Clipboard manager fetches content right away
This is a follow-up of gtk#6402 (closed). While playing with GdkContentProvider
in order to provide the clipboard data asynchronously we found out that some content is fetched right away as soon as we advertise the mime-type.
This is due to the clipboard manager introduced with commit 5c009c20 in order to fix #206 (closed).
However, fetching the content as soon as the content type is advertised makes remote desktop features like Delayed Rendering of Clipboard Data impossible to implement on the client side. This feature allows the user to perform copy&paste operations remotely without transfer the content locally. The content is transferred locally only when a local application requests it. This is done to preserve bandwidth.
On X11 this isn't an issue because we are able to advertise the mime-type just after the application loses its focus. On Wayland you can advertise the mime-type only when focused, and there is no way to know when an application is about to lose the focus.
CC people that might be interested on this: @carlosg, @felipeborges, @pnowack