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>

0 files changed, 0 insertions, 0 deletions