Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt
  • Unsolved
Collapse
qtws26_logo

The Qt Event of the Year: Qt World Summit 2026

Save Your Spot >
Brand Logo
  1. Home
  2. Qt Development
  3. General and Desktop
  4. ignore shift to move between edit text
Qt 6.12 LTS is out! See what's new in the release blog

ignore shift to move between edit text

Scheduled Pinned Locked Moved Unsolved General and Desktop
22 Posts 4 Posters 15.2k Views 1 Watching
  • Oldest to Newest
  • Newest to Oldest
  • Most Votes
Reply
  • Reply as topic
Log in to reply
This topic has been deleted. Only users with topic management privileges can see it.
  • R rest

    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())
          {
            ui->leInformation->setFocus();
            ui->leInformation->setFocusPolicy(Qt::StrongFocus);
            ui->leInformation->KeyPressEvent(event);
          }
          else
          {
            ui->lePath->setFocus();
            ui->lePath->setFocusPolicy(Qt::StrongFocus);
            ui->lePath->KeyPressEvent(event);
          }
        }
    
    

    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 alt text like here B should have been on second edit

    R Offline
    R Offline
    rest
    wrote on last edited by
    #2

    0_1523539075426_dsds.PNG

    R 1 Reply Last reply
    0
    • R rest

      0_1523539075426_dsds.PNG

      R Offline
      R Offline
      rest
      wrote on last edited by
      #3

      help please i tried a lot and nothing

      1 Reply Last reply
      0
      • VRoninV Offline
        VRoninV Offline
        VRonin
        wrote on last edited by VRonin
        #4

        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?

        "La mort n'est rien, mais vivre vaincu et sans gloire, c'est mourir tous les jours"
        ~Napoleon Bonaparte

        On a crusade to banish setIndexWidget() from the holy land of Qt

        R 1 Reply Last reply
        0
        • VRoninV VRonin

          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?

          R Offline
          R Offline
          rest
          wrote on last edited by rest
          #5

          @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 .

          JonBJ 1 Reply Last reply
          0
          • R rest

            @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 .

            JonBJ Offline
            JonBJ Offline
            JonB
            wrote on last edited by
            #6

            @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..

            R 1 Reply Last reply
            1
            • JonBJ JonB

              @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..

              R Offline
              R Offline
              rest
              wrote on last edited by
              #7

              @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

              1 Reply Last reply
              0
              • mrjjM Offline
                mrjjM Offline
                mrjj
                Lifetime Qt Champion
                wrote on last edited by
                #8

                Hi
                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
                ui->leInformation->KeyPressEvent(event);
                (then we can maybe do different, like remove shift)

                R 1 Reply Last reply
                0
                • mrjjM mrjj

                  Hi
                  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
                  ui->leInformation->KeyPressEvent(event);
                  (then we can maybe do different, like remove shift)

                  R Offline
                  R Offline
                  rest
                  wrote on last edited by
                  #9

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

                  mrjjM 1 Reply Last reply
                  0
                  • R rest

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

                    mrjjM Offline
                    mrjjM Offline
                    mrjj
                    Lifetime Qt Champion
                    wrote on last edited by
                    #10

                    @rest
                    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.
                    http://doc.qt.io/qt-5/qobject.html#installEventFilter

                    https://stackoverflow.com/questions/26368659/qwidget-how-to-receive-keypressevent-inside-child-widgets

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

                    1 Reply Last reply
                    2
                    • R Offline
                      R Offline
                      rest
                      wrote on last edited by
                      #11

                      so i made some debugging and when shift is pressed he gets inside my if and changes focus
                      alt text
                      0_1523557300643_dsdsdsdsds.PNG

                      1 Reply Last reply
                      0
                      • R Offline
                        R Offline
                        rest
                        wrote on last edited by
                        #12

                        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?

                        mrjjM 1 Reply Last reply
                        0
                        • R rest

                          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?

                          mrjjM Offline
                          mrjjM Offline
                          mrjj
                          Lifetime Qt Champion
                          wrote on last edited by
                          #13

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

                          Qt::ShiftModifier

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

                          1 Reply Last reply
                          2
                          • R Offline
                            R Offline
                            rest
                            wrote on last edited by
                            #14

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

                            JonBJ 1 Reply Last reply
                            0
                            • R rest

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

                              JonBJ Offline
                              JonBJ Offline
                              JonB
                              wrote on last edited by
                              #15

                              @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?

                              R 1 Reply Last reply
                              1
                              • JonBJ JonB

                                @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?

                                R Offline
                                R Offline
                                rest
                                wrote on last edited by
                                #16

                                @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

                                mrjjM JonBJ 2 Replies Last reply
                                0
                                • R rest

                                  @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

                                  mrjjM Offline
                                  mrjjM Offline
                                  mrjj
                                  Lifetime Qt Champion
                                  wrote on last edited by
                                  #17

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

                                  1 Reply Last reply
                                  0
                                  • R rest

                                    @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

                                    JonBJ Offline
                                    JonBJ Offline
                                    JonB
                                    wrote on last edited by
                                    #18

                                    @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?

                                    R 1 Reply Last reply
                                    2
                                    • R Offline
                                      R Offline
                                      rest
                                      wrote on last edited by
                                      #19

                                      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..

                                      1 Reply Last reply
                                      0
                                      • JonBJ JonB

                                        @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?

                                        R Offline
                                        R Offline
                                        rest
                                        wrote on last edited by
                                        #20

                                        @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

                                        1 Reply Last reply
                                        0
                                        • mrjjM Offline
                                          mrjjM Offline
                                          mrjj
                                          Lifetime Qt Champion
                                          wrote on last edited by
                                          #21

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

                                          1 Reply Last reply
                                          0

                                          • Login

                                          • Login or register to search.
                                          • First post
                                            Last post
                                          0
                                          • Categories
                                          • Recent
                                          • Tags
                                          • Popular
                                          • Users
                                          • Groups
                                          • Search
                                          • Get Qt
                                          • Unsolved