Introduction to Motif Programming
(lectures programs)

Example 1 xecute.c:

Executes a command after the user confirms the action.

The interface is composed of:

A container widget: BulletinBoardWidget, that contains:

· one LabelWidget and

· two PushButtonWidget

E.g.: % xecute "list all files?" "ls -lt"

This produces the following GUI:

xecute.c outline:

void main ( int argc, char **argv )
{

Widget shell, msg, bb, yes, no;
XtAppContext   app;
XmString xmstr;
Dimension height;

shell = XtAppInitialize( &app, "Xecute", NULL, 0, &argc, argv, NULL, NULL, 0 );
bb = XtVaCreateManagedWidget ("bboard",xmBulletinBoardWidgetClass,shell,NULL );

xmstr = XmStringCreate ( argv[1], XmFONTLIST_DEFAULT_TAG );
msg = XtVaCreateManagedWidget ( "message", xmLabelWidgetClass, bb,
XmNlabelString, xmstr, XmNx, 0, XmNy, 0, NULL );

XtVaGetValues ( msg, XmNheight, &height, NULL );

//Retrieve the height of label widget, so we know where to place the buttons

yes = XtVaCreateManagedWidget ( "yes", xmPushButtonWidgetClass, bb,
XmNx, 0, XmNy, height + 20, NULL );

no = XtVaCreateManagedWidget ( "no", xmPushButtonWidgetClass, bb,
XmNx, 200, XmNy, height + 20, NULL );

XtAddCallback ( yes, XmNactivateCallback, YesCallback, ( XtPointer ) argv[2] );

XtAddCallback ( no, XmNactivateCallback, NoCallback, NULL );

XtRealizeWidget ( shell );
XtAppMainLoop ( app );

}

void YesCallback ( Widget w, XtPointer clientData, XtPointer callData )
{

char * cmd = (char *) clientData;
if ( cmd )
system ( cmd );
exit ( 0 );

}

void NoCallback ( Widget w, XtPointer clientData, XtPointer callData)
{

exit ( 0 );

}

Example 2: A drawing editor:

The code to create this interface is:  editor.c

void main ( int argc, char **argv )
{

Widget shell, canvas, panel, commands, options;
XtAppContext app;

shell = XtAppInitialize( &app, "Editor", NULL, 0, &argc, argv, NULL, NULL, 0 );

panel = XtCreateManagedWidget ( "panel", xmFormWidgetClass, shell, NULL, 0 );

commands =
XtVaCreateManagedWidget ( "commands", xmRowColumnWidgetClass, panel, XmNnumColumns, 3,
XmNorientation, XmHORIZONTAL,
XmNtopAttachment, XmATTACH_FORM,
XmNrightAttachment, XmATTACH_FORM,
XmNleftAttachment, XmATTACH_FORM,
XmNbottomAttachment, XmATTACH_NONE, NULL );

options =
XtVaCreateManagedWidget ( "options", xmRowColumnWidgetClass, panel, XmNnumColumns, 1,
XmNorientation, XmVERTICAL,
XmNtopAttachment, XmATTACH_WIDGET,
XmNtopWidget, commands,
XmNrightAttachment, XmATTACH_NONE,
XmNleftAttachment, XmATTACH_FORM,
XmNbottomAttachment,XmATTACH_FORM, NULL );

canvas =
XtVaCreateManagedWidget ( "canvas", xmDrawingAreaWidgetClass, panel,
XmNtopAttachment, XmATTACH_WIDGET,
XmNtopWidget, commands,
XmNrightAttachment, XmATTACH_FORM,
XmNleftWidget, options,
XmNleftAttachment, XmATTACH_WIDGET,
XmNbottomAttachment,XmATTACH_FORM, NULL );

XtCreateManagedWidget ("button1", xmPushButtonWidgetClass, commands, NULL, 0 );
XtCreateManagedWidget ("button2", xmPushButtonWidgetClass, commands, NULL, 0 );
XtCreateManagedWidget ("button3", xmPushButtonWidgetClass, commands, NULL, 0 );

XtCreateManagedWidget ( "button1", xmPushButtonWidgetClass, options, NULL, 0 );
XtCreateManagedWidget ( "button2", xmPushButtonWidgetClass, options, NULL, 0 );
XtCreateManagedWidget ( "button3", xmPushButtonWidgetClass, options, NULL, 0 );

XtRealizeWidget ( shell );
XtAppMainLoop ( app );

}

Resource files : Editor & Editor.color

*options*button1*labelString: Option 1
*options*button2*labelString: Option 2
*options*button3*labelString: Option 3

*commands*button1*labelString: Command One
*commands*button2*labelString: Command Two
*commands*button3*labelString: Command Three

 
! Color resources. 
 
*foreground: white
*XmDrawingArea*background: khaki
*options*background: Blue
*commands*background: Green
*options*XmPushButton*background: Red
*commands*XmPushButton*background: grey50

To associate the resource file with the program before execution:

Use:

% setenv XENVIRONMENT Editor

% editor

Try color:

% setenv XENVIRONMENT Editor.color

% editor

Example 3: editor2.c Adding life to editor: Quit & Draw Squares

Widget         quit;
Display        *display;
int            screen;
long           fgcolor, bgcolor;
XGCValues  gcval;
GC             draw;
Window        window;
int            pointx, pointy;
int            FirstPt = TRUE;

void main ( int argc, char **argv )
{

......
code here is the same as editor.c
......

change:

XtCreateManagedWidget("button1",xmPushButtonWidgetClass,commands,NULL, 0 );
        XtCreateManagedWidget("button2",xmPushButtonWidgetClass,commands,NULL, 0 );
        XtCreateManagedWidget("button3",xmPushButtonWidgetClass,commands,NULL, 0 );

to:

quit = XtCreateManagedWidget ("Quit",xmPushButtonWidgetClass,commands,NULL, 0 );
no = XtCreateManagedWidget ("no",xmPushButtonWidgetClass,commands,NULL, 0 );
yes = XtCreateManagedWidget ("yes",xmPushButtonWidgetClass,commands,NULL, 0 );

Add the call back:

XtAddCallback ( quit, XmNactivateCallback, quitCallback ,  NULL );
XtAddCallback ( no, XmNactivateCallback, noCallback ,  NULL );
XtAddCallback ( yes, XmNactivateCallback, yesCallback ,  NULL );

Add the following code to draw lines on the canvas:

display = XtDisplay(shell);
screen = DefaultScreen(display);

XtVaGetValues ( canvas, XmNforeground, &gcval.foreground,
                        XmNbackground, &gcval.background, NULL );

gcval.foreground = gcval.foreground ^ gcval.background;
draw = XtGetGC ( canvas, GCForeground | GCBackground , &gcval );

XtAddEventHandler(canvas, ButtonPressMask, FALSE, HandleBoardEvents, NULL);

.....

}

void quitCallback ( Widget w, XtPointer clientData, XtPointer callData)
{

Colormap cmap;
XColor color, ignore;
char *colorname = "red";

XtSetArg(wargs[0], XmNlabelString,
XmStringCreateLocalized("Are you sure?"));
XtSetValues(quit, wargs, 1);

XtVaSetValues( quit, XmNsensitive, False, NULL);

XtMapWidget(no);
XtMapWidget(yes);

cmap = DefaultColormap (display, screen);
XAllocNamedColor(display, cmap, colorname, &color, &ignore);
XtSetArg(wargs[0], XmNbackground, color.pixel);
XtSetValues(quit, wargs, 1);

}

void yesCallback ( Widget w, XtPointer clientData, XtPointer callData)
{

exit(0);

}

void noCallback (Widget w, XtPointer clientData, XtPointer callData)
{

XtSetArg(wargs[0], XmNlabelString, XmStringCreateLocalized("      QUIT     "));




XtSetValues(quit, wargs, 1); 
XtVaSetValues( quit, XmNsensitive, True, NULL);

XtMapWidget(quit);
XtUnmapWidget(no);
XtUnmapWidget(yes);

}

void HandleBoardEvents( Widget w, XtPointer clientData, XEvent *event, Boolean *flag )
{

XDrawRectangle (XtDisplay(w), XtWindow(w), draw,

event->xbutton.x, event->xbutton.y, 10, 10);

}

Use:

% setenv XENVIRONMENT Editor.color

to associate the resource file with the program before execution.

% editor2