Volume 6A: Motif Programming Manual

14 The Scale Widget

This chapter describes how to use the Scale widget to represent a range of values. The widget can be manipulated to

change the value.

The Scale widget displays a numeric value that falls within upper and lower bounds. The widget allows the user to

change that value interactively using a slider mechanism similar to that of a ScrollBar. This style of interface is useful

when it is inconvenient or inappropriate to have the user change a value using the keyboard. The widget is also

extremely intuitive to use; inexperienced users often understand how a Scale works when they first see one. the figure

shows how a Scale can be used with other widgets in an application.

A Scale widget in an application

A Scale can be oriented either horizontally or vertically. The values given to a Scale are stored as integers, but decimal

representation of values is possible through the use of a resource that allows you to place a decimal point in the value.

A Scale can be put in output−only mode, in which it is sometimes called a gauge. When a Scale is read−only, it

implies that the value is controlled by another widget or that it is being used to report status information specific to the

application. The standard way to create a read−only Scale is to specify that it is insensitive. Unfortunately, this

technique has the side−effect of graying out the widget. One workaround is to create a Scale ...