RadioButtonRef

public struct RadioButtonRef : RadioButtonProtocol, GWeakCapturing

A single radio button performs the same basic function as a GtkCheckButton, as its position in the object hierarchy reflects. It is only when multiple radio buttons are grouped together that they become a different user interface component in their own right.

Every radio button is a member of some group of radio buttons. When one is selected, all other radio buttons in the same group are deselected. A GtkRadioButton is one way of giving the user a choice from many options.

Radio button widgets are created with gtk_radio_button_new(), passing nil as the argument if this is the first radio button in a group. In subsequent calls, the group you wish to add this button to should be passed as an argument. Optionally, gtk_radio_button_new_with_label() can be used if you want a text label on the radio button.

Alternatively, when adding widgets to an existing group of radio buttons, use gtk_radio_button_new_from_widget() with a GtkRadioButton that already has a group assigned to it. The convenience function gtk_radio_button_new_with_label_from_widget() is also provided.

To retrieve the group a GtkRadioButton is assigned to, use gtk_radio_button_get_group().

To remove a GtkRadioButton from one group and make it part of a new one, use gtk_radio_button_set_group().

The group list does not need to be freed, as each GtkRadioButton will remove itself and its list item when it is destroyed.

CSS nodes

(plain Language Example):

radiobutton
├── radio
╰── <child>

A GtkRadioButton with indicator (see gtk_toggle_button_set_mode()) has a main CSS node with name radiobutton and a subnode with name radio.

(plain Language Example):

button.radio
├── radio
╰── <child>

A GtkRadioButton without indicator changes the name of its main node to button and adds a .radio style class to it. The subnode is invisible in this case.

How to create a group of two radio buttons.

(C Language Example):

void create_radio_buttons (void) {

   GtkWidget *window, *radio1, *radio2, *box, *entry;
   window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
   box = gtk_box_new (GTK_ORIENTATION_VERTICAL, 2);
   gtk_box_set_homogeneous (GTK_BOX (box), TRUE);

   // Create a radio button with a GtkEntry widget
   radio1 = gtk_radio_button_new (NULL);
   entry = gtk_entry_new ();
   gtk_container_add (GTK_CONTAINER (radio1), entry);


   // Create a radio button with a label
   radio2 = gtk_radio_button_new_with_label_from_widget (GTK_RADIO_BUTTON (radio1),
                                                         "I’m the second radio button.");

   // Pack them into a box, then show all the widgets
   gtk_box_pack_start (GTK_BOX (box), radio1);
   gtk_box_pack_start (GTK_BOX (box), radio2);
   gtk_container_add (GTK_CONTAINER (window), box);
   gtk_widget_show_all (window);
   return;
}

When an unselected button in the group is clicked the clicked button receives the GtkToggleButton::toggled signal, as does the previously selected button. Inside the GtkToggleButton::toggled handler, gtk_toggle_button_get_active() can be used to determine if the button has been selected or deselected.

The RadioButtonRef type acts as a lightweight Swift reference to an underlying GtkRadioButton instance. It exposes methods that can operate on this data type through RadioButtonProtocol conformance. Use RadioButtonRef only as an unowned reference to an existing GtkRadioButton instance.