Gui: Only promt overwrite message of auto-naming tool when there are actual elements in the layer selector

gds-render-gui.c

@@ -758,6 +758,10 @@ static void auto_naming_clicked(GtkWidget *button, gpointer user_data)
 
 	gui = RENDERER_GUI(user_data);
 
+	/* Don't do anything if the selector is empty. */
+	if (!layer_selector_contains_elements(gui->layer_selector))
+		return;
+
 	/* Ask for overwrite */
 	dialog = GTK_DIALOG(gtk_message_dialog_new(gui->main_window, GTK_DIALOG_USE_HEADER_BAR, GTK_MESSAGE_QUESTION,
 						   GTK_BUTTONS_YES_NO, "Overwrite existing layer names?"));

include/gds-render/layer/layer-selector.h

@@ -118,6 +118,18 @@ void layer_selector_auto_color_layers(LayerSelector *layer_selector, ColorPalett
  */
 void layer_selector_auto_name_layers(LayerSelector *layer_selector, gboolean overwrite);
 
+/**
+ * @brief Check if the given layer selector contains layer elements.
+ *
+ * This function checks whether there are elements present.
+ * If an invalid object pointer \p layer_selector is passed,
+ * the function returns FALSE
+ *
+ * @param[in] layer_selector Selector to check
+ * @return True, if there is at least one layer present inside the selector
+ */
+gboolean layer_selector_contains_elements(LayerSelector *layer_selector);
+
 G_END_DECLS
 
 #endif /* __LAYER_SELECTOR_H__ */

layer/layer-selector.c

@@ -883,4 +883,19 @@ void layer_selector_auto_name_layers(LayerSelector *layer_selector, gboolean ove
 	g_list_free(le_list);
 }
 
+gboolean layer_selector_contains_elements(LayerSelector *layer_selector)
+{
+	GList *layer_element_list;
+
+	/* Check objects */
+	g_return_val_if_fail(LAYER_IS_SELECTOR(layer_selector), FALSE);
+	g_return_val_if_fail(GTK_IS_LIST_BOX(layer_selector->list_box), FALSE);
+
+	/* Get a list of the child elements inside the list boy associated with this selector */
+	layer_element_list = gtk_container_get_children(GTK_CONTAINER(layer_selector->list_box));
+
+	/* Return TRUE if there is an element in the list, else return FALSE */
+	return (layer_element_list ? TRUE : FALSE);
+}
+
 /** @} */