[Linux] X11 Xwindow Keyboard Event

為了與UX溝通，用了一招蠢方法，發送Keyboard event到UX，原本想建一個虛擬的Keyboard node，一直建不起來，沒想到可以從X11下手，X11可以看成一個application，這支程式就是對X11下keyevent。

Compiler using

gcc -o xsendkey -lX11 xsendkey.c


#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#ifdef WIN32
# include 'windows_x11.h'
#else
# define NeedFunctionPrototypes 1
# include <X11/Xlib.h>
# include <X11/keysym.h>
# if XlibSpecificationRelease != 6
# error Requires X11R6
# endif
#endif

static char *progname = NULL;
static char *displayname = NULL;
static Window window = 0;
static Display *display = NULL;
static char keyname[1024];
static int shift = 0;
static int keysym = 0;

int MyErrorHandler(Display *my_display, XErrorEvent *event)
{
fprintf(stderr, '%s: XSendEvent(0x%lx) failed.\n', progname, window);
return 1;
}

void SendEvent(XKeyEvent *event)
{
XSync(display, False);
XSetErrorHandler(MyErrorHandler);
XSendEvent(display, window, True, KeyPressMask, (XEvent*)event);
XSync(display, False);
XSetErrorHandler(NULL);
}

void SendKeyPressedEvent(KeySym keysym, unsigned int shift)
{
XKeyEvent event;

// Meta not yet implemented (Alt used instead ;->)
int meta_mask=0;

event.display = display;
event.window = window;
event.root = RootWindow(display, 0); // XXX nonzero screens?
event.subwindow = None;
event.time = CurrentTime;
event.x = 1;
event.y = 1;
event.x_root = 1;
event.y_root = 1;
event.same_screen = True;
event.type = KeyPress;
event.state = 0;

//
// press down shift keys one at a time...
//

if (shift & ShiftMask) {
event.keycode = XKeysymToKeycode(display, XK_Shift_L);
SendEvent(&event);
event.state |= ShiftMask;
}
if (shift & ControlMask) {
event.keycode = XKeysymToKeycode(display, XK_Control_L);
SendEvent(&event);
event.state |= ControlMask;
}

if (shift & Mod1Mask) {
event.keycode = XKeysymToKeycode(display, XK_Alt_L);
SendEvent(&event);
event.state |= Mod1Mask;
}
if (shift & meta_mask) {
event.keycode = XKeysymToKeycode(display, XK_Meta_L);
SendEvent(&event);
event.state |= meta_mask;
}

//
// Now with shift keys held down, send event for the key itself...
//


// fprintf(stderr, 'sym: 0x%x, name: %s\n', keysym, keyname);
if (keysym != NoSymbol) {
event.keycode = XKeysymToKeycode(display, keysym);
// fprintf(stderr, 'code: 0x%x, %d\n', event.keycode, event.keycode );
SendEvent(&event);

event.type = KeyRelease;
SendEvent(&event);
}

//
// Now release all the shift keys...
//

if (shift & ShiftMask) {
event.keycode = XKeysymToKeycode(display, XK_Shift_L);
SendEvent(&event);
event.state &= ~ShiftMask;
}
if (shift & ControlMask) {
event.keycode = XKeysymToKeycode(display, XK_Control_L);
SendEvent(&event);
event.state &= ~ControlMask;
}
if (shift & Mod1Mask) {
event.keycode = XKeysymToKeycode(display, XK_Alt_L);
SendEvent(&event);
event.state &= ~Mod1Mask;
}
if (shift & meta_mask) {
event.keycode = XKeysymToKeycode(display, XK_Meta_L);
SendEvent(&event);
event.state &= ~meta_mask;
}
}

void usage()
{
fprintf(stderr,
'usage: %s [-window <id>|root]\n'
' [-count <count>]\n'
' [-display <name>] [Modifier+[Modifier+]]Key\n'
'(looks up keysyms in <X11/keysymdef.h>)\n'
'"Alt", "Control", "Shift" are replaced by\n'
'"Alt_L", "Control_L", "Shift_L"...\n'
' example:\n'
' %s Control+Alt+Right\n', progname, progname);
exit(1);
}

int main(int argc, char **argv)
{
int ii, Junk;
int c;
char *temp;
unsigned long count = 1;
progname = argv[0];

for(ii=1; ii<argc; ii++) {
if(strcmp(argv[ii], '-display') == 0) {
if(++ii == argc)
usage();

displayname = argv[ii];
}
else if(strcmp(argv[ii], '-count') == 0) {
if(++ii == argc)
usage();

count = strtoul(argv[ii],NULL,0);
}
else if(strcmp(argv[ii], '-window') == 0) {
if(++ii == argc)
usage();

if(strcmp(argv[ii], 'root') == 0)
window = (Window)-1;
else
window = (Window)strtoul(argv[ii], NULL, 0);
}
else if(argv[ii][0] == "-") {
fprintf(stderr, '%s: bad option `%s".\n',
progname, argv[ii]);
usage();
}
else {
strncpy(keyname, argv[ii], 1023);
keysym = 0;
shift = 0;
// fprintf(stderr, 'keyname: %s\n', keyname);
temp = strtok((char *)keyname, '+');
while (temp != NULL) {
// fprintf(stderr, 'temp: %s\n', temp);
if (strcmp(temp, 'Alt') == 0)
c = XK_Alt_L;
else if (strcmp(temp, 'Control') == 0)
c = XK_Control_L;
else if (strcmp(temp, 'Shift') == 0)
c = XK_Shift_L;
else
c = XStringToKeysym(temp);

if (c == 0) {
fprintf(stderr, 'unknown: %s\n', temp);
usage();
}

switch (c) {
case XK_Shift_L:
case XK_Shift_R:
shift |= ShiftMask;
break;
case XK_Control_L:
case XK_Control_R:
shift |= ControlMask;
break;
case XK_Caps_Lock:
case XK_Shift_Lock:
shift |= LockMask;
break;
case XK_Meta_L:
case XK_Meta_R:
case XK_Alt_L:
case XK_Alt_R:
shift |= Mod1Mask;
break;
case XK_Super_L:
case XK_Super_R:
case XK_Hyper_L:
case XK_Hyper_R:
break;
default:
keysym = c;
}
// fprintf(stderr, 'keysym: 0x%x, shift: %d\n', keysym, shift);
temp = strtok(NULL, '+');
}
/* keysym = strtoul(argv[ii], NULL, 0); */
}
}
if (keyname[0] == 0) {
fprintf(stderr, '%s: you must specify a keyname.\n', progname);
exit(1);
}

if(displayname == NULL)
displayname = getenv('DISPLAY');

if(displayname == NULL)
displayname = ':0.0';

display = XOpenDisplay(displayname);

if(display == NULL)
{
fprintf(stderr, '%s: can"t open display `%s".\n',
progname, displayname);
exit(1);
}

if(window == 0)
XGetInputFocus(display, &window, &Junk);

if(window == (Window)-1)
{
window = RootWindow(display, 0); // XXX nonzero screens?
}

// now do the work:
for (ii=0;ii<(int)count;ii++)
SendKeyPressedEvent(keysym, shift);

XCloseDisplay(display);

return 0;
}