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Forum Update on Monday, May 27th 2025

Compose pointer to property of object

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c++pointerobjectsproperties
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  • M McLion
    5 Apr 2016, 09:58

    Tried quickly ... and the Map is exactly what I need.
    Thanks a million! .... I'll be back ;-)

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    mrjj
    Lifetime Qt Champion
    wrote on 5 Apr 2016, 10:02 last edited by
    #15

    @McLion
    super
    notice if you reuse the key
    map[1] =webGUI ;
    map[1] =nextwebGUI ;
    It will replace the web *.

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    • M Offline
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      McLion
      wrote on 5 Apr 2016, 10:03 last edited by
      #16

      Thanks for the heads-up.
      I'll do some testing and experiment.

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      • M Offline
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        McLion
        wrote on 5 Apr 2016, 14:16 last edited by
        #17

        So far, everything related to this threads question and the QMap as solution seems to work.

        I stumbled over something else while relacing the QwebView from the Designer by my 'on-demand' created one:
        I can not load an url, it crashes with sig11.

        I get the following connect error on bootup:

        QMetaObject::connectSlotsByName: No matching signal for on_webGUI_loadFinished(bool)
        

        which I dont understand and may be the cause.
        I have connected:

        connect(webGUI, SIGNAL(loadFinished(bool)), this, SLOT(on_webGUI_loadFinished(bool)));
        

        and in *.h as private slot:

        void on_webGUI_loadFinished(bool arg1);
        

        This worked before, with the QWebView from the Designer.
        Any idea? Thanks.

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        • M Offline
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          mrjj
          Lifetime Qt Champion
          wrote on 5 Apr 2016, 14:26 last edited by
          #18

          @McLion said:

          no matching signal for on_webGUI_loadFinished(bool)

          Hi
          this warning comes as you name slot on_XXX
          This will trigger Qt auto connect feature so when you use
          a concrete connect you should rename it so it dont
          start with on__
          (right click it- refactor->rename)

          also please do
          qDebug() << "loadfin:" << connect(webGUI, SIGNAL(loadFinixxxx

          to see if it returns true; ( as in , it can connect)

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          • M Offline
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            McLion
            wrote on 5 Apr 2016, 14:39 last edited by
            #19

            I wasn't aware that using on_ in the name will trigger any functionality!
            Refactoring solved this problem - Thanks !

            However, the signal 11 crash when trying to load an url seems to have some other cause .... I'm searching ;-)

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            • J Offline
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              jsulm
              Lifetime Qt Champion
              wrote on 5 Apr 2016, 15:47 last edited by
              #20

              You're most probably dereferencing a null pointer. Signal 11 means SIGSEGV (segmentation error).

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

              M 1 Reply Last reply 6 Apr 2016, 08:21
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              • J jsulm
                5 Apr 2016, 15:47

                You're most probably dereferencing a null pointer. Signal 11 means SIGSEGV (segmentation error).

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                McLion
                wrote on 6 Apr 2016, 08:21 last edited by
                #21

                @jsulm
                Yes - Thanks . Problem loacted, but not yet solved:

                void QTGUI_MainWindow::populateJavaScriptWindowObject()
                {
                  QWebView * webGUI = qobject_cast<QWebView *>(sender());
                  webGUI->page()->mainFrame()->addToJavaScriptWindowObject("NativeBridge", this);
                }
                

                The sender is the JS and not the QWebView and so I do not get the pointer to the QWebView that I need. Instead, the pointer is 0x0 and then - of course - the addToJ... crashes.

                Any idea how I get the pointer to the QWebView from which the JS is sending?
                Thanks

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                • J Offline
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                  jsulm
                  Lifetime Qt Champion
                  wrote on 6 Apr 2016, 08:42 last edited by
                  #22

                  What is JS?

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

                  M 1 Reply Last reply 6 Apr 2016, 08:45
                  0
                  • J jsulm
                    6 Apr 2016, 08:42

                    What is JS?

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                    McLion
                    wrote on 6 Apr 2016, 08:45 last edited by
                    #23

                    @jsulm
                    JavaScript (in/from QWebKit ... more precise page()->mainFrame().

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                    • M Offline
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                      McLion
                      wrote on 6 Apr 2016, 11:33 last edited by
                      #24

                      I posted this as a separate question in the WebKit group.

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                      • M Offline
                        M Offline
                        McLion
                        wrote on 6 Apr 2016, 14:57 last edited by
                        #25

                        Got it solved :-)

                        QWebFrame * webGUIframe = qobject_cast<QWebFrame >(sender());
                        QWebView * webGUI = (QWebView
                        )(webGUIframe->parent())->parent();
                        webGUI->page()->mainFrame()->addToJavaScriptWindowObject("NativeBridge", this);

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                        6 Apr 2016, 11:33

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