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. Connecting two sliders manually?
Forum Updated to NodeBB v4.3 + New Features

Connecting two sliders manually?

Scheduled Pinned Locked Moved Solved General and Desktop
connectqslider
20 Posts 4 Posters 4.6k Views 2 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.
  • L lansing
    8 Aug 2018, 16:09

    @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?

    M Offline
    M Offline
    mrjj
    Lifetime Qt Champion
    wrote on 8 Aug 2018, 16:12 last edited by mrjj 8 Aug 2018, 16:13
    #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 8 Aug 2018, 16:40
    2
    • M mrjj
      8 Aug 2018, 16:12

      @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 8 Aug 2018, 16:40 last edited by
      #9

      @mrjj

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

      M 1 Reply Last reply 8 Aug 2018, 16:48
      1
      • L lansing
        8 Aug 2018, 16:40

        @mrjj

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

        M Offline
        M Offline
        mrjj
        Lifetime Qt Champion
        wrote on 8 Aug 2018, 16:48 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 8 Aug 2018, 19:50
        1
        • M mrjj
          8 Aug 2018, 16:48

          @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 8 Aug 2018, 19:50 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.

          M 1 Reply Last reply 8 Aug 2018, 20:07
          0
          • L lansing
            8 Aug 2018, 19:50

            @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.

            M Offline
            M Offline
            mrjj
            Lifetime Qt Champion
            wrote on 8 Aug 2018, 20:07 last edited by
            #12

            @lansing
            Are you sure ctor do match ?

            L 1 Reply Last reply 8 Aug 2018, 20:18
            0
            • M mrjj
              8 Aug 2018, 20:07

              @lansing
              Are you sure ctor do match ?

              L Offline
              L Offline
              lansing
              wrote on 8 Aug 2018, 20:18 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
              • S Offline
                S Offline
                SGaist
                Lifetime Qt Champion
                wrote on 8 Aug 2018, 20:20 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 8 Aug 2018, 20:30
                1
                • S SGaist
                  8 Aug 2018, 20:20

                  Hi,

                  Why inheriting from QAbstractSlider if you want to customise QSlider ?

                  L Offline
                  L Offline
                  lansing
                  wrote on 8 Aug 2018, 20:30 last edited by
                  #15

                  @SGaist

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

                  M 1 Reply Last reply 8 Aug 2018, 20:33
                  0
                  • L lansing
                    8 Aug 2018, 20:30

                    @SGaist

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

                    M Offline
                    M Offline
                    mrjj
                    Lifetime Qt Champion
                    wrote on 8 Aug 2018, 20:33 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
                    • S Offline
                      S Offline
                      SGaist
                      Lifetime Qt Champion
                      wrote on 8 Aug 2018, 20:33 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 8 Aug 2018, 20:54 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

                        M 1 Reply Last reply 8 Aug 2018, 21:00
                        0
                        • S Offline
                          S Offline
                          SGaist
                          Lifetime Qt Champion
                          wrote on 8 Aug 2018, 20:56 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
                            8 Aug 2018, 20:54

                            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

                            M Offline
                            M Offline
                            mrjj
                            Lifetime Qt Champion
                            wrote on 8 Aug 2018, 21:00 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
                            3

                            17/20

                            8 Aug 2018, 20:33

                            • Login

                            • Login or register to search.
                            17 out of 20
                            • First post
                              17/20
                              Last post
                            0
                            • Categories
                            • Recent
                            • Tags
                            • Popular
                            • Users
                            • Groups
                            • Search
                            • Get Qt Extensions
                            • Unsolved