diff options
author | Morten Johan Sørvig <morten.sorvig@qt.io> | 2020-09-08 15:44:47 +0200 |
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committer | Morten Johan Sørvig <morten.sorvig@qt.io> | 2020-09-10 17:28:11 +0200 |
commit | 7238123521708ec94edd816d5b668978c002b17a (patch) | |
tree | 5b9ff50b539009c54f92764c3cbeef885af023ba /src/plugins/platforms/xcb | |
parent | b3c991ae8f9da6d8eb26f10b3d4ab08587588c9e (diff) |
X11: set fallback logical DPI to 96
Returning physical DPI from logicalDpi() is problematic,
as explained in commit 77e04acb.
The most predictable implementation is to never return
physical DPI from QPlaformScreen::logicalDpi(). Other
platform plugins already does this, and this change
brings xcb in line with the rest of Qt.
We have the QPlatformScreen::physicalSize() API which
covers returning physical DPI (indirectly); Options
for selecting which one to use can be implemented on
top of these (see QT_USE_PHYSICAL_DPI).
Change-Id: Ifc41229fa63734a2eb06b3acefd97b2ed3e57c2d
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
Diffstat (limited to 'src/plugins/platforms/xcb')
-rw-r--r-- | src/plugins/platforms/xcb/qxcbscreen.cpp | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/src/plugins/platforms/xcb/qxcbscreen.cpp b/src/plugins/platforms/xcb/qxcbscreen.cpp index c17be437ce..82e256657c 100644 --- a/src/plugins/platforms/xcb/qxcbscreen.cpp +++ b/src/plugins/platforms/xcb/qxcbscreen.cpp @@ -690,12 +690,12 @@ QDpi QXcbScreen::logicalDpi() const if (forcedDpi > 0) return QDpi(forcedDpi, forcedDpi); - // Fall back to physical virtual desktop DPI, but prevent - // using DPI values lower than 96. This ensuers that connecting - // to e.g. a TV works somewhat predictabilly. - QDpi virtualDesktopPhysicalDPi = m_virtualDesktop->dpi(); - return QDpi(std::max(virtualDesktopPhysicalDPi.first, 96.0), - std::max(virtualDesktopPhysicalDPi.second, 96.0)); + // Fall back to 96 DPI in case no logical DPI is set. We don't want to + // return physical DPI here, since that is a differnt type of DPI: Logical + // DPI typically accounts for user preference and viewing distance, and is + // quantized into DPI classes (96, 144, 192, etc); pysical DPI is an exact + // physical measure. + return QDpi(96, 96); } QPlatformCursor *QXcbScreen::cursor() const |