I can't say for sure why q*linecontrol passes an empty rect to
the updateNeeded() signal when an input mask is set; presumably
the empty rect at some point has meant "full update", but there
are a few problems with this. Surely a full update is wrong,
even if the semantics have been lost in translation somewhere
(likely the qlinecontrol refactoring). This fix ensures
that empty rects from updateNeeded() are interpreted as a request
to update the whole widget. A further improvement would be to
ensure the line control doesn't request a full update when an
input mask is set. The cursor is usually wider when a mask is
set but because of QLineEdit::paintEvent()'s implementation,
there is currently a mismatch between the cursor width as seen
by q*linecontrol and what is actually drawn, which causes
rendering artifacts if updateNeeded() sends the cursorRect().
Since QLineEdit and Q*LineControl aren't actively developed, it's
best to keep this fix minimal, although the performance cost of
updating the whole line edit when an input mask is set is
unfortunate.
Task-number: QTBUG-7174
Change-Id: Ie51e015d760915e07b0220b770f04fc958d93a12
Reviewed-by: Andy Shaw <andy.shaw@digia.com>
Reviewed-by: Girish Ramakrishnan <girish.1.ramakrishnan@nokia.com>
a9cda51517