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ignore shift to move between edit text

  • my problem is with a code scanner and using focus with keypressevent
    i have two edits and my keyboard event is like this

        void CWidget::keyPressEvent(QKeyEvent *event)
          if(focusWidget() == ui->lePath && !ui->lePath->text().isEmpty())

    if i scan a code with digits and lowercase letters everything is fine.
    if i scan with uppercase letters some of text goes to the other edit
    because of the way uppercase are managed with shift, shift changing between the two edits too. how i can make them not change between those too like here B should have been on second edit

  • 0_1523539075426_dsds.PNG

  • help please i tried a lot and nothing

  • I think there's a better way to do this than intercepting keys.
    What is the behaviour you want?
    What I see here is:
    The first key goes into the line you are focusing, the second key goes on the other line, the third key on the original line and so on. is it corrrect?

  • @VRonin my scenario is like this -

    1. I have a barcode scanner connect to laptop with usb as are those in markets.
    2. when i scan first bar code to be inserted in first edit when i scan another barcode to go in second edit.

    But my problem now is like this each time i scan a barcode who contains a uppercase letter the part of code until the uppercase letter goes where it should be and the rest goes to the other edit is like im using, but other thing i saw is when i press shift he moves me between edit like i m using tab .

  • @rest
    At some level I think you're telling us that your bar code scanner generates key events for the characters it meets?...

    I guess SHIFT itself raises a CWidget::keyPressEvent? So (given what you're doing), you better make your keyPressEvent code look to see if its the SHIFT key and not do the focus swap in that case. Your focus swap code is what is causing it to act like TAB.

    I suspect apart from that that your approach is wrong, but the above is to answer your question as to why it behaves as it does..

  • @JonB so how you think i should approach this? i still think i need the keypressevent .. i don't have so much experience with working with qt and events

  • Lifetime Qt Champion

    Did you use debugger and check what key combination that makes it
    "tab" to next edit ?
    I wondering if the jump happens when u pass the key to
    (then we can maybe do different, like remove shift)

  • @mrjj i will make some debugging now, but is not about that cause i commented ui->leInformation->KeyPressEvent(event); and is the same

  • Lifetime Qt Champion

    if you dont forward the keys at all , it still jumps ?
    Ok, it sounds like the input trigger key navigation.

    I assume you are using an USB scanner in hid keyboard mode.

    You might want to install event filter on Application to find out what is going on.

    Its hard to suggest what to do when we dont really know why input makes it focus next control.

  • so i made some debugging and when shift is pressed he gets inside my if and changes focus


  • but witch one of the variables gets me the key pressed? i tried something like this !event->key() == Qt::ShiftModifier and doesnt work, there is another way to check?

  • Lifetime Qt Champion

    @rest said in ignore shift to move between edit text:


    if(event->modifiers() & Qt::ShiftModifier){...}

  • @mrjj thank you so much, i will try everything and see what works

  • @rest
    Be careful: I'm thinking you will get one event for just the SHIFT press, and then Qt::ShiftModifier will also still be true for the event which arrives for the B.

    I don't get the whole intention of what you're trying to achieve with your code. You decide where input is to go based on:

    if(focusWidget() == ui->lePath && !ui->lePath->text().isEmpty())

    Why? What's the logic here? What's the idea of switching focus here?

  • @JonB if i scanned a barcode means that focus is on first edit and he is not empty means i should change focus on second edit for scanning there, this is what i thought i don t have so much experience on this i don t really know how i can make this work

  • Lifetime Qt Champion

    How do you know first barcode data is 100% received ?
    Since it comes key pr key. Is there an end of input char ?

  • @rest
    But aren't you saying the "key presses for the barcode" are for each letter? When the second key arrives in lePath (it has the focus, and it's no longer empty), won't your code send it to leInformation?

  • No, i dont have something like that .. i don t know how to check this.. gets so difficult. first i had just one edit text and everything worked fine..

  • @JonB what you mean with second key? everything is well until the uppercase gets in, if i scan only digits everything is fine for both edits

  • Lifetime Qt Champion

    You can try to use only click focus and not strong focus.

  • I realised i was doing something not necessary and my key event exactly checking that shift so i put my setfocus for first edit text in constructor and verified in key pressed event if event->text is empty to ignore it.

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