GTK+ Forums

    ...
    /* Put combo_box entry in a string */
    const char *string;
    string = gtk_entry_get_text (GTK_ENTRY (GTK_COMBO (combo_box)->entry));

    /* Attach a signal handler to the button */
    g_signal_connect (G_OBJECT (button), "clicked",
                      G_CALLBACK (callback_button_pressed), (gpointer) string);
   ...

/* Callback for button pressing */
static void callback_button_pressed( GtkWidget *widget, gpointer data)
{
char returnString[50];
aFunctionWhichModifiesTheReturnString(returnString);
g_print("With the value %s the returning value was %s", (gchar *) data, returnString); /* this works well */
}

...
    /* Attach a signal handler to the button */
    g_signal_connect (G_OBJECT (button), "clicked",
                      G_CALLBACK (callback_button_pressed), (gpointer) combo_box);
    g_object_add_data (G_OBJECT (combo_box), "label", (gpointer) label);
   ...

/* Callback for button pressing */
static void callback_button_pressed( GtkWidget *widget, GtkComboBox *combo_box)
{
  const gchar *str;
  gchar *returnString;
  GtkWidget *label;

  returnString = aFunctionWhichReturnsAString (str);
  label = GTK_WIDGET (g_object_get_data (G_OBJECT (combo_box), "label"));

  str = gtk_entry_get_text (GTK_ENTRY (GTK_COMBO (combo_box)->entry));
  g_print ("With the value %s the returning value was %s", str, returnString);
  gtk_label_set_text (GTK_LABEL (label), returnString);
  g_free (returnString);
}

typdedef struct
{
  GtkWidget *combo_box, *label, *image;
} AppWidgets;

...
AppWidgets *w = g_slice_new (AppWidgets);

/* Attach a signal handler to the button */
g_signal_connect (G_OBJECT (button), "clicked",
                  G_CALLBACK (callback_button_pressed), (gpointer) w);
...

/* Callback for button pressing */
static void callback_button_pressed (GtkWidget *widget, GtkComboBox *combo_box, AppWidgets *w)
{
  const gchar *str;
  gchar *returnString;

  returnString = aFunctionWhichReturnsAString (str);

  str = gtk_entry_get_text (GTK_ENTRY (GTK_COMBO (w->combo_box)->entry));
  g_print ("With the value %s the returning value was %s", str, returnString);
  gtk_label_set_text (GTK_LABEL (w->label), returnString);
  g_free (returnString);
}

/* Callback for button pressing */
static void callback_button_pressed (GtkWidget *widget, GtkComboBox *combo_box, AppWidgets *w)
{
   const gchar *str;
   str = gtk_entry_get_text (GTK_ENTRY (GTK_COMBO (w->combo_box)->entry));
   g_print("The string in from the combo box is %s!\n", str); /* program never gets in here... */
}

#include <gtk/gtk.h>
#include <glib-object.h>

typedef struct {
        GtkWidget *label, *label2, *combo_box;
} AppWidgets;

static gboolean delete_event( GtkWidget *widget, GdkEvent  *event, gpointer data);
static void callback_button_pressed (GtkWidget *widget, GtkComboBox *combo_box, AppWidgets *w);

int main( int   argc,
          char *argv[] )
{
    /* Create needed widgets */
    GtkWidget *window;
    GtkWidget *table;
    GtkWidget *button;
    GtkWidget *image;
    GtkWidget *combo_box;
    GtkWidget *label;
    GtkWidget *label2;

    /* Create a new AppWidgets object */
    AppWidgets *w = g_slice_new (AppWidgets);   

    /* Initialize GTK */
    gtk_init (&argc, &argv);
   
    /* Create window and set a title and borders for it */
    window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
    g_set_application_name("Test program");
    gtk_container_set_border_width (GTK_CONTAINER (window), 20);

    gtk_widget_set_size_request (window, 712, 400);

    /* Set a handler for delete_event that immediately
     * exits GTK. */
    g_signal_connect (G_OBJECT (window), "delete_event",
                      G_CALLBACK (delete_event), NULL);

    /* Create table and add it to window */
    table = gtk_table_new (5, 5, TRUE);
    gtk_container_add (GTK_CONTAINER (window), table);

    /* Create image and add it into the table */
    image = gtk_image_new_from_file("logo.png");
    gtk_table_attach_defaults (GTK_TABLE (table), image, 0, 5, 0,1);
    gtk_widget_show(image);

    /* Create the labels and attach them to the table */
    label = gtk_label_new ("This is the first label");
    gtk_table_attach_defaults(GTK_TABLE (table), label, 0, 3, 1, 2);
    gtk_widget_show (label);

    label2 = gtk_label_new ("This is the second label");
    gtk_table_attach_defaults (GTK_TABLE (table), label2, 0, 3, 2, 3);
    gtk_widget_show (label2);

    /* Create button and add it into the table */
    button = gtk_button_new_with_label("Push me");
    gtk_table_attach_defaults (GTK_TABLE (table), button, 3, 5, 1, 2);
    gtk_widget_show (button);

    /* Create combo box and add it into the table */
    combo_box = gtk_combo_box_new_text();

    gtk_combo_box_append_text (GTK_COMBO_BOX (combo_box), "Entry 1");
    gtk_combo_box_append_text (GTK_COMBO_BOX (combo_box), "Entry 2");
    gtk_combo_box_append_text (GTK_COMBO_BOX (combo_box), "Entry 3");
    gtk_combo_box_set_active (GTK_COMBO_BOX (combo_box), 0);

    gtk_table_attach_defaults (GTK_TABLE (table), combo_box, 3, 5, 2, 3);
    gtk_widget_show (combo_box);

    /* Attach a signal handler to the button */
    g_signal_connect (G_OBJECT (button), "clicked",
                  G_CALLBACK (callback_button_pressed), (gpointer) w);

    /* Show all widgets in the Window */
    gtk_widget_show_all(GTK_WIDGET(window));
    gtk_main ();
   
    return 0;
}

/* Callback to close the window */
static gboolean delete_event( GtkWidget *widget, GdkEvent  *event, gpointer data)
{
    gtk_main_quit ();
    return FALSE;
}

/* Callback for button pressing */
static void callback_button_pressed (GtkWidget *widget, GtkComboBox *combo_box, AppWidgets *w)
{
  const gchar *str;
  str = gtk_combo_box_get_active_text (GTK_COMBO_BOX (w->combo_box));
  g_print("The text was %s\n", str);
}

w->combo_box = gtk_combo_box_new_text();

w->combo_box = gtk_combo_box_entry_new ();