[webkit-gtk] How to load and process different URI with webkitgtk using multi-thread

[Gavin Lambert]

Quoth zzy_same:
> ThreadA: Initialize the “main_window” and “web view”;  g_signal_connect
“web_view” 
> and “resource-load-finished”; run gtk_main
> ThreadB(main thread): call threadA;  then call
webkit_web_view_load_uri(web_view, uri) 
> and wait for “resource-load-finished” callback function to do some
printout;

You can't do that sort of thing.  UI components (including the public API of
WebKit) tend to be thread-bound, so must always be accessed from the same
thread they were created on.

For the above scenario (which is a bit weird -- usually the main thread is
the one running the GUI), you would need to call load_uri from ThreadA, and
also process the load-finished callback on that thread too.  You can then
extract whatever data you need and use some thread-safe mechanism to pass
that across to your non-UI thread.  (For worker thread -> UI thread
notifications you can use Glib::Dispatcher; I'm not sure if that works the
other way around though.)