Set Focus to GtkEntry when GtkNotebook Tab selected

["Thomas A. Moulton" <tom moulton us>]

I have the following object:

GtkWindow
  GtkNotebook
    GtkBox
         GtkScrolledWindow, GtkTextArea
         GtkEntry

I am trying to have the Entry get focus when I change Tabs

When the program starts it does focus on Tab 1's entry but I can not get 
it to keep focus
without clicking the entry area manually.

I set gtk_widget_set_can_focus(GTK_WIDGET(entry), 1);

notebook
g_signal_connect(G_OBJECT(nb), "switch-page", 
G_CALLBACK(ChatNB_switch_page_cb), NULL);

G_MODULE_EXPORT void ChatNB_switch_page_cb(GtkNotebook *notebook, 
GtkWidget *page, guint page_num, gpointer user_data) {
    printf("switch-page %d\r\n", page_num);fflush(stdout);
    if (page_num >= 0 && page_num < 5 && entries[page_num] != NULL) {
        gtk_widget_grab_focus(GTK_WIDGET(entries[page_num]));
    }
}

I have looked around and seen that this question is often asked but 
answers are not clear...

i run the program below and click Tab 1 and then Tab 2

tom

Full single file example

/*
 ============================================================================
 Name        : Scrolled.c
 Author      : Tom Moulton
 Version     :
 Copyright   : (c) 2013 Thoomas A. Moulton, Public Domain
 Description : Hello World in GTK+
 ============================================================================
 */

#include <gtk/gtk.h>
#include <string.h>
GtkNotebook *nb;
GtkEntry *entries[5];

void Enter_Chat(GtkEntry *entry, GtkTextBuffer *buf) {
    char line[512];
    const gchar *cmd;
    GtkTextIter endit;

    cmd = gtk_entry_get_text(entry);
    strcpy(line, cmd);
    strcat(line, "\r\n");
    gtk_entry_set_text(entry, "");

    gtk_text_buffer_get_end_iter(buf, &endit);
    gtk_text_buffer_insert_with_tags(buf, &endit, line, -1, NULL, NULL);
}

gboolean Enter_focus_in_event(GtkEntry *entry, gpointer *buf) {
    printf("Entry %x focus in event\r\n", (unsigned 
int)entry);fflush(stdout);
    //gtk_widget_grab_focus(GTK_WIDGET(entry));
    return TRUE;
}

void Enter_grab_focus(GtkEntry *entry, gpointer *buf) {
    printf("Entry %x grabbed focus\r\n", (unsigned 
int)entry);fflush(stdout);
}

void Chat_scroll_to_end(GtkTextBuffer *buf, GtkTextView *text) {
    GtkTextMark *mark;
    mark = gtk_text_buffer_get_mark(buf, "eob");
    gtk_text_view_scroll_mark_onscreen(text, mark);
}

void ChatNew(gchar *name) {
    GtkBox *chat;
    GtkTextBuffer *buf;
    GtkTextView *text;
    GtkEntry *entry;
    GtkScrolledWindow *scroll;
    GtkTextIter endit;
    GtkLabel *label;
    gint pg;

    text = (GtkTextView *)gtk_text_view_new();
    gtk_text_view_set_editable(text, FALSE);
    gtk_text_view_set_wrap_mode(text, GTK_WRAP_WORD_CHAR);
    gtk_text_view_set_cursor_visible(text, FALSE);
    buf = gtk_text_buffer_new(NULL);
    gtk_text_view_set_buffer(text, buf);

    scroll = (GtkScrolledWindow *)gtk_scrolled_window_new(NULL, NULL);
    gtk_scrolled_window_set_policy(scroll, GTK_POLICY_NEVER, 
GTK_POLICY_ALWAYS);
    gtk_container_add(GTK_CONTAINER(scroll), GTK_WIDGET(text));

    entry =  (GtkEntry *)gtk_entry_new();
    gtk_widget_set_size_request(GTK_WIDGET(entry), -1, 30);
    gtk_entry_set_has_frame(entry, 0);
    gtk_widget_set_can_focus(GTK_WIDGET(entry), 1);

    chat = GTK_BOX(gtk_box_new(GTK_ORIENTATION_VERTICAL, 0));
    gtk_box_pack_start(chat, GTK_WIDGET(scroll), TRUE, TRUE, 0);
    gtk_box_pack_end(chat, (GtkWidget *)entry, FALSE, TRUE, 0);

    g_signal_connect(G_OBJECT(entry), "activate", 
G_CALLBACK(Enter_Chat), (gpointer)buf);
    g_signal_connect(G_OBJECT(entry), "focus-in-event", 
G_CALLBACK(Enter_focus_in_event), NULL);
    g_signal_connect(G_OBJECT(entry), "grab-focus", 
G_CALLBACK(Enter_grab_focus), NULL);

    gtk_text_buffer_get_end_iter(buf, &endit);
    gtk_text_buffer_create_mark(buf, "eob", &endit, FALSE);
    g_signal_connect(G_OBJECT(buf), "changed", 
G_CALLBACK(Chat_scroll_to_end), (gpointer)text);
    label = (GtkLabel *)gtk_label_new(name);
    pg = gtk_notebook_append_page(nb, GTK_WIDGET(chat), 
GTK_WIDGET(label));
    if (pg != -1) entries[pg] = entry;
}

G_MODULE_EXPORT void ChatNB_switch_page_cb(GtkNotebook *notebook, 
GtkWidget *page, guint page_num, gpointer user_data) {
    printf("switch-page %d\r\n", page_num);fflush(stdout);
    if (page_num >= 0 && page_num < 5 && entries[page_num] != NULL) {
        gtk_widget_grab_focus(GTK_WIDGET(entries[page_num]));
    }
}

int main (int argc, char *argv[])
 {
    GtkWidget *window;

    entries[0] = NULL;
    entries[1] = NULL;
    entries[2] = NULL;
    entries[3] = NULL;
    entries[4] = NULL;

    gtk_init (&argc, &argv);

    /* create the main, top level, window */
    window = gtk_window_new (GTK_WINDOW_TOPLEVEL);

    /* give it the title */
    gtk_window_set_title (GTK_WINDOW (window), "Hello World");
    gtk_window_set_default_size(GTK_WINDOW (window), 800, 600);

    /* Connect the destroy signal of the window to gtk_main_quit
     * When the window is about to be destroyed we get a notification and
     * stop the main GTK+ loop
     */
    g_signal_connect (window, "destroy", G_CALLBACK (gtk_main_quit), 
NULL);

    nb = (GtkNotebook *)gtk_notebook_new();
    ChatNew("Tab #1");
    ChatNew("Tab #2");

    g_signal_connect(G_OBJECT(nb), "switch-page", 
G_CALLBACK(ChatNB_switch_page_cb), NULL);

    /* and insert it into the main window  */
    gtk_container_add (GTK_CONTAINER (window), GTK_WIDGET(nb));

    /* make sure that everything, window and label, are visible */
    gtk_widget_show_all (window);

    /* start the main loop, and let it rest there until the application 
is closed */
    gtk_main ();

    return 0;
 }