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Qml with c++ backend freezes on android

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  • P PouryaTorabi

    Hi everyone

    I have written a simple code that the user inputs a number in a label and the c++ backend receives it and does some calculation and send it back to the UI. It works well without any problem but if call the c++ functions and then minimize the app and want to maximize it again it freezes, If I don't call any c++ functions it won't freeze, does anyone know the problem?

    J.HilkJ Offline
    J.HilkJ Offline
    J.Hilk
    Moderators
    wrote on last edited by
    #2

    hi @PouryaTorabi

    do you happen to have the input keyboard open when you minimize the app?

    currently there's a bug in 5.12 that causes the ui freeze when you minimize the app with virtual keyboard open.


    Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


    Q: What's that?
    A: It's blue light.
    Q: What does it do?
    A: It turns blue.

    P 2 Replies Last reply
    2
    • J.HilkJ J.Hilk

      hi @PouryaTorabi

      do you happen to have the input keyboard open when you minimize the app?

      currently there's a bug in 5.12 that causes the ui freeze when you minimize the app with virtual keyboard open.

      P Offline
      P Offline
      PouryaTorabi
      wrote on last edited by
      #3

      @J.Hilk Yes I have a keyboard but even if I close the keyboard it still freezes. So you mean the problem is not from c++? I thought may be it is possible to use c++ as the backend.

      1 Reply Last reply
      0
      • J.HilkJ J.Hilk

        hi @PouryaTorabi

        do you happen to have the input keyboard open when you minimize the app?

        currently there's a bug in 5.12 that causes the ui freeze when you minimize the app with virtual keyboard open.

        P Offline
        P Offline
        PouryaTorabi
        wrote on last edited by
        #4

        @J.Hilk Is there any solution or should I switch to another language for android?

        J.HilkJ 1 Reply Last reply
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        • P PouryaTorabi

          @J.Hilk Is there any solution or should I switch to another language for android?

          J.HilkJ Offline
          J.HilkJ Offline
          J.Hilk
          Moderators
          wrote on last edited by
          #5

          @PouryaTorabi
          what I meant was this bug
          https://bugreports.qt.io/browse/QTBUG-72101

          Seems to be fixed in the newest versions of Qt


          Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


          Q: What's that?
          A: It's blue light.
          Q: What does it do?
          A: It turns blue.

          P 1 Reply Last reply
          1
          • J.HilkJ J.Hilk

            @PouryaTorabi
            what I meant was this bug
            https://bugreports.qt.io/browse/QTBUG-72101

            Seems to be fixed in the newest versions of Qt

            P Offline
            P Offline
            PouryaTorabi
            wrote on last edited by
            #6

            @J.Hilk This is the kit I use, so I shouldn't have problem.
            0_1551259224416_5988f0e6-35bd-4ff2-995b-9c01a2425110-image.png

            J.HilkJ 1 Reply Last reply
            0
            • P PouryaTorabi

              @J.Hilk This is the kit I use, so I shouldn't have problem.
              0_1551259224416_5988f0e6-35bd-4ff2-995b-9c01a2425110-image.png

              J.HilkJ Offline
              J.HilkJ Offline
              J.Hilk
              Moderators
              wrote on last edited by
              #7

              @PouryaTorabi said in Qml with c++ backend freezes on android:

              @J.Hilk This is the kit I use, so I shouldn't have problem.

              actually no,
              you're using 5.12.0
              the fixed versions are: 5.12.1, 5.14.0 Alpha


              Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


              Q: What's that?
              A: It's blue light.
              Q: What does it do?
              A: It turns blue.

              1 Reply Last reply
              2
              • P Offline
                P Offline
                PouryaTorabi
                wrote on last edited by
                #8

                I had a hard time configuring the kit. Is there any easy way to update to qt5.12.1 or I have to download and install the qt5.12.1?

                J.HilkJ 1 Reply Last reply
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                • P PouryaTorabi

                  I had a hard time configuring the kit. Is there any easy way to update to qt5.12.1 or I have to download and install the qt5.12.1?

                  J.HilkJ Offline
                  J.HilkJ Offline
                  J.Hilk
                  Moderators
                  wrote on last edited by
                  #9

                  @PouryaTorabi
                  if you simply download the 5.12.1 (via maintenance tool) QtCreator should automatically select the settings from your 5.12.0 kit and apply them to the 5.12.1 one


                  Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


                  Q: What's that?
                  A: It's blue light.
                  Q: What does it do?
                  A: It turns blue.

                  1 Reply Last reply
                  0
                  • P Offline
                    P Offline
                    PouryaTorabi
                    wrote on last edited by
                    #10

                    After a lot of struggling I had to download and install qt 5.12.1 which also installed Qt creator 4.8.1, I also had to change the ndk version, it didn't work with the ndk r14 so I used ndk r19, then built the project again and the bug was solved.
                    There were no update for qt5.12.1 in the maintenance tool.
                    Thanks for your help @J-Hilk .

                    1 Reply Last reply
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                    • P Offline
                      P Offline
                      PSI_lbc
                      wrote on last edited by
                      #11

                      This is a year old, sorry to bring it back up...

                      I have an existing app that had been running perfectly on all Android OSes up until the Android 9 release..then the app started to have "freezes" issues. Nothing changed in the app which was built using qt5.8.1, so the freeze is obviously related to changes in the Android OS.

                      So I'm going to recompile the app to "fix" the "freeze" issue.

                      Does the Freeze Fix only exist in qt5.12.1 or is it in all Qt versions greater than qt5.12.1 ?

                      Specifically is it in qt5.12.7 ?

                      jsulmJ 1 Reply Last reply
                      0
                      • P PSI_lbc

                        This is a year old, sorry to bring it back up...

                        I have an existing app that had been running perfectly on all Android OSes up until the Android 9 release..then the app started to have "freezes" issues. Nothing changed in the app which was built using qt5.8.1, so the freeze is obviously related to changes in the Android OS.

                        So I'm going to recompile the app to "fix" the "freeze" issue.

                        Does the Freeze Fix only exist in qt5.12.1 or is it in all Qt versions greater than qt5.12.1 ?

                        Specifically is it in qt5.12.7 ?

                        jsulmJ Offline
                        jsulmJ Offline
                        jsulm
                        Lifetime Qt Champion
                        wrote on last edited by
                        #12

                        @PSI_lbc If the fix is in 5.12.1 then it will be in all newer versions as well

                        https://forum.qt.io/topic/113070/qt-code-of-conduct

                        1 Reply Last reply
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