Fixed Container

GTK+ 2.0 Tutorial
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# Fixed Container

The Fixed container allows you to place widgets at a fixed position within it's window, relative to it's upper left hand corner. The position of the widgets can be changed dynamically.

There are only a few functions associated with the fixed widget:

    GtkWidget* gtk_fixed_new( void );

    void gtk_fixed_put( GtkFixed  *fixed,
                        GtkWidget *widget,
                        gint       x,
                        gint       y );

    void gtk_fixed_move( GtkFixed  *fixed,
                         GtkWidget *widget,
                         gint       x,
                         gint       y );

The function gtk_fixed_new() allows you to create a new Fixed container.

gtk_fixed_put() places `widget` in the container `fixed` at the position specified by `x` and `y`.

gtk_fixed_move() allows the specified widget to be moved to a new position.

    void gtk_fixed_set_has_window( GtkFixed  *fixed,
                                   gboolean   has_window );

    gboolean gtk_fixed_get_has_window( GtkFixed *fixed );

Normally, Fixed widgets don't have their own X window. Since this is different from the behaviour of Fixed widgets in earlier releases of GTK, the function gtk_fixed_set_has_window() allows the creation of Fixed widgets with their own window. It has to be called before realizing the widget.

The following example illustrates how to use the Fixed Container.

    #include <gtk/gtk.h>

    /* I'm going to be lazy and use some global variables to
     * store the position of the widget within the fixed
     * container */
    gint x = 50;
    gint y = 50;

    /* This callback function moves the button to a new position
     * in the Fixed container. */
    static void move_button( GtkWidget *widget,
                             GtkWidget *fixed )
    {
      x = (x + 30) % 300;
      y = (y + 50) % 300;
      gtk_fixed_move (GTK_FIXED (fixed), widget, x, y);
    }

    int main( int   argc,
              char *argv[] )
    {
      /* GtkWidget is the storage type for widgets */
      GtkWidget *window;
      GtkWidget *fixed;
      GtkWidget *button;
      gint i;

      /* Initialise GTK */
      gtk_init (&argc, &argv);

      /* Create a new window */
      window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
      gtk_window_set_title (GTK_WINDOW (window), "Fixed Container");

      /* Here we connect the "destroy" event to a signal handler */
      g_signal_connect (window, "destroy",
    		    G_CALLBACK (gtk_main_quit), NULL);

      /* Sets the border width of the window. */
      gtk_container_set_border_width (GTK_CONTAINER (window), 10);

      /* Create a Fixed Container */
      fixed = gtk_fixed_new ();
      gtk_container_add (GTK_CONTAINER (window), fixed);
      gtk_widget_show (fixed);

      for (i = 1 ; i <= 3 ; i++) {
        /* Creates a new button with the label "Press me" */
        button = gtk_button_new_with_label ("Press me");

        /* When the button receives the "clicked" signal, it will call the
         * function move_button() passing it the Fixed Container as its
         * argument. */
        g_signal_connect (button, "clicked",
    		      G_CALLBACK (move_button), (gpointer) fixed);

        /* This packs the button into the fixed containers window. */
        gtk_fixed_put (GTK_FIXED (fixed), button, i*50, i*50);

        /* The final step is to display this newly created widget. */
        gtk_widget_show (button);
      }

      /* Display the window */
      gtk_widget_show (window);

      /* Enter the event loop */
      gtk_main ();

      return 0;
    }

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