Re: Updated proposal for making the GtkFileChooser code asynchronous

[Tim Janik <timj imendio com>]

On Fri, 9 Dec 2005, Kristian Rietveld wrote:

> 1. Let's start out with a somewhat more general change.  We need to be able
>   to cancel currently running asynchronous operations.  For this we need
>   to have a handle on an operation, so we need to introduce a
>   GtkFileSystemHandle.  The GtkFileSystemHandle will be a GObject:
>
>   struct _GtkFileSystemHandle
>   {
>     GObject parent_instance;
>
>     GtkFileSystem *file_system;
>
>     guint cancelled : 1;		/* indicates whether the operation
> 					   has been cancelled or not */
>   };
>
>   struct _GtkFileSystemHandleClass
>   {
>     GObjectClass parent_class;
>   };
>
>   File system backends can of course subclass GtkFileSystemHandle and
>   add their own fields as required.  We will add a call which we can use to
>   actually cancel an operation:
>
>   void gtk_file_system_cancel_operation (GtkFileSystemHandle  *handle);

is ->cancelled to be exported as a GObject property ::cancelled as well,
so one could possibly listen to ::notify::cancelled?

> 4. gtk_file_system_create_folder() needs to be changed in order to be able
>   to operate asynchronously.  The new prototypes:
>
>   typedef void (* GtkFileSystemCreateFolderCallback) (GtkFileSystemHandle
> *handle,
>                                                       const GtkFilePath        *path
>                                                       GError                   *error,
>                                                       gpointer                  data);
>
>   GtkFileSystemHandle *gtk_file_system_create_folder (GtkFileSystem                      *file_system,
>                                                       const GtkFilePath                  *path,
>                                                       GtkFileSystemCreateFolderCallback   callback,
>                                                       gpointer                            data);
>
>   The error reporting works on the same way as the other functions.

does cancellation of gtk_file_system_create_folder() guarantee that no
new folder was created?
- what happens if gtk_file_system_cancel_operation() is called after a
  successfull mkdir() but before GtkFileSystemCreateFolderCallback() is called?
- what happens if gtk_file_system_cancel_operation() is called after
  GtkFileSystemCreateFolderCallback() was called (or from within)?

> thanks,
>
> -kris.

---
ciaoTJ