[Qgis-developer] Qt Minimum Version

[Tom Elwertowski]

Hi all,

Would it be a problem to make Qt 4.2 the minimum version for QGIS 8.0?

The API has been changed to provide better Mac-compatibility. Moving to 
Qt4.2/Mac without using the new API, however, results in a decline in 
the appearance of Mac buttons.

In Qt4.0/Mac, adjacent buttons that ought to have the same size don't. 
This has been fixed by adding a QDialogButtonBox layout class. Using 
this class, however, will make QGIS unbuildable for < Qt 4.2.

The QMessageBox API has also been changed to support cross-platform 
button layouts. In addition to better looking button sizes on a Mac, 
QDialogButtonBox and the new QMessageBox automatically swap the 
affirmative and cancel buttons so that the affirmative button is on the 
right for a Mac (where it belongs :) ).

Another benefit of Qt4.2/Mac is that a Mac crash when closing the QGIS 
Attribute Table window has been fixed. There is a new Mac crash, 
however, when opening the Vector Properties dialog. Since Raster 
Properties opens ok, it may be a case of needing to update something. I 
have found that removing Qt3 compatibility calls sometimes fixes 
Mac-only problems. Perhaps obsolete Qt4.0 routines are now causing Mac 
problems as well.

Tom