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Forum Update on Monday, May 27th 2025

QWS VNC doesn't work on Portrait mode

Scheduled Pinned Locked Moved Mobile and Embedded
vncqwsembedded4.8rotate
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  • SGaistS SGaist

    Yes that's what I had in mind, without forgetting the main screen first.

    K Offline
    K Offline
    kumararajas
    wrote on last edited by
    #18

    @SGaist Oh ya, I missed the main screen

    So here is the code which I can do the test:

    // Main screen
    QSize s = QSize(qt_screen->deviceWidth(), qt_screen->deviceHeight());
    tpos = qt_screen->mapFromDevice(pos, s);
    
    // Subscreens
    QList<QScreen*> screens = qt_screen->subScreens();
    if (screens.size()) 
    {
        for (int i = 0; i < screens.size(); ++i) 
        {
            QScreen *screen = screens.at(i);
            QSize s = QSize(screen->deviceWidth(), screen->deviceHeight());
            tpos = screen->mapFromDevice(pos, s);
            break;
        }
    }
    

    Right?

    --Kumar

    1 Reply Last reply
    0
    • SGaistS SGaist

      Yes that's what I had in mind, without forgetting the main screen first.

      K Offline
      K Offline
      kumararajas
      wrote on last edited by
      #19

      @SGaist Below the patch code, I see

          QPoint tpos;
          // Main screen
          QSize s = QSize(qt_screen->deviceWidth(), qt_screen->deviceHeight());
          tpos = qt_screen->mapFromDevice(pos, s);
      
          // Sub screens
          QList<QScreen*> screens = qt_screen->subScreens();
          if (screens.size()) 
          {
              for (int i = 0; i < screens.size(); ++i) 
              {
                  QScreen *screen = screens.at(i);
                  QSize s = QSize(screen->deviceWidth(), screen->deviceHeight());
                  tpos = screen->mapFromDevice(pos, s);
                  break;
              }
          }
      
          if (qt_last_x) {
               *qt_last_x = tpos.x();
               *qt_last_y = tpos.y();
          }
          QWSServer::mousePosition = tpos;
          qwsServerPrivate->mouseState = state;
      

      We use the tpos and mouse the mousePosition just once. Even though, we have many subscreens, we just do it once.

      Is this correct?

      Should we not do this in a loop for all the screens?

      Please let me know.

      --Kumar

      K 1 Reply Last reply
      0
      • K kumararajas

        @SGaist Below the patch code, I see

            QPoint tpos;
            // Main screen
            QSize s = QSize(qt_screen->deviceWidth(), qt_screen->deviceHeight());
            tpos = qt_screen->mapFromDevice(pos, s);
        
            // Sub screens
            QList<QScreen*> screens = qt_screen->subScreens();
            if (screens.size()) 
            {
                for (int i = 0; i < screens.size(); ++i) 
                {
                    QScreen *screen = screens.at(i);
                    QSize s = QSize(screen->deviceWidth(), screen->deviceHeight());
                    tpos = screen->mapFromDevice(pos, s);
                    break;
                }
            }
        
            if (qt_last_x) {
                 *qt_last_x = tpos.x();
                 *qt_last_y = tpos.y();
            }
            QWSServer::mousePosition = tpos;
            qwsServerPrivate->mouseState = state;
        

        We use the tpos and mouse the mousePosition just once. Even though, we have many subscreens, we just do it once.

        Is this correct?

        Should we not do this in a loop for all the screens?

        Please let me know.

        K Offline
        K Offline
        kumararajas
        wrote on last edited by
        #20

        Looks like I am in a wrong direction.

        I suspect "Transformed" driver is not having problem.

        I think, it is "multi" screen driver is what not working good.

        Because, when VNC option is selected, Transformed works food.
        When LinuxFb is selected, Transformed works good.

        When both are used, there lies the problem.

        I guess, we may have to look at Multi Screen driver source code to see how it has been implemented.

        Can you please point me to the right location?

        Thanks,
        Kumara

        --Kumar

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        0
        • SGaistS Offline
          SGaistS Offline
          SGaist
          Lifetime Qt Champion
          wrote on last edited by
          #21

          I'd take a look a the qscreenmulti_qws.cpp file

          Interested in AI ? www.idiap.ch
          Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

          K 2 Replies Last reply
          0
          • SGaistS SGaist

            I'd take a look a the qscreenmulti_qws.cpp file

            K Offline
            K Offline
            kumararajas
            wrote on last edited by
            #22

            @SGaist Oh!
            Any thing you found?

            --Kumar

            1 Reply Last reply
            0
            • SGaistS SGaist

              I'd take a look a the qscreenmulti_qws.cpp file

              K Offline
              K Offline
              kumararajas
              wrote on last edited by
              #23

              @SGaist Later I gave a try with

              export QWS_DISPLAY="VNC:Transformed:Rot270"
              

              I dont know the magic behind this.

              In my LCD display UI, looks good. And even touch works well.

              And now, in the VNC client, Application was rotated. So, I used RealVNC client and rotated the screen to 270.
              With that, UI looks good and even operation works well.

              I dont know what magic behind the scene.

              But the problem I see is, display refresh in VNC client. The screen doesnt gets refreshed. There is a hug lag while updating the screen..

              I am totally confused now, to understand the problem.

              Based on your experience,
              Where do you see the problem?

              Thanks a lot for your immense support!

              --Kumar

              1 Reply Last reply
              0
              • SGaistS Offline
                SGaistS Offline
                SGaist
                Lifetime Qt Champion
                wrote on last edited by
                #24

                90 and 270 are "complementary" meaning that 270 is equivalent to -90 so it might be that the position calculation were done wrong (or just not taking the angle in account correctly)

                Do you mean that with 90, the refreshing is done correctly on both but not the mouse handling and with 270, the refreshing is wrong but the mouse move are handled correctly ?

                Interested in AI ? www.idiap.ch
                Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                K 2 Replies Last reply
                0
                • SGaistS SGaist

                  90 and 270 are "complementary" meaning that 270 is equivalent to -90 so it might be that the position calculation were done wrong (or just not taking the angle in account correctly)

                  Do you mean that with 90, the refreshing is done correctly on both but not the mouse handling and with 270, the refreshing is wrong but the mouse move are handled correctly ?

                  K Offline
                  K Offline
                  kumararajas
                  wrote on last edited by
                  #25

                  @SGaist No. With both 90 or 270, I can see the mouse move is perfect. But the refreshing is not working good.

                  --Kumar

                  1 Reply Last reply
                  0
                  • SGaistS SGaist

                    90 and 270 are "complementary" meaning that 270 is equivalent to -90 so it might be that the position calculation were done wrong (or just not taking the angle in account correctly)

                    Do you mean that with 90, the refreshing is done correctly on both but not the mouse handling and with 270, the refreshing is wrong but the mouse move are handled correctly ?

                    K Offline
                    K Offline
                    kumararajas
                    wrote on last edited by kumararajas
                    #26

                    @SGaist Sam, any further thoughts?

                    I don't want to give up. I want to fix this Qt bug. For sure, I will need your / Qt experts help.

                    Thank you,
                    Kumara

                    --Kumar

                    K 1 Reply Last reply
                    0
                    • K kumararajas

                      @SGaist Sam, any further thoughts?

                      I don't want to give up. I want to fix this Qt bug. For sure, I will need your / Qt experts help.

                      Thank you,
                      Kumara

                      K Offline
                      K Offline
                      kumararajas
                      wrote on last edited by
                      #27

                      Still no success so far.

                      Any thoughts on how to handle this?

                      Thank you!
                      Kumara

                      --Kumar

                      1 Reply Last reply
                      0
                      • SGaistS Offline
                        SGaistS Offline
                        SGaist
                        Lifetime Qt Champion
                        wrote on last edited by
                        #28

                        Can you remind me the current "multiscreen" setup you have ?

                        Interested in AI ? www.idiap.ch
                        Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

                        1 Reply Last reply
                        0
                        • M Offline
                          M Offline
                          majis
                          wrote on last edited by
                          #29

                          This is a quite old topic but what is the current situation for this problem?

                          1 Reply Last reply
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