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QDial pointer start position(value - 0) at top

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  • mrjjM mrjj

    Hi
    Did you try with
    alt text

    If that is not working with Dial then you have to do it manually.

    S Offline
    S Offline
    sayan275
    wrote on last edited by
    #3
    This post is deleted!
    mrjjM 1 Reply Last reply
    0
    • S sayan275

      This post is deleted!

      mrjjM Offline
      mrjjM Offline
      mrjj
      Lifetime Qt Champion
      wrote on last edited by
      #4

      @sayan275
      Hi
      Ok you must have something that block images then.
      Anyway, it show the property
      "inverted appearance "
      that normally flips a slider to be reversed.
      But sadly it didn't work with 0-360 as the zero is still in the bottom.

      http://imagizer.imageshack.com/img922/2451/awXZvi.png

      S 1 Reply Last reply
      0
      • mrjjM mrjj

        @sayan275
        Hi
        Ok you must have something that block images then.
        Anyway, it show the property
        "inverted appearance "
        that normally flips a slider to be reversed.
        But sadly it didn't work with 0-360 as the zero is still in the bottom.

        http://imagizer.imageshack.com/img922/2451/awXZvi.png

        S Offline
        S Offline
        sayan275
        wrote on last edited by
        #5

        @mrjj sorry I got your posted image..its the property.
        dbfebf2e-5bc1-4907-89ed-a71b586dfc3d-image.png
        Yes it didn't work...I tried all possible combinations with the flags available.
        Can we rotated a widget? .. can't remember any api.
        Meanwhile I got the expected output by calculating with +/- 180

        //    if(value > 180)
        //        value -= 180;
        //    else if(value <= 180)
        //        value += 180;
        

        I didn't want to update the value in this manner.

        @mrjj Anyways thanks for your reply.

        mrjjM 1 Reply Last reply
        0
        • S sayan275

          @mrjj sorry I got your posted image..its the property.
          dbfebf2e-5bc1-4907-89ed-a71b586dfc3d-image.png
          Yes it didn't work...I tried all possible combinations with the flags available.
          Can we rotated a widget? .. can't remember any api.
          Meanwhile I got the expected output by calculating with +/- 180

          //    if(value > 180)
          //        value -= 180;
          //    else if(value <= 180)
          //        value += 180;
          

          I didn't want to update the value in this manner.

          @mrjj Anyways thanks for your reply.

          mrjjM Offline
          mrjjM Offline
          mrjj
          Lifetime Qt Champion
          wrote on last edited by
          #6

          @sayan275
          well we cant rotate a widget as such
          but we could subclass it and then flip the painter.
          If that works in terms of navigation, im not sure.

          void QDial::paintEvent(QPaintEvent *)
          {
              QStylePainter p(this);
              QStyleOptionSlider option;
              initStyleOption(&option);
              p.drawComplexControl(QStyle::CC_Dial, option);
          }
          
          

          use p and
          https://doc.qt.io/qt-5/qtwidgets-painting-transformations-example.html
          to flip it and see :)

          S 1 Reply Last reply
          1
          • mrjjM mrjj

            @sayan275
            well we cant rotate a widget as such
            but we could subclass it and then flip the painter.
            If that works in terms of navigation, im not sure.

            void QDial::paintEvent(QPaintEvent *)
            {
                QStylePainter p(this);
                QStyleOptionSlider option;
                initStyleOption(&option);
                p.drawComplexControl(QStyle::CC_Dial, option);
            }
            
            

            use p and
            https://doc.qt.io/qt-5/qtwidgets-painting-transformations-example.html
            to flip it and see :)

            S Offline
            S Offline
            sayan275
            wrote on last edited by
            #7

            @mrjj Thanks for the suggestion.
            I'll try out the overriding the paintEvent()

            Pablo J. RoginaP 1 Reply Last reply
            0
            • S sayan275

              @mrjj Thanks for the suggestion.
              I'll try out the overriding the paintEvent()

              Pablo J. RoginaP Offline
              Pablo J. RoginaP Offline
              Pablo J. Rogina
              wrote on last edited by
              #8

              @sayan275 just in case, do you really need the dial to wrap?

              Upvote the answer(s) that helped you solve the issue
              Use "Topic Tools" button to mark your post as Solved
              Add screenshots via postimage.org
              Don't ask support requests via chat/PM. Please use the forum so others can benefit from the solution in the future

              S 1 Reply Last reply
              0
              • mrjjM Offline
                mrjjM Offline
                mrjj
                Lifetime Qt Champion
                wrote on last edited by mrjj
                #9

                Hi
                Just as a note.

                void MyDial::paintEvent(QPaintEvent *event)
                {
                    QStylePainter p(this);
                    QStyleOptionSlider option;
                    initStyleOption(&option);
                    p.translate(0, height());
                    p.scale(1.0, -1.0);
                    p.drawComplexControl(QStyle::CC_Dial, option);
                }
                

                Did draw as we wanted and using keys (left , right ) moves it ok
                but click and drag with the mouse it jumps back to the old zero.

                So sadly was not a solution as navigation did went banans.

                1 Reply Last reply
                2
                • Pablo J. RoginaP Pablo J. Rogina

                  @sayan275 just in case, do you really need the dial to wrap?

                  S Offline
                  S Offline
                  sayan275
                  wrote on last edited by
                  #10

                  @Pablo-J-Rogina yes...we need to wrap...so that the starting and endpoints are similar.

                  J.HilkJ 1 Reply Last reply
                  0
                  • S sayan275

                    @Pablo-J-Rogina yes...we need to wrap...so that the starting and endpoints are similar.

                    J.HilkJ Offline
                    J.HilkJ Offline
                    J.Hilk
                    Moderators
                    wrote on last edited by J.Hilk
                    #11

                    @sayan275
                    here ya go:

                    //.h
                    #ifndef JHDIAL_H
                    #define JHDIAL_H
                    
                    #include <QDial>
                    
                    class JhDial : public QDial
                    {
                        Q_OBJECT
                        Q_PROPERTY(int adjustedValue READ adjustedValue WRITE setAdjustedValue NOTIFY adjustedValueChanged)
                    public:
                        explicit JhDial(QWidget *parent = nullptr);
                    
                        inline int adjustedValue() const { return m_adjustedValue; }
                    
                    signals:
                        void adjustedValueChanged(int adjustedValue);
                    
                    public slots:
                        void setAdjustedValue(int adjustedValue);
                    
                    private:
                        int mapValueToRange(int y, int y_min, int y_max, int x_min, int x_max);
                        void adjustValue(int value);
                        int m_adjustedValue = -1;
                    };
                    
                    #endif // JHDIAL_H
                    
                    
                    //.cpp
                    #include "jhdial.h"
                    
                    JhDial::JhDial(QWidget *parent) : QDial(parent)
                    {
                        connect(this, &QDial::valueChanged, this, &JhDial::adjustValue);
                    
                        setWrapping(true);
                        setRange(0,360);
                        setAdjustedValue(0);
                    }
                    
                    void JhDial::setAdjustedValue(int adjustedValue)
                    {
                        if (m_adjustedValue == adjustedValue)
                            return;
                    
                        if(adjustedValue < 180)
                            setValue(mapValueToRange(adjustedValue,0,179,180,360));
                        else
                            setValue(mapValueToRange(adjustedValue,180,360, 0, 180));
                    
                    }
                    
                    int JhDial::mapValueToRange(int y, int y_min, int y_max, int x_min, int x_max)
                    {
                        return qRound((y-y_min)/static_cast<double>(y_max-y_min)*(x_max-x_min)+x_min);
                    }
                    
                    void JhDial::adjustValue(int value)
                    {
                        if(value < 180)
                            m_adjustedValue = mapValueToRange(value,0, 179, 180, 360);
                        else
                            m_adjustedValue = mapValueToRange(value,180, 360, 0, 180);
                    
                        emit adjustedValueChanged(m_adjustedValue);
                    }
                    
                    

                    You may have to adjust the borders for the mapping, so that they don't overlap, I mad this in a rush ;)
                    you had to, cleaned it up a bit.


                    Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


                    Q: What's that?
                    A: It's blue light.
                    Q: What does it do?
                    A: It turns blue.

                    S 1 Reply Last reply
                    3
                    • J.HilkJ J.Hilk

                      @sayan275
                      here ya go:

                      //.h
                      #ifndef JHDIAL_H
                      #define JHDIAL_H
                      
                      #include <QDial>
                      
                      class JhDial : public QDial
                      {
                          Q_OBJECT
                          Q_PROPERTY(int adjustedValue READ adjustedValue WRITE setAdjustedValue NOTIFY adjustedValueChanged)
                      public:
                          explicit JhDial(QWidget *parent = nullptr);
                      
                          inline int adjustedValue() const { return m_adjustedValue; }
                      
                      signals:
                          void adjustedValueChanged(int adjustedValue);
                      
                      public slots:
                          void setAdjustedValue(int adjustedValue);
                      
                      private:
                          int mapValueToRange(int y, int y_min, int y_max, int x_min, int x_max);
                          void adjustValue(int value);
                          int m_adjustedValue = -1;
                      };
                      
                      #endif // JHDIAL_H
                      
                      
                      //.cpp
                      #include "jhdial.h"
                      
                      JhDial::JhDial(QWidget *parent) : QDial(parent)
                      {
                          connect(this, &QDial::valueChanged, this, &JhDial::adjustValue);
                      
                          setWrapping(true);
                          setRange(0,360);
                          setAdjustedValue(0);
                      }
                      
                      void JhDial::setAdjustedValue(int adjustedValue)
                      {
                          if (m_adjustedValue == adjustedValue)
                              return;
                      
                          if(adjustedValue < 180)
                              setValue(mapValueToRange(adjustedValue,0,179,180,360));
                          else
                              setValue(mapValueToRange(adjustedValue,180,360, 0, 180));
                      
                      }
                      
                      int JhDial::mapValueToRange(int y, int y_min, int y_max, int x_min, int x_max)
                      {
                          return qRound((y-y_min)/static_cast<double>(y_max-y_min)*(x_max-x_min)+x_min);
                      }
                      
                      void JhDial::adjustValue(int value)
                      {
                          if(value < 180)
                              m_adjustedValue = mapValueToRange(value,0, 179, 180, 360);
                          else
                              m_adjustedValue = mapValueToRange(value,180, 360, 0, 180);
                      
                          emit adjustedValueChanged(m_adjustedValue);
                      }
                      
                      

                      You may have to adjust the borders for the mapping, so that they don't overlap, I mad this in a rush ;)
                      you had to, cleaned it up a bit.

                      S Offline
                      S Offline
                      sayan275
                      wrote on last edited by
                      #12

                      @J-Hilk Thanks ...I tried this.

                      1 Reply Last reply
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