Shared scrollbar between 2 Text widgets EXAMPLE

[Marc Aubry <marc upr41 univ-rennes1 fr>]

As requested, here is an example of my shared scrollbar...

	Version #1 (Owen's one): the program does'nt segfault but the two Text
Widgets are not scrolling together.

	Version #2 (my version): the two Text Widgets are scrolling together
but the program segfaults when scrolling while there is two much lines
in one text widget !


/* Shared Scrollbar */

#include <gtk/gtk.h>

void delete_event (GtkWidget *widget, gpointer *data);
void realize_text (GtkWidget *widget, GtkWidget *text);
void text_scrolling (GtkAdjustment *adj1, GtkAdjustment *adj2);

void delete_event (GtkWidget *widget, gpointer *data)
{
    gtk_main_quit ();
}

void realize_text (GtkWidget *widget, GtkWidget *text)
{
    guint i;
    gchar buffer[32];

    gtk_text_freeze (GTK_TEXT (text));
    for (i=0; i<10; i++)
    {
        sprintf (buffer, "One line #%d\n", i);
        gtk_text_insert (GTK_TEXT (text), NULL, &text->style->black,
NULL,
                          buffer, -1);

    }
    gtk_text_thaw (GTK_TEXT (text));
}

void text_scrolling (GtkAdjustment *adj1, GtkAdjustment *adj2)
{
    adj2->value = CLAMP (adj1->value, 0, adj2->upper - adj2->page_size);
    gtk_signal_emit_by_name (GTK_OBJECT (adj2), "value_changed");
}

int main (int argc, char *argv[])
{
    GtkWidget *window, *text, *text2;
    GtkWidget *vscrollbar;
    GtkWidget *main_vbox, *hbox, *textbox;
    GtkWidget *button;


    gtk_init (&argc, &argv);

    window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
    gtk_window_set_title (GTK_WINDOW (window), "Shared Scrollbar");
    gtk_signal_connect (GTK_OBJECT (window), "destroy",
                        GTK_SIGNAL_FUNC (gtk_main_quit), NULL);
    gtk_container_border_width (GTK_CONTAINER (window), 5);
    gtk_widget_set_usize (GTK_WIDGET (window), 600, 400);

    main_vbox = gtk_vbox_new (FALSE, 1);
    gtk_container_add (GTK_CONTAINER (window), main_vbox);


    textbox = gtk_hbox_new (FALSE, 0);

    text = gtk_text_new (NULL, NULL);
    gtk_text_set_editable (GTK_TEXT(text), TRUE);
    gtk_box_pack_start (GTK_BOX(textbox), text, TRUE, TRUE, 0);

    text2 = gtk_text_new (NULL, NULL);
    gtk_text_set_editable (GTK_TEXT(text2), TRUE);
    gtk_widget_set_usize (GTK_WIDGET (text2), 80, 0);
    gtk_box_pack_start (GTK_BOX(textbox), text2, FALSE, FALSE, 0);

    gtk_widget_show (text);
    gtk_widget_show (text2);

    vscrollbar = gtk_vscrollbar_new (GTK_TEXT (text)->vadj);

    /* VERSION #1 */
//    gtk_signal_connect ( GTK_OBJECT(GTK_TEXT (text)->vadj), "changed",
//                         GTK_SIGNAL_FUNC (text_scrolling),
GTK_TEXT(text2)->vadj )
;
    /* VERSION #2 */
    gtk_text_set_adjustments (GTK_TEXT (text2), NULL, GTK_TEXT
(text)->vadj);

    gtk_box_pack_start (GTK_BOX(textbox), vscrollbar, FALSE, FALSE, 0);
    gtk_widget_show (vscrollbar);

    gtk_box_pack_start (GTK_BOX(main_vbox), textbox, TRUE, TRUE, 0);


    hbox = gtk_hbox_new (TRUE, 0);
    button = gtk_button_new_with_label ("Quit");
    gtk_signal_connect ( GTK_OBJECT(button), "clicked",
                         GTK_SIGNAL_FUNC (delete_event), NULL);
    gtk_box_pack_start (GTK_BOX (hbox), button, TRUE, TRUE, 0);
    gtk_widget_show (button);
    button = gtk_button_new_with_label ("Add Text (Left)");
    gtk_signal_connect ( GTK_OBJECT(button), "clicked",
                         GTK_SIGNAL_FUNC (realize_text), text);
    gtk_box_pack_start (GTK_BOX (hbox), button, TRUE, TRUE, 0);
    gtk_widget_show (button);
    button = gtk_button_new_with_label ("Add Text (Right)");
    gtk_signal_connect ( GTK_OBJECT(button), "clicked",
                         GTK_SIGNAL_FUNC (realize_text), text2);
    gtk_box_pack_start (GTK_BOX (hbox), button, TRUE, TRUE, 0);
    gtk_widget_show (button);


    gtk_box_pack_start (GTK_BOX(main_vbox), hbox, FALSE, FALSE, 0);

    gtk_widget_show (textbox);
    gtk_widget_show (hbox);
    gtk_widget_show (main_vbox);
    gtk_widget_show (window);

    gtk_main ();
    return 0;
}