GTK application for looping other apps - problem with freeze UI - c

Question

My problem is the operation of the for loop with GUI application. I am writing a program that opens other programs by clicking on the run button (for testing), during the run my UI starts to hang. How to make my UI work simultaneously with another application without freezing? And so that all elements are clickable during the for loop
main.c - gtk code
#include <gtk/gtk.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/wait.h>
GtkWidget *window;
GtkWidget *run_button;
GtkWidget *stop_button;
GtkWidget *button_box;
int main(int argc, char **argv)
{
gtk_init(&argc, &argv);
window = gtk_window_new(GTK_WINDOW_TOPLEVEL);
gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER_ALWAYS);
gtk_window_set_title(GTK_WINDOW(window), "Application - Launch GUI Tests");
gtk_window_set_default_size(GTK_WINDOW(window), 600, 480);
/* create button box - start / stop buttons */
button_box = gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 0);
gtk_box_set_homogeneous(GTK_BOX(button_box), TRUE);
stop_button = gtk_button_new_with_label("Stop");
run_button = gtk_button_new_with_label("Run");
/* button box pack */
gtk_box_pack_start(GTK_BOX(button_box), stop_button, FALSE, TRUE, 0);
gtk_box_pack_start(GTK_BOX(button_box), run_button, FALSE, TRUE, 0);
gtk_container_add(GTK_CONTAINER(window), button_box);
/* signals */
g_signal_connect(G_OBJECT(window), "destroy", gtk_main_quit, NULL);
g_signal_connect(G_OBJECT(run_button), "clicked", G_CALLBACK(on_run_button_clicked), NULL);
gtk_widget_show_all(window);
gtk_main();
return 0;
}
when I click on the run button this code starts working (below)
void on_run_button_clicked(GtkWidget *run_button)
{
char *list[] = {"xfce4-terminal", "gnome-application", "test-app", "firefox"};
pid_t child;
int status;
for (int i = 0; *(list + i); i++) {
switch(child = fork()) {
case -1:
perror("child - fork error");
exit(EXIT_FAILURE);
case 0: /* child process exec another program */
execlp(list[i], list[i], NULL);
exit(127);
default: /* the parent waits until the program is closed */
wait(&status);
//check_status(status);
}
}
}
And the applications are started in turn until the user closes them, but the problem is that the main application starts to hang and the stop button is unavailable. How to fix it? Helps me, please

Answer 1

Looks like gtk_main() in main() isn't able to do its thing because on_run_button_clicked() is stuck in wait().
You need to make sure on_run_button_clicked() actually returns.