自学教程：C++ GTH_TASK函数代码示例

static voidprocess_current_file (GthPixbufListTask *self){	GthFileData *file_data;	GList       *singleton;	if (self->priv->current == NULL) {		gth_task_completed (GTH_TASK (self), NULL);		return;	}	_g_object_unref (self->priv->original_pixbuf);	self->priv->original_pixbuf = NULL;	_g_object_unref (self->priv->new_pixbuf);	self->priv->new_pixbuf = NULL;	gth_task_progress (GTH_TASK (self),			   NULL,			   NULL,			   FALSE,			   ((double) self->priv->n_current + 1) / (self->priv->n_files + 1));	file_data = self->priv->current->data;	singleton = g_list_append (NULL, g_object_ref (file_data->file));	_g_query_all_metadata_async (singleton,				     FALSE,				     TRUE,				     "*",				     gth_task_get_cancellable (GTH_TASK (self)),				     file_info_ready_cb,				     self);	_g_object_list_unref (singleton);}

static voidask_authorization_dialog_loaded_cb (OAuthAskAuthorizationDialog *dialog,				    gpointer                     user_data){	PicasaWebService *self = user_data;	const char       *title;	title = oauth_ask_authorization_dialog_get_title (dialog);	if (title == NULL)		return;	if (g_str_has_prefix (title, PICASA_WEB_REDIRECT_TITLE)) {		const char *authorization_code;		gtk_widget_hide (GTK_WIDGET (dialog));		gth_task_dialog (GTH_TASK (self), FALSE, NULL);		authorization_code = title + strlen (PICASA_WEB_REDIRECT_TITLE);		_picasa_web_service_get_refresh_token (self,						       authorization_code,						       gth_task_get_cancellable (GTH_TASK (self)),						       refresh_token_ready_cb,						       self);	}}

static voidauto_select_account (DialogData *data){	gtk_widget_hide (data->dialog);	if (data->conn != NULL)		gth_task_dialog (GTH_TASK (data->conn), FALSE);	if (data->accounts != NULL) {		if (data->email != NULL) {			connect_to_server (data);		}		else if (data->accounts->next == NULL) {			data->email = g_strdup ((char *)data->accounts->data);			connect_to_server (data);		}		else {			GtkWidget *dialog;			gth_task_dialog (GTH_TASK (data->conn), TRUE);			dialog = picasa_account_chooser_dialog_new (data->accounts, data->email);			g_signal_connect (dialog,					  "response",					  G_CALLBACK (account_chooser_dialog_response_cb),					  data);			gtk_window_set_title (GTK_WINDOW (dialog), _("Choose Account"));			gtk_window_set_transient_for (GTK_WINDOW (dialog), GTK_WINDOW (data->browser));			gtk_window_set_modal (GTK_WINDOW (dialog), TRUE);			gtk_window_present (GTK_WINDOW (dialog));		}	}	else		account_properties_dialog (data, NULL);}

static voidfile_buffer_ready_cb (void     **buffer,		      gsize      count,		      GError    *error,		      gpointer   user_data){	GthPixbufListTask *self = user_data;	GInputStream      *istream;	GdkPixbuf         *pixbuf;	if (error != NULL) {		gth_task_completed (GTH_TASK (self), error);		return;	}	istream = g_memory_input_stream_new_from_data (*buffer, count, NULL);	pixbuf = gdk_pixbuf_new_from_stream (istream, gth_task_get_cancellable (GTH_TASK (self)), &error);	if (pixbuf != NULL) {		self->priv->original_pixbuf = gdk_pixbuf_apply_embedded_orientation (pixbuf);		g_object_unref (pixbuf);	}	else		self->priv->original_pixbuf = NULL;	g_object_unref (istream);	if (self->priv->original_pixbuf == NULL) {		gth_task_completed (GTH_TASK (self), error);		return;	}	gth_pixbuf_task_set_source (GTH_PIXBUF_TASK (self->priv->task), self->priv->original_pixbuf);	gth_task_exec (self->priv->task, gth_task_get_cancellable (GTH_TASK (self)));}

static voidorganize_files_dialog_response_cb (GtkDialog *dialog,				   int        response_id,				   gpointer   user_data){	GthOrganizeTask *self = user_data;	if (response_id == GTK_RESPONSE_DELETE_EVENT) {		if (self->priv->organized)			response_id = GTK_RESPONSE_CLOSE;		else			response_id = GTK_RESPONSE_CANCEL;	}	switch (response_id) {	case GTK_RESPONSE_CANCEL:		gth_task_cancel (GTH_TASK (self));		break;	case GTK_RESPONSE_CLOSE:		gth_task_completed (GTH_TASK (self), NULL);		break;	case GTK_RESPONSE_OK:		save_catalogs (self);		break;	}}

static voidlist_albums_ready_cb (GObject      *source_object,		      GAsyncResult *result,		      gpointer      user_data){	DialogData       *data = user_data;	PicasaWebService *picasaweb = PICASA_WEB_SERVICE (source_object);	GError           *error = NULL;	_g_object_list_unref (data->albums);	data->albums = picasa_web_service_list_albums_finish (picasaweb, result, &error);	if (error != NULL) {		gth_task_dialog (GTH_TASK (data->service), TRUE, NULL);		_gtk_error_dialog_from_gerror_show (GTK_WINDOW (data->browser), _("Could not get the album list"), error);		g_clear_error (&error);		gtk_dialog_response (GTK_DIALOG (data->dialog), GTK_RESPONSE_DELETE_EVENT);		return;	}	update_album_list (data);	gth_task_dialog (GTH_TASK (data->service), TRUE, NULL);	gtk_window_set_transient_for (GTK_WINDOW (data->dialog), GTK_WINDOW (data->browser));	gtk_window_set_modal (GTK_WINDOW (data->dialog), FALSE);	gtk_window_present (GTK_WINDOW (data->dialog));}

static voidpixbuf_saved_cb (GthFileData *file_data,		 GError      *error,		 gpointer     user_data){	GthPixbufListTask *self = user_data;	GFile             *parent;	GList             *file_list;	if (error != NULL) {		if (g_error_matches (error, G_IO_ERROR, G_IO_ERROR_EXISTS)) {			if (self->priv->overwrite_mode == GTH_OVERWRITE_SKIP) {				process_next_file (self);			}			else  {				GthFileData *file_data;				GtkWidget   *dialog;				gth_task_dialog (GTH_TASK (self), TRUE);				file_data = self->priv->current->data;				dialog = gth_overwrite_dialog_new (NULL,								   self->priv->new_pixbuf,								   file_data->file,								   GTH_OVERWRITE_RESPONSE_YES,								   (self->priv->n_files == 1));				g_signal_connect (dialog,						  "response",						  G_CALLBACK (overwrite_dialog_response_cb),						  self);				gtk_widget_show (dialog);			}		}		else			gth_task_completed (GTH_TASK (self), error);		return;	}	parent = g_file_get_parent (file_data->file);	file_list = g_list_append (NULL, file_data->file);	gth_monitor_folder_changed (gth_main_get_default_monitor (),				    parent,				    file_list,				    GTH_MONITOR_EVENT_CHANGED);	g_list_free (file_list);	g_object_unref (parent);	process_next_file (self);}

voidfacebook_service_get_user_info (FacebookService     *self,				const char          *fields,				GCancellable        *cancellable,				GAsyncReadyCallback  callback,				gpointer             user_data){	GHashTable  *data_set;	SoupMessage *msg;	gth_task_progress (GTH_TASK (self->priv->conn), _("Connecting to the server"), _("Getting account information"), TRUE, 0.0);	data_set = g_hash_table_new (g_str_hash, g_str_equal);	g_hash_table_insert (data_set, "method", "facebook.users.getInfo");	g_hash_table_insert (data_set, "uids", (char *) facebook_connection_get_user_id (self->priv->conn));	g_hash_table_insert (data_set, "fields", (char *) fields);	facebook_connection_add_api_sig (self->priv->conn, data_set);	msg = soup_form_request_new_from_hash ("POST", FACEBOOK_HTTPS_REST_SERVER, data_set);	facebook_connection_send_message (self->priv->conn,					  msg,					  cancellable,					  callback,					  user_data,					  facebook_service_get_user_info,					  get_user_info_ready_cb,					  self);	g_hash_table_destroy (data_set);}

static voidask_authorization_dialog_response_cb (GtkDialog *dialog,				      int        response_id,				      gpointer   user_data){	WebService *self = user_data;	switch (response_id) {	case GTK_RESPONSE_DELETE_EVENT:	case GTK_RESPONSE_CANCEL:		gtk_widget_destroy (GTK_WIDGET (dialog));		gtk_dialog_response (GTK_DIALOG (self->priv->dialog), GTK_RESPONSE_DELETE_EVENT);		break;	case GTK_RESPONSE_OK:		gtk_widget_destroy (GTK_WIDGET (dialog));		gth_task_dialog (GTH_TASK (self), FALSE, NULL);		web_service_get_user_info (self,					   self->priv->cancellable,					   get_user_info_ready_cb,					   self);		break;	default:		break;	}}

static voidshow_authentication_error_dialog (WebService  *self,				  GError     **error){	GtkWidget *dialog;	if (g_error_matches (*error, WEB_SERVICE_ERROR, WEB_SERVICE_ERROR_TOKEN_EXPIRED)) {		web_service_ask_authorization (self);		return;	}	dialog = _gtk_message_dialog_new (GTK_WINDOW (self->priv->browser),					  GTK_DIALOG_MODAL,					  GTK_STOCK_DIALOG_ERROR,					  _("Could not connect to the server"),					  (*error)->message,					  _("Choose _Account..."), WEB_AUTHENTICATION_RESPONSE_CHOOSE_ACCOUNT,					  GTK_STOCK_CANCEL, GTK_RESPONSE_CANCEL,					  NULL);	gth_task_dialog (GTH_TASK (self), TRUE, dialog);	g_signal_connect (dialog,			  "delete-event",			  G_CALLBACK (gtk_true),			  NULL);	g_signal_connect (dialog,			  "response",			  G_CALLBACK (authentication_error_dialog_response_cb),			  self);	gtk_widget_show (dialog);	g_clear_error (error);}

static voidpixbuf_task_progress_cb (GthTask    *task,		         const char *description,		         const char *details,		         gboolean    pulse,		         double      fraction,		         gpointer    user_data){	GthPixbufListTask *self = user_data;	double             total_fraction;	double             file_fraction;	total_fraction =  ((double) self->priv->n_current + 1) / (self->priv->n_files + 1);	if (pulse)		file_fraction = 0.5;	else		file_fraction = fraction;	if (details == NULL) {		GthFileData *file_data;		file_data = self->priv->current->data;		details = g_file_info_get_display_name (file_data->info);	}	gth_task_progress (GTH_TASK (self),			   description,			   details,			   FALSE,			   total_fraction + (file_fraction / (self->priv->n_files + 1)));}

static voidpixbuf_task_dialog_cb (GthTask  *task,		       gboolean  opened,		       gpointer  user_data){	gth_task_dialog (GTH_TASK (user_data), opened);}

static voidconnect_to_server (DialogData *data){	if (data->conn == NULL) {		data->conn = google_connection_new (GOOGLE_SERVICE_PICASA_WEB_ALBUM);		data->progress_dialog = gth_progress_dialog_new (GTK_WINDOW (data->browser));		gth_progress_dialog_add_task (GTH_PROGRESS_DIALOG (data->progress_dialog), GTH_TASK (data->conn));	}#ifdef HAVE_GNOME_KEYRING	if ((data->password == NULL) && gnome_keyring_is_available ()) {		gnome_keyring_find_password (GNOME_KEYRING_NETWORK_PASSWORD,					     find_password_cb,					     data,					     NULL,					     "user", data->email,					     "server", "picasaweb.google.com",					     "protocol", "http",					     NULL);		return;	}#endif	connect_to_server_step2 (data);}

voidfacebook_service_get_albums (FacebookService     *self,			     const char          *user_id,			     GCancellable        *cancellable,			     GAsyncReadyCallback  callback,			     gpointer             user_data){	GHashTable  *data_set;	SoupMessage *msg;	g_return_if_fail (user_id != NULL);	gth_task_progress (GTH_TASK (self->priv->conn), _("Getting the album list"), NULL, TRUE, 0.0);	data_set = g_hash_table_new (g_str_hash, g_str_equal);	g_hash_table_insert (data_set, "method", "facebook.photos.getAlbums");	g_hash_table_insert (data_set, "uid", (char *) user_id);	facebook_connection_add_api_sig (self->priv->conn, data_set);	msg = soup_form_request_new_from_hash ("GET", FACEBOOK_HTTPS_REST_SERVER, data_set);	facebook_connection_send_message (self->priv->conn,					  msg,					  cancellable,					  callback,					  user_data,					  facebook_service_get_albums,					  get_albums_ready_cb,					  self);	g_hash_table_destroy (data_set);}

voidfacebook_service_upload_photos (FacebookService     *self,				FacebookAlbum       *album,				GList               *file_list, /* GFile list */				GCancellable        *cancellable,				GAsyncReadyCallback  callback,				gpointer             user_data){	gth_task_progress (GTH_TASK (self->priv->conn), _("Uploading the files to the server"), NULL, TRUE, 0.0);	post_photos_data_free (self->priv->post_photos);	self->priv->post_photos = g_new0 (PostPhotosData, 1);	self->priv->post_photos->album = _g_object_ref (album);	self->priv->post_photos->cancellable = _g_object_ref (cancellable);	self->priv->post_photos->callback = callback;	self->priv->post_photos->user_data = user_data;	self->priv->post_photos->total_size = 0;	self->priv->post_photos->n_files = 0;	_g_query_all_metadata_async (file_list,				     FALSE,				     TRUE,				     "*",				     self->priv->post_photos->cancellable,				     upload_photos_info_ready_cb,				     self);}

static voidreorder_done_cb (GObject  *object,	         GError   *error,	         gpointer  user_data){	gth_task_completed (GTH_TASK (user_data), error);}

static voidupload_photo_wrote_body_data_cb (SoupMessage *msg,                		 SoupBuffer  *chunk,                		 gpointer     user_data){	PicasaWebService *self = user_data;	GthFileData      *file_data;	char             *details;	double            current_file_fraction;	if (self->priv->post_photos->current == NULL)		return;	self->priv->post_photos->wrote_body_data_size += chunk->length;	if (self->priv->post_photos->wrote_body_data_size > msg->request_body->length)		return;	file_data = self->priv->post_photos->current->data;	/* Translators: %s is a filename */	details = g_strdup_printf (_("Uploading '%s'"), g_file_info_get_display_name (file_data->info));	current_file_fraction = (double) self->priv->post_photos->wrote_body_data_size / msg->request_body->length;	gth_task_progress (GTH_TASK (self),			   NULL,			   details,			   FALSE,			   (double) (self->priv->post_photos->uploaded_size + (g_file_info_get_size (file_data->info) * current_file_fraction)) / self->priv->post_photos->total_size);	g_free (details);}

static voidphotoset_combobox_changed_cb (GtkComboBox *widget,			      gpointer     user_data){	DialogData  *data = user_data;	GtkTreeIter  iter;	if (! gtk_combo_box_get_active_iter (widget, &iter)) {		gth_file_list_clear (GTH_FILE_LIST (data->file_list), _("No album selected"));		return;	}	_g_object_unref (data->photoset);	gtk_tree_model_get (gtk_combo_box_get_model (widget),			    &iter,			    PHOTOSET_DATA_COLUMN, &data->photoset,			    -1);	gth_import_preferences_dialog_set_event (GTH_IMPORT_PREFERENCES_DIALOG (data->preferences_dialog), data->photoset->title);	gth_task_dialog (GTH_TASK (data->service), FALSE, NULL);	flickr_service_list_photos (data->service,				    data->photoset,				    "original_format, url_sq, url_t, url_s, url_m, url_z, url_b, url_o",				    data->cancellable,				    list_photos_ready_cb,				    data);}

voidpicasa_web_service_list_albums (PicasaWebService    *self,			        GCancellable        *cancellable,			        GAsyncReadyCallback  callback,			        gpointer             user_data){	OAuthAccount *account;	SoupMessage  *msg;	char         *url;	account = web_service_get_current_account (WEB_SERVICE (self));	g_return_if_fail (account != NULL);	gth_task_progress (GTH_TASK (self), _("Getting the album list"), NULL, TRUE, 0.0);	url = g_strconcat ("https://picasaweb.google.com/data/feed/api/user/", account->id, NULL);	msg = soup_message_new ("GET", url);	_picasa_web_service_add_headers (self, msg);	_web_service_send_message (WEB_SERVICE (self),				   msg,				   cancellable,				   callback,				   user_data,				   picasa_web_service_list_albums,				   list_albums_ready_cb,				   self);	g_free (url);}

voidpicasa_web_service_post_photos (PicasaWebService    *self,			        PicasaWebAlbum      *album,			        GList               *file_list, /* GFile list */			        int                  max_width,			        int                  max_height,			        GCancellable        *cancellable,			        GAsyncReadyCallback  callback,			        gpointer             user_data){	g_return_if_fail (album != NULL);	g_return_if_fail (self->priv->post_photos == NULL);	gth_task_progress (GTH_TASK (self),			   _("Uploading the files to the server"),			   "",			   TRUE,			   0.0);	self->priv->post_photos = g_new0 (PostPhotosData, 1);	self->priv->post_photos->album = g_object_ref (album);	self->priv->post_photos->max_width = max_width;	self->priv->post_photos->max_height = max_height;	self->priv->post_photos->cancellable = _g_object_ref (cancellable);	self->priv->post_photos->callback = callback;	self->priv->post_photos->user_data = user_data;	_g_query_all_metadata_async (file_list,				     GTH_LIST_DEFAULT,				     "*",				     self->priv->post_photos->cancellable,				     post_photos_info_ready_cb,				     self);}

static voidget_request_token_ready_cb (GObject      *source_object,	        	    GAsyncResult *result,	        	    gpointer      user_data){	OAuthService *self = user_data;	GError       *error = NULL;	char         *url;	GtkWidget    *dialog;	if (! oauth_service_get_request_token_finish (self, result, &error)) {		gth_task_completed (GTH_TASK (self), error);		return;	}	url = self->priv->consumer->get_authorization_url (self);	dialog = oauth_ask_authorization_dialog_new (url);	_gtk_window_resize_to_fit_screen_height (dialog, 1024);	_web_service_set_auth_dialog (WEB_SERVICE (self), GTK_DIALOG (dialog));	g_signal_connect (OAUTH_ASK_AUTHORIZATION_DIALOG (dialog),			  "load-request",			  G_CALLBACK (ask_authorization_dialog_load_request_cb),			  self);	gtk_widget_show (dialog);	g_free (url);}

static voidalbum_combobox_changed_cb (GtkComboBox *widget,			   gpointer     user_data){	DialogData  *data = user_data;	GtkTreeIter  iter;	if (! gtk_combo_box_get_active_iter (widget, &iter)) {		gth_file_list_clear (GTH_FILE_LIST (data->file_list), _("No album selected"));		return;	}	_g_object_unref (data->album);	gtk_tree_model_get (gtk_combo_box_get_model (widget),			    &iter,			    ALBUM_DATA_COLUMN, &data->album,			    -1);	gth_import_preferences_dialog_set_event (GTH_IMPORT_PREFERENCES_DIALOG (data->preferences_dialog), data->album->title);	gth_task_dialog (GTH_TASK (data->service), FALSE, NULL);	picasa_web_service_list_photos (data->service,					data->album,					data->cancellable,					list_photos_ready_cb,					data);}

static voidconnect_to_server_step2 (DialogData *data){	if (data->password == NULL) {		gth_task_dialog (GTH_TASK (data->conn), TRUE);		account_properties_dialog (data, data->email);	}	else {		gth_task_dialog (GTH_TASK (data->conn), FALSE);		google_connection_connect (data->conn,					   data->email,					   data->password,					   data->challange,					   data->cancellable,					   connection_ready_cb,					   data);	}}

static voidlist_photos_ready_cb (GObject      *source_object,		      GAsyncResult *result,		      gpointer      user_data){	DialogData *data = user_data;	GError     *error = NULL;	GList      *list;	GList      *scan;	gth_task_dialog (GTH_TASK (data->service), TRUE, NULL);	_g_object_list_unref (data->photos);	data->photos = flickr_service_list_photos_finish (data->service, result, &error);	if (error != NULL) {		if (data->service != NULL)			gth_task_dialog (GTH_TASK (data->service), TRUE, NULL);		_gtk_error_dialog_from_gerror_show (GTK_WINDOW (data->browser), _("Could not get the photo list"), error);		g_clear_error (&error);		gtk_widget_destroy (data->dialog);		return;	}	list = NULL;	for (scan = data->photos; scan; scan = scan->next) {		FlickrPhoto *photo = scan->data;		GthFileData *file_data;		if (photo->url[FLICKR_URL_O] == NULL)			continue;		file_data = gth_file_data_new_for_uri (photo->url[FLICKR_URL_O], (photo->mime_type != NULL) ? photo->mime_type : "image/jpeg");		g_file_info_set_file_type (file_data->info, G_FILE_TYPE_REGULAR);		g_file_info_set_size (file_data->info, FAKE_SIZE); /* set a fake size to make the progress dialog work correctly */		g_file_info_set_attribute_object (file_data->info, "flickr::object", G_OBJECT (photo));		list = g_list_prepend (list, file_data);	}	gth_file_list_set_files (GTH_FILE_LIST (data->file_list), list);	update_selection_status (data);	gtk_widget_set_sensitive (GET_WIDGET ("download_button"), list != NULL);	_g_object_list_unref (list);}

static voidoverwrite_dialog_response_cb (GtkDialog *dialog,                              gint       response_id,                              gpointer   user_data){	GthPixbufListTask *self = user_data;	if (response_id != GTK_RESPONSE_OK)		self->priv->overwrite_response = GTH_OVERWRITE_RESPONSE_UNSPECIFIED;	else		self->priv->overwrite_response = gth_overwrite_dialog_get_response (GTH_OVERWRITE_DIALOG (dialog));	gtk_widget_hide (GTK_WIDGET (dialog));	gth_task_dialog (GTH_TASK (self), FALSE);	switch (self->priv->overwrite_response) {	case GTH_OVERWRITE_RESPONSE_NO:	case GTH_OVERWRITE_RESPONSE_ALWAYS_NO:	case GTH_OVERWRITE_RESPONSE_UNSPECIFIED:		if (self->priv->overwrite_response == GTH_OVERWRITE_RESPONSE_ALWAYS_NO)			self->priv->overwrite_mode = GTH_OVERWRITE_SKIP;		process_next_file (self);		break;	case GTH_OVERWRITE_RESPONSE_YES:	case GTH_OVERWRITE_RESPONSE_ALWAYS_YES:		if (self->priv->overwrite_response == GTH_OVERWRITE_RESPONSE_ALWAYS_YES)			self->priv->overwrite_mode = GTH_OVERWRITE_OVERWRITE;		pixbuf_task_save_current_pixbuf (self, NULL, TRUE);		break;	case GTH_OVERWRITE_RESPONSE_RENAME:		{			GFile *parent;			GFile *new_destination;			if (self->priv->destination_folder != NULL) {				parent = g_object_ref (self->priv->destination_folder);			}			else {				GthFileData *file_data;				file_data = self->priv->current->data;				parent = g_file_get_parent (file_data->file);			}			new_destination = g_file_get_child_for_display_name (parent, gth_overwrite_dialog_get_filename (GTH_OVERWRITE_DIALOG (dialog)), NULL);			pixbuf_task_save_current_pixbuf (self, new_destination, FALSE);			g_object_unref (new_destination);			g_object_unref (parent);		}		break;	}	gtk_widget_destroy (GTK_WIDGET (dialog));}

static voidpost_photos_ready_cb (GObject      *source_object,		      GAsyncResult *result,		      gpointer      user_data){	DialogData       *data = user_data;	PicasaWebService *picasaweb = PICASA_WEB_SERVICE (source_object);	GError           *error = NULL;	gth_task_dialog (GTH_TASK (data->conn), TRUE);	if (! picasa_web_service_post_photos_finish (picasaweb, result, &error)) {		if (data->conn != NULL)			gth_task_dialog (GTH_TASK (data->conn), TRUE);		_gtk_error_dialog_from_gerror_show (GTK_WINDOW (data->browser), _("Could not upload the files"), &error);		return;	}	export_completed_with_success (data);}

static voidshow_export_dialog (DialogData *data){	update_account_list (data);	update_album_list (data);	gth_task_dialog (GTH_TASK (data->conn), TRUE);	gtk_window_set_transient_for (GTK_WINDOW (data->dialog), GTK_WINDOW (data->browser));	gtk_window_set_modal (GTK_WINDOW (data->dialog), FALSE);	gtk_window_present (GTK_WINDOW (data->dialog));}