Numeric input widgets

Gtk4 provides a few different widgets for user input of numeric values.

GtkScale

The GtkScale widget allows users to select a value by sliding a knob within a predefined range. It is a subclass of GtkRange and displays a slider and, optionally, text showing the current value.

A GtkScale is typically created using one of the following constructors:

GtkScale(orientation, range::AbstractRange) creates a new GtkScale with the specified orientation (:h/Orientation_HORIZONTAL or :v/Orientation_VERTICAL), with the range of allowed values defined by range.
GtkScale(orientation, min_val, max_val, step) creates a new GtkScale with the range of allowed values defined by min_val, max_val, and step.
GtkScale(orientation, adj::GtkAdjustment) creates a new GtkScale using an existing GtkAdjustment object to manage the range and value.

Example

using Gtk4

# Create a horizontal scale for integers from 0 to 100
scale = GtkScale(:h, 0.0, 100.0, 1.0)

# Set the initial value
Gtk4.value(scale, 50.0)

Useful properties and signals

property	type
`value`	`Float64`	The current value of the slider. Get/set using `Gtk4.value(widget)` and `Gtk4.value(widget, val)`.
`draw_value`	`Bool`	Whether the current value is displayed next to the slider. Defaults to `false`.
`digits`	`Int`	The number of decimal places to display for the value.
`adjustment`	`GtkAdjustment`	The `GtkAdjustment` managing the scale's range, value, and step.

The most important signal for interacting with the scale's value is inherited from GtkRange:

signal	arguments	returns
"value-changed"	self::GtkScale	`Nothing`	Emitted when the value is changed

The GtkSpinButton widget allows a user to select a value from a numerical range by typing in a text field or by clicking a pair of up/down buttons. A GtkSpinButton is typically created using one of the following constructors:

GtkSpinButton(min_val, max_val, step_increment) creates a new GtkSpinButton with the specified minimum value min_val, maximum value max_val, and increment size step_increment.
GtkSpinButton(adj::GtkAdjustment, climb_rate::Real, digits::Integer) creates a new GtkSpinButton using an existing GtkAdjustment object to manage the range and value. The argument climb_rate is an internal scaling factor applied to the step increment when the arrow buttons are held down, while digits is the number of decimal places to display.

Example

using Gtk4

# Create a spin button for integer values from 1 to 10 with step 1
spin = GtkSpinButton(1.0, 10.0, 1.0)

# Set the initial value
Gtk4.value(spin, 5.0)

Useful properties and signals

property	type
`value`	`Float64`	The current numerical value of the widget. Get/set using `Gtk4.value(widget)` and `Gtk4.value(widget, val)`.
`adjustment`	`GtkAdjustment`	The object managing the range, value, and step increment.
`digits`	`Int`	The number of decimal places to display.
`numeric`	`Bool`	Whether only numeric characters are allowed in the entry field. Defaults to `false`.

The most common signal for tracking changes is:

signal	arguments	returns
"value-changed"	self::GtkSpinButton	`Nothing`	Emitted when the value is changed.