SpinButtonRef

public struct SpinButtonRef : SpinButtonProtocol, GWeakCapturing

A GtkSpinButton is an ideal way to allow the user to set the value of some attribute.

Rather than having to directly type a number into a GtkEntry, GtkSpinButton allows the user to click on one of two arrows to increment or decrement the displayed value. A value can still be typed in, with the bonus that it can be checked to ensure it is in a given range.

The main properties of a GtkSpinButton are through an adjustment. See the [classGtk.Adjustment] documentation for more details about an adjustment’s properties.

Note that GtkSpinButton will by default make its entry large enough to accommodate the lower and upper bounds of the adjustment. If this is not desired, the automatic sizing can be turned off by explicitly setting [propertyGtk.Editable:width-chars] to a value != -1.

Using a GtkSpinButton to get an integer

// Provides a function to retrieve an integer value from a GtkSpinButton
// and creates a spin button to model percentage values.

int
grab_int_value (GtkSpinButton *button,
                gpointer       user_data)
{
  return gtk_spin_button_get_value_as_int (button);
}

void
create_integer_spin_button (void)
{

  GtkWidget *window, *button;
  GtkAdjustment *adjustment;

  adjustment = gtk_adjustment_new (50.0, 0.0, 100.0, 1.0, 5.0, 0.0);

  window = gtk_window_new ();

  // creates the spinbutton, with no decimal places
  button = gtk_spin_button_new (adjustment, 1.0, 0);
  gtk_window_set_child (GTK_WINDOW (window), button);

  gtk_widget_show (window);
}

Using a GtkSpinButton to get a floating point value

// Provides a function to retrieve a floating point value from a
// GtkSpinButton, and creates a high precision spin button.

float
grab_float_value (GtkSpinButton *button,
                  gpointer       user_data)
{
  return gtk_spin_button_get_value (button);
}

void
create_floating_spin_button (void)
{
  GtkWidget *window, *button;
  GtkAdjustment *adjustment;

  adjustment = gtk_adjustment_new (2.500, 0.0, 5.0, 0.001, 0.1, 0.0);

  window = gtk_window_new ();

  // creates the spinbutton, with three decimal places
  button = gtk_spin_button_new (adjustment, 0.001, 3);
  gtk_window_set_child (GTK_WINDOW (window), button);

  gtk_widget_show (window);
}

CSS nodes

spinbutton.horizontal
├── text
│    ├── undershoot.left
│    ╰── undershoot.right
├── button.down
╰── button.up

spinbutton.vertical
├── button.up
├── text
│    ├── undershoot.left
│    ╰── undershoot.right
╰── button.down

GtkSpinButtons main CSS node has the name spinbutton. It creates subnodes for the entry and the two buttons, with these names. The button nodes have the style classes .up and .down. The GtkText subnodes (if present) are put below the text node. The orientation of the spin button is reflected in the .vertical or .horizontal style class on the main node.

Accessiblity

GtkSpinButton uses the GTK_ACCESSIBLE_ROLE_SPIN_BUTTON role.

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