ArcGIS Engine Developer Guide

C++ APPLICATION PROGRAMMING INTERFACE
}
return 0;
Step 2: Create the widgets
With the toolkit initialized, you can create the single widget you are using in this
application. There are two ways to create widgets:
• Using a function specific to the particular widget:
XmCreatePushButton()
• Using a function for generic widget creation (and sometimes managing it at
the same time):
XtVaCreateWidget()
XtVaCreateManagedWidget()
Although you will see both in the C++ samples for Motif, here you will use the
second method, but will not manage the widget at its creation (simply to separate
that step for the purpose of this introduction).
int main(int argc, char* argv[])
{
XtSetLanguageProc(NULL, NULL, NULL);
XtAppContext app_context;
Widget topLevel = XtVaAppInitialize(&app_context, "XApplication",
NULL, 0, &argc, argv, NULL, NULL);
XmString label = XmStringCreateLocalized("Push the button.");
Widget button = XtVaCreateWidget("button",
xmPushButtonWidgetClass, topLevel,
XmNlabelString,
label,
NULL);
XmStringFree(label);
}
return 0;
The parameters have the following roles:
• “button”—the name of the widget in the resource database, which can be used
for specifications in a resource file. If a label is not provided, it will act as the
widget’s label.
• xmPushButtonWidgetClass—the class of the widget to be created. For example,
to create an ArcGIS control widget, you would give mwCtlWidgetClass.
• topLevel—the parent of the widget, which must be a manager widget that was
already created.
• XmNlabelString, label, NULL—resource settings. For more information on the
resources available on different widgets and how to use them, see the Motif
reference at the end of this topic. Some common resources used in the C++
samples for Motif are those to set the size and placement of the widget. In
addition, there is a custom resource that goes with the ArcGIS controls:
MwNprogID.
236 • ArcGIS Engine Developer Guide