Volume 6A: Motif Programming Manual

Widget scale_w;

int value;

void

XmScaleGetValue (scale_w, value)

Widget scale_w;

int *value;

The advantage of using the Motif convenience routines, rather than the Xt routines, is that the Motif routines

manipulate data in the widget directly, rather than using the set and get methods of the Scale. As a result, there is less

overhead involved, although the added overhead of the Xt methods are negligible.

14.3 Scale Orientation and Movement

A Scale can be either vertical or horizontal and the maximum and minimum values can be on either end of the Scale.

By default, as shown in the examples so far, the Scale is oriented vertically with the maximum on the top and the

minimum on the bottom. The XmN-orientation resource can be set to XmHORIZONTAL to produce a horizontal

Scale. The XmNprocessingDirection resource controls the location of the maximum and minimum values. The

possible values for the resource are:

XmMAX_ON_TOP

XmMAX_ON_BOTTOM

XmMAX_ON_LEFT

XmMAX_ON_RIGHT

Unfortunately, you cannot set the processing direction unless you know the orientation of the Scale, so if you

hard−code one resource, you should set both of them. If the Scale is oriented vertically, the default value is

XmMAX_ON_TOP, but if it is horizontal, the default depends on the value of XmNstringDirection. If you use a

font that is read from right to left, then the maximum value is displayed on the left rather than on the right.

As the user drags the slider, the value of the Scale changes incrementally in the direction of ...