QClipboard duplicate image

Perdrix

I have code in my application to copy the content of a widget called picture to the clipboard.

			QClipboard* clipboard = QGuiApplication::clipboard();

			QPixmap pix{ picture->grab() };
			clipboard->setPixmap(pix);

which works fine. When that code is called the content of the widget is added to the system clipboard.

The oddness happens when the the application is closed: A duplicate of the last copy is added to the system clipboard.

FWIW this is using Qt 6.8.0 MSVC2022 on Windows 11

ChrisW67

Does this still happen if you call QClipboard::clear() before exiting?

Edit. Perhaps only clear it if is yours.

if (clipboard->ownsClipboard())
  clipboard->clear();

Perdrix

Won't that delete what I already placed on the clipboard? I don't want to do that ...

Christian Ehrlicher

How do you know that there is a second image added? Does it also happen with a small reproducer? A simple main() adding an image to the clipboard?

ChrisW67

@Perdrix Yes, but as a debugging step it will also tell you if the duplication (if there is one) happens during exit.

Perdrix

I know because I use a Gadget that keeps track of all items added to the clipboard. When the code above is executed the image is shown in the gadget, and then when I exit the application it is added again.

Perdrix

Still a problem