[PyQt] Problem Loading Default QSetting

[David Boddie]

On Mon, 05 Jan 2009 10:47:25 -0800, Brent Villalobos wrote:

> If I understand the documentation correctly, the
> QtCore.QSettings.value() method's second argument can be a QVariant
> default value.  However, when I provide a key that does not exist, I'm
> not defaulting to that value.  Observe when I try to read the settings
> for a configuration that does not exist:
>  >>> from PyQt4 import QtCore
>  >>> settings = QtCore.QSettings('MyComp', 'NoConfig')
>  >>> settings.beginGroup('NoExist')
>  >>> print settings.value("pos", QtCore.QVariant(100, 100)).toSize()
> PyQt4.QtCore.QSize(-1, -1)
>
> Why am I receiving a QSize(-1, -1) object instead of QSize(100, 100)?

Because you're actually calling the constructor of QVariant that takes
a type code and a sip.voidptr instance:

http://www.riverbankcomputing.com/static/Docs/PyQt4/html/qvariant.html#QVariant-3

Since QVariant can accept lots of different object types, what you want to do
is pass a QSize instance to it:

print settings.value("pos", QtCore.QVariant(QtCore.QSize(100, 100))).toSize()

David