Add a GCancellable to EActivity.

EActivity now uses a GCancellable to manage cancellations, instead of
having its own redundant cancellation API.  API changes are as follows:

  + e_activity_get_cancellable()
  + e_activity_set_cancellable()

  - e_activity_cancel()
  - e_activity_is_cancelled()
  - e_activity_get_allow_cancel()
  - e_activity_set_allow_cancel()

EActivity's "cancelled" signal remains, but only as a repeater for
GCancellable::cancelled signals.  It should not be emitted directly.

The presence of a GCancellable implies that cancellation is allowed.
EActivity does not create its own default GCancellable, it has to be
given one.

If a CamelOperation (cast as a GCancellable) is given, EActivity will
configure itself to listen for status updates from the CamelOperation
and propagate the information to its own "primary-text" and "percent"
properties.

These changes allowed me to start cleaning up some of the incredibly
convoluted logic in mail-mt.c -- in particular, mail_operation_status()
is completely gone now.  mail-mt.c is still in a transitional state --
much more significant changes coming soon.

1 files changed, 2 insertions, 1 deletions

diff --git a/modules/calendar/e-memo-shell-view-private.c b/modules/calendar/e-memo-shell-view-private.c
index 061e3c0170..a33296daf5 100644
--- a/modules/calendar/e-memo-shell-view-private.c
+++ b/modules/calendar/e-memo-shell-view-private.c
@@ -375,8 +375,9 @@ e_memo_shell_view_set_status_message (EMemoShellView *memo_shell_view,
 		}
 
 	} else if (activity == NULL) {
-		activity = e_activity_new (status_message);
+		activity = e_activity_new ();
 		e_activity_set_percent (activity, percent);
+		e_activity_set_primary_text (activity, status_message);
 		e_shell_backend_add_activity (shell_backend, activity);
 
 	} else {