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  1. Qt
  2. QTBUG-86170

QLabel::setPixmap appears truncated under high screen device pixel ratio

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: Not Evaluated
    • Resolution: Done
    • Affects Version/s: 5.11.3
    • Fix Version/s: 5.15.2
    • Labels:
      None
    • Environment:
      linux x11
    • Platform/s:
      Linux/X11
    • Commits:
      eb98bed4e76bb0fa6bad8474f2f370334cb70f6c (qt/qtbase/dev) dbffdb66544dd0c74a17b92487a79f5781c85057 (qt/qtbase/5.15)

      Description

      When the device pixel ratio is greater than 1,  use QLabel::setPixmap,  the content of one pixel on the right and bottom side of the QLabel will be truncated

      The following code is an example of mine.

          QApplication app(argc, argv);
          QWidget w;
          QHBoxLayout hlayout;
          QPixmap pix(98, 98);
          QPainter p(&pix);
          
          pix.fill(Qt::black);
          p.setRenderHint(QPainter::Antialiasing);
          p.setBrush(Qt::gray);
          p.setPen(Qt::NoPen);
          p.drawEllipse(0, 0, pix.width(), pix.height());
      
          w.setLayout(&hlayout);
      
          QLabel label1;
          pix.setDevicePixelRatio(1.25);
          label1.setPixmap(pix);
          hlayout.addWidget(&label1);
      
          QLabel label2;
          pix.setDevicePixelRatio(1);
          label2.setPixmap(pix);
          hlayout.addWidget(&label2);
      
          w.setPalette(QPalette(Qt::red));
          w.show();
      

      Compare the left side and the upper side, and you'll see the right side and the lower side are clearly truncated

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              Assignee:
              sorvig Morten Sørvig
              Reporter:
              chen_bin Chen Bin
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                Dates

                Created:
                Updated:
                Resolved:

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