Question

i want to display text on my window and a “next” button ,but when i am running code it is giving me error.

with next button i want to move to next window where i am displaying something else.
can somebody also tell me how to do this.

(try:1914): Gtk-WARNING **: Attempting to add a widget with type GtkVBox to a GtkWindow, but as a GtkBin subclass a GtkWindow can only contain one widget at a time; it already contains a widget of type GtkLabel

my code is:

#include <gtk/gtk.h>

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

        GtkWidget *window;
        GtkWidget *next;

        GtkWidget *label;
        GtkWidget *vbox;
        GtkWidget *hbox;
        GtkWidget *halign;
        GtkWidget *valign;


        gtk_init (&argc, &argv);

        window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
        gtk_window_set_title(GTK_WINDOW(window), "Center");//title position
        gtk_window_set_default_size(GTK_WINDOW(window),600,500);//size
        gtk_window_set_position(GTK_WINDOW(window), GTK_WIN_POS_CENTER);//position
        label = gtk_label_new("Cold was my soul\n\
                        Untold was the pain\n\
                        I faced when you left me\n\
                        A rose in the rain....\n\
                        So I swore to the razor\n\
                        That never, enchained\n\
                        Would your dark nails of faith\n\
                        Be pushed through my veins again\n\
                        \n\
                        Bared on your tomb\n\
                        I'm a prayer for your loneliness\n\
                        And would you ever soon\n\
                        Come above onto me?\n\
                        For once upon a time\n\
                        On the binds of your lowliness\n\
                        I could always find the slot for your sacred key ");

 gtk_label_set_justify(GTK_LABEL(label), GTK_JUSTIFY_CENTER);
        gtk_container_add(GTK_CONTAINER(window), label);
        vbox = gtk_vbox_new(FALSE, 5);

        valign = gtk_alignment_new(0, 1, 0, 0);
        gtk_container_add(GTK_CONTAINER(vbox), valign);
        gtk_container_add(GTK_CONTAINER(window), vbox);

        hbox = gtk_hbox_new(TRUE, 3);

        next = gtk_button_new_with_label("Next");
        gtk_widget_set_size_request(next, 70, 30);
        gtk_container_add(GTK_CONTAINER(hbox), next);
        //      close = gtk_button_new_with_label("Close");
        //      gtk_container_add(GTK_CONTAINER(hbox), close);

        halign = gtk_alignment_new(1, 0, 0, 0);
        gtk_container_add(GTK_CONTAINER(halign), hbox);

        gtk_box_pack_start(GTK_BOX(vbox), halign, FALSE, FALSE, 0);
        g_signal_connect(G_OBJECT(next), "clicked",
                        G_CALLBACK(gtk_main_quit), G_OBJECT(window));

        gtk_widget_show_all(window);

        g_signal_connect_swapped(G_OBJECT(window), "destroy", G_CALLBACK(gtk_main_quit), NULL);


        gtk_main ();

        return 0;
}

Answer 1

The message is pretty clear: A GtkWindow can contain only one child widget but you have filled it already with the label. To achieve what you want, you have to add vbox (that is able to contain several widgets) to the window and then label to vbox.