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libtdevnc/x11vnc/selection.c

299 lines
7.5 KiB

/* -- selection.c -- */
#include "x11vnc.h"
#include "cleanup.h"
#include "connections.h"
/*
* Selection/Cutbuffer/Clipboard handlers.
*/
int own_selection = 0; /* whether we currently own PRIMARY or not */
int set_cutbuffer = 0; /* to avoid bouncing the CutText right back */
int sel_waittime = 15; /* some seconds to skip before first send */
Window selwin; /* special window for our selection */
/*
* This is where we keep our selection: the string sent TO us from VNC
* clients, and the string sent BY us to requesting X11 clients.
*/
char *xcut_str = NULL;
void selection_request(XEvent *ev);
int check_sel_direction(char *dir, char *label, char *sel, int len);
void cutbuffer_send(void);
void selection_send(XEvent *ev);
/*
* Our callbacks instruct us to check for changes in the cutbuffer
* and PRIMARY selection on the local X11 display.
*
* We store the new cutbuffer and/or PRIMARY selection data in this
* constant sized array selection_str[].
* TODO: check if malloc does not cause performance issues (esp. WRT
* SelectionNotify handling).
*/
static char selection_str[PROP_MAX+1];
/*
* An X11 (not VNC) client on the local display has requested the selection
* from us (because we are the current owner).
*
* n.b.: our caller already has the X_LOCK.
*/
void selection_request(XEvent *ev) {
XSelectionEvent notify_event;
XSelectionRequestEvent *req_event;
XErrorHandler old_handler;
unsigned int length;
unsigned char *data;
#ifndef XA_LENGTH
unsigned long XA_LENGTH = XInternAtom(dpy, "LENGTH", True);
#endif
req_event = &(ev->xselectionrequest);
notify_event.type = SelectionNotify;
notify_event.display = req_event->display;
notify_event.requestor = req_event->requestor;
notify_event.selection = req_event->selection;
notify_event.target = req_event->target;
notify_event.time = req_event->time;
if (req_event->property == None) {
notify_event.property = req_event->target;
} else {
notify_event.property = req_event->property;
}
if (xcut_str) {
length = strlen(xcut_str);
} else {
length = 0;
}
/* the window may have gone away, so trap errors */
trapped_xerror = 0;
old_handler = XSetErrorHandler(trap_xerror);
if (ev->xselectionrequest.target == XA_LENGTH) {
/* length request */
XChangeProperty(ev->xselectionrequest.display,
ev->xselectionrequest.requestor,
ev->xselectionrequest.property,
ev->xselectionrequest.target, 32, PropModeReplace,
(unsigned char *) &length, sizeof(unsigned int));
} else {
/* data request */
data = (unsigned char *)xcut_str;
XChangeProperty(ev->xselectionrequest.display,
ev->xselectionrequest.requestor,
ev->xselectionrequest.property,
ev->xselectionrequest.target, 8, PropModeReplace,
data, length);
}
if (! trapped_xerror) {
XSendEvent(req_event->display, req_event->requestor, False, 0,
(XEvent *)&notify_event);
}
if (trapped_xerror) {
rfbLog("selection_request: ignored XError while sending "
"PRIMARY selection to 0x%x.\n", req_event->requestor);
}
XSetErrorHandler(old_handler);
trapped_xerror = 0;
XFlush(dpy);
}
int check_sel_direction(char *dir, char *label, char *sel, int len) {
int db = 0, ok = 1;
if (sel_direction) {
if (strstr(sel_direction, "debug")) {
db = 1;
}
if (strcmp(sel_direction, "debug")) {
if (strstr(sel_direction, dir) == NULL) {
ok = 0;
}
}
}
if (db) {
char str[40];
int n = 40;
strncpy(str, sel, n);
str[n-1] = '\0';
if (len < n) {
str[len] = '\0';
}
rfbLog("%s: %s...\n", label, str);
if (ok) {
rfbLog("%s: %s-ing it.\n", label, dir);
} else {
rfbLog("%s: NOT %s-ing it.\n", label, dir);
}
}
return ok;
}
/*
* CUT_BUFFER0 property on the local display has changed, we read and
* store it and send it out to any connected VNC clients.
*
* n.b.: our caller already has the X_LOCK.
*/
void cutbuffer_send(void) {
Atom type;
int format, slen, dlen, len;
unsigned long nitems = 0, bytes_after = 0;
unsigned char* data = NULL;
selection_str[0] = '\0';
slen = 0;
/* read the property value into selection_str: */
do {
if (XGetWindowProperty(dpy, DefaultRootWindow(dpy),
XA_CUT_BUFFER0, nitems/4, PROP_MAX/16, False,
AnyPropertyType, &type, &format, &nitems, &bytes_after,
&data) == Success) {
dlen = nitems * (format/8);
if (slen + dlen > PROP_MAX) {
/* too big */
rfbLog("warning: truncating large CUT_BUFFER0"
" selection > %d bytes.\n", PROP_MAX);
XFree(data);
break;
}
memcpy(selection_str+slen, data, dlen);
slen += dlen;
selection_str[slen] = '\0';
XFree(data);
}
} while (bytes_after > 0);
selection_str[PROP_MAX] = '\0';
if (! all_clients_initialized()) {
rfbLog("cutbuffer_send: no send: uninitialized clients\n");
return; /* some clients initializing, cannot send */
}
/* now send it to any connected VNC clients (rfbServerCutText) */
if (!screen) {
return;
}
len = strlen(selection_str);
if (check_sel_direction("send", "cutbuffer_send", selection_str, len)) {
rfbSendServerCutText(screen, selection_str, len);
}
}
/*
* "callback" for our SelectionNotify polling. We try to determine if
* the PRIMARY selection has changed (checking length and first CHKSZ bytes)
* and if it has we store it and send it off to any connected VNC clients.
*
* n.b.: our caller already has the X_LOCK.
*
* TODO: if we were willing to use libXt, we could perhaps get selection
* timestamps to speed up the checking... XtGetSelectionValue().
*
* Also: XFIXES has XFixesSelectSelectionInput().
*/
#define CHKSZ 32
void selection_send(XEvent *ev) {
Atom type;
int format, slen, dlen, oldlen, newlen, toobig = 0, len;
static int err = 0, sent_one = 0;
char before[CHKSZ], after[CHKSZ];
unsigned long nitems = 0, bytes_after = 0;
unsigned char* data = NULL;
/*
* remember info about our last value of PRIMARY (or CUT_BUFFER0)
* so we can check for any changes below.
*/
oldlen = strlen(selection_str);
strncpy(before, selection_str, CHKSZ);
selection_str[0] = '\0';
slen = 0;
/* read in the current value of PRIMARY: */
do {
if (XGetWindowProperty(dpy, ev->xselection.requestor,
ev->xselection.property, nitems/4, PROP_MAX/16, True,
AnyPropertyType, &type, &format, &nitems, &bytes_after,
&data) == Success) {
dlen = nitems * (format/8);
if (slen + dlen > PROP_MAX) {
/* too big */
toobig = 1;
XFree(data);
if (err) { /* cut down on messages */
break;
} else {
err = 5;
}
rfbLog("warning: truncating large PRIMARY"
" selection > %d bytes.\n", PROP_MAX);
break;
}
memcpy(selection_str+slen, data, dlen);
slen += dlen;
selection_str[slen] = '\0';
XFree(data);
}
} while (bytes_after > 0);
if (! toobig) {
err = 0;
} else if (err) {
err--;
}
if (! sent_one) {
/* try to force a send first time in */
oldlen = -1;
sent_one = 1;
}
/* look for changes in the new value */
newlen = strlen(selection_str);
strncpy(after, selection_str, CHKSZ);
if (oldlen == newlen && strncmp(before, after, CHKSZ) == 0) {
/* evidently no change */
return;
}
if (newlen == 0) {
/* do not bother sending a null string out */
return;
}
if (! all_clients_initialized()) {
rfbLog("selection_send: no send: uninitialized clients\n");
return; /* some clients initializing, cannot send */
}
/* now send it to any connected VNC clients (rfbServerCutText) */
if (!screen) {
return;
}
len = newlen;
if (check_sel_direction("send", "selection_send", selection_str, len)) {
rfbSendServerCutText(screen, selection_str, len);
}
}