Clipboard.setContent

Sets a new content provider on clipboard.

The clipboard will claim the [gdk.display.Display]'s resources and advertise these new contents to other applications.

In the rare case of a failure, this function will return false. The clipboard will then continue reporting its old contents and ignore provider.

If the contents are read by either an external application or the clipboard's read functions, clipboard will select the best format to transfer the contents and then request that format from provider.