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Connecting two sliders manually?

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connectqslider
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  • L lansing

    @mrjj

    Thank you, I followed this setup and it works. The older slider was created from a custom class, it has signal for valueChanged but doesn't have one for rangeChanged, so I added one and emit it right after the range set by the old slider.

    I have a second problem, I want the new slider to have 1 singleStep on wheel scroll instead of 3, and when I click anywhere on the slider I want it to jump right to that point instead of doing those mini jumps. I have looked at the doc, it doesn't have anything to change them, does that mean I have to extend the QSlider class myself?

    mrjjM Offline
    mrjjM Offline
    mrjj
    Lifetime Qt Champion
    wrote on last edited by mrjj
    #8

    @lansing
    Well it does have a singleStep property
    but you mean ONLY on wheel ?
    http://doc.qt.io/qt-5/qabstractslider.html#singleStep-prop

    As far as i know u have to subclass to get jump on click
    https://stackoverflow.com/questions/11132597/qslider-mouse-direct-jump

    L 1 Reply Last reply
    2
    • mrjjM mrjj

      @lansing
      Well it does have a singleStep property
      but you mean ONLY on wheel ?
      http://doc.qt.io/qt-5/qabstractslider.html#singleStep-prop

      As far as i know u have to subclass to get jump on click
      https://stackoverflow.com/questions/11132597/qslider-mouse-direct-jump

      L Offline
      L Offline
      lansing
      wrote on last edited by
      #9

      @mrjj

      Apparently the setSingleStep only applies to keyboard...ok I'll just subclass it.

      mrjjM 1 Reply Last reply
      1
      • L lansing

        @mrjj

        Apparently the setSingleStep only applies to keyboard...ok I'll just subclass it.

        mrjjM Offline
        mrjjM Offline
        mrjj
        Lifetime Qt Champion
        wrote on last edited by
        #10

        @lansing
        hmm yes, seems to take 3 ticks regardless.
        Its handled here

        void QAbstractSlider::wheelEvent(QWheelEvent * e)
        {
            Q_D(QAbstractSlider);
            e->ignore();
            int delta = e->delta();
            if (e->inverted())
                delta = -delta;
            if (d->scrollByDelta(e->orientation(), e->modifiers(), delta))
                e->accept();
        }
        

        so maybe it depends on how mwheel is setup.

        L 1 Reply Last reply
        1
        • mrjjM mrjj

          @lansing
          hmm yes, seems to take 3 ticks regardless.
          Its handled here

          void QAbstractSlider::wheelEvent(QWheelEvent * e)
          {
              Q_D(QAbstractSlider);
              e->ignore();
              int delta = e->delta();
              if (e->inverted())
                  delta = -delta;
              if (d->scrollByDelta(e->orientation(), e->modifiers(), delta))
                  e->accept();
          }
          

          so maybe it depends on how mwheel is setup.

          L Offline
          L Offline
          lansing
          wrote on last edited by
          #11

          @mrjj

          Ok now I got into a QSlider paradox...

          I created the slider object in the ui, then I created a new slider subclass base on QAbstractSlider. Then in the ui I tried to promote the slider object to the new subclass, but in the "base class" selection, it doesn't have QAbstractSlider as a choice, so I chose "QSlider" and the program ended complaining about constructor doesn't match. But I have to use QAbstractSlider as the base class because Qslider doesn't have control for wheelEvent.

          mrjjM 1 Reply Last reply
          0
          • L lansing

            @mrjj

            Ok now I got into a QSlider paradox...

            I created the slider object in the ui, then I created a new slider subclass base on QAbstractSlider. Then in the ui I tried to promote the slider object to the new subclass, but in the "base class" selection, it doesn't have QAbstractSlider as a choice, so I chose "QSlider" and the program ended complaining about constructor doesn't match. But I have to use QAbstractSlider as the base class because Qslider doesn't have control for wheelEvent.

            mrjjM Offline
            mrjjM Offline
            mrjj
            Lifetime Qt Champion
            wrote on last edited by
            #12

            @lansing
            Are you sure ctor do match ?

            L 1 Reply Last reply
            0
            • mrjjM mrjj

              @lansing
              Are you sure ctor do match ?

              L Offline
              L Offline
              lansing
              wrote on last edited by
              #13

              @mrjj

              It complains about setTickInterval being not a member of the class

              Here's my new slider header

              class NewSlider: public QAbstractSlider
              {
              public:
                  NewSlider(QWidget * parent = nullptr);
              }
              
              1 Reply Last reply
              0
              • SGaistS Offline
                SGaistS Offline
                SGaist
                Lifetime Qt Champion
                wrote on last edited by
                #14

                Hi,

                Why inheriting from QAbstractSlider if you want to customise QSlider ?

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

                L 1 Reply Last reply
                1
                • SGaistS SGaist

                  Hi,

                  Why inheriting from QAbstractSlider if you want to customise QSlider ?

                  L Offline
                  L Offline
                  lansing
                  wrote on last edited by
                  #15

                  @SGaist

                  Hi, because QSlider doesn't have access to wheelEvent, which is one of the thing I need.

                  mrjjM 1 Reply Last reply
                  0
                  • L lansing

                    @SGaist

                    Hi, because QSlider doesn't have access to wheelEvent, which is one of the thing I need.

                    mrjjM Offline
                    mrjjM Offline
                    mrjj
                    Lifetime Qt Champion
                    wrote on last edited by
                    #16

                    @lansing
                    Hi
                    QSlider also have
                    void wheelEvent(QWheelEvent * e)
                    you can just override it. (its a virtual function )

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

                      I understand you want to reimplement the wheelEvent method but inheriting from QAbstractSlider means that you're going to reimplement also the painting, etc. to make your custom slider match the design of QSlider. On the other hand, subclassing QSlider and reimplement the wheelEvent there will reduce highly the work needed.

                      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
                      1
                      • L Offline
                        L Offline
                        lansing
                        wrote on last edited by
                        #18

                        Oh it does have a wheelEvent...I was looking at the document and I couldn't find the word on the page, so I thought it doesn't have.

                        http://doc.qt.io/qt-5/qslider.html

                        mrjjM 1 Reply Last reply
                        0
                        • SGaistS Offline
                          SGaistS Offline
                          SGaist
                          Lifetime Qt Champion
                          wrote on last edited by
                          #19

                          When in doubt look at the base class(s) implementation and/or the link named List of all members, including inherited members.

                          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
                          2
                          • L lansing

                            Oh it does have a wheelEvent...I was looking at the document and I couldn't find the word on the page, so I thought it doesn't have.

                            http://doc.qt.io/qt-5/qslider.html

                            mrjjM Offline
                            mrjjM Offline
                            mrjj
                            Lifetime Qt Champion
                            wrote on last edited by
                            #20

                            @lansing
                            Pro Tip. ;)

                            If you right click your custom class name
                            alt text

                            You can easy see and insert functions from base

                            alt text

                            1 Reply Last reply
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