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Transparency in Table/Tree View/WIdget with setAlternatingRowColors and Delegate

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  • mrjjM Offline
    mrjjM Offline
    mrjj
    Lifetime Qt Champion
    wrote on last edited by
    #2

    Hi
    Its just a bug in that sample.

    You can fix it by clipping to the cell rect.

    alt text

    void StarRating::paint(QPainter *painter, const QRect &rect,
                           const QPalette &palette, EditMode mode) const
    {
        painter->save();
        painter->setClipRect(rect); <<<<<<<<<<<<<<<<<<<<<<<<<<<< NEW we clip it.
        painter->setRenderHint(QPainter::Antialiasing, true);
        painter->setPen(Qt::NoPen);
        painter->setBrush(mode == EditMode::Editable ?
                              palette.highlight() :
                              palette.windowText());
    
        const int yOffset = (rect.height() - PaintingScaleFactor) / 2;
        painter->translate(rect.x(), rect.y() + yOffset);
        painter->scale(PaintingScaleFactor, PaintingScaleFactor);
    
        for (int i = 0; i < myMaxStarCount; ++i) {
            if (i < myStarCount)
                painter->drawPolygon(starPolygon, Qt::WindingFill);
            else if (mode == EditMode::Editable)
                painter->drawPolygon(diamondPolygon, Qt::WindingFill);
            painter->translate(1.0, 0.0);
        }
    
        painter->restore();
    }
    
    1 Reply Last reply
    2
    • gde23G Offline
      gde23G Offline
      gde23
      wrote on last edited by
      #3

      @mrjj Thanks for the hint.
      I've tried your approach with clipping.
      This works, however it leads to strange behavior at the border making some parts of the editor overlap the scrollbar on the side of the view sometimes.

      I guess setClipRect() overwrites the default clipping in that area?

      mrjjM 1 Reply Last reply
      0
      • gde23G gde23

        @mrjj Thanks for the hint.
        I've tried your approach with clipping.
        This works, however it leads to strange behavior at the border making some parts of the editor overlap the scrollbar on the side of the view sometimes.

        I guess setClipRect() overwrites the default clipping in that area?

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

        @gde23
        Hi
        I dont think its due to clipping as setClipRect()
        cannot make it possible to draw outside the client rect into other widgets as far as i know, so
        so i think its something else. :)

        Can you tell me how to reproduce the effect or can you show a picture?

        1 Reply Last reply
        1
        • gde23G Offline
          gde23G Offline
          gde23
          wrote on last edited by
          #5

          @mrjj
          I currently cannot reproduce it with the stardelegate example, only with my larger project where it is hard to isolate a minimal example.

          Here is a screenshot that shows what I mean:overlap.png

          My delegates have something like a row-header for each row (the grey bar) and it overlaps to the right out of the view into the neighboring widget (blue/grey) and over the scrollbar. This is not only the case for the row-header but any part of the delegate sometimes overlaps, its kind of random.

          However the problem only occurs as soon as I add setCliptRect(), without that line it works as expected.

          My painter function looks something like this:

          //... set editor data and so on
          QStyleOptionViewItem option_widget = option;
          QStyledItemDelegate::initStyleOption(&option_widget, index);
          painter->save();
          painter->setClipRect(option.rect);
          editor->setPalette(option_widget.palette);
          editor->resize(option_widget.rect.size());
          painter->translate(option_widget.rect.topLeft());
          editor->render(painter, QPoint(), QRegion(), QWidget::DrawChildren);
          painter->restore();
          
          mrjjM 1 Reply Last reply
          0
          • gde23G gde23

            @mrjj
            I currently cannot reproduce it with the stardelegate example, only with my larger project where it is hard to isolate a minimal example.

            Here is a screenshot that shows what I mean:overlap.png

            My delegates have something like a row-header for each row (the grey bar) and it overlaps to the right out of the view into the neighboring widget (blue/grey) and over the scrollbar. This is not only the case for the row-header but any part of the delegate sometimes overlaps, its kind of random.

            However the problem only occurs as soon as I add setCliptRect(), without that line it works as expected.

            My painter function looks something like this:

            //... set editor data and so on
            QStyleOptionViewItem option_widget = option;
            QStyledItemDelegate::initStyleOption(&option_widget, index);
            painter->save();
            painter->setClipRect(option.rect);
            editor->setPalette(option_widget.palette);
            editor->resize(option_widget.rect.size());
            painter->translate(option_widget.rect.topLeft());
            editor->render(painter, QPoint(), QRegion(), QWidget::DrawChildren);
            painter->restore();
            
            mrjjM Offline
            mrjjM Offline
            mrjj
            Lifetime Qt Champion
            wrote on last edited by
            #6

            @gde23
            Hi
            I think it's your editor as only a widget can overlap the scrollbar this way.
            You should not be able to paint outside the viewport() as far as i know and even if you could we
            limit painter to the cell rect.

            have you checked the values from
            editor->resize(option_widget.rect.size());
            and see if that could extend out over the scrollbar.

            gde23G 1 Reply Last reply
            1
            • mrjjM mrjj

              @gde23
              Hi
              I think it's your editor as only a widget can overlap the scrollbar this way.
              You should not be able to paint outside the viewport() as far as i know and even if you could we
              limit painter to the cell rect.

              have you checked the values from
              editor->resize(option_widget.rect.size());
              and see if that could extend out over the scrollbar.

              gde23G Offline
              gde23G Offline
              gde23
              wrote on last edited by
              #7

              @mrjj

              The whole editor is not resizing over the border (as you also can see in the picture only the editor-header-widget overlays the outer area.

              I've found out something more: The problem only occurs when a stylesheet is set.
              It is enough to have following general entry in there:

              QWidget {
                  color: #000000;
                  background: #f0f0f0;
                  border: 2px solid transparent;
                  font-size: 9pt;
              }
              

              when I change it to

              QWidget {
                  color: #000000;
              }
              

              the problem is gone,
              however with

              QWidget {
                  color: #000000;
                  background: #f0f0f0;
              }
              

              its still there .
              This does not make a lot of sense to me.

              mrjjM 1 Reply Last reply
              0
              • gde23G gde23

                @mrjj

                The whole editor is not resizing over the border (as you also can see in the picture only the editor-header-widget overlays the outer area.

                I've found out something more: The problem only occurs when a stylesheet is set.
                It is enough to have following general entry in there:

                QWidget {
                    color: #000000;
                    background: #f0f0f0;
                    border: 2px solid transparent;
                    font-size: 9pt;
                }
                

                when I change it to

                QWidget {
                    color: #000000;
                }
                

                the problem is gone,
                however with

                QWidget {
                    color: #000000;
                    background: #f0f0f0;
                }
                

                its still there .
                This does not make a lot of sense to me.

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

                @gde23
                But do you need setClipRect ?
                It was just to clip the stars in old sample.

                Yes it make little sense as stylesheet should not realyl matter.

                I still think its your editor widget you see.

                gde23G 1 Reply Last reply
                1
                • mrjjM mrjj

                  @gde23
                  But do you need setClipRect ?
                  It was just to clip the stars in old sample.

                  Yes it make little sense as stylesheet should not realyl matter.

                  I still think its your editor widget you see.

                  gde23G Offline
                  gde23G Offline
                  gde23
                  wrote on last edited by gde23
                  #9

                  @mrjj
                  My editer is a Qwigdet with a layout on it and inside the layout there are other widgets.
                  I have not reimplemented any painting for it, so it just uses the default paint routines.

                  The paint from the delegate is this:

                  void TreeItemDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option,const QModelIndex &index) const
                  {
                  QWidget* editor = nullptr;
                  editor = new DummyDelegate();
                  
                  QStyleOptionViewItem option_widget = option;
                  QStyledItemDelegate::initStyleOption(&option_widget, index);
                  
                  painter->save();
                  painter->setClipRect(option.rect);
                  editor->setPalette(option_widget.palette);
                  editor->resize(option_widget.rect.size());
                  painter->translate(option_widget.rect.topLeft());
                  editor->render(painter, QPoint(), QRegion(), QWidget::DrawChildren);
                  painter->restore();
                  
                  delete editor;
                  }
                  

                  What also maybe could cause the problem is, that the TreeView I'm am using has a frozen column, like in the FrozenTableView example. Really hard to isolate the source of the problem. I guess I'll have to try to recreate it on a minimal example.
                  EDIT: nope, that wasn't involved. Still there without frozen columns

                  1 Reply Last reply
                  0
                  • mrjjM Offline
                    mrjjM Offline
                    mrjj
                    Lifetime Qt Champion
                    wrote on last edited by
                    #10

                    Hi
                    I think its the editor as that would also explain
                    QWidget {
                    color: #000000;
                    background: #f0f0f0;
                    }

                    so to test that please
                    do
                    editor->resize(option_widget.rect.size());
                    editor->resize(QRect(0,0,50,50);

                    and if that grey thing then is small, then you know why.

                    1 Reply Last reply
                    1
                    • gde23G Offline
                      gde23G Offline
                      gde23
                      wrote on last edited by
                      #11

                      Thanks for the further hint. I've tried that, the grey header is smaller now, but it still may overlap.
                      What I've also noticed is, that the Text seems to be renderd twice with a small ofset somehow when it is overlapping.
                      overlap2.png

                      Also with the text when i do not clip to rect the overlap is gone.

                      mrjjM 1 Reply Last reply
                      0
                      • gde23G gde23

                        Thanks for the further hint. I've tried that, the grey header is smaller now, but it still may overlap.
                        What I've also noticed is, that the Text seems to be renderd twice with a small ofset somehow when it is overlapping.
                        overlap2.png

                        Also with the text when i do not clip to rect the overlap is gone.

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

                        @gde23
                        oK so it really just is the "editor" you new to render with.
                        That explains why it can be over scrollbar :)

                        gde23G 1 Reply Last reply
                        1
                        • mrjjM mrjj

                          @gde23
                          oK so it really just is the "editor" you new to render with.
                          That explains why it can be over scrollbar :)

                          gde23G Offline
                          gde23G Offline
                          gde23
                          wrote on last edited by gde23
                          #13

                          @mrjj
                          Ok :) so but what could be the reason? Or do you have any ideas for fixing it?

                          EDIT: I've also tested some "compact mode" where i can remove the header from the cells, and the view will be shown without the cell headers.

                          When I switch to compact mode the artefacts stay there for a while and only dissapear after a few clicks or something.
                          So at that moment the editors arent even there any more. Could this be a timing problem maybe?

                          mrjjM 1 Reply Last reply
                          0
                          • gde23G gde23

                            @mrjj
                            Ok :) so but what could be the reason? Or do you have any ideas for fixing it?

                            EDIT: I've also tested some "compact mode" where i can remove the header from the cells, and the view will be shown without the cell headers.

                            When I switch to compact mode the artefacts stay there for a while and only dissapear after a few clicks or something.
                            So at that moment the editors arent even there any more. Could this be a timing problem maybe?

                            mrjjM Offline
                            mrjjM Offline
                            mrjj
                            Lifetime Qt Champion
                            wrote on last edited by
                            #14

                            @gde23
                            Can you show how DummyDelegate is defined?

                            Is it a widget ?

                            You could try to just hide it as it will render anyway
                            editor = new DummyDelegate();
                            editor ->hide()

                            1 Reply Last reply
                            1
                            • gde23G Offline
                              gde23G Offline
                              gde23
                              wrote on last edited by
                              #15

                              Dummy Delegate is just a normal widget with layouts on it that hold other widgets

                              DummyDelegat::DummyDelegat(QWidget *parent):
                                  QWidget(parent),
                                  m_compact_mode(false)
                              {
                                  m_main_layout = new QVBoxLayout();
                                  m_main_layout->setSpacing(2);
                                  m_main_layout->setContentsMargins(0, 0, 0, 0);
                              
                                  m_main_layout->setAlignment(Qt::AlignTop);
                                  this->setLayout(m_main_layout);
                              
                                  m_header = new QWidget(this);
                                  m_header->setFixedHeight(12);
                              
                                  m_main_layout->addWidget(m_header);
                              
                                  m_header_layout = new QHBoxLayout();
                                  m_header_layout->setContentsMargins(5, 0, 0, 0);
                                  m_header_layout->setSpacing(2);
                                  m_header->setLayout(m_header_layout);
                              
                                  m_header_icon_label = new QLabel(this);
                                  m_header_icon_label->setFixedHeight(12);
                                  m_header_icon_label->setFixedWidth(12);
                              
                                  m_header_layout->addWidget(m_header_icon_label);
                              
                                  m_header_label = new QLabel(this);
                                  m_header_layout->addWidget(m_header_label);
                              }
                              
                              mrjjM 1 Reply Last reply
                              0
                              • gde23G gde23

                                Dummy Delegate is just a normal widget with layouts on it that hold other widgets

                                DummyDelegat::DummyDelegat(QWidget *parent):
                                    QWidget(parent),
                                    m_compact_mode(false)
                                {
                                    m_main_layout = new QVBoxLayout();
                                    m_main_layout->setSpacing(2);
                                    m_main_layout->setContentsMargins(0, 0, 0, 0);
                                
                                    m_main_layout->setAlignment(Qt::AlignTop);
                                    this->setLayout(m_main_layout);
                                
                                    m_header = new QWidget(this);
                                    m_header->setFixedHeight(12);
                                
                                    m_main_layout->addWidget(m_header);
                                
                                    m_header_layout = new QHBoxLayout();
                                    m_header_layout->setContentsMargins(5, 0, 0, 0);
                                    m_header_layout->setSpacing(2);
                                    m_header->setLayout(m_header_layout);
                                
                                    m_header_icon_label = new QLabel(this);
                                    m_header_icon_label->setFixedHeight(12);
                                    m_header_icon_label->setFixedWidth(12);
                                
                                    m_header_layout->addWidget(m_header_icon_label);
                                
                                    m_header_label = new QLabel(this);
                                    m_header_layout->addWidget(m_header_label);
                                }
                                
                                mrjjM Offline
                                mrjjM Offline
                                mrjj
                                Lifetime Qt Champion
                                wrote on last edited by
                                #16

                                @gde23

                                Ok so it really is just a floating Widget.

                                Did you try to hide it ?

                                gde23G 1 Reply Last reply
                                1
                                • mrjjM mrjj

                                  @gde23

                                  Ok so it really is just a floating Widget.

                                  Did you try to hide it ?

                                  gde23G Offline
                                  gde23G Offline
                                  gde23
                                  wrote on last edited by
                                  #17

                                  @mrjj Hiding the editor in the paint() method after creation does not make any difference

                                  mrjjM 1 Reply Last reply
                                  0
                                  • gde23G gde23

                                    @mrjj Hiding the editor in the paint() method after creation does not make any difference

                                    mrjjM Offline
                                    mrjjM Offline
                                    mrjj
                                    Lifetime Qt Champion
                                    wrote on last edited by
                                    #18

                                    @gde23
                                    Ok. I have no idea then
                                    as its clearly the grey we see.

                                    I wonder one thing
                                    You don't give it a parent when you new it -
                                    so how do you avoid it having borders etc like a Window normally have?

                                    editor = new DummyDelegate( NO PARENT );

                                    Also you could try to give it a parent to see if that keeps it inside

                                    gde23G 1 Reply Last reply
                                    1
                                    • mrjjM mrjj

                                      @gde23
                                      Ok. I have no idea then
                                      as its clearly the grey we see.

                                      I wonder one thing
                                      You don't give it a parent when you new it -
                                      so how do you avoid it having borders etc like a Window normally have?

                                      editor = new DummyDelegate( NO PARENT );

                                      Also you could try to give it a parent to see if that keeps it inside

                                      gde23G Offline
                                      gde23G Offline
                                      gde23
                                      wrote on last edited by
                                      #19

                                      @mrjj I've tried setting the treeview as parent when creating the editor: No change :(

                                      Anyway, thanks a lot for all the hints you gave. I'll really try to set up a minimal example now as soon as i find some time.

                                      mrjjM 1 Reply Last reply
                                      0
                                      • gde23G gde23

                                        @mrjj I've tried setting the treeview as parent when creating the editor: No change :(

                                        Anyway, thanks a lot for all the hints you gave. I'll really try to set up a minimal example now as soon as i find some time.

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

                                        @gde23
                                        Hi
                                        Ok that is very , very odd then.
                                        You're welcome.
                                        Im sure it has a rational explanation.
                                        A minimal example would be good.! :)

                                        gde23G 1 Reply Last reply
                                        1
                                        • mrjjM mrjj

                                          @gde23
                                          Hi
                                          Ok that is very , very odd then.
                                          You're welcome.
                                          Im sure it has a rational explanation.
                                          A minimal example would be good.! :)

                                          gde23G Offline
                                          gde23G Offline
                                          gde23
                                          wrote on last edited by
                                          #21

                                          @mrjj Yeah :) I finally got it working with your help.

                                          The trick is to first add the View as a parent for the DelgateEditor.
                                          Now we still get the overlap. However now when you remove painter->setClipRect(option.rect); from paint() is does not paint into neighboring cells any more, so you do not need that line of code anymore and without that line of code the problem is gone :)

                                          Thanks again for all the help, I never would have come up with that idea. (And I still don't get why it did not work in the first place)

                                          mrjjM 1 Reply Last reply
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