diff options
author | Holger Hans Peter Freyther <holger@moiji-mobile.com> | 2012-04-02 11:59:04 +0200 |
---|---|---|
committer | Qt by Nokia <qt-info@nokia.com> | 2012-04-15 06:14:00 +0200 |
commit | 83fc52e3b4005d946c731577f8f49becae948c39 (patch) | |
tree | 180ff69aae6462273a79585d7da5ed4a1b19b747 /src/widgets | |
parent | 5cb2fbe088ee5b15c2a35ba175e3c39a2fac5c03 (diff) |
widgets: Fix painting to a fully transparent top level widget
QWS used to have a line to change the composite mode from SourceOver
to Source for the top level widget. This wasn't used with QPA and I
removed the internal DontSetCompositionMode in qtbase. It turns out that
the QWS way is the most efficient one to initialize the background of
the widget.
The alternative is to have the QPlatformBackingStore::beginPaint
always clear the entire to be painted area and then paint the background
of the widget. The difference of painting each pixel once or twice is
noticable on embedded platforms and in the range of one to two fps.
Reproduce the issue with:
echo "QWidget {background: transparent}" > style.css
./examples/widgets/wiggly/wiggly -stylesheet style.css
Task-number: QTBUG-24526
Change-Id: Ica4c980bb3bf6eb87ddb5b510ac7493292d01543
Reviewed-by: Samuel Rødal <samuel.rodal@nokia.com>
Reviewed-by: Girish Ramakrishnan <girish.1.ramakrishnan@nokia.com>
Diffstat (limited to 'src/widgets')
-rw-r--r-- | src/widgets/kernel/qwidget.cpp | 12 | ||||
-rw-r--r-- | src/widgets/kernel/qwidget_p.h | 3 |
2 files changed, 13 insertions, 2 deletions
diff --git a/src/widgets/kernel/qwidget.cpp b/src/widgets/kernel/qwidget.cpp index f02a67d9ea..662c9b7403 100644 --- a/src/widgets/kernel/qwidget.cpp +++ b/src/widgets/kernel/qwidget.cpp @@ -2137,7 +2137,15 @@ void QWidgetPrivate::paintBackground(QPainter *painter, const QRegion &rgn, int if ((flags & DrawAsRoot) && !(q->autoFillBackground() && autoFillBrush.isOpaque())) { const QBrush bg = q->palette().brush(QPalette::Window); - fillRegion(painter, rgn, bg); + if (!(flags & DontSetCompositionMode)) { + //copy alpha straight in + QPainter::CompositionMode oldMode = painter->compositionMode(); + painter->setCompositionMode(QPainter::CompositionMode_Source); + fillRegion(painter, rgn, bg); + painter->setCompositionMode(oldMode); + } else { + fillRegion(painter, rgn, bg); + } } if (q->autoFillBackground()) @@ -5229,6 +5237,8 @@ void QWidgetPrivate::render(QPaintDevice *target, const QPoint &targetOffset, else flags |= DontSubtractOpaqueChildren; + flags |= DontSetCompositionMode; + if (target->devType() == QInternal::Printer) { QPainter p(target); render_helper(&p, targetOffset, paintRegion, renderFlags); diff --git a/src/widgets/kernel/qwidget_p.h b/src/widgets/kernel/qwidget_p.h index 8107b6ca74..d3fcdce6a8 100644 --- a/src/widgets/kernel/qwidget_p.h +++ b/src/widgets/kernel/qwidget_p.h @@ -284,7 +284,8 @@ public: DrawInvisible = 0x08, DontSubtractOpaqueChildren = 0x10, DontDrawOpaqueChildren = 0x20, - DontDrawNativeChildren = 0x40 + DontDrawNativeChildren = 0x40, + DontSetCompositionMode = 0x80 }; enum CloseMode { |