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  4. QWS VNC doesn't work on Portrait mode
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

    Silly idea (and just to verify) but what about just dropping the if and do the transform for all screens anyway ?

    K Offline
    K Offline
    kumararajas
    wrote on last edited by
    #16

    @SGaist You mean to try this kind of code:

    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;
        }
    }
    

    instead of

    if (qt_screen->isTransformed()) 
        {
            QSize s = QSize(qt_screen->deviceWidth(), qt_screen->deviceHeight());
            tpos = qt_screen->mapFromDevice(pos, s);
        } 
        else 
        {
            //tpos = pos;
            // Only in case of Multi Display
            // If main screen is not transformed, then check if sub screens are transformed
            QList<QScreen*> screens = qt_screen->subScreens();
            if (screens.size() && !bRemote) 
            {
                for (int i = 0; i < screens.size(); ++i) 
                {
                    QScreen *screen = screens.at(i);
                    if (screen->isTransformed())
                    {
                        QSize s = QSize(screen->deviceWidth(), screen->deviceHeight());
                        tpos = screen->mapFromDevice(pos, s);
                        break;
                    }
                }
            }
        }
    

    Sam, if you confirm, I can make these changes and build my packages.

    Thanks,
    Kumara

    --Kumar

    1 Reply Last reply
    0
    • SGaistS Offline
      SGaistS Offline
      SGaist
      Lifetime Qt Champion
      wrote on last edited by
      #17

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

      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

        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

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        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

            1 Reply Last reply
            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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