/* Size Groups * * GtkSizeGroup provides a mechanism for grouping a number of * widgets together so they all request the same amount of space. * This is typically useful when you want a column of widgets to  * have the same size, but you can't use a GtkTable widget. *  * Note that size groups only affect the amount of space requested, * not the size that the widgets finally receive. If you want the * widgets in a GtkSizeGroup to actually be the same size, you need * to pack them in such a way that they get the size they request * and not more. For example, if you are packing your widgets * into a table, you would not include the GTK_FILL flag. */#include <gtk/gtk.h>static GtkWidget *window = NULL;/* Convenience function to create a combo box holding a number of strings */GtkWidget *create_combo_box (const char **strings){  GtkWidget *combo_box;  const char **str;  combo_box = gtk_combo_box_new_text ();    for (str = strings; *str; str++)    gtk_combo_box_append_text (GTK_COMBO_BOX (combo_box), *str);  gtk_combo_box_set_active (GTK_COMBO_BOX (combo_box), 0);  return combo_box;}static voidadd_row (GtkTable     *table,	 int           row,	 GtkSizeGroup *size_group,	 const char   *label_text,	 const char  **options){  GtkWidget *combo_box;  GtkWidget *label;  label = gtk_label_new_with_mnemonic (label_text);  gtk_misc_set_alignment (GTK_MISC (label), 0, 1);  gtk_table_attach (GTK_TABLE (table), label,		    0, 1,                  row, row + 1,		    GTK_EXPAND | GTK_FILL, 0,		    0,                     0);    combo_box = create_combo_box (options);  gtk_label_set_mnemonic_widget (GTK_LABEL (label), combo_box);  gtk_size_group_add_widget (size_group, combo_box);  gtk_table_attach (GTK_TABLE (table), combo_box,		    1, 2,                  row, row + 1,		    0,                     0,		    0,                     0);}static voidtoggle_grouping (GtkToggleButton *check_button,		 GtkSizeGroup    *size_group){  GtkSizeGroupMode new_mode;  /* GTK_SIZE_GROUP_NONE is not generally useful, but is useful   * here to show the effect of GTK_SIZE_GROUP_HORIZONTAL by   * contrast.   */  if (gtk_toggle_button_get_active (check_button))    new_mode = GTK_SIZE_GROUP_HORIZONTAL;  else    new_mode = GTK_SIZE_GROUP_NONE;    gtk_size_group_set_mode (size_group, new_mode);}GtkWidget *do_sizegroup (GtkWidget *do_widget){  GtkWidget *table;  GtkWidget *frame;  GtkWidget *vbox;  GtkWidget *check_button;  GtkSizeGroup *size_group;  static const char *color_options[] = {    "Red", "Green", "Blue", NULL  };    static const char *dash_options[] = {    "Solid", "Dashed", "Dotted", NULL  };    static const char *end_options[] = {    "Square", "Round", "Arrow", NULL  };    if (!window)    {      window = gtk_dialog_new_with_buttons ("GtkSizeGroup",					    GTK_WINDOW (do_widget),					    0,					    GTK_STOCK_CLOSE,					    GTK_RESPONSE_NONE,					    NULL);      gtk_window_set_resizable (GTK_WINDOW (window), FALSE);            g_signal_connect (window, "response",			G_CALLBACK (gtk_widget_destroy), NULL);      g_signal_connect (window, "destroy",			G_CALLBACK (gtk_widget_destroyed), &window);      vbox = gtk_vbox_new (FALSE, 5);      gtk_box_pack_start (GTK_BOX (GTK_DIALOG (window)->vbox), vbox, TRUE, TRUE, 0);      gtk_container_set_border_width (GTK_CONTAINER (vbox), 5);      size_group = gtk_size_group_new (GTK_SIZE_GROUP_HORIZONTAL);            /* Create one frame holding color options       */      frame = gtk_frame_new ("Color Options");      gtk_box_pack_start (GTK_BOX (vbox), frame, TRUE, TRUE, 0);      table = gtk_table_new (2, 2, FALSE);      gtk_container_set_border_width (GTK_CONTAINER (table), 5);      gtk_table_set_row_spacings (GTK_TABLE (table), 5);      gtk_table_set_col_spacings (GTK_TABLE (table), 10);      gtk_container_add (GTK_CONTAINER (frame), table);      add_row (GTK_TABLE (table), 0, size_group, "_Foreground", color_options);      add_row (GTK_TABLE (table), 1, size_group, "_Background", color_options);      /* And another frame holding line style options       */      frame = gtk_frame_new ("Line Options");      gtk_box_pack_start (GTK_BOX (vbox), frame, FALSE, FALSE, 0);      table = gtk_table_new (2, 2, FALSE);      gtk_container_set_border_width (GTK_CONTAINER (table), 5);      gtk_table_set_row_spacings (GTK_TABLE (table), 5);      gtk_table_set_col_spacings (GTK_TABLE (table), 10);      gtk_container_add (GTK_CONTAINER (frame), table);      add_row (GTK_TABLE (table), 0, size_group, "_Dashing", dash_options);      add_row (GTK_TABLE (table), 1, size_group, "_Line ends", end_options);      /* And a check button to turn grouping on and off */      check_button = gtk_check_button_new_with_mnemonic ("_Enable grouping");      gtk_box_pack_start (GTK_BOX (vbox), check_button, FALSE, FALSE, 0);            gtk_toggle_button_set_active (GTK_TOGGLE_BUTTON (check_button), TRUE);      g_signal_connect (check_button, "toggled",			G_CALLBACK (toggle_grouping), size_group);    }  if (!GTK_WIDGET_VISIBLE (window))    gtk_widget_show_all (window);  else    gtk_widget_destroy (window);  return window;}