Motif Widget Writer's Guide Migration Version

Motif 2.1 Widget Writer's Guide

XmeToHorizontalPixels

Converts from real-world dimensions to pixels

Format

#include <Xm/XmP.h>
XmImportOperator
XmeToHorizontalPixelsWidget widgetint
offsetXtArgVal *value

DESCRIPTION

XmeToHorizontalPixels converts a horizontal distance from a real-world dimensional unit (such as thousandths of an inch) to pixels. This conversion is based on the horizontal resolution of the screen. The choice of real-world dimensional unit is stored in the XmNunitType resource.

For example, suppose that widget has an XmNunitType resource value of Xm1000TH_INCHES. If the input value were 2000 (meaning 2000/1000 inches or 2 inches), then XmeToHorizontalPixels determines how many horizontal pixels fall within 2 inches. Because different screens have different resolutions, the returned value might be 160 pixels on one screen and 200 pixels on another.

XmeToHorizontalPixels is an XmImportProc.

Typically, your widget will call this function from a synthetic resource record.

widget

Specifies the widget containing the resource named by offset.

offset

Specifies the offset (in bytes) of a synthetic resource field in the widget record.

value

Specifies a value in the XmNunitType real-world dimensional units used by widget and returns a value in pixels.

RETURN

Returns one of the following XmImportOperator values:

XmSYNTHETIC_NONE

The caller of the XmImportProc is not responsible for copying the converted value into the resource specified by offset.

XmSYNTHETIC_LOAD

The caller of the XmImportProc is responsible for copying the converted value into the resource specified by offset.

Motif's synthetic resource mechanism is typically the caller of XmeToHorizontalPixels. Therefore, if XmeToHorizontalPixels returns XmSYTHETIC_LOAD, Motif synthetic resource mechanism will take care of copying (and casting) value into the resource symbolized by offset.

RELATED

XmeFromHorizontalPixels(3), XmeFromVerticalPixels(3), and XmeToVerticalPixels(3).