2 object an performs

#1

Hello people. I have an object_A that has a GtkComboBox and another object_B that has a GtkButton, both are separate files.
I would like to know how do I implement a function in object_B that by clicking on object_B’s GtkButton, object_A’s GtkComboBox performs a certain action. In C language.

#2

That’s more of a question about the C programming language. We’d need to know more, for example, are you using global variables? If that corresponds to your situation you can use the C extern modifier:

So that would become:

a.c

#include <gtk/gtk.h>

GtkWidget *combo;

int main() {
}

b.c

#include <gtk/gtk.h>

GtkWidget *button;
extern GtkWidget *combo;

void button_clicked(GtkWidget* widget, gpointer user_data) {
  /* use combo here */
}
#3

A better solution would be to avoid global variables: pass the data around as function arguments.

a.c

#include <gtk/gtk.h>
#include "b.h"

GtkWidget *combo;

int main() {
  combo = gtk_combo_box_new();
  /* set up combo box */

  create_button(combo);
}

b.h

#include <gtk/gtk.h>

/* function declaration */
void create_button(GtkWidget *combo);

b.c

#include <gtk/gtk.h>

GtkWidget *button

void on_button_clicked(GtkWidget *widget, gpointer user_data) {
  GtkWidget *combo = GTK_WIDGET(user_data);
  /* use combo here */
}

void create_button(GtkWidget *combo) {
  button = gtk_button_new();
  /* set up button */

  g_signal_connect(button, "clicked", G_CALLBACK(on_button_clicked), (gpointer)combo);
}