The Xme functions are bound into the standard Motif library (typically stored in file libXm.a). Therefore, you do not need to bind your widget with any special libraries in order to call an Xme function. Similarly, you do not need a Motif source license in order to call an Xme function.

You call an Xme function just as you would call any Xm convenience function. That is, you must include the appropriate header file, and you must provide the correct type and number of arguments to the call. The reference pages in Chapter 17 detail the required information for each Xme function.

Motif provides two Xme functions for handling traits. These functions are summarized in Table 8-1. See Chapter 5 for details on traits.

Motif provides several Xme functions for rendering geometric objects (arrows, diamonds, and so on). Whenever possible, your Motif widgets should render geometric objects with these Xme routines. By using the Xme functions, you are ensuring that the geometric objects in your Motif widget will look like the geometric objects in other Motif widgets.

Table 8-2 lists the Xme functions pertaining to drawing.

For example, the ExmSimple widget calls the XmeDrawShadows function to draw its border shadows. In order to make this call, the Simple.c file includes the header file for the Xme drawing functions as follows:

#include <Xm/DrawP.h>

The call to XmeDrawShadows appears as follows:

XmeDrawShadows (XtDisplay (sw), XtWindow (sw),
                sw->primitive.top_shadow_GC,
                sw->primitive.bottom_shadow_GC,
                sw->primitive.highlight_thickness,
                sw->primitive.highlight_thickness,
                sw->core.width - (2 * sw->primitive.highlight_thickness),
                sw->core.height - (2 * sw->primitive.highlight_thickness),
                sw->primitive.shadow_thickness,
                XmSHADOW_ETCHED_OUT);

Most Motif widgets inherit routines to draw and erase window decorations. However, if your widget takes the responsibility for its own window decorations, then your widget will draw the decorations with XmeDrawHighlight and XmeDrawShadows and clear the decorations with XmeClearBorders. Actually, the XmeClearBorders call can be used to clear out any rectangular area, not just window decorations.

If you want to draw shadows around any polygon (instead of just a rectangle), call XmeDrawPolygonShadows instead of XmeDrawShadows.

XmeDrawDiamond, XmeDrawCircle, and XmeDrawIndicator are particularly useful for creating toggle indicators.

Motif provides four Xme functions that govern resolution independence. (See Chapter 6 for information about resolution independence.)

The four functions shown in Table 8-3 are typically called from a synthetic resource table rather than from a widget method.

Table 8-4 contains a list of Xme functions that are useful for manipulating strings.

See Chapter 9 for complete details on using these functions.

Motif provides widget writers with several Xme functions for implementing the Uniform Transfer Model (UTM). UTM is a mechanism for transferring data between and within widgets. UTM was introduced in Motif Release 2.0. (See Chapter 10 for details.)

Table 8-5 summarizes the Xme functions useful for transferring data between and within widgets.

In addition to the list of Xme routines shown in the previous table, Motif provides many Xm data transfer routines. The Xm routines are detailed in the Motif Programmer's Reference.

Motif provides the Xme calls shown in Table 8-6 to help widget writers manage geometry:

See Chapter 12 for examples involving these functions.

Motif provides the Xme calls shown in Table 8-7 to help widget writers handle focus changes.

Motif also provides the Xme functions shown in Table 8-8.