---
name: "XmSpinBoxValidatePosition"
section: "3"
platform: "linux"
package: "openmotif"
version: "2.3.8-4"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/XmSpinBoxValidatePosition"
---

# XmSpinBoxValidatePosition(3)

translate the current value of the specified XmSpinBox child into a valid position

## NAME

**XmSpinBoxValidatePosition** — translate the current value of the specified XmSpinBox child into a valid position

## SYNOPSIS

```
#include <Xm/SpinBox.h>
int XmSpinBoxValidatePosition(
Widget textfield,
int *position);
```

## DESCRIPTION

The **XmSpinBoxValidatePosition** function is a utility that can be used by applications wanting to implement a policy for tracking user modifications to editable **XmSpinBox** children of type **XmNUMERIC**. The specifics of when and how the user's modifications take effect is left up to the application.

- *text\_field*

  The *text\_field* argument specifies the widget ID of the child of the **XmSpinBox** that is being modified. The requirement on *text\_field* is that it holds the **accessTextual** trait (already a requirement for children of **XmSpinBox**). This way, **XmSpinBox** can extract the string out of the *text\_field* widget (even if it is not an **XmTextField**).

- *position*

  The location pointed to by the position argument is assigned the result of the translation done by **XmSpinBoxValidatePosition**. **XmSpinBoxValidatePosition** first checks to make sure this is an **XmNUMERIC** **XmSpinBox** child. If it is not, **XSmpinBoxValidatePosition** sets position to the current position and returns **XmCURRENT\_VALUE**.

**XmSpinBoxValidatePosition** attempts to translate the input string to a floating point number. If this translation fails, **XmSpinBoxValidatePosition** sets position to the current position and returns **XmCURRENT\_VALUE**.

**XmSpinBoxValidatePosition** converts the floating point number to an integer using the **XmNdecimalPoints** resource. Extra decimal places are truncated. The resulting integer is range checked to make sure it falls within the valid range defined by **XmNminimumValue** and **XmNmaximumValue** inclusive. If the input falls outside this range, **XmSpinBoxValidatePosition** sets position to the nearest limit and returns either **XmMINIMUM\_VALUE** or **XmMAXIMUM\_VALUE**.

Finally, **XmSpinBoxValidatePosition** checks the integer to make sure it belongs to the series defined by **XmNminimumValue ... XmNminimumValue + ((n - 1) \* XmNincrementValue)**. If the integer does not belong to this series, **XmSpinBoxValidatePosition** sets position to the nearest element which is less than or equal to the integer and returns **XmINCREMENT\_VALUE**.

Otherwise, **XmSpinBoxValidatePosition** assigns the integer to position and returns **XmVALID\_VALUE**.

## RETURN VALUE

The **XmSpinBoxValidatePosition** function returns the status of the validation. The set of possible values returned is as follows:

- **XmCURRENT\_VALUE**

  Cannot convert, returning current position\_value.

- **XmMINIMUM\_VALUE**

  Less than min.

- **XmMAXIMUM\_VALUE**

  More than max.

- **XmINCREMENT\_VALUE**

  Not on increment.

- **XmVALID\_VALUE**

  Okay.

## EXAMPLES

This first example demonstrates how the **XmSpinBoxValidatePosition** function could be used from inside an **XmNmodifyVerifyCallback** callback installed on the **XmSpinBox** or the **XmSimpleSpinBox**:

```
/*
 * Install a callback on a spin box arrow press.
 */
  XtAddCallback(sb, XmNmodifyVerifyCallback, ModifyVerifyCB, NULL);
  XtAddCallback(simple_sb, XmNmodifyVerifyCallback, ModifyVerifyCB, NULL);
```

with the callback doing:

```
void ModifyVerifyCB(widget, call_data, client_data) {
    XmSpinBoxCallbackStruct *cbs = (XmSpinBoxCallbackStruct*) call_data;
    int position;
    Widget textual = NULL;
    if (XtIsSubclass(w, xmSimpleSpinBoxWidgetClass))
    {
        Arg args[1];
        XtSetArg(args[0], XmNtextField, &textual);
        XtGetValues(w, args, 1);
    }
    else if (XtIsSubclass(w, xmSpinBoxWidgetClass))
      textual = cbs->widget;
    else
      textual = (Widget) NULL;
    ...
    if (XmSpinBoxValidatePosition(textual, &position) == XmCURRENT_VALUE)
      XBell(XtDisplay(w), 0);
    else
      cbs->position = position;
}
```

This second example demonstrates how the **XmSpinBoxValidatePosition** function could be used from inside an **XmNactivateCallback** callback installed on the **TextField** child of the **XmSpinBox**:

```
/*
 * Install a callback on a spin box arrow press.
 */
XtAddCallback(tf, XmNactivateCallback, ModifyVerifyChildCB, NULL);
```

with the callback doing:

```
void ModifyVerifyChildCB(widget, call_data, client_data) {
    int     position;
    Widget  textual = widget;
    Arg     args[1];
    if (XmSpinBoxValidatePosition (textual, &position) == XmCURRENT_VALUE)
      XBell(XtDisplay(widget), 0);
    /* Set the position constraint resource of the textfield */
    XtSetArg(args[0], XmNposition, position);
    XtSetValues(textual, args, 1);
}
```

## SEE ALSO

[**XmSpinBox**(3)](/XmSpinBox/3.md), [**XmCreateSpinBox**(3)](/XmCreateSpinBox/3.md)