X gurus? [OFFTOPIC]

[cgw at alum.mit.edu]

In article <slrn8bp5kk.ig.msabin at localhost.localdomain>, msabin at cdc.net (Mike Sabin) wrote:
>  I am programming for the X Windows environment
>  on Linux, and need to accomplish the following two
>  things:
> 
> 1. At a certain time, I need to get the x-y coordinates
> of my mouse pointer, no matter where my pointer is at
> the time (it could be over the window for some other
> application, but I want a function call to return
> the coordinates to my application)
> 
> 2. At a certain time, I need to artificially generate
> a button 1 mouse click, whereever the mouse pointer is
> currently located (e.g. over another application's 
> window).  My program must do this, without me actually
> having to click on the mouse or hit any key.
> 
> Can it be done in python? 

As far as I know, it can't be done with code in the standard Python distribution.  And, since
Sjoerd Mullender's X module does not have support for XTEST, that won't help you either,
at least not without some modifications.

However, I just happen to have some simple C programs which do exactly what you want,
and you can call these from a Python script via "os.popen" or the like.  These could easily 
be modified to be a dynamically-loaded Python module, instead.

Here they are.  Hope this comes in useful.

File 1:  xpos.c.  Gets the current x-y position of the pointer.
Compile with "gcc -o xpos xpos.c -I/usr/X11R6/include -L/usr/X11R6/lib -lX11"
Usage:  "xpos", no arguments, prints mouse pointer position on stdout

#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <stdlib.h>
#include <stdio.h>

int
main(int argc,char **argv)
{
	Display *display;
	Window root, root_return, child_return;
	char *display_name;
	int screen;
	int root_x_return, root_y_return;
	int win_x_return, win_y_return;
	unsigned int mask_return;

	if (! (display_name = getenv("DISPLAY")) ){
		fprintf(stderr,"environment variable DISPLAY must be set\n");
		exit(-1);
	}
	if (! (display = XOpenDisplay(display_name)) ){
		fprintf(stderr,"%s: Cannot open display %s\n", argv[0], 
			display_name);
		exit(-1);
	}
	screen = DefaultScreen(display);
	root = RootWindow(display,screen);
	XQueryPointer(display, root, &root_return, &child_return,
		      &root_x_return, &root_y_return,
		      &win_x_return, &win_y_return,
		      &mask_return);
	printf("%d %d\n",root_x_return,root_y_return);
	return 0;
}


File 2: "xmouse.c"  Simulates a mouse-button event.
Compile with "gcc -o xmouse xmouse.c -I/usr/X11R6/include -L/usr/X11R6/lib -lX11 -lXtst"
Usage:  xmouse whichbutton u|d    (which button is 1,2, or 3,  u for button-up, d for button down.  A "click" is a button down followed by a button up)

#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/extensions/XTest.h>
#include <stdlib.h>
#include <stdio.h>

int
main(int argc,char **argv)
{
	Display *display;
	Window root;
	char *display_name;
	Status status;
	int screen;
	int but;
	int event_base,error_base,major_version,minor_version;
	int verbose=0;
	int press=0;
	int release = 0;

	if (argc<3){
	  Usage: fprintf(stderr,"Usage: %s but u|d\n",argv[0]);
	  exit(-1);
	}

	but=atoi(argv[1]);
	if (argv[2][0]=='u')
	  release = 1;
	else if (argv[2][0]=='d')
	  press = 1;
	else
	  goto Usage;

	if (! (display_name = getenv("DISPLAY")) ){
	    fprintf(stderr,"environment variable DISPLAY must be set\n");
	    exit(-1);
	}
	
	if (! (display = XOpenDisplay(display_name)) ){
	    fprintf(stderr,"%s: Cannot open display %s\n", 
		    argv[0], display_name);
	    exit(-1);
	}
	    
	screen = DefaultScreen(display);
	root = RootWindow(display,screen);
	status = XTestQueryExtension(display,&event_base,&error_base,  
				     &major_version,&minor_version);

	if (status){
	    if (verbose)
		printf("display %s supports XTEST %d.%d\n",display_name,
		       major_version,minor_version);
	    
	} else {
	    printf("display %s does not support XTEST\n",display_name);
	    exit(-1);
	}
	XTestFakeButtonEvent(display,but,press,10);
	XFlush(display);
	return 0;
}