gxid.c

gtk是linux一款强大的夸平台的图形化开发工具

/* 
 * gxid version 0.3
 *
 * Copyright 1997 Owen Taylor <[e-mail]>
*/
#undef	G_LOG_DOMAIN

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <signal.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <X11/Xlib.h>
#include <X11/extensions/XInput.h>

#include "gxid_proto.h"

/* #define DEBUG_CLIENTS  */
/* #define DEBUG_EVENTS */

char *program_name;
Display *dpy;
Window root_window;		/* default root window of dpy */
int port = 0;		        /* port to listen on */
int socket_fd = 0;		/* file descriptor of socket */
typedef struct GxidWindow_ GxidWindow;

typedef struct GxidDevice_ GxidDevice;
struct GxidDevice_ {
  XID id;
  int exclusive;
  int ispointer;
  
  XDevice *xdevice;
  int motionnotify_type;
  int changenotify_type;
};

struct GxidWindow_ {
  Window xwindow;
  /* Immediate child of root that is ancestor of window */
  Window root_child;
  int num_devices;
  GxidDevice **devices;
};

GxidDevice **devices = NULL;
int num_devices = 0;
GxidWindow **windows = NULL;
int num_windows = 0;

void
handler(int signal)
{
  fprintf(stderr,"%s: dying on signal %d\n",program_name,signal);
  if (socket_fd)
    close(socket_fd);
  exit(1);
}

void
init_socket(void)
{
  struct sockaddr_in sin;

  socket_fd = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
  if (socket_fd < 0)
    {
      fprintf (stderr, "%s: error getting socket\n",
	       program_name);
      exit(1);
    }
  
  sin.sin_family = AF_INET;
  sin.sin_port = htons(port);
  sin.sin_addr.s_addr = INADDR_ANY;
  
  if (bind(socket_fd,(struct sockaddr *)(&sin),
	   sizeof(struct sockaddr_in)) < 0)
    {
      fprintf (stderr,"%s: cannot bind to port %d\n",
	       program_name,port);
      exit(1);
    }

  if (listen(socket_fd,5) < 0)
    {
      fprintf (stderr,"%s: error listening on socket\n",
	       program_name);
      exit(1);
    };
}

#define NUM_EVENTC 2
static void
enable_device(GxidDevice *dev)
{
  XEventClass xevc[NUM_EVENTC];
  int num_eventc = NUM_EVENTC;
  int i,j;

  if (!dev->xdevice) 
    {
      if (dev->ispointer) return;

      dev->xdevice = XOpenDevice(dpy, dev->id);
      if (!dev->xdevice) return;
      
      DeviceMotionNotify (dev->xdevice, dev->motionnotify_type,
			  xevc[0]);
      ChangeDeviceNotify (dev->xdevice, dev->changenotify_type,
			  xevc[1]);

      /* compress out zero event classes */
      for (i=0,j=0;i<NUM_EVENTC;i++)
	{
	  if (xevc[i]) {
	    xevc[j] = xevc[i];
	    j++;
	  }
      }
      num_eventc = j;
      
      XSelectExtensionEvent (dpy, root_window, xevc, num_eventc);
    }
}

/* switch the core pointer from whatever it is now to something else,
   return true on success, false otherwise */
static int
switch_core_pointer(void)
{
  GxidDevice *old_pointer = 0;
  GxidDevice *new_pointer = 0;
  int result;
  int i;

  for (i=0;i<num_devices;i++)
    {
      if (devices[i]->ispointer)
	old_pointer = devices[i];
      else
	if (!new_pointer && !devices[i]->exclusive)
	  new_pointer = devices[i];
    }

  if (!old_pointer || !new_pointer)
    return 0;

#ifdef DEBUG_EVENTS
  fprintf(stderr,"gxid: Switching core from %ld to %ld\n",
	 old_pointer->id,new_pointer->id);
#endif
  result = XChangePointerDevice(dpy,new_pointer->xdevice, 0, 1);
  if (result != Success)
    {
      fprintf(stderr,"gxid: Error %d switching core from %ld to %ld\n",
	      result, old_pointer->id, new_pointer->id);
    }
  else
    {
      new_pointer->ispointer = 1;
      old_pointer->ispointer = 0;
      if (!old_pointer->xdevice)
	enable_device(old_pointer);
    }

  return 1;
}

void
disable_device(GxidDevice *dev)
{
  if (dev->xdevice)
    {
      if (dev->ispointer)
	return;
      XCloseDevice(dpy,dev->xdevice);
      dev->xdevice = 0;
    }
}

GxidDevice *
init_device(XDeviceInfo *xdevice)
{
  GxidDevice *dev = (GxidDevice *)malloc(sizeof(GxidDevice));
  XAnyClassPtr class;
  int num_axes, i;

  dev->id = xdevice->id;
  dev->exclusive = 0;
  dev->xdevice = NULL;

  dev->ispointer = (xdevice->use == IsXPointer);

  /* step through the classes */

  num_axes = 0;
  class = xdevice->inputclassinfo;
  for (i=0;i<xdevice->num_classes;i++) 
    {
      if (class->class == ValuatorClass) 
	{
	  XValuatorInfo *xvi = (XValuatorInfo *)class;
	  num_axes = xvi->num_axes;
	}
      class = (XAnyClassPtr)(((char *)class) + class->length);
    }

  /* return NULL if insufficient axes */
  if (num_axes < 2)
    {
      free((void *)dev);
      return NULL;
    }

  if (!dev->ispointer)
      enable_device(dev);
  return dev;
}

void
init_xinput(void)
{
  char **extensions;
  XDeviceInfo   *xdevices;
  int num_xdevices;
  int num_extensions;
  int i;

  extensions = XListExtensions(dpy, &num_extensions);
  for (i = 0; i < num_extensions &&
	 (strcmp(extensions[i], "XInputExtension") != 0); i++);
  XFreeExtensionList(extensions);
  if (i == num_extensions)	/* XInput extension not found */
    {
      fprintf(stderr,"XInput extension not found\n");
      exit(1);
    }

  xdevices = XListInputDevices(dpy, &num_xdevices);
  devices = (GxidDevice **)malloc(num_xdevices * sizeof(GxidDevice *));

  num_devices = 0;
  for(i=0; i<num_xdevices; i++)
    {
      GxidDevice *dev = init_device(&xdevices[i]);
      if (dev)
	  devices[num_devices++] = dev;
    }
  XFreeDeviceList(xdevices);
}

/* If this routine needs fixing, the corresponding routine
   in gdkinputgxi.h will need it too. */

Window
gxi_find_root_child(Display *dpy, Window w)
{
  Window root,parent;
  Window *children;
  int nchildren;

  parent = w;
  do 
    {
      w = parent;
      XQueryTree (dpy, w, &root, &parent, &children, &nchildren);
      if (children)
	XFree (children);
    } 
  while (parent != root);
  
  return w;
}

int
handle_claim_device(GxidClaimDevice *msg)
{
  int i,j;
  XID devid;
  XID winid;
  int exclusive;
  GxidDevice *device = NULL;
  GxidWindow *window = NULL;

  if (msg->length != sizeof(GxidClaimDevice))
    {
      fprintf(stderr,"Bad length for ClaimDevice message\n");
      return GXID_RETURN_ERROR;
    }

  devid = ntohl(msg->device);
  winid = ntohl(msg->window);
  exclusive = ntohl(msg->exclusive);

#ifdef DEBUG_CLIENTS
  fprintf(stderr,"device %ld claimed (window 0x%lx)\n",devid,winid);
#endif  

  for (i=0;i<num_devices;i++)
    {
      if (devices[i]->id == devid)
	{
	  device = devices[i];
	  break;
	}
    }
  if (!device)
    {
      fprintf(stderr,"%s: Unknown device id %ld\n",program_name,devid);
      return GXID_RETURN_ERROR;
    }

  if (device->exclusive)
    {
      /* already in use */
      fprintf(stderr,
	      "%s: Device %ld already claimed in exclusive mode\n",
	      program_name,devid);
      return GXID_RETURN_ERROR;
    }

  if (exclusive)
    {
      for (i=0;i<num_windows;i++)
	{
	  for (j=0;j<windows[i]->num_devices;j++)
	    if (windows[i]->devices[j]->id == devid)
	      {
		/* already in use */
		fprintf(stderr,
			"%s: Can't establish exclusive use of device %ld\n",
			program_name,devid);
		return GXID_RETURN_ERROR;
	      }
	}
      if (device->ispointer)
	if (!switch_core_pointer())
	  {
	    fprintf(stderr,
		    "%s: Can't free up core pointer %ld\n",
		    program_name,devid);
	    return GXID_RETURN_ERROR;
	  }

      device->exclusive = 1;
      disable_device(device);
      XSelectInput(dpy,winid,StructureNotifyMask);
    }
  else				/* !exclusive */
    {
      /* FIXME: this is a bit improper. We probably should do this only
	 when a window is first claimed. But we might be fooled if
	 an old client died without releasing it's windows. So until
	 we look for client-window closings, do it here 
	 
	 (We do look for closings now...)
	 */
      
      XSelectInput(dpy,winid,EnterWindowMask|StructureNotifyMask);
    }

  for (i=0;i<num_windows;i++)
    {
      if (windows[i]->xwindow == winid)
        {
	  window = windows[i];
	  break;
	}
    }

  /* Create window structure if no devices have been previously
     claimed on it */
  if (!window)
    {
      num_windows++;
      windows = (GxidWindow **)realloc(windows,
				       sizeof(GxidWindow*)*num_windows);
      window = (GxidWindow *)malloc(sizeof(GxidWindow));
      windows[num_windows-1] = window;

      window->xwindow = winid;
      window->root_child = gxi_find_root_child(dpy,winid);
      window->num_devices = 0;
      window->devices = 0;
    }

  
  for (i=0;i<window->num_devices;i++)
    {
      if (window->devices[i] == device)
	return GXID_RETURN_OK;
    }
  
  window->num_devices++;
  window->devices = (GxidDevice **)realloc(window->devices,
					    sizeof(GxidDevice*)*num_devices);
  /* we need add the device to the window */
  window->devices[i] = device;

  return GXID_RETURN_OK;
}

int
handle_release_device(GxidReleaseDevice *msg)
{
  int i,j;
  XID devid;
  XID winid;

  GxidDevice *device = NULL;

  if (msg->length != sizeof(GxidReleaseDevice))
    {
      fprintf(stderr,"Bad length for ReleaseDevice message\n");
      return GXID_RETURN_ERROR;
    }

  devid = ntohl(msg->device);
  winid = ntohl(msg->window);

#ifdef DEBUG_CLIENTS
  fprintf(stderr,"device %ld released (window 0x%lx)\n",devid,winid);
#endif  

  for (i=0;i<num_devices;i++)
    {
      if (devices[i]->id == devid)
	{