'\"
'\" Copyright (c) 1997 Maorong Zou
'\" 
.TH EZ 3 "" EZWGL "EZWGL Functions"
.BS
.SH NAME
EZ \- introduction to EZWGL, the EZ widget and graphics library

.SH SYNOPSIS
.sp
The EZ widget and graphics library (EZWGL) is a C library 
written on top of Xlib. It is designed for developing
graphics user interface under the X window system programming
environment.

.SH DESCRIPTION
EZWGL consists of two parts, a  widget library and a
graphics library. The widget library implements about a twenty or 
so commonly used widgets, including \fBbutton\fR, \fBlabel\fR,
\fBframe\fR, \fBentry\fR, \fBtext-widget\fR, \fBlistbox\fR, 
\fBslider\fR, \fBnotebook\fR, \fBcombox\fR, \fBmenu\fR, 
\fBfile-selector\fR, \fBlist-tree\fR,
\fBwork-area\fR, \fBspin-button\fR, \fBgradient-bar\fR,
\fBhistogram\fR, \fBspread-sheet\fR and \fB3D-canvas\fR.
The widget library also implements a \fIdrag-and-drop\fR
mechanism and a resource management scheme.  
The graphics library implements
about 100 OpenGL(TM) like graphics functions that
provides high level support for 3D graphics, including features like
\fBzbuffer\fR, \fBdouble-buffer\fR and \fBlighting\fR.
.PP
An EZWGL application consists of following components.
.in +1
.sp
\fI1.\fR Include the one and only header file "\fBEZ.h\fR"
.sp
\fI2.\fR Initialize the library by calling \fBEZ_Initialize\fR
.sp
\fI3.\fR Create widgets using \fBEZ_CreateWidget\fR
.sp
\fI4.\fR Register widget callbacks and event handlers using
\fBEZ_AddWidgetCallBack\fR and \fBEZ_AddEventHandler\fR
.sp
\fI5.\fR Map widgets by invoking \fBEZ_DisplayWidget\fR on your
toplevel widgets
.sp
\fI6.\fR Processing events using \fBEZ_EventMainLoop\fR or
\fBEZ_ServiceEvents\fR or \fBEZ_WaitAndServiceNextEvent\fR
.in -1
.PP
Here is a simple example that demonstrates these steps.
.sp
.nf
#include "EZ.h"                     /* the header file      */
static  void doexit(EZ_Widget *w, void *d)
{
  EZ_Shutdown();
  exit(0);
}

main(int argc, char **argv)
{
  EZ_Widget *hello;

  EZ_Initialize(argc,argv,0);       /* initialize EZWGL    */

          /* create a button and set its foreground red    */
  hello = EZ_CreateWidget(EZ_WIDGET_NORMAL_BUTTON, NULL,
                          EZ_LABEL_STRING, "Hello World",
                          EZ_FOREGROUND,   "red",
                          0);

  EZ_AddWidgetCallBack(hello,       /* register call back  */
        EZ_CALLBACK, doexit, NULL, 0);

  EZ_DisplayWidget(hello);          /* show the button     */

  EZ_EventMainLoop();               /* handle mouse inputs */
}
.fi

.SH "SEE ALSO"
EZ_Initialize(3), EZ_CreateWidget(3), EZ_DisplayWidget(3), EZ_Shutdown(3)