AXNumValidatedTF is a Xojo TextField subclass (32/64 bits) for Windows, macOS and Linux allowing the input validation of a defined numeric range, using the system Locale settings for decimal and grouping text formatting.

• Raise Events when the entered value is in / out of Range (active catching / propagation of the value).
• Optionally displays a message Dialog when the entered value is out of range.
• Optionally stays in focus when the entered value is out of range.
• Use of Locale settings for Grouping and Decimal separators.
• Adaptive formatting during the value validation.
• Instance ToolTip / HelpTag set to the accepted value Range
• Set the length of the decimal part for Real numbers.
• IsInRange property to passively check if the value is inside the defined range.
• Xojo API 2.0 / API 1.0 versions of the Class.
• macOS / Windows / Linux (32/64 bits) compatible.

Buy the AXNumValidatedTF License from the product Page

Among other features, the user can set the kind of numerical input (Integer or Real), Minimum and Maximum values for the accepted numerical input, the decimal length for real numbers, and the default value for the field. It also provides properties to enforce the input of a numerical value in the defined range (the focus stays in the field) and the optional display of an error message dialog.

As part of the validation process, AXNumValidatedTF properly formats the displayed number, including the use of the Grouping and Decimal character defined in the system Locale settings, the deletion of left side zeroes and even trying to fix the incorrect use of the Grouping and Decimal characters as part of the input from the user (for example, “10,00.32” is formatted as “1,000.32” after the validation when the “,” character is set for number Grouping and “.” as the decimal separator).

AXNumValidatedTF formats the Minimum and Maximum values, showing them as a hint in the ToolTip (API 2.0) or HelpTag (API 1) for each of the instances used in the Layout of the App.

Besides the usual Methods and Properties available in a TextField, AXNumValidatedTF adds its own Properties, Methods and Events to simplify the access and notification of the entered values. For example:

• IsInRange As Boolean

Is a Property set to True when the entered value is in the defined Range, and False otherwise.

For those cases when an active notification or propagation of the value is needed, it also provide the following Event Handlers:

• ValueInRange (Value As Double). Fires when the entered value is inside the defined numeric range for the field.
• ValueOutOfRange (Value As Double). Fires when the entered value is not in the defined numeric range for the field.

Copy the AXNumValidated folder from the Xojo Demo Project and paste it into your own Xojo Project. Make sure you're copying the right API 2.0 or API 1.0 version of the Demo project.

If your app window's layouts already include the TextFields you want to use for validation, select them and use the Inspector Panel and change their Superclass to AXNumValidatedTF.

Then, and using the Inspector Panel or via code, set the ValueType (Integer / Real), MinValue, MaxValue and DecimalPositions properties for the instance. Optionally, you can set the ForceValueInRange and DisplayValidationMessage properties.

If you want your instance to be notified when the value is in or out of range, implement the ValueInRange and/or ValueOutOfRange Event Handlers.

AXNumValidatedTF is fully functional when running from the Xojo IDE (debug), but you'll need a License in order for it to work in compiled apps.

The validation process of the entered data is fired when the field looses the focus or when the user press the Return key.

AXNumValidatedTF class is aware of any on-the-fly changes in the System Grouping and Decimal separator characters settings; but these are not reflected in some of the Xojo functions used during the validation process. Until this changes, the App should be restarted so these Xojo functions are aware of the new system Locale settings for numeric formatting.

AXNumValidatedTF requires Xojo 2017r3 or later, and is compatible with projects using both API 2.0 and API 1.