** Fix for bug #315101

2007-11-05  Milan Crha  <mcrha@redhat.com>

	** Fix for bug #315101

	* drag and drop to other source for multiselect
	* gui/comp-util.h:
	* gui/comp-util.c: (cal_comp_selection_set_string_list),
	(cal_comp_selection_get_string_list): Two new helper functions
	to set and get list of strings into GtkSelectionData.
	* gui/e-tasks.c: (get_selected_components_cb),
	(do_for_selected_components), (obtain_list_of_components),
	(table_drag_data_get):
	* gui/e-memos.c: (get_selected_components_cb),
	(do_for_selected_components), (obtain_list_of_components),
	(table_drag_data_get): Pass list of selected components as data
	for drag and drop instead of focused component from the list.
	* gui/e-tasks.c: (table_drag_data_delete):
	* gui/e-memos.c: (table_drag_data_delete): Obsolete now.
	* gui/tasks-component.c: (selector_tree_drag_data_received):
	* gui/memos-component.c: (selector_tree_drag_data_received):
	Receiving list of components, so made changes here to reflect it.


svn path=/trunk/; revision=34496

6 files changed, 420 insertions, 121 deletions

diff --git a/calendar/gui/comp-util.c b/calendar/gui/comp-util.c
index 6919302b73..0be96dbefa 100644
--- a/calendar/gui/comp-util.c
+++ b/calendar/gui/comp-util.c
@@ -432,3 +432,72 @@ cal_comp_util_get_n_icons (ECalComponent *comp)
 
 	return num_icons;
 }
+
+/**
+ * cal_comp_selection_set_string_list
+ * Stores list of strings into selection target data.
+ * Use @ref cal_comp_selection_get_string_list to get this list from target data.
+ *
+ * @param data Selection data, where to put list of strings.
+ * @param str_list List of strings. (Each element is of type const gchar *.)
+ **/
+void
+cal_comp_selection_set_string_list (GtkSelectionData *data, GSList *str_list)
+{
+	/* format is "str1\0str2\0...strN\0" */
+	GSList *p;
+	GByteArray *array;
+
+	g_return_if_fail (data != NULL);
+
+	if (!str_list)
+		return;
+
+	array = g_byte_array_new ();
+	for (p = str_list; p; p = p->next) {
+		const guint8 *c = p->data;
+
+		if (c)
+			g_byte_array_append (array, c, strlen ((const char *) c) + 1);
+	}
+
+	gtk_selection_data_set (data, data->target, 8, array->data, array->len);
+	g_byte_array_free (array, TRUE);
+}
+
+/**
+ * cal_comp_selection_get_string_list
+ * Converts data from selection to list of strings. Data should be assigned
+ * to selection data with @ref cal_comp_selection_set_string_list.
+ * Each string in newly created list should be freed by g_free.
+ * List itself should be freed by g_slist_free.
+ *
+ * @param data Selection data, where to put list of strings.
+ * @return Newly allocated GSList of strings.
+ **/
+GSList *
+cal_comp_selection_get_string_list (GtkSelectionData *data)
+{
+	/* format is "str1\0str2\0...strN\0" */
+	char *inptr, *inend;
+	GSList *list;
+
+	g_return_val_if_fail (data != NULL, NULL);
+
+	list = NULL;
+	inptr = (char *)data->data;
+	inend = (char *)(data->data + data->length);
+
+	while (inptr < inend) {
+		char *start = inptr;
+
+		while (inptr < inend && *inptr)
+			inptr++;
+
+		list = g_slist_prepend (list, g_strndup (start, inptr - start));
+
+		inptr++;
+	}
+
+	return list;
+}
diff --git a/calendar/gui/comp-util.h b/calendar/gui/comp-util.h
index 651fde686a..dfc5165b66 100644
--- a/calendar/gui/comp-util.h
+++ b/calendar/gui/comp-util.h
@@ -22,7 +22,9 @@
 #ifndef COMP_UTIL_H
 #define COMP_UTIL_H
 
+#include <glib.h>
 #include <gtk/gtkwidget.h>
+#include <gtk/gtkselection.h>
 #include <libecal/e-cal-component.h>
 #include <libecal/e-cal.h>
 
@@ -47,4 +49,7 @@ ECalComponent *cal_comp_event_new_with_current_time (ECal *client, gboolean all_
 ECalComponent *cal_comp_task_new_with_defaults (ECal *client);
 ECalComponent *cal_comp_memo_new_with_defaults (ECal *client);
 
+void    cal_comp_selection_set_string_list (GtkSelectionData *data, GSList *str_list);
+GSList *cal_comp_selection_get_string_list (GtkSelectionData *data);
+
 #endif
diff --git a/calendar/gui/e-memos.c b/calendar/gui/e-memos.c
index d20d909808..a028f5e47b 100644
--- a/calendar/gui/e-memos.c
+++ b/calendar/gui/e-memos.c
@@ -341,6 +341,94 @@ setup_config (EMemos *memos)
 	priv->notifications = g_list_prepend (priv->notifications, GUINT_TO_POINTER (not));
 }
 
+struct AffectedComponents {
+	EMemoTable *memo_table;
+	GSList *components; /* contains pointers to ECalModelComponent */
+};
+
+/**
+ * get_selected_components_cb
+ * Helper function to fill list of selected components in EMemoTable.
+ * This function is called from e_table_selected_row_foreach.
+ **/
+static void
+get_selected_components_cb (int model_row, gpointer data)
+{
+	struct AffectedComponents *ac = (struct AffectedComponents *) data;
+
+	if (!ac || !ac->memo_table)
+		return;
+
+	ac->components = g_slist_prepend (ac->components, e_cal_model_get_component_at (E_CAL_MODEL (e_memo_table_get_model (ac->memo_table)), model_row));
+}
+
+/**
+ * do_for_selected_components
+ * Calls function func for all selected components in memo_table.
+ *
+ * @param memo_table Table with selected components of our interest.
+ * @param func Function to be called on each selected component from cal_table.
+ *        The first parameter of this function is a pointer to ECalModelComponent and
+ *        the second parameter of this function is pointer to cal_table
+ * @param user_data User data, will be passed to func.
+ **/
+static void
+do_for_selected_components (EMemoTable *memo_table, GFunc func, gpointer user_data)
+{
+	ETable *etable;
+	struct AffectedComponents ac;
+
+	g_return_if_fail (memo_table != NULL);
+
+	ac.memo_table = memo_table;
+	ac.components = NULL;
+
+	etable = e_table_scrolled_get_table (E_TABLE_SCROLLED (memo_table->etable));
+	e_table_selected_row_foreach (etable, get_selected_components_cb, &ac);
+
+	g_slist_foreach (ac.components, func, user_data);
+	g_slist_free (ac.components);
+}
+
+/**
+ * obtain_list_of_components
+ * As a callback function to convert each ECalModelComponent to string
+ * of format "source_uid\ncomponent_str" and add this newly allocated
+ * string to the list of components. Strings should be freed with g_free.
+ *
+ * @param data ECalModelComponent object.
+ * @param user_data Pointer to GSList list, where to put new strings.
+ **/
+static void
+obtain_list_of_components (gpointer data, gpointer user_data)
+{
+	GSList **list;
+	ECalModelComponent *comp_data;
+
+	list = (GSList **) user_data;
+	comp_data = (ECalModelComponent *) data;
+
+	if (list && comp_data) {
+		char *comp_str;
+		icalcomponent *vcal;
+
+		vcal = e_cal_util_new_top_level ();
+		e_cal_util_add_timezones_from_component (vcal, comp_data->icalcomp);
+		icalcomponent_add_component (vcal, icalcomponent_new_clone (comp_data->icalcomp));
+
+		comp_str = icalcomponent_as_ical_string (vcal);
+		if (comp_str) {
+			ESource *source = e_cal_get_source (comp_data->client);
+			const char *source_uid = e_source_peek_uid (source);
+
+			*list = g_slist_prepend (*list, g_strdup_printf ("%s\n%s", source_uid, comp_str));
+			g_free (comp_str);
+		}
+
+		icalcomponent_free (vcal);
+	}
+}
+
 static void
 table_drag_data_get (ETable             *table,
 		     int                 row,
@@ -352,35 +440,20 @@ table_drag_data_get (ETable             *table,
 		     EMemos             *memos)
 {
 	EMemosPrivate *priv;
-	ECalModelComponent *comp_data;
 
 	priv = memos->priv;
 
-	if (priv->current_uid) {
-		ECalModel *model;
+	if (info == TARGET_VCALENDAR) {
+		/* we will pass an icalcalendar component for both types */
+		GSList *components = NULL;
 
-		model = e_memo_table_get_model (
-			E_MEMO_TABLE (priv->memos_view));
+		do_for_selected_components (E_MEMO_TABLE (priv->memos_view), obtain_list_of_components, &components);
 
-		comp_data = e_cal_model_get_component_at (model, row);
+		if (components) {
+			cal_comp_selection_set_string_list (selection_data, components);
 
-		if (info == TARGET_VCALENDAR) {
-			/* we will pass an icalcalendar component for both types */
-			char *comp_str;
-			icalcomponent *vcal;
-		
-			vcal = e_cal_util_new_top_level ();
-			e_cal_util_add_timezones_from_component (vcal, comp_data->icalcomp);
-			icalcomponent_add_component (
-			        vcal,
-				icalcomponent_new_clone (comp_data->icalcomp));
-
-			comp_str = icalcomponent_as_ical_string (vcal);
-			if (comp_str) {
-				gtk_selection_data_set (selection_data, selection_data->target,
-							8, (unsigned char *)comp_str, strlen (comp_str));
-			}
-			icalcomponent_free (vcal);
+			g_slist_foreach (components, (GFunc)g_free, NULL);
+			g_slist_free (components);
 		}
 	}
 }
@@ -392,22 +465,11 @@ table_drag_data_delete (ETable         *table,
 			GdkDragContext *context,
 			EMemos         *memos)
 {
-	EMemosPrivate *priv;
-	ECalModelComponent *comp_data;
-	ECalModel *model;
-	gboolean read_only = TRUE;
-	
-	priv = memos->priv;
-	
-	model = e_memo_table_get_model (
-		E_MEMO_TABLE (priv->memos_view));
-	comp_data = e_cal_model_get_component_at (model, row);
-
-	e_cal_is_read_only (comp_data->client, &read_only, NULL);
-	if (read_only)
-		return;
-
-	e_cal_remove_object (comp_data->client, icalcomponent_get_uid (comp_data->icalcomp), NULL);
+	/* Moved components are deleted from source immediately when moved,
+	   because some of them can be part of destination source, and we
+	   don't want to delete not-moved tasks. There is no such information
+	   which event has been moved and which not, so skip this method.
+	*/
 }
 
 #define E_MEMOS_TABLE_DEFAULT_STATE					\
diff --git a/calendar/gui/e-tasks.c b/calendar/gui/e-tasks.c
index 13c1be8a4c..44e417b5bb 100644
--- a/calendar/gui/e-tasks.c
+++ b/calendar/gui/e-tasks.c
@@ -429,6 +429,94 @@ setup_config (ETasks *tasks)
 	priv->notifications = g_list_prepend (priv->notifications, GUINT_TO_POINTER (not));
 }
 
+struct AffectedComponents {
+	ECalendarTable *cal_table;
+	GSList *components; /* contains pointers to ECalModelComponent */
+};
+
+/**
+ * get_selected_components_cb
+ * Helper function to fill list of selected components in ECalendarTable.
+ * This function is called from e_table_selected_row_foreach.
+ **/
+static void
+get_selected_components_cb (int model_row, gpointer data)
+{
+	struct AffectedComponents *ac = (struct AffectedComponents *) data;
+
+	if (!ac || !ac->cal_table)
+		return;
+
+	ac->components = g_slist_prepend (ac->components, e_cal_model_get_component_at (E_CAL_MODEL (ac->cal_table->model), model_row));
+}
+
+/**
+ * do_for_selected_components
+ * Calls function func for all selected components in cal_table.
+ *
+ * @param cal_table Table with selected components of our interest.
+ * @param func Function to be called on each selected component from cal_table.
+ *        The first parameter of this function is a pointer to ECalModelComponent and
+ *        the second parameter of this function is pointer to cal_table
+ * @param user_data User data, will be passed to func.
+ **/
+static void
+do_for_selected_components (ECalendarTable *cal_table, GFunc func, gpointer user_data)
+{
+	ETable *etable;
+	struct AffectedComponents ac;
+
+	g_return_if_fail (cal_table != NULL);
+
+	ac.cal_table = cal_table;
+	ac.components = NULL;
+
+	etable = e_table_scrolled_get_table (E_TABLE_SCROLLED (cal_table->etable));
+	e_table_selected_row_foreach (etable, get_selected_components_cb, &ac);
+
+	g_slist_foreach (ac.components, func, user_data);
+	g_slist_free (ac.components);
+}
+
+/**
+ * obtain_list_of_components
+ * As a callback function to convert each ECalModelComponent to string
+ * of format "source_uid\ncomponent_str" and add this newly allocated
+ * string to the list of components. Strings should be freed with g_free.
+ *
+ * @param data ECalModelComponent object.
+ * @param user_data Pointer to GSList list, where to put new strings.
+ **/
+static void
+obtain_list_of_components (gpointer data, gpointer user_data)
+{
+	GSList **list;
+	ECalModelComponent *comp_data;
+
+	list = (GSList **) user_data;
+	comp_data = (ECalModelComponent *) data;
+
+	if (list && comp_data) {
+		char *comp_str;
+		icalcomponent *vcal;
+
+		vcal = e_cal_util_new_top_level ();
+		e_cal_util_add_timezones_from_component (vcal, comp_data->icalcomp);
+		icalcomponent_add_component (vcal, icalcomponent_new_clone (comp_data->icalcomp));
+
+		comp_str = icalcomponent_as_ical_string (vcal);
+		if (comp_str) {
+			ESource *source = e_cal_get_source (comp_data->client);
+			const char *source_uid = e_source_peek_uid (source);
+
+			*list = g_slist_prepend (*list, g_strdup_printf ("%s\n%s", source_uid, comp_str));
+			g_free (comp_str);
+		}
+
+		icalcomponent_free (vcal);
+	}
+}
+
 static void
 table_drag_data_get (ETable             *table,
 		     int                 row,
@@ -440,33 +528,20 @@ table_drag_data_get (ETable             *table,
 		     ETasks             *tasks)
 {
 	ETasksPrivate *priv;
-	ECalModelComponent *comp_data;
 
 	priv = tasks->priv;
 
-	if (priv->current_uid) {
-		ECalModel *model;
+	if (info == TARGET_VCALENDAR) {
+		/* we will pass an icalcalendar component for both types */
+		GSList *components = NULL;
 
-		model = e_calendar_table_get_model (E_CALENDAR_TABLE (priv->tasks_view));
-		comp_data = e_cal_model_get_component_at (model, row);
+		do_for_selected_components (E_CALENDAR_TABLE (priv->tasks_view), obtain_list_of_components, &components);
 
-		if (info == TARGET_VCALENDAR) {
-			/* we will pass an icalcalendar component for both types */
-			char *comp_str;
-			icalcomponent *vcal;
-		
-			vcal = e_cal_util_new_top_level ();
-			e_cal_util_add_timezones_from_component (vcal, comp_data->icalcomp);
-			icalcomponent_add_component (
-			        vcal,
-				icalcomponent_new_clone (comp_data->icalcomp));
-
-			comp_str = icalcomponent_as_ical_string (vcal);
-			if (comp_str) {
-				gtk_selection_data_set (selection_data, selection_data->target,
-							8, (unsigned char *)comp_str, strlen (comp_str));
-			}
-			icalcomponent_free (vcal);
+		if (components) {
+			cal_comp_selection_set_string_list (selection_data, components);
+
+			g_slist_foreach (components, (GFunc)g_free, NULL);
+			g_slist_free (components);
 		}
 	}
 }
@@ -501,21 +576,11 @@ table_drag_data_delete (ETable         *table,
 			GdkDragContext *context,
 			ETasks         *tasks)
 {
-	ETasksPrivate *priv;
-	ECalModelComponent *comp_data;
-	ECalModel *model;
-	gboolean read_only = TRUE;
-	priv = tasks->priv;
-	
-	model = e_calendar_table_get_model (E_CALENDAR_TABLE (priv->tasks_view));
-	comp_data = e_cal_model_get_component_at (model, row);
-
-	e_cal_is_read_only (comp_data->client, &read_only, NULL);
-	if (read_only)
-		return;
-
-	if(gdk_drag_drop_succeeded(context))
-		e_cal_remove_object (comp_data->client, icalcomponent_get_uid (comp_data->icalcomp), NULL);
+	/* Moved components are deleted from source immediately when moved,
+	   because some of them can be part of destination source, and we
+	   don't want to delete not-moved tasks. There is no such information
+	   which event has been moved and which not, so skip this method.
+	*/
 }
 
 #define E_TASKS_TABLE_DEFAULT_STATE					\
diff --git a/calendar/gui/memos-component.c b/calendar/gui/memos-component.c
index 5024a5f2e7..40b71cf5f5 100644
--- a/calendar/gui/memos-component.c
+++ b/calendar/gui/memos-component.c
@@ -758,6 +758,8 @@ selector_tree_drag_data_received (GtkWidget *widget,
 	gboolean success = FALSE;
 	icalcomponent *icalcomp = NULL;
 	ECal *client = NULL;
+	GSList *components, *p;
+	MemosComponent *component = MEMOS_COMPONENT (user_data);
 
 	if (!gtk_tree_view_get_dest_row_at_pos (GTK_TREE_VIEW (widget),
 						x, y, &path, &pos))
@@ -771,47 +773,97 @@ selector_tree_drag_data_received (GtkWidget *widget,
 	
 	gtk_tree_model_get (model, &iter, 0, &source, -1);
 
-	if (E_IS_SOURCE_GROUP (source) || e_source_get_readonly (source))
+	if (E_IS_SOURCE_GROUP (source) || e_source_get_readonly (source) || !data->data)
 		goto finish;
 
-	icalcomp = icalparser_parse_string ((char *)data->data);
-	
-	if (icalcomp) {
-		char * uid;
+	client = auth_new_cal_from_source (source, E_CAL_SOURCE_TYPE_JOURNAL);
+
+	if (!client || !e_cal_open (client, TRUE, NULL))
+		goto  finish;
+
+	components = cal_comp_selection_get_string_list (data);
+	for (p = components; p; p = p->next) {
+		const char * uid;
+		char *old_uid = NULL;
+		icalcomponent *tmp_icalcomp = NULL;
+		GError *error = NULL;
+		char *comp_str; /* do not free this! */
+
+		/* p->data is "source_uid\ncomponent_string" */
+		comp_str = strchr (p->data, '\n');
+		if (!comp_str)
+			continue;
+
+		comp_str [0] = 0;
+		comp_str++;
+		icalcomp = icalparser_parse_string (comp_str);
+
+		if (!icalcomp)
+			continue;
 
 		/* FIXME deal with GDK_ACTION_ASK */
 		if (context->action == GDK_ACTION_COPY) {
+			old_uid = g_strdup (icalcomponent_get_uid (icalcomp));
 			uid = e_cal_component_gen_uid ();
 			icalcomponent_set_uid (icalcomp, uid);
 		}
 
-		client = auth_new_cal_from_source (source, 
-						   E_CAL_SOURCE_TYPE_JOURNAL);
-		
-		if (client) {
-			if (e_cal_open (client, TRUE, NULL)) {
+		uid = icalcomponent_get_uid (icalcomp);
+		if (!old_uid)
+			old_uid = g_strdup (uid);
+
+		if (!e_cal_get_object (client, uid, NULL, &tmp_icalcomp, &error)) {
+			if ((error != NULL) && (error->code != E_CALENDAR_STATUS_OBJECT_NOT_FOUND))
+				g_message ("Failed to search the object in destination task list: %s",error->message);
+			else {
+				/* this will report success by last item, but we don't care */
 				success = update_objects (client, icalcomp);
+
+				if (success && context->action == GDK_ACTION_MOVE) {
+					/* remove components rather here, because we know which has been moved */
+					ESource *source_source;
+					ECal *source_client;
+
+					source_source = e_source_list_peek_source_by_uid (component->priv->source_list, p->data);
+
+					if (source_source && !E_IS_SOURCE_GROUP (source_source) && !e_source_get_readonly (source_source)) {
+						source_client = auth_new_cal_from_source (source_source, E_CAL_SOURCE_TYPE_JOURNAL);
+
+						if (source_client) {
+							gboolean read_only = TRUE;
+
+							e_cal_is_read_only (source_client, &read_only, NULL);
+
+							if (!read_only && e_cal_open (source_client, TRUE, NULL))
+								e_cal_remove_object (source_client, old_uid, NULL);
+							else if (!read_only)
+								g_message ("Cannot open source client to remove old memo");
+
+							g_object_unref (source_client);
+						} else
+							g_message ("Cannot create source client to remove old memo");
+					}
+				}
 			}
-			
-			g_object_unref (client);
-		}
-		
+
+			g_clear_error (&error);
+		} else
+			icalcomponent_free (tmp_icalcomp);
+
+		g_free (old_uid);
 		icalcomponent_free (icalcomp);
 	}
+	g_slist_foreach (components, (GFunc)g_free, NULL);
+	g_slist_free (components);
 
  finish:
+	if (client)
+		g_object_unref (client);
 	if (source)
 		g_object_unref (source);
 	if (path)
 		gtk_tree_path_free (path);
 
-	if (!success && context->action == GDK_ACTION_MOVE) {
-		/* because the delete parameter of 'gtk_drag_finish' doesn't work
-		   as expected, then we change context->action to GDK_ACTION_COPY 
-		   to prevent from deleting data when the drag was unsuccessful.
-		*/
-		context->action = GDK_ACTION_COPY;
-	}
 	gtk_drag_finish (context, success, success && context->action == GDK_ACTION_MOVE, time);
 }	
 
diff --git a/calendar/gui/tasks-component.c b/calendar/gui/tasks-component.c
index cc87d9d287..2f8c563aa7 100644
--- a/calendar/gui/tasks-component.c
+++ b/calendar/gui/tasks-component.c
@@ -742,6 +742,8 @@ selector_tree_drag_data_received (GtkWidget *widget,
 	gboolean success = FALSE;
 	icalcomponent *icalcomp = NULL;
 	ECal *client = NULL;
+	GSList *components, *p;
+	TasksComponent *component = TASKS_COMPONENT (user_data);
 
 	if (!gtk_tree_view_get_dest_row_at_pos (GTK_TREE_VIEW (widget),
 						x, y, &path, &pos))
@@ -755,48 +757,92 @@ selector_tree_drag_data_received (GtkWidget *widget,
 	
 	gtk_tree_model_get (model, &iter, 0, &source, -1);
 
-	if (E_IS_SOURCE_GROUP (source) || e_source_get_readonly (source))
+	if (E_IS_SOURCE_GROUP (source) || e_source_get_readonly (source) || !data->data)
 		goto finish;
 
-	icalcomp = icalparser_parse_string ((char *)data->data);
+	client = auth_new_cal_from_source (source, E_CAL_SOURCE_TYPE_TODO);
 
-	if (icalcomp) {
+	if (!client || !e_cal_open (client, TRUE, NULL))
+		goto  finish;
+
+	components = cal_comp_selection_get_string_list (data);
+	for (p = components; p; p = p->next) {
 		const char * uid;
-		
+		char *old_uid = NULL;
+		icalcomponent *tmp_icalcomp = NULL;
+		GError *error = NULL;
+		char *comp_str; /* do not free this! */
+
+		/* p->data is "source_uid\ncomponent_string" */
+		comp_str = strchr (p->data, '\n');
+		if (!comp_str)
+			continue;
+
+		comp_str [0] = 0;
+		comp_str++;
+		icalcomp = icalparser_parse_string (comp_str);
+
+		if (!icalcomp)
+			continue;
+
 		/* FIXME deal with GDK_ACTION_ASK */
 		if (context->action == GDK_ACTION_COPY) {
+			old_uid = g_strdup (icalcomponent_get_uid (icalcomp));
 			uid = e_cal_component_gen_uid ();
 			icalcomponent_set_uid (icalcomp, uid);
 		}
 
-		client = auth_new_cal_from_source (source, 
-						   E_CAL_SOURCE_TYPE_TODO);
-		
-		if (client) {
-			if (e_cal_open (client, TRUE, NULL)) {
-				icalcomponent *tmp_icalcomp = NULL;
-				GError *error = NULL;
-				uid = icalcomponent_get_uid (icalcomp);
-				if (!e_cal_get_object (client, uid, NULL, &tmp_icalcomp, &error)) {
-			        	if ((error != NULL) && (error->code != E_CALENDAR_STATUS_OBJECT_NOT_FOUND))
-						 g_message ("Failed to search the object in destination task list: %s",error->message);
-					else {
-						success = TRUE;
-						update_objects (client, icalcomp);
-					}
+		uid = icalcomponent_get_uid (icalcomp);
+		if (!old_uid)
+			old_uid = g_strdup (uid);
+
+		if (!e_cal_get_object (client, uid, NULL, &tmp_icalcomp, &error)) {
+			if ((error != NULL) && (error->code != E_CALENDAR_STATUS_OBJECT_NOT_FOUND))
+				g_message ("Failed to search the object in destination task list: %s",error->message);
+			else {
+				/* this will report success by last item, but we don't care */
+				success = update_objects (client, icalcomp);
 
-					g_clear_error (&error);
-				} else 
-					icalcomponent_free (tmp_icalcomp);
+				if (success && context->action == GDK_ACTION_MOVE) {
+					/* remove components rather here, because we know which has been moved */
+					ESource *source_source;
+					ECal *source_client;
+
+					source_source = e_source_list_peek_source_by_uid (component->priv->source_list, p->data);
+
+					if (source_source && !E_IS_SOURCE_GROUP (source_source) && !e_source_get_readonly (source_source)) {
+						source_client = auth_new_cal_from_source (source_source, E_CAL_SOURCE_TYPE_TODO);
+
+						if (source_client) {
+							gboolean read_only = TRUE;
+
+							e_cal_is_read_only (source_client, &read_only, NULL);
+
+							if (!read_only && e_cal_open (source_client, TRUE, NULL))
+								e_cal_remove_object (source_client, old_uid, NULL);
+							else if (!read_only)
+								g_message ("Cannot open source client to remove old task");
+
+							g_object_unref (source_client);
+						} else
+							g_message ("Cannot create source client to remove old task");
+					}
+				}
 			}
 
-			g_object_unref (client);
-		}
+			g_clear_error (&error);
+		} else
+			icalcomponent_free (tmp_icalcomp);
 
+		g_free (old_uid);
 		icalcomponent_free (icalcomp);
 	}
+	g_slist_foreach (components, (GFunc)g_free, NULL);
+	g_slist_free (components);
 
  finish:
+	if (client)
+		g_object_unref (client);
 	if (source)
 		g_object_unref (source);
 	if (path)