[Development] Feature freeze and Alpha

Hans-Peter Jansen hpj at urpla.net
Thu Feb 9 23:27:55 CET 2012

Dear Lars,

On Thursday 09 February 2012, 21:00:40 John Layt wrote:
> On Sunday 05 Feb 2012 14:12:48 lars.knoll at nokia.com wrote:
> > Is there anything that I have now forgotten that really *must* be
> > in 5.0 (i.e. it really can't be done in a BC/SC way for Qt 5.1)? If
> > you have such an item, please speak up, otherwise I'll consider the
> > above exception list as final.

sorry for chiming in that late, but my past attempts to direct some 
perception of the audience on a long time flaw of Qt seem to have 
failed so far. Please allow me to quote myself with a historical Qt bug 
report and a post to qt5-feedback:


It's about QDateEdit, QTimeEdit and QDateTimeEdit allowing to keep 
invalid dates, times and datetimes invalid (with databases, a NULL 
value of such a field usually has a special meaning (think "death-day" 
of still living people). Current behavior since Qt3 is: if the user 
just tabs over such a field in a (database) form, the widgets force a 
valid date/time value: leading to a value of 2000-01-01 00:00:00 for a 
QDateTimeEdit. Needless to say, that this behavior isn't desired almost 
all the time. At least, the auto completion should be controllable in 
some way. Some dates might only be valid as past or as future dates.
While the bug says, that QDateTime needs modifications, but didn't 
describe, which, I beg to differ. QDate and QTime _do_ allow invalid 
values. What it takes is keep invalid QDates and QTimes as long as the 
user doesn't change one value (at least) and allow the user to 
invalidate the values.  

Here's some food for implementation thoughts: how about adding some 
global boolean flag (application wide), that allows enabling invalid 
Q{Date,Time,DateTime} in their respective edit widgets. If that flag is 
enabled, change the widget behavior in a way, that 
 * tabbing over it will keep an invalid date{time}, 
 * allow to explicitely set an invalid date{time} programatically,
 * disable auto completion,
 * set an invalid date{time}, if the user presses delete, or removes all
   values with backspace, 
 * and finally add a widget property to control this behavior..

This should be possible without violating source code compatibility of 
these widgets. Sorry for not providing a patch, but being a PyQt hacker 
myself, my C++ skills are pretty rusty at best.

Anyway, I would love to see Qt5 appearing without this very flaw, and I 
bet, that a considerable amout of Qt developers will be very grateful 
for such an improvement.

Thanks in advance,

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