Grab the key in X11

本文是搜集网上的资料整理而成的。

方法1：

#include <X11/Xlib.h>#include <stdio.h>main(){  Window root;  XEvent e;  int F2,F3,F4,F5,F6;     // Open the display  Display *dpy = XOpenDisplay(0);  if (!dpy)return;  // Get the root window -- so keys will be global  root = DefaultRootWindow(dpy);     F2 = XKeysymToKeycode(dpy, XStringToKeysym("F2"));  F3 = XKeysymToKeycode(dpy, XStringToKeysym("F3"));  F4 = XKeysymToKeycode(dpy, XStringToKeysym("F4"));  F5 = XKeysymToKeycode(dpy, XStringToKeysym("F5"));  F6 = XKeysymToKeycode(dpy, XStringToKeysym("F6"));     // register the keys  XGrabKey(dpy, F2, 0, root, True, GrabModeAsync, GrabModeAsync);  XGrabKey(dpy, F3, 0, root, True, GrabModeAsync, GrabModeAsync);  XGrabKey(dpy, F4, 0, root, True, GrabModeAsync, GrabModeAsync);  XGrabKey(dpy, F5, 0, root, True, GrabModeAsync, GrabModeAsync);  XGrabKey(dpy, F6, 0, root, True, GrabModeAsync, GrabModeAsync);     // wait for events  for(;;) {  XNextEvent(dpy, &e);  if (e.type == KeyPress){  if (e.xkey.keycode == F4)  break;  else{  if (e.xkey.keycode == F2)printf("F2!!!\n");  else if (e.xkey.keycode == F3)printf("F3!!!\n");  else if (e.xkey.keycode == F5)printf("F5!!!\n");  else if (e.xkey.keycode == F6)printf("F6!!!\n");  }  }  }  // clean up  XUngrabKey(dpy, F2, 0, root);  XUngrabKey(dpy, F3, 0, root);  XUngrabKey(dpy, F4, 0, root);  XUngrabKey(dpy, F5, 0, root);  XUngrabKey(dpy, F6, 0, root);}

方法2：

#include <X11/Xlib.h>#include <X11/extensions/record.h>#include <pthread.h>#include <stdio.h>#include <stdlib.h>#include <glib-2.0/glib.h>static gboolean stop_thread = FALSE;static Display* dpy = 0;static XRecordContext rc;static pthread_t thread;GMainLoop *main_loop;void* intercept_key_thread(void* data);void key_pressed_cb(XPointer arg, XRecordInterceptData *d);int main(int argc, char *argv[]){pthread_create(&thread, NULL, intercept_key_thread, NULL);main_loop = g_main_loop_new (NULL, FALSE);     g_main_loop_run (main_loop);  g_main_loop_unref (main_loop);  return 0;}void* intercept_key_thread(void* data) {  XRecordClientSpec rcs;  XRecordRange* rr;  dpy = XOpenDisplay(0);  if (!(rr = XRecordAllocRange())) {    fprintf(stderr, "XRecordAllocRange error\n");    exit(1);  }  rr->device_events.first = KeyPress;  rr->device_events.last = MotionNotify;  rcs = XRecordAllClients;  if (!(rc = XRecordCreateContext(dpy, 0, &rcs, 1, &rr, 1))) {    fprintf(stderr, "XRecordCreateContext error\n");    exit(1);  }  XFree(rr);  if (!XRecordEnableContext(dpy, rc, key_pressed_cb, data)) {    fprintf(stderr, "XRecordEnableContext error\n");    exit(1);  }  return 0;}void stop_intercept_key_thread(void) {  void* result;  stop_thread = TRUE;  if (0 != pthread_join(thread, &result)) {    fprintf(stderr, "pthread_join error\n");    exit(1);  }}void key_pressed_cb(XPointer arg, XRecordInterceptData *d) {  if (stop_thread) {    if (!XRecordDisableContext(dpy, rc)) {      fprintf(stderr, "XRecordDisableContext error\n");      exit(1);    }    if (!XRecordFreeContext(dpy, rc)) {      fprintf(stderr, "XRecordFreeContext error\n");      exit(1);    }    pthread_exit(0);  }  if (d->category != XRecordFromServer) return;  unsigned char type = ((unsigned char*)d->data)[0] & 0x7F;  unsigned char keycode = ((unsigned char*)d->data)[1];  if (type == KeyPress) {printf("key: %d\n", keycode);  }}

编译方法：

gcc file.c  `pkg-config --cflags --libs  glib-2.0` -lpthread -lX11 -lXtst

方法3：

/** * Author:      jouyouyun <[e-mail]> * Maintainer:  jouyouyun <[e-mail]> * * This program 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 <http://www.gnu.org/licenses/>. **/ #include <glib.h>#include <X11/Xlib.h>#include <X11/extensions/record.h> static void event_cb (XPointer user_data, XRecordInterceptData *hook); int main (int argc, char *argv[]){    Display *ctrl_disp = XOpenDisplay(NULL);    Display *data_disp = XOpenDisplay(NULL);     if ( !ctrl_disp || !data_disp ) {        g_warning ("Unable to connect to X11 display!");        return -1;    }     gint major, minor, dummy;     if ( !XQueryExtension (ctrl_disp, "XTEST", &major, &minor, &dummy) ) {        g_warning ("XTest extension missing!");        return -1;    }     if ( !XRecordQueryVersion (ctrl_disp, &major, &minor) ) {        g_warning ("Failed to obtain xrecord version!");        return -1;    }     XSynchronize(ctrl_disp, True);    XFlush (ctrl_disp);     XRecordRange *range = XRecordAllocRange ();    /*     * 设定事件监听的范围     * 监听 first ~ last 之间的事件     */    range->device_events.first = KeyPress;    range->device_events.last = ButtonRelease;     XRecordClientSpec spec = XRecordAllClients;    XRecordContext context = XRecordCreateContext (                                 data_disp, 0, &spec, 1, &range, 1 );     if ( !context ) {        g_warning ("Failed to create context!");        return -1;    }     if ( !XRecordEnableContext(data_disp, context, event_cb, NULL) ) {        g_warning ("Failed to enable context!");        return -1;    }     /*    if ( !XRecordEnableContextAsync (data_disp, context, event_cb, NULL) ) {        g_warning ("Failed to enable context!");        return -1;    }     XRecordProcessReplies (data_disp);    */     XRecordDisableContext(data_disp, context);    XRecordFreeContext (data_disp, context);    XFree(range);     XCloseDisplay (data_disp);    XCloseDisplay (ctrl_disp);    return 0;} static voidevent_cb (XPointer user_data, XRecordInterceptData *hook){    if ( hook->category != XRecordFromServer ) {        g_warning ("Data not from server!");        return;    }     int event_type = hook->data[0];    KeyCode keycode = hook->data[1];    g_print ("Intercepted event type: %d, code: %d\n",             event_type, keycode);     switch (event_type) {        case KeyPress:            g_print ("key press event!\n");            break;         case KeyRelease:            g_print ("key release event!\n");            break;         case ButtonPress:            g_print ("button press event!\n");            break;         case ButtonRelease:            g_print ("button release event!\n");            break;         default:            /* FIXME: other events grab */            break;    }}

References:

1. https://github.com/Aitjcize/Qwertickle/blob/master/src/qwertickle.c

2. http://incise.org/tinywm.html

3. http://jouyouyun.is-programmer.com/posts/42193.html