XwinDisplayEvent

Syntax

int XwinDisplayEvent(struct XwinDisplay *dp,int wnum, struct XwinWindow **win,int mode,struct timeval *tmout);

Header

base/xwin.h

Library

xwin

Description

The XwinDisplayEvent function processes events associated with an X terminal.

The argument dp points the control structure of the X terminal display to process events from.

The function will process events directed to a list of X windows. The argument win is an array containing the window pointer and the argument wnum is the number of window pointers contained in the array.

The function will block waiting for certain X events to occur. The type of events accepted is controlled by the argument mode. A value of zero will block until a close window or terminate event occurs. A non-zero value will block until a close window, terminate or button press event occurs.

The final argument tout defines the length of time that the function should block waiting for an event. If this is a NULL pointer the function will block indefinitely until an event occurs. Otherwise the function will wait the specified length of time for an event.

Returns

Returns zero if the function timed out, (1) if a close window or terminate event occurs and (2) if a button is pressed. On error, (-1) is returned.

Errors

On error, (-1) is returned.

Example

Source Code: XwinDisplayEvent.c

/* XwinDisplayEvent.c
   ================== 
   Author: R.J.Barnes
 Copyright (c) 2012 The Johns Hopkins University/Applied Physics Laboratory

This file is part of the Radar Software Toolkit (RST).

RST is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see <https://www.gnu.org/licenses/>.

Modifications:



#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xos.h>
#include <X11/Xatom.h>

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>

#include "rfbuffer.h"
#include "xwin.h"


struct FrameBuffer *fbuf=NULL;

int main(int argc,char *argv[]) {

  struct XwinDisplay *dp;
  struct XwinWindow *win;

  int wdt=300,hgt=300;
  unsigned int border=0;
  int flg;


  char *display_name=NULL;
 
  char *progname;
  int status=0;
 
  int x=30,y=40;
  int vx=3,vy=4;

  struct timeval tmout;

  progname=argv[0];

  dp=XwinOpenDisplay(display_name,&flg);
  win=XwinMakeWindow(0,0,wdt,hgt,border,
                     dp,"Test Window",
                    "Test Window","Test Window",
                    "basic",argc,argv,&flg);
                           

  if ((fbuf=FrameBufferMake("Test",wdt,hgt,24))==NULL) {
     fprintf(stderr,"failed to make frame buffer.");
     exit(-1);
  }

  XwinFrameBufferWindow(fbuf,win);

  XwinShowWindow(win);

  while(status !=1) {

    tmout.tv_sec=0;
    tmout.tv_usec=0.05*1e6;

    status=XwinDisplayEvent(dp,1,&win,1,&tmout);
    x=x+vx;
    y=y+vy;

    if (x>wdt) {
      x=wdt-1;
      vx=-vx;
    }

    if (y>hgt) {
      y=hgt-1;
      vy=-vy;
    }
    if (x<0) {
      x=0;
      vx=-vx;
    }
    if (y<0) {
      y=0;
      vy=-vy;
    }

    FrameBufferEllipse(fbuf,NULL,x,y,4,4,1,
                          0xffffff,0x0f,0,NULL,NULL);

   
    XwinFrameBufferWindow(fbuf,win);
   
  }
 
  XwinFreeWindow(win);

  XwinCloseDisplay(dp);

  return 0;
}