Example 1.2 of the tutorial : Window drawing callback
[Tutorial]

Create, open and handle a proportional window. More...

/*
 * WinDom: a high level GEM library
 * Copyright (c) 1997-2006 windom authors (see AUTHORS file)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
 *
 * $Source: /cvsroot/windom/htdocs/doc/html/group__tut1__2.html,v $
 *
 * CVS info:
 *   $Author: bercegeay $
 *   $Date: 2006/06/22 11:58:28 $
 *   $Revision: 1.5 $
 */

#include <stdlib.h>
#include <windom.h>

struct circle {
  short color;
  short interior;
  short style;
};

static
void __CDECL evnt_destroy_circle( WINDOW *win, short msg[], void *C) {
    free( C);             /* free memory */
    WindClose( win);          /* close the window */
    WindDelete( win);         /* delete the window */
}

static
void __CDECL evnt_draw_circle( WINDOW *win, short msg[], void *data) {
    short x, y, w, h;
    struct circle *circ = (struct circle *)data;

    /* Get the workspace coordinates */
    WindGet( win, WF_WORKXYWH, &x, &y, &w, &h);

    /* Clear the background */
    WindClear( win);

    /* Set VDI attributes */
    vsf_color( win->graf->handle, circ->color);
    vsf_interior( win->graf->handle, circ->interior);
    vsf_style( win->graf->handle, circ->style);

    /* Drawing the circle */
    v_circle( win->graf->handle, x+w/2-1, y+h/2-1, MIN( w, h)/3);
}

int main( void) {
    WINDOW *win;
    struct circle *C;

    /* Init WinDom */
    ApplInit();

    /* Create a circle data */
    C = (struct circle *) malloc( sizeof( struct circle));
    C->color = BLACK;
    C->interior = FIS_SOLID;
    C->style = 0;

    /* Create the window */
    win = WindCreate( WAT_ALL, app.x, app.y, app.w, app.h);

    /* Declare new event message */
    EvntDataAttach( win, WM_REDRAW, evnt_draw_circle, C);
    EvntDataAttach( win, WM_DESTROY, evnt_destroy_circle, C);

    /* Open the window */
    WindOpen( win, app.x, app.y, app.w/2, app.h/2);
    WindSetStr( win, WF_NAME, "WinDom tutorial 1-2 : drawing a circle" );

    /* Handle GEM event */
    while( wglb.first) EvntWindom( MU_MESAG+MU_KEYBD);

    ApplExit();
    return EXIT_SUCCESS;
}

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