NumberInput

A text input that is limited to numeric input.

Usage

import toga

widget = toga.NumberInput(min=1, max=10, step=0.001)
widget.value = 2.718

NumberInput’s properties can accept Decimal, int, float, or str containing numbers, but they always return Decimal objects to ensure precision is retained.

Reference

class toga.NumberInput(id=None, style=None, step=1, min=None, max=None, value=None, readonly=False, on_change=None, **kwargs)

Bases: Widget

Create a new number input widget.

Parameters:

  • id (str | None) – The ID for the widget.

  • style (StyleT | None) – A style object. If no style is provided, a default style will be applied to the widget.

  • step (NumberInputT) – The amount that any increment/decrement operations will apply to the widget’s current value.

  • min (NumberInputT | None) – If provided, value will be guaranteed to be greater than or equal to this minimum.

  • max (NumberInputT | None) – If provided, value will be guaranteed to be less than or equal to this maximum.

  • value (NumberInputT | None) – The initial value for the widget.

  • readonly (bool) – Can the value of the widget be modified by the user?

  • on_change (toga.widgets.numberinput.OnChangeHandler | None) – A handler that will be invoked when the value of the widget changes.

  • kwargs – Initial style properties.

property max: Decimal | None

The maximum bound for the widget’s value.

Returns None if there is no maximum bound.

When setting this property, the current value and min will be clipped against the new maximum value.

property min: Decimal | None

The minimum bound for the widget’s value.

Returns None if there is no minimum bound.

When setting this property, the current value and max will be clipped against the new minimum value.

property on_change: OnChangeHandler

The handler to invoke when the value of the widget changes.

property readonly: bool

Can the value of the widget be modified by the user?

This only controls manual changes by the user (i.e., typing at the keyboard). Programmatic changes are permitted while the widget has readonly enabled.

property step: Decimal

The amount that any increment/decrement operations will apply to the widget’s current value. (Not all backends provide increment and decrement buttons.)

property value: Decimal | None

Current value of the widget, rounded to the same number of decimal places as step, or None if no value has been set.

If this property is set to a value outside of the min/max range, it will be clipped.

While the widget is being edited by the user, it is possible for the UI to contain a value which is outside of the min/max range, or has too many decimal places. In this case, this property will return a value that has been clipped and rounded, and the visible text will be updated to match as soon as the widget loses focus.

protocol toga.widgets.numberinput.OnChangeHandler

typing.Protocol.

Classes that implement this protocol must have the following methods / attributes:

__call__(widget, **kwargs)

A handler to invoke when the value is changed.

Parameters:

  • widget (NumberInput) – The NumberInput that was changed.

  • kwargs (Any) – Ensures compatibility with arguments added in future versions.

Return type:

object