Skip to content
  • Categories
  • Recent
  • Tags
  • Popular
  • Users
  • Groups
  • Search
  • Get Qt Extensions
  • Unsolved
Collapse
Brand Logo
  1. Home
  2. Qt Development
  3. General and Desktop
  4. How to use virtual keyboard on Raspberry Pi 4
Forum Updated to NodeBB v4.3 + New Features

How to use virtual keyboard on Raspberry Pi 4

Scheduled Pinned Locked Moved Unsolved General and Desktop
25 Posts 4 Posters 5.2k Views 3 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.
  • I IknowQT

    @sierdzio

    Is there a way to check whether it is eglfs or x11?
    I am not very good at Linux.

    ===============================================

    I tried the option to change the qt platform.
    export QT_QPA_PLATFORM="x11"

    qt.qpa.plugin: Could not find the Qt platform plugin "x11" in ""
    This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem.
    
    Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, webgl, xcb.
    

    Do I need to install x11?
    Is there a command to find out which platform is currently set?

    JKSHJ Offline
    JKSHJ Offline
    JKSH
    Moderators
    wrote on last edited by
    #10

    @IknowQT said in How to use virtual keyboard on Raspberry Pi 4:

    Is there a way to check whether it is eglfs or x11?

    Your plugin debug output will show which platform plugin was loaded.

    I tried the option to change the qt platform.
    export QT_QPA_PLATFORM="x11"

    Use QT_QPA_PLATFORM="xcb"

    Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

    I 1 Reply Last reply
    1
    • JKSHJ JKSH

      @IknowQT said in How to use virtual keyboard on Raspberry Pi 4:

      Is there a way to check whether it is eglfs or x11?

      Your plugin debug output will show which platform plugin was loaded.

      I tried the option to change the qt platform.
      export QT_QPA_PLATFORM="x11"

      Use QT_QPA_PLATFORM="xcb"

      I Offline
      I Offline
      IknowQT
      wrote on last edited by
      #11

      @JKSH

      I tried again after changing to xcb platform, but the virtual keyboard still does not work.

      1 Reply Last reply
      0
      • JKSHJ JKSH

        @IknowQT said in How to use virtual keyboard on Raspberry Pi 4:

        I tried the example called basic.
        The virtual keyboard works normally.

        OK, that's good.

        Now, modify that example code: Convert the QGuiApplication into a QApplication, and then create + show a QTextEdit. What happens when you click on the QTextEdit? What happens when you click on one of the fields in the QQuickView?

        JKSHJ Offline
        JKSHJ Offline
        JKSH
        Moderators
        wrote on last edited by
        #12

        @IknowQT said in How to use virtual keyboard on Raspberry Pi 4:

        I tried again after changing to xcb platform, but the virtual keyboard still does not work.

        See my earlier post:

        Now, modify that example code: Convert the QGuiApplication into a QApplication, and then create + show a QTextEdit. What happens when you click on the QTextEdit? What happens when you click on one of the fields in the QQuickView?

        Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

        I 1 Reply Last reply
        0
        • JKSHJ JKSH

          @IknowQT said in How to use virtual keyboard on Raspberry Pi 4:

          I tried again after changing to xcb platform, but the virtual keyboard still does not work.

          See my earlier post:

          Now, modify that example code: Convert the QGuiApplication into a QApplication, and then create + show a QTextEdit. What happens when you click on the QTextEdit? What happens when you click on one of the fields in the QQuickView?

          I Offline
          I Offline
          IknowQT
          wrote on last edited by
          #13

          @JKSH

          #include <QQuickView>
          #include <QGuiApplication>
          #include <QQmlEngine>
          #include <QtWidgets/QApplication>
          
          int main(int argc, char *argv[])
          {
              qputenv("QT_IM_MODULE", QByteArray("qtvirtualkeyboard"));
          
              QGuiApplication app(argc, argv);
              QApplication n = qobject_cast<QApplication>(app);
          
          
              QQuickView view(QString("qrc:/%2").arg(MAIN_QML));
              if (view.status() == QQuickView::Error)
                  return -1;
              view.setResizeMode(QQuickView::SizeRootObjectToView);
              view.show();
          
              return app.exec();
          }
          

          Are you talking about converting QGuiApplication to QApplication?
          An error occurs. >:

          jsulmJ 2 Replies Last reply
          0
          • I IknowQT

            @JKSH

            #include <QQuickView>
            #include <QGuiApplication>
            #include <QQmlEngine>
            #include <QtWidgets/QApplication>
            
            int main(int argc, char *argv[])
            {
                qputenv("QT_IM_MODULE", QByteArray("qtvirtualkeyboard"));
            
                QGuiApplication app(argc, argv);
                QApplication n = qobject_cast<QApplication>(app);
            
            
                QQuickView view(QString("qrc:/%2").arg(MAIN_QML));
                if (view.status() == QQuickView::Error)
                    return -1;
                view.setResizeMode(QQuickView::SizeRootObjectToView);
                view.show();
            
                return app.exec();
            }
            

            Are you talking about converting QGuiApplication to QApplication?
            An error occurs. >:

            jsulmJ Offline
            jsulmJ Offline
            jsulm
            Lifetime Qt Champion
            wrote on last edited by
            #14

            @IknowQT said in How to use virtual keyboard on Raspberry Pi 4:

            An error occurs. >:

            And what is the error?

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

            I 1 Reply Last reply
            0
            • jsulmJ jsulm

              @IknowQT said in How to use virtual keyboard on Raspberry Pi 4:

              An error occurs. >:

              And what is the error?

              I Offline
              I Offline
              IknowQT
              wrote on last edited by
              #15

              @jsulm

              9195a10e-057d-4228-ac65-0820c3174555-image.png

              1 Reply Last reply
              0
              • I IknowQT

                @JKSH

                #include <QQuickView>
                #include <QGuiApplication>
                #include <QQmlEngine>
                #include <QtWidgets/QApplication>
                
                int main(int argc, char *argv[])
                {
                    qputenv("QT_IM_MODULE", QByteArray("qtvirtualkeyboard"));
                
                    QGuiApplication app(argc, argv);
                    QApplication n = qobject_cast<QApplication>(app);
                
                
                    QQuickView view(QString("qrc:/%2").arg(MAIN_QML));
                    if (view.status() == QQuickView::Error)
                        return -1;
                    view.setResizeMode(QQuickView::SizeRootObjectToView);
                    view.show();
                
                    return app.exec();
                }
                

                Are you talking about converting QGuiApplication to QApplication?
                An error occurs. >:

                jsulmJ Offline
                jsulmJ Offline
                jsulm
                Lifetime Qt Champion
                wrote on last edited by
                #16

                @IknowQT said in How to use virtual keyboard on Raspberry Pi 4:

                QGuiApplication app(argc, argv);
                QApplication n = qobject_cast<QApplication>(app);

                What is this actually?!

                Why not simply

                QApplication app(argc, argv);
                

                ?

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

                I 1 Reply Last reply
                0
                • jsulmJ jsulm

                  @IknowQT said in How to use virtual keyboard on Raspberry Pi 4:

                  QGuiApplication app(argc, argv);
                  QApplication n = qobject_cast<QApplication>(app);

                  What is this actually?!

                  Why not simply

                  QApplication app(argc, argv);
                  

                  ?

                  I Offline
                  I Offline
                  IknowQT
                  wrote on last edited by
                  #17

                  @jsulm
                  I didn't quite understand what you mean to convert QguiApplication.

                  @JKSH
                  The keyboard works normally when you follow the steps you mentioned.

                  int main(int argc, char *argv[])
                  {
                      qputenv("QT_IM_MODULE", QByteArray("qtvirtualkeyboard"));
                  
                      QApplication app(argc, argv);
                      //QApplication app2 = static_cast<QApplication>(app);
                  
                  
                      QQuickView view(QString("qrc:/%2").arg(MAIN_QML));
                      if (view.status() == QQuickView::Error)
                          return -1;
                      view.setResizeMode(QQuickView::SizeRootObjectToView);
                      view.show();
                  
                      return app.exec();
                  }
                  
                  JKSHJ 1 Reply Last reply
                  0
                  • I IknowQT

                    @jsulm
                    I didn't quite understand what you mean to convert QguiApplication.

                    @JKSH
                    The keyboard works normally when you follow the steps you mentioned.

                    int main(int argc, char *argv[])
                    {
                        qputenv("QT_IM_MODULE", QByteArray("qtvirtualkeyboard"));
                    
                        QApplication app(argc, argv);
                        //QApplication app2 = static_cast<QApplication>(app);
                    
                    
                        QQuickView view(QString("qrc:/%2").arg(MAIN_QML));
                        if (view.status() == QQuickView::Error)
                            return -1;
                        view.setResizeMode(QQuickView::SizeRootObjectToView);
                        view.show();
                    
                        return app.exec();
                    }
                    
                    JKSHJ Offline
                    JKSHJ Offline
                    JKSH
                    Moderators
                    wrote on last edited by
                    #18

                    @IknowQT said in How to use virtual keyboard on Raspberry Pi 4:

                    The keyboard works normally when you follow the steps you mentioned.

                    I also said:

                    ...create + show a QTextEdit. What happens when you click on the QTextEdit? What happens when you click on one of the fields in the QQuickView?

                    Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

                    I 1 Reply Last reply
                    0
                    • JKSHJ JKSH

                      @IknowQT said in How to use virtual keyboard on Raspberry Pi 4:

                      The keyboard works normally when you follow the steps you mentioned.

                      I also said:

                      ...create + show a QTextEdit. What happens when you click on the QTextEdit? What happens when you click on one of the fields in the QQuickView?

                      I Offline
                      I Offline
                      IknowQT
                      wrote on last edited by
                      #19

                      @JKSH

                      I tried what you did, the result is that once you click on lineedit made into widget the keyboard appears

                      However, the keyboard appears within the quick screen UI area.
                      It seems certain that the keyboard reacts when lineEdit is clicked.

                      JKSHJ 1 Reply Last reply
                      0
                      • I IknowQT

                        @JKSH

                        I tried what you did, the result is that once you click on lineedit made into widget the keyboard appears

                        However, the keyboard appears within the quick screen UI area.
                        It seems certain that the keyboard reacts when lineEdit is clicked.

                        JKSHJ Offline
                        JKSHJ Offline
                        JKSH
                        Moderators
                        wrote on last edited by
                        #20

                        @IknowQT said in How to use virtual keyboard on Raspberry Pi 4:

                        I tried what you did, the result is that once you click on lineedit made into widget the keyboard appears

                        ...

                        It seems certain that the keyboard reacts when lineEdit is clicked.

                        Great! You now have Qt Virtual Keyboard working with a QWidget.

                        However, the keyboard appears within the quick screen UI area.

                        I'm not sure what you mean -- the keyboard is always meant to appear in the bottom half of the screen.

                        Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

                        I 2 Replies Last reply
                        0
                        • JKSHJ JKSH

                          @IknowQT said in How to use virtual keyboard on Raspberry Pi 4:

                          I tried what you did, the result is that once you click on lineedit made into widget the keyboard appears

                          ...

                          It seems certain that the keyboard reacts when lineEdit is clicked.

                          Great! You now have Qt Virtual Keyboard working with a QWidget.

                          However, the keyboard appears within the quick screen UI area.

                          I'm not sure what you mean -- the keyboard is always meant to appear in the bottom half of the screen.

                          I Offline
                          I Offline
                          IknowQT
                          wrote on last edited by IknowQT
                          #21

                          @JKSH

                          e557f7fe-ff5b-4c45-b913-a9f5c05f9af1-image.png

                          I popped up a UI called form and clicked lineEdit. The virtual keyboard appears, but it does not appear in the form widget, but in the quick view.

                          int main(int argc, char *argv[])
                          {
                              qputenv("QT_IM_MODULE", QByteArray("qtvirtualkeyboard"));
                          
                              QApplication app(argc, argv);
                              //QApplication app2 = static_cast<QApplication>(app);
                          
                              Form* f = new Form();
                              f->show();
                          
                              QQuickView view(QString("qrc:/%2").arg(MAIN_QML));
                              if (view.status() == QQuickView::Error)
                                  return -1;
                              view.setResizeMode(QQuickView::SizeRootObjectToView);
                              view.show();
                              return app.exec();
                          }
                          
                          I 1 Reply Last reply
                          0
                          • I IknowQT

                            @JKSH

                            e557f7fe-ff5b-4c45-b913-a9f5c05f9af1-image.png

                            I popped up a UI called form and clicked lineEdit. The virtual keyboard appears, but it does not appear in the form widget, but in the quick view.

                            int main(int argc, char *argv[])
                            {
                                qputenv("QT_IM_MODULE", QByteArray("qtvirtualkeyboard"));
                            
                                QApplication app(argc, argv);
                                //QApplication app2 = static_cast<QApplication>(app);
                            
                                Form* f = new Form();
                                f->show();
                            
                                QQuickView view(QString("qrc:/%2").arg(MAIN_QML));
                                if (view.status() == QQuickView::Error)
                                    return -1;
                                view.setResizeMode(QQuickView::SizeRootObjectToView);
                                view.show();
                                return app.exec();
                            }
                            
                            I Offline
                            I Offline
                            IknowQT
                            wrote on last edited by
                            #22

                            @JKSH

                            Please reply if there is another way.

                            1 Reply Last reply
                            0
                            • JKSHJ JKSH

                              @IknowQT said in How to use virtual keyboard on Raspberry Pi 4:

                              I tried what you did, the result is that once you click on lineedit made into widget the keyboard appears

                              ...

                              It seems certain that the keyboard reacts when lineEdit is clicked.

                              Great! You now have Qt Virtual Keyboard working with a QWidget.

                              However, the keyboard appears within the quick screen UI area.

                              I'm not sure what you mean -- the keyboard is always meant to appear in the bottom half of the screen.

                              I Offline
                              I Offline
                              IknowQT
                              wrote on last edited by
                              #23

                              @JKSH
                              If you don't know, answer that you don't know
                              I think it's a courtesy to anyone waiting for an answer.

                              JKSHJ 1 Reply Last reply
                              0
                              • I IknowQT

                                @JKSH
                                If you don't know, answer that you don't know
                                I think it's a courtesy to anyone waiting for an answer.

                                JKSHJ Offline
                                JKSHJ Offline
                                JKSH
                                Moderators
                                wrote on last edited by
                                #24

                                @IknowQT said in How to use virtual keyboard on Raspberry Pi 4:

                                @JKSH
                                If you don't know, answer that you don't know
                                I think it's a courtesy to anyone waiting for an answer.

                                I'm sorry for keeping you waiting without a response.

                                I don't know why your virtual keyboard appears inside the Qt Quick window; I was planning to investigate but my RPi was deployed to another task.

                                Qt Doc Search for browsers: forum.qt.io/topic/35616/web-browser-extension-for-improved-doc-searches

                                1 Reply Last reply
                                0
                                • I Offline
                                  I Offline
                                  IknowQT
                                  wrote on last edited by
                                  #25

                                  Can anyone suggest a solution to this problem?
                                  No one is interested. Is there no way or is it just being on the lookout?

                                  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 Extensions
                                  • Unsolved