On Linux the correspondence between cursor functions and names
of cursors has never been standardized. Projects have either
assembled their own cursor function-to-name lookup table or
borrowed the table from other projects. The origins of our table
is described in QTBUG-71423.
On Ubuntu the default theme is called Adwaita. Before
bd72950fbe, we would not find a
cursor for 'openhand' and would fall-back to QXcbCursor::
createNonStandardCursor(). Which was sub-optimal, because the
cursors created by the fall-back path don't look like the
themed ones. But the situation was worse after bd72950fb (hence
the regression) - the 'openhand' fall-back name 'fleur' is a
symbolic link to 'grabbing', so we would get into a situation
where Qt::OpenHandCursor displays the same as Qt::ClosedHandCursor.
This patch adds a correct fall-back name for 'openhand' on Adwaita,
which is 'grab'. 'grab' actually is a symbolic link to 'hand1', but
'hand1' with other theams is a pointing hand cursor, that is why we
use the symbolic link's name in this case.
The lookup table still appears to be incomplete when comparing e.g
with KWin. Eventually we need to revise the table and put in a common
place so it can be shared between X11 and Wayland, but is out-of-scope
for this patch (see QTBUG-71423).
Fixes: QTBUG-71296
Task-number: QTBUG-71423
Change-Id: I247ed4b346c2cd3fe1c7fd0440d3763e0033346b
Reviewed-by: Frederik Gladhorn <frederik.gladhorn@qt.io>
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