui->label_7->setText("button Released");
    }
    

    and touch controller sends this event.

    maybe, it sends mouseReleaseEvent properly not every time i when i touch



  • i found a bug,
    in my project i have a dial control...
    firstly i touched to control and manipulated a litlle bit,
    then i touched free area (without any controls or widgets) and noticed than dial reacts on my touching and rotates in direct of my touch spot (i did not touch dial but it turned).


  • Qt Champions 2016

    @Andrey-Shmelew
    Well you can check with mouseReleaseEvent if it fires every time.
    If yes, then something else is still not 100% like a mouse.

    I had some issues with some widgets that look for mouse move and mouse leave events ( focusin/out)
    which is not (always) send with a touch. But I dont remember a plain combobox being an issue.

    Have you tested with some non Qt app ?
    Does it accept the touch fully as a mouse?



  • @mrjj
    i will answer tomorrow! need to go :(
    Thank you!



  • @mrjj
    Hello and Happy New Year!

    I installed VLC media player on my beaglebone, and have been playing with controls (combobox, scrollbars etc...), and all was going well, no bugs with comboboxes, touch screen clicks and releases fine.
    I noticed that combobox in VLC player and combobox in QT are differented of each other.

    VLC acceps the touch fully as a mouse, i suppose.


  • Qt Champions 2016

    @Andrey-Shmelew
    Hi
    Happy new year to you too

    Ok it does sound like it is working as it should. Maybe VLC is very touch friendly.

    Can we test with one app ( nothing as well used with touch as VLC ) to test ?

    Still think its just controller that slips a mouse up sometimes but not sure yet.



  • @mrjj said in Simulate left mouse button unclick (release button):

    Can we test with one app ( nothing as well used with touch as VLC ) to test ?

    yes, sure, i will try evrethyng i can


  • Qt Champions 2016

    @Andrey-Shmelew
    Super
    Did you also check with main window that
    void MainWindow::mouseReleaseEvent(QMouseEvent* event)
    {
    qDebug() << ("button Released");
    }

    is always called?
    Make sure only to click on the mainwindow.



  • @mrjj said in Simulate left mouse button unclick (release button):

    is always called

    if only i did not press combobox...

    As soon as I clicked combobox, no matter how many times I clicked on the mainwindow, label_7 is always "Only left button"

    qDebug() << ("button Released"); is not working in linux app, so i use label_7 as debug out


  • Qt Champions 2016

    @Andrey-Shmelew
    Yes combo is special as it drop down a floating window and use event filer for selection so
    it is not canceled correctly, it will then eat all events and nothing else can be clicked.

    ehh qDebug() not working in linux ? you mean outside Creator or ?
    Dont matter. Label is fine :)



  • @mrjj
    Hello!

    So, the problem is not solved,
    should i use events filter?

    thanks!


  • Qt Champions 2016

    @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.



  • @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 ...


  • Qt Champions 2016

    @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.


  • Moderators

    @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);
    }
    


  • @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


  • Moderators

    @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.



  • @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.



  • @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.



  • 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


  • Qt Champions 2016

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



  • @mrjj

    it was faulty Touch Hardware Driver IMHO


  • Qt Champions 2016

    @Andrey-Shmelew

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

    Happy programming


Log in to reply
 

Looks like your connection to Qt Forum was lost, please wait while we try to reconnect.