layer element created, dialog for multiple files added

main.c

@@ -20,6 +20,8 @@
 #include <stdio.h>
 #include "gdsparse.h"
 #include <gtk/gtk.h>
+#include "layer-element.h"
+
 
 enum cell_store_columns {
 	LIBRARY,
@@ -29,9 +31,9 @@ enum cell_store_columns {
 
 
 struct open_button_data {
-		GtkWindow *main_window;
-		GList **list_ptr;
-		GtkTreeStore *cell_store;
+	GtkWindow *main_window;
+	GList **list_ptr;
+	GtkTreeStore *cell_store;
 };
 
 
@@ -58,6 +60,7 @@ void on_load_gds(gpointer button, gpointer user)
 	GtkTreeStore *store = ptr->cell_store;
 	GtkWidget *open_dialog;
 	GtkFileChooser *file_chooser;
+	GtkWidget *msg_dialog;
 	GtkFileFilter *filter;
 	GtkStyleContext *button_style;
 	gint dialog_result;
@@ -80,11 +83,24 @@ void on_load_gds(gpointer button, gpointer user)
 		/* Get File name */
 		filename = gtk_file_chooser_get_filename(file_chooser);
 
-		/* Clear Display */
-		gtk_tree_store_clear(store);
-		/* Delete parsed GDS data */
-		clear_lib_list(ptr->list_ptr);
+		if (*ptr->list_ptr) {
+			/* Libraries present */
+			msg_dialog =
+					gtk_message_dialog_new(ptr->main_window, GTK_DIALOG_USE_HEADER_BAR,
+							       GTK_MESSAGE_QUESTION, GTK_BUTTONS_YES_NO,
+							       "There's already data present? Delete old data?");
+			dialog_result = gtk_dialog_run(GTK_DIALOG(msg_dialog));
+			gtk_widget_destroy(msg_dialog);
+		} else
+			dialog_result = GTK_RESPONSE_YES;
 
+		/* Clear Display Will be completely refreshed in any case */
+		gtk_tree_store_clear(store);
+
+		if (dialog_result == GTK_RESPONSE_YES) {
+			/* Delete parsed GDS data */
+			clear_lib_list(ptr->list_ptr);
+		}
 		/* Parse new GDSII file */
 		gds_result = parse_gds_from_file(filename, ptr->list_ptr);
 
@@ -145,6 +161,7 @@ int main(int argc, char **argv)
 	GList *gds_libs = NULL;
 	GtkTreeView *cell_tree;
 	GtkTreeStore *cell_store;
+
 	struct open_button_data open_data;
 
 	gtk_init(&argc, &argv);
@@ -165,6 +182,7 @@ int main(int argc, char **argv)
 			 "clicked", G_CALLBACK(on_load_gds), (gpointer)&open_data);
 
 
+
 	gtk_main();
 
 	return 0;