[Qt-interest] Is possible to use partial window opacity? (i.e. Leave certain areas Opaque)

[Samuel Rødal]

techsgin wrote:
 > Hi All
 >
 > Is possible to use partial window opacity? (i.e. Leave certain areas 
Opaque)
 >
 > We are trying to make a semi-transparent window where we show an image
 > which is opaque at the middle.
 >
 > * (Like the full screen mode in picasa).
 >
 > We are using “setWindowOpacity ( 0.5 )” but this applies to the entire
 > window, and we cannot isolate the child widget that display the image.
 >
 > Any ideas?
 >
 > We had in mind may be to float an extra frameless child window on to of
 > the semi-transparent one? But it sounds like the wrong way.
 >
 > Thanks
 >
 > TechSgin

Hello,

In Qt 4.5 we've added the Qt::WA_TranslucentBackground window attribute 
to be able to have per-pixel opacity for top-level windows. Another 
option which should also in earlier Qt versions could be to use 
QWidget::setMask() in combination with setWindowOpacity().

Regards,
Samuel