[Development] Speaking about Icons.

Corentin Jabot corentin.jabot at gmail.com
Mon May 14 17:05:46 CEST 2012


The methods setWindowIcon are not yet implemented in Qt5.
That concerns QWindow, QWidget and QApplication.

I guess the reason for that is that QIcon is part of QtWidget and not QtGui.
QIcon seems not movable, it use a lot of QWidget styles stuffs

For that reason the not-implemented QWindow::setWindowIcon ( as well
as QPlatformWindow::setWindowIcon) take a QImage as parameter.
So it will only use one image for all sizes the system required, and
icon will certainly look ugly as they are upscale/downscale too much.

For that reason I think we need something like a QWindowIcon or a
QApplicationIcon to stores a different QImage for different size.
It's a sub-optimal solution, because the setWindowIcon will have
different signature in QtGui and QtWidget.

So ..

Can you think of something better ?
What should be the features & api of QWindow Icon.  ?
Is it still time for this change in 5.0 ? or should we wait 5.1 ?  I
think in both case, we have to start using it privately if we want
keep QWidget::setWindowIcon working.

This change is mostly required for linux, since windows will use the
icon provided by the RC file and Mac using the one declared by

I worked on a small ugly change about this issue
https://codereview.qt-project.org/#change,25373 , just to see what
would need to be done.

Corentin Jabot.

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