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  • SGaistS SGaist

    Hi,

    You can trigger a repaint in the hoverEnterEvent.

    U Offline
    U Offline
    user4592357
    wrote on last edited by
    #5

    @SGaist
    yes, but how should i draw a "border" around the line?

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    • SGaistS Offline
      SGaistS Offline
      SGaist
      Lifetime Qt Champion
      wrote on last edited by
      #6

      Paint a rectangle that is slightly bigger that the geometry of your widget.

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

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      • U user4592357

        @SGaist
        yes, but how should i draw a "border" around the line?

        K Offline
        K Offline
        kenchan
        wrote on last edited by
        #7

        @user4592357 the same draw function needs to know when it needs to draw the highlight or just the line... how you do that depends on details of your implementation which you have not shared with us yet. I am sure you can figure some way to do it though :-).

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        • K kenchan

          @user4592357 the same draw function needs to know when it needs to draw the highlight or just the line... how you do that depends on details of your implementation which you have not shared with us yet. I am sure you can figure some way to do it though :-).

          U Offline
          U Offline
          user4592357
          wrote on last edited by
          #8

          @kenchan
          it is in Python, sorry. my tries are in vain:

          class Item(QGraphicsItem):
          
              def __init__(self, x, y):
                  super(ErrorItem, self).__init__()
                  self.__x = x
                  self.__y = y
          
                  self.__hovered = False
          
                  self.setAcceptHoverEvents(True)
          
              def paint(self, painter, option, widget):
                  pen = QPen(Qt.red)
                  pen.setWidth(4)
                  painter.setPen(pen)
          
                  painter.drawLine(QPoint(0, 0), QPoint(100, 100))
                  painter.drawLine(QPoint(0, 100), QPoint(100, 0))
          
                  if self.__hovered:
                      # what should go here?
                      pen.setColor(Qt.white)
                      pen.setWidth(8)
                      self.__hovered = False
                      # painter.drawLine(QPoint(-50, -50), QPoint(103, 103))
          
              def boundingRect(self):
                  return QRectF(0, 0, 100, 100)
          
              def hoverEnterEvent(self, event):
                  # self.setGraphicsEffect(QGraphicsColorizeEffect())
                  self.__hovered = True
                  
              def hoverLeaveEvent(self, event):
                  self.setGraphicsEffect(None)
          
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          • U user4592357

            @kenchan
            it is in Python, sorry. my tries are in vain:

            class Item(QGraphicsItem):
            
                def __init__(self, x, y):
                    super(ErrorItem, self).__init__()
                    self.__x = x
                    self.__y = y
            
                    self.__hovered = False
            
                    self.setAcceptHoverEvents(True)
            
                def paint(self, painter, option, widget):
                    pen = QPen(Qt.red)
                    pen.setWidth(4)
                    painter.setPen(pen)
            
                    painter.drawLine(QPoint(0, 0), QPoint(100, 100))
                    painter.drawLine(QPoint(0, 100), QPoint(100, 0))
            
                    if self.__hovered:
                        # what should go here?
                        pen.setColor(Qt.white)
                        pen.setWidth(8)
                        self.__hovered = False
                        # painter.drawLine(QPoint(-50, -50), QPoint(103, 103))
            
                def boundingRect(self):
                    return QRectF(0, 0, 100, 100)
            
                def hoverEnterEvent(self, event):
                    # self.setGraphicsEffect(QGraphicsColorizeEffect())
                    self.__hovered = True
                    
                def hoverLeaveEvent(self, event):
                    self.setGraphicsEffect(None)
            
            K Offline
            K Offline
            kenchan
            wrote on last edited by kenchan
            #9

            @user4592357 Sorry I don't develop Qt with Python...
            Maybe you could put the line drawing bits after the if statement and make that just change the colour and the thickness?
            Since you can draw the line normally then that should work as before, right?
            The next issue will be if your hovered flag is getting changed when the event is fired. Can you debug that to check it?
            Finally i guess you will want to force the scene to redraw, if that is the problem you are seeing.
            I would have thought that the scene would be redrawn when the hover events happen?
            I believe the default implementation of hoveredEnterEvent() function just calls update(). Maybe you should call update() or something?
            I think you should reset the hovered flag to false in the hoverLeaveEvent so it only happens when you are actually hovering over it :-)

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            • K kenchan

              @user4592357 Sorry I don't develop Qt with Python...
              Maybe you could put the line drawing bits after the if statement and make that just change the colour and the thickness?
              Since you can draw the line normally then that should work as before, right?
              The next issue will be if your hovered flag is getting changed when the event is fired. Can you debug that to check it?
              Finally i guess you will want to force the scene to redraw, if that is the problem you are seeing.
              I would have thought that the scene would be redrawn when the hover events happen?
              I believe the default implementation of hoveredEnterEvent() function just calls update(). Maybe you should call update() or something?
              I think you should reset the hovered flag to false in the hoverLeaveEvent so it only happens when you are actually hovering over it :-)

              U Offline
              U Offline
              user4592357
              wrote on last edited by
              #10

              @kenchan
              drawing the line thicker isn't a problem, but i don't know how to draw a red line (normal) + the highlight (outline) around it which is white

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              • U user4592357

                @kenchan
                drawing the line thicker isn't a problem, but i don't know how to draw a red line (normal) + the highlight (outline) around it which is white

                K Offline
                K Offline
                kenchan
                wrote on last edited by
                #11

                @user4592357
                if you can draw it one way you can draw it the other way right?
                So what exactly is the problem now then, the events are not working? the events work but your draw functions is not getting called when expect?

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                • K kenchan

                  @user4592357
                  if you can draw it one way you can draw it the other way right?
                  So what exactly is the problem now then, the events are not working? the events work but your draw functions is not getting called when expect?

                  U Offline
                  U Offline
                  user4592357
                  wrote on last edited by
                  #12

                  @kenchan
                  as you can see in code, i set a boolean in hover event and in paint() check - if it's hovered draw outline, but it doesn't. i also tried to call update() inside hoverEnterEvent - still no luck

                  K 2 Replies Last reply
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                  • U user4592357

                    @kenchan
                    drawing the line thicker isn't a problem, but i don't know how to draw a red line (normal) + the highlight (outline) around it which is white

                    K Offline
                    K Offline
                    kenchan
                    wrote on last edited by
                    #13

                    @user4592357
                    What don't you understand about how to draw it?
                    If you want an outline around a line the easiest way is to draw a thin line on top of a thicker line using the same two points.
                    You draw the thick one first then you draw the thin one on top. If you want to make absolutely sure that the thin one is on top you can set the z value of it to be above the thick one.

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                    • U user4592357

                      @kenchan
                      as you can see in code, i set a boolean in hover event and in paint() check - if it's hovered draw outline, but it doesn't. i also tried to call update() inside hoverEnterEvent - still no luck

                      K Offline
                      K Offline
                      kenchan
                      wrote on last edited by
                      #14

                      @user4592357
                      And does you hovered flag actually get set?

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                      • U user4592357

                        @kenchan
                        as you can see in code, i set a boolean in hover event and in paint() check - if it's hovered draw outline, but it doesn't. i also tried to call update() inside hoverEnterEvent - still no luck

                        K Offline
                        K Offline
                        kenchan
                        wrote on last edited by kenchan
                        #15

                        @user4592357
                        Are you adding the pen thickness to your bounding rect?
                        Also, I think you must call prepareGeometyChange() if you change the shape or size of the bounding box etc.
                        You usually call this in a setting function that results in a change in shape. In your case you probably want to do it in your event function.

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                        • K kenchan

                          @user4592357
                          And does you hovered flag actually get set?

                          U Offline
                          U Offline
                          user4592357
                          wrote on last edited by
                          #16

                          @kenchan
                          z value of what? QLine?

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                          • U user4592357

                            @kenchan
                            z value of what? QLine?

                            K Offline
                            K Offline
                            kenchan
                            wrote on last edited by
                            #17

                            @user4592357
                            Ah, sorry that is a property of your graphics item :-) no, I think just the draw order should work for the painter.

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                            • U user4592357

                              @kenchan
                              z value of what? QLine?

                              K Offline
                              K Offline
                              kenchan
                              wrote on last edited by
                              #18

                              @user4592357
                              So, did you have any luck with it yet?

                              U 1 Reply Last reply
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                              • K kenchan

                                @user4592357
                                So, did you have any luck with it yet?

                                U Offline
                                U Offline
                                user4592357
                                wrote on last edited by
                                #19

                                @kenchan
                                no this is what i get:

                                no hover:
                                alt text

                                after hover:
                                alt text

                                code:

                                    def paint(self, painter, option, widget):
                                        pen = QPen(Qt.red)
                                        if self.__hovered:
                                            # what should go here?
                                            self.__hovered = False
                                            pen.setColor(Qt.white)
                                            pen.setWidth(8)
                                            painter.setPen(pen)
                                            painter.drawLine(QPoint(0, 0), QPoint(100, 100))
                                            painter.drawLine(QPoint(0, 100), QPoint(100, 0))
                                
                                        pen.setWidth(4)
                                        painter.setPen(pen)
                                
                                        line = QLine(QPoint(0, 0), QPoint(100, 100))
                                        painter.drawLine(line)
                                        painter.drawLine(QPoint(0, 100), QPoint(100, 0))
                                
                                    def boundingRect(self):
                                        return QRectF(0, 0, 108, 108)
                                
                                    def hoverEnterEvent(self, event):
                                        # self.setGraphicsEffect(QGraphicsColorizeEffect())
                                        self.__hovered = True
                                        self.update()
                                        self.prepareGeometryChange()
                                
                                    def hoverLeaveEvent(self, event):
                                        self.setGraphicsEffect(None)
                                
                                K 1 Reply Last reply
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                                • U user4592357

                                  @kenchan
                                  no this is what i get:

                                  no hover:
                                  alt text

                                  after hover:
                                  alt text

                                  code:

                                      def paint(self, painter, option, widget):
                                          pen = QPen(Qt.red)
                                          if self.__hovered:
                                              # what should go here?
                                              self.__hovered = False
                                              pen.setColor(Qt.white)
                                              pen.setWidth(8)
                                              painter.setPen(pen)
                                              painter.drawLine(QPoint(0, 0), QPoint(100, 100))
                                              painter.drawLine(QPoint(0, 100), QPoint(100, 0))
                                  
                                          pen.setWidth(4)
                                          painter.setPen(pen)
                                  
                                          line = QLine(QPoint(0, 0), QPoint(100, 100))
                                          painter.drawLine(line)
                                          painter.drawLine(QPoint(0, 100), QPoint(100, 0))
                                  
                                      def boundingRect(self):
                                          return QRectF(0, 0, 108, 108)
                                  
                                      def hoverEnterEvent(self, event):
                                          # self.setGraphicsEffect(QGraphicsColorizeEffect())
                                          self.__hovered = True
                                          self.update()
                                          self.prepareGeometryChange()
                                  
                                      def hoverLeaveEvent(self, event):
                                          self.setGraphicsEffect(None)
                                  
                                  K Offline
                                  K Offline
                                  kenchan
                                  wrote on last edited by
                                  #20

                                  @user4592357
                                  Hmm so that red thing is your thin line version?

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                                  • K kenchan

                                    @user4592357
                                    Hmm so that red thing is your thin line version?

                                    U Offline
                                    U Offline
                                    user4592357
                                    wrote on last edited by
                                    #21

                                    @kenchan
                                    yes

                                    K 2 Replies Last reply
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                                    • U user4592357

                                      @kenchan
                                      yes

                                      K Offline
                                      K Offline
                                      kenchan
                                      wrote on last edited by
                                      #22

                                      @user4592357
                                      so, it is drawing it but in the wrong place?

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                                      • U user4592357

                                        @kenchan
                                        yes

                                        K Offline
                                        K Offline
                                        kenchan
                                        wrote on last edited by
                                        #23

                                        @user4592357
                                        you are still not reseting the hover flag in hoverleave so it is always on, right?

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                                        • K kenchan

                                          @user4592357
                                          you are still not reseting the hover flag in hoverleave so it is always on, right?

                                          U Offline
                                          U Offline
                                          user4592357
                                          wrote on last edited by
                                          #24

                                          @kenchan
                                          i reset it after drawing the white line.
                                          it is drawing above red line instead of around it

                                          K 1 Reply Last reply
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