what's the equivalent with DPtoLP in windows

[cocalele]

I has used QPainter::setWindow to map my logic cooridnate system to meet with the view cooridnate, then at the slot of mousePress event, how can I map back the device cooridnate to logic cooridnate. I know in windows programing, the function LPtoDP do this. Is there an equivalent in Qt or any other method?

Thanks

[wysota]

There is a family of "mapTo" and "mapFrom" methods in various classes. The painter always operates on "logic" coordinates. The widget should operate on "physical" ones.

[cocalele]

There is a family of "mapTo" and "mapFrom" methods in various classes. The painter always operates on "logic" coordinates. The widget should operate on "physical" ones.

Thank you. But I need a little more help. How can I get the display_id which is needed by QScreen constructor?

[zlatko]

Try leave it in 0 :rolleyes:

[wysota]

Thank you. But I need a little more help. How can I get the display_id which is needed by QScreen constructor?

What do you need a QScreen object for?

[cocalele]

What do you need a QScreen object for?

I want to use the member of QScreen mapFromDevice.

It seems QScreen is part of Qtopia, I even can't find the head file QScreen in my Qt installation directory

[wysota]

How about QWidget's:


QPoint mapFrom ( QWidget * parent, const QPoint & pos ) const
QPoint mapFromGlobal ( const QPoint & pos ) const
QPoint mapFromParent ( const QPoint & pos ) const
QPoint mapTo ( QWidget * parent, const QPoint & pos ) const
QPoint mapToGlobal ( const QPoint & pos ) const
QPoint mapToParent ( const QPoint & pos ) const