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  1. Qt
  2. QTBUG-27828

QWindowsVistaStyle::drawPrimitive(PE_PanelItemViewItem) alters QPainter state

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    Details

    • Type: Bug
    • Status: Closed
    • Priority: Not Evaluated
    • Resolution: Done
    • Affects Version/s: 4.8.2
    • Fix Version/s: 5.0.0 Beta 2
    • Component/s: GUI: Painting
    • Labels:
      None
    • Environment:
      Windows 7
    • Commits:
      96ebbad5f03d6db5fa81f284ccbdaf4b6259c27b, Qt 4: c240761fd00bd4a284a261d926a27265bcc84ca9

      Description

      after a call to drawPrimitive(PE_PanelItemViewItem), the painter's brush origin is left altered.

      In 4.8.2, the offending line is line 749 of src/gui/styles/qwindowsvistastyle.cpp:

      QWindowsVistaStyle::drawPrimitive(...)
      ...
          case PE_PanelItemViewItem:
      ...
                      if (vopt->backgroundBrush.style() != Qt::NoBrush) {
                          QPointF oldBO = painter->brushOrigin();
                          painter->setBrushOrigin(vopt->rect.topLeft());
                          painter->fillRect(vopt->rect, vopt->backgroundBrush);
                      }
      

      The old brush origin is saved, but not restored. This means when my custom item delegate draws content after drawing the background panel, its gradients are corrupted by the change of brush origin.

      In Qt5, this code seems to have moved to src/widgets/styles/qwindowsvistastyle.cpp, and oldBO is gone. This changed in revision http://qt.gitorious.org/qt/qtbase/commit/abe5a0a432116963d22c4ef501a4dfd2393d66fb, but Friedemann Kleint's comment for this was just "Warnings fixes", so I think he just removed it without realizing that the warning had caught a real bug (the saved value was not restored).

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            Assignee:
            kleint Friedemann Kleint
            Reporter:
            puetzk Kevin Puetz
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              Dates

              Created:
              Updated:
              Resolved:

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