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Items in QGraphicsScene are not movable

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  • sanojsubranS sanojsubran

    Try adding the statement QGraphicsScene::mousePressEvent( event ); before the end of the function

    faiszalkhanF Offline
    faiszalkhanF Offline
    faiszalkhan
    wrote on last edited by
    #7

    @sanojsubran I tried that but it results in a compilation error.

    mrjjM 1 Reply Last reply
    0
    • faiszalkhanF faiszalkhan

      @sanojsubran I tried that but it results in a compilation error.

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

      @faiszalkhan
      Hi
      Can you list that error ?
      Since its the base class that do the actual moving,
      its critical to call it so lets find out what was wrong ?

      faiszalkhanF 1 Reply Last reply
      1
      • mrjjM mrjj

        @faiszalkhan
        Hi
        Can you list that error ?
        Since its the base class that do the actual moving,
        its critical to call it so lets find out what was wrong ?

        faiszalkhanF Offline
        faiszalkhanF Offline
        faiszalkhan
        wrote on last edited by faiszalkhan
        #9

        @mrjj @sanojsubran It was my bad. The solution worked. However I'm not very sure as to what we did there :(

        1 Reply Last reply
        0
        • faiszalkhanF Offline
          faiszalkhanF Offline
          faiszalkhan
          wrote on last edited by faiszalkhan
          #10

          The problem is not completely solved. StateItem is a custom graphics item which inherits QGraphicsItem.
          The constructor of StateItem is as shown below,

          StateItem::StateItem(QPointF pos)
          {
          /* Get the position from the caller */
          drawPos = new QPointF(pos.x(), pos.y());

          //TODO: Set item as movable
          setFlags(QGraphicsItem::ItemIsMovable);

          }

          This graphics Item is displayed on the scene but still is not movable.

          Please help!
          Thanks!

          1 Reply Last reply
          0
          • SGaistS Offline
            SGaistS Offline
            SGaist
            Lifetime Qt Champion
            wrote on last edited by
            #11

            Hi,

            Your original problem was that by not calling the base class method implementation, you don't get the behaviour from the base class.

            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
            • faiszalkhanF Offline
              faiszalkhanF Offline
              faiszalkhan
              wrote on last edited by
              #12

              Since I am inheriting the QGraphicsItem in StateItem to create custom shape. Am I missing out something for setFlags(QGraphicsItem::ItemIsMovable); in the constructor to not work ?

              Thanks

              1 Reply Last reply
              0
              • mrjjM Offline
                mrjjM Offline
                mrjj
                Lifetime Qt Champion
                wrote on last edited by
                #13

                Hi
                You might need
                setFlag(QGraphicsItem::ItemIsMovable);
                setFlag(QGraphicsItem::ItemIsSelectable);

                If we look at
                http://doc.qt.io/qt-5/qtwidgets-graphicsview-diagramscene-example.html

                It all it does to flag the items.

                faiszalkhanF 1 Reply Last reply
                1
                • mrjjM mrjj

                  Hi
                  You might need
                  setFlag(QGraphicsItem::ItemIsMovable);
                  setFlag(QGraphicsItem::ItemIsSelectable);

                  If we look at
                  http://doc.qt.io/qt-5/qtwidgets-graphicsview-diagramscene-example.html

                  It all it does to flag the items.

                  faiszalkhanF Offline
                  faiszalkhanF Offline
                  faiszalkhan
                  wrote on last edited by
                  #14

                  @mrjj said in Items in QGraphicsScene are not movable:

                  setFlag(QGraphicsItem::ItemIsMovable);
                  setFlag(QGraphicsItem::ItemIsSelectable);

                  Hi @mrjj , tried the same but still not working.

                  1 Reply Last reply
                  0
                  • mrjjM Offline
                    mrjjM Offline
                    mrjj
                    Lifetime Qt Champion
                    wrote on last edited by
                    #15

                    Ok. cant tell what is wrong then.
                    You might have overridden a virtual and forgot to call base class.

                    Have a look at the diagram sample and see if can spot anything you
                    did different.

                    Or try the StateItem in a default scene/view.

                    faiszalkhanF 1 Reply Last reply
                    0
                    • mrjjM mrjj

                      Ok. cant tell what is wrong then.
                      You might have overridden a virtual and forgot to call base class.

                      Have a look at the diagram sample and see if can spot anything you
                      did different.

                      Or try the StateItem in a default scene/view.

                      faiszalkhanF Offline
                      faiszalkhanF Offline
                      faiszalkhan
                      wrote on last edited by
                      #16

                      @mrjj I just have the constructor, paint function and bounding rect. The file is as follows,

                      StateItem::StateItem(QPointF pos)
                      {

                      /* Get the position from the caller */
                      drawPos = new QPointF(pos.x(), pos.y());
                      
                      //TODO: Set item as movable
                      

                      // setFlags(QGraphicsItem::ItemIsFocusable);
                      // setFlags(QGraphicsItem::ItemIsSelectable);
                      setFlags(QGraphicsItem::ItemIsMovable);

                      // QGraphicsItem::QGraphicsItem();
                      }

                      QRectF StateItem::boundingRect() const
                      {
                      //TODO: Return a rectangle of calculated size
                      qreal penWidth = 1;
                      return QRectF(-10 - penWidth / 2, -10 - penWidth / 2,
                      20 + penWidth, 20 + penWidth);

                      }

                      /* Explicit call to this function is not required */
                      void StateItem::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget widget)
                      {
                      /
                      Set the pen */
                      QPen blackpen(Qt::black);
                      blackpen.setWidth(2);
                      painter->setPen(blackpen);

                      /* Set colour of the state */
                      QColor statecolor(229,231,233);
                      QBrush statebrush(statecolor);
                      painter->setBrush(statebrush);
                      
                      /* Draw state item */
                      painter->drawRoundedRect(drawPos->x(),drawPos->y(),100,50,8,8); //x,y,width,height,xradius,yradius
                      
                      QPoint p(drawPos->x(),(drawPos->y() + 10));
                      QPoint q((drawPos->x() + 100), (drawPos->y() + 10));
                      QLine stateLine(p,q);
                      painter->drawLine(stateLine);
                      

                      // QGraphicsItem::paint(painter,option,widget);

                      }

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

                        Hi
                        Dont it need to be selectable to be moveable ?
                        It all seems fine
                        try use the DiagramTextItem from the diagram sample (its available directly in Creator)

                        If that cant move, it means its your view or scene.

                        //! [0]
                        DiagramTextItem::DiagramTextItem(QGraphicsItem *parent)
                            : QGraphicsTextItem(parent)
                        {
                            setFlag(QGraphicsItem::ItemIsMovable); // BOTH 
                            setFlag(QGraphicsItem::ItemIsSelectable);
                        }
                        //! [0]
                        
                        //! [1]
                        QVariant DiagramTextItem::itemChange(GraphicsItemChange change,
                                             const QVariant &value)
                        {
                            if (change == QGraphicsItem::ItemSelectedHasChanged)
                                emit selectedChange(this);
                            return value;
                        }
                        //! [1]
                        
                        //! [2]
                        void DiagramTextItem::focusOutEvent(QFocusEvent *event)
                        {
                            setTextInteractionFlags(Qt::NoTextInteraction);
                            emit lostFocus(this);
                            QGraphicsTextItem::focusOutEvent(event);
                        }
                        //! [2]
                        
                        //! [5]
                        void DiagramTextItem::mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event)
                        {
                            if (textInteractionFlags() == Qt::NoTextInteraction)
                                setTextInteractionFlags(Qt::TextEditorInteraction);
                            QGraphicsTextItem::mouseDoubleClickEvent(event);
                        }
                        
                        faiszalkhanF 1 Reply Last reply
                        0
                        • mrjjM mrjj

                          Hi
                          Dont it need to be selectable to be moveable ?
                          It all seems fine
                          try use the DiagramTextItem from the diagram sample (its available directly in Creator)

                          If that cant move, it means its your view or scene.

                          //! [0]
                          DiagramTextItem::DiagramTextItem(QGraphicsItem *parent)
                              : QGraphicsTextItem(parent)
                          {
                              setFlag(QGraphicsItem::ItemIsMovable); // BOTH 
                              setFlag(QGraphicsItem::ItemIsSelectable);
                          }
                          //! [0]
                          
                          //! [1]
                          QVariant DiagramTextItem::itemChange(GraphicsItemChange change,
                                               const QVariant &value)
                          {
                              if (change == QGraphicsItem::ItemSelectedHasChanged)
                                  emit selectedChange(this);
                              return value;
                          }
                          //! [1]
                          
                          //! [2]
                          void DiagramTextItem::focusOutEvent(QFocusEvent *event)
                          {
                              setTextInteractionFlags(Qt::NoTextInteraction);
                              emit lostFocus(this);
                              QGraphicsTextItem::focusOutEvent(event);
                          }
                          //! [2]
                          
                          //! [5]
                          void DiagramTextItem::mouseDoubleClickEvent(QGraphicsSceneMouseEvent *event)
                          {
                              if (textInteractionFlags() == Qt::NoTextInteraction)
                                  setTextInteractionFlags(Qt::TextEditorInteraction);
                              QGraphicsTextItem::mouseDoubleClickEvent(event);
                          }
                          
                          faiszalkhanF Offline
                          faiszalkhanF Offline
                          faiszalkhan
                          wrote on last edited by
                          #18

                          @mrjj Dont it need to be selectable to be moveable ?

                          No, Only setting it as moveable also works. I have standard QGraphicsRectItem and QGraphicsEllipseItem also in the same scene which are moving. So I don't think its the view or the scene.

                          :'(

                          mrjjM 1 Reply Last reply
                          0
                          • faiszalkhanF faiszalkhan

                            @mrjj Dont it need to be selectable to be moveable ?

                            No, Only setting it as moveable also works. I have standard QGraphicsRectItem and QGraphicsEllipseItem also in the same scene which are moving. So I don't think its the view or the scene.

                            :'(

                            mrjjM Offline
                            mrjjM Offline
                            mrjj
                            Lifetime Qt Champion
                            wrote on last edited by
                            #19

                            @faiszalkhan
                            Ok, there is something i dont see then. :)
                            if you provide both StateItem.h and cpp
                            i can try run it and see.

                            faiszalkhanF 1 Reply Last reply
                            0
                            • sanojsubranS Offline
                              sanojsubranS Offline
                              sanojsubran
                              wrote on last edited by
                              #20

                              Hi,

                              Comment your overriden paint method for StateItem and check whether it is working.

                              Also please tell how you are updating the variable "drawPos".

                              Regards,
                              San

                              1 Reply Last reply
                              0
                              • mrjjM mrjj

                                @faiszalkhan
                                Ok, there is something i dont see then. :)
                                if you provide both StateItem.h and cpp
                                i can try run it and see.

                                faiszalkhanF Offline
                                faiszalkhanF Offline
                                faiszalkhan
                                wrote on last edited by faiszalkhan
                                #21
                                This post is deleted!
                                1 Reply Last reply
                                0
                                • faiszalkhanF Offline
                                  faiszalkhanF Offline
                                  faiszalkhan
                                  wrote on last edited by
                                  #22
                                  This post is deleted!
                                  1 Reply Last reply
                                  0
                                  • faiszalkhanF Offline
                                    faiszalkhanF Offline
                                    faiszalkhan
                                    wrote on last edited by
                                    #23

                                    I had previously given a static bounding rect value as the previous implementation was static. Now that the value is dynamic I had not changed the contents of the bounding rect as the size has not changed from the previous implementation.

                                    Making the changes in the bounding rect solved the problem.

                                    Thanks a lot to @mrjj @sanojsubran @SGaist !

                                    1 Reply Last reply
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