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The RowColumn Widget

This the simplest widget in terms of how it manages the positioning of its child widgets.

Widgets are positioned as follows:

Let us now look at two programs that illustrate the above principles: rowcol1.c and rowcol2.c.

rowcol1.c lays 4 PushButtons vertically (default) whereas rowcol2.c sets the XmNorientation resource for a horizontal layout of the same 4 buttons.

The output of the programs looks like this.

Fig. 7 RowColumn program outputs

The rowcol1.c program is as follows:


#include <Xm/PushB.h>
#include <Xm/RowColumn.h>

main(argc, argv)
int argc;
char *argv[];
{
    Widget top_widget, rowcol;
    XtAppContext app;

    top_widget = XtVaAppInitialize(&app, "rowcol", NULL, 0, 
        &argc, argv, NULL, NULL);

    rowcol = XtVaCreateManagedWidget("rowcolumn",
        xmRowColumnWidgetClass, top_widget, NULL);


    (void) XtVaCreateManagedWidget("button 1",
        xmPushButtonWidgetClass, rowcol, NULL);

    (void) XtVaCreateManagedWidget("button 2",
        xmPushButtonWidgetClass, rowcol, NULL);

    (void) XtVaCreateManagedWidget("button 3",
        xmPushButtonWidgetClass, rowcol, NULL);
        
    (void) XtVaCreateManagedWidget("button 4",
        xmPushButtonWidgetClass, rowcol, NULL);

    XtRealizeWidget(top_widget);
    XtAppMainLoop(app);
}
rowcol1.c does not achieve much. It provides no callback functions to perform any tasks. It simply creates a RowColumn widget, rowcol, and creates 4 child buttons with this. Note that rowcol is a child of app - the application shell widget.

Note: that we must include the <Xm/RowColumn.h> header file

rowcol2.c is identical to rowcol1.c except that the XmNorietation resource is set at the rowcol widget creation with:

XmNorientation, XmHORIZONTAL,


Dave.Marshall@cm.cf.ac.uk
Tue May 24 16:52:56 BST 1994