xclip.c

ReactOS是一些高手根据Windows XP的内核编写出的类XP。内核实现机理和API函数调用几乎相同。甚至可以兼容XP的程序。喜欢研究系统内核的人可以看一看。

/* -*- c-basic-offset: 8 -*-
   rdesktop: A Remote Desktop Protocol client.
   Protocol services - Clipboard functions
   Copyright (C) Erik Forsberg <[e-mail]> 2003
   Copyright (C) Matthew Chapman 2003

   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 2 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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include <X11/Xlib.h>
#include <X11/Xatom.h>
#include "rdesktop.h"

/*
  To gain better understanding of this code, one could be assisted by the following documents:
  - Inter-Client Communication Conventions Manual (ICCCM)
    HTML: http://tronche.com/gui/x/icccm/
    PDF:  http://ftp.xfree86.org/pub/XFree86/4.5.0/doc/PDF/icccm.pdf
  - MSDN: Clipboard Formats
    http://msdn.microsoft.com/library/en-us/winui/winui/windowsuserinterface/dataexchange/clipboard/clipboardformats.asp
*/

#ifdef HAVE_ICONV
#ifdef HAVE_LANGINFO_H
#ifdef HAVE_ICONV_H
#include <langinfo.h>
#include <iconv.h>
#define USE_UNICODE_CLIPBOARD
#endif
#endif
#endif

#ifdef USE_UNICODE_CLIPBOARD
#define RDP_CF_TEXT CF_UNICODETEXT
#else
#define RDP_CF_TEXT CF_TEXT
#endif


/* Translate LF to CR-LF. To do this, we must allocate more memory.
   The returned string is null-terminated, as required by CF_TEXT.
   Does not stop on embedded nulls.
   The length is updated. */
static void
crlf2lf(uint8 * data, uint32 * length)
{
	uint8 *dst, *src;
	src = dst = data;
	while (src < data + *length)
	{
		if (*src != '\x0d')
			*dst++ = *src;
		src++;
	}
	*length = dst - data;
}

#ifdef USE_UNICODE_CLIPBOARD
/* Translate LF to CR-LF. To do this, we must allocate more memory.
   The returned string is null-terminated, as required by CF_UNICODETEXT.
   The size is updated. */
static uint8 *
utf16_lf2crlf(uint8 * data, uint32 * size)
{
	uint8 *result;
	uint16 *inptr, *outptr;
	Bool swap_endianess;

	/* Worst case: Every char is LF */
	result = xmalloc((*size * 2) + 2);
	if (result == NULL)
		return NULL;

	inptr = (uint16 *) data;
	outptr = (uint16 *) result;

	/* Check for a reversed BOM */
	swap_endianess = (*inptr == 0xfffe);

	while ((uint8 *) inptr < data + *size)
	{
		uint16 uvalue = *inptr;
		if (swap_endianess)
			uvalue = ((uvalue << 8) & 0xff00) + (uvalue >> 8);
		if (uvalue == 0x0a)
			*outptr++ = swap_endianess ? 0x0d00 : 0x0d;
		*outptr++ = *inptr++;
	}
	*outptr++ = 0;		/* null termination */
	*size = (uint8 *) outptr - result;

	return result;
}
#else
/* Translate LF to CR-LF. To do this, we must allocate more memory.
   The length is updated. */
static uint8 *
lf2crlf(uint8 * data, uint32 * length)
{
	uint8 *result, *p, *o;

	/* Worst case: Every char is LF */
	result = xmalloc(*length * 2);

	p = data;
	o = result;

	while (p < data + *length)
	{
		if (*p == '\x0a')
			*o++ = '\x0d';
		*o++ = *p++;
	}
	*length = o - result;

	/* Convenience */
	*o++ = '\0';

	return result;
}
#endif

static void
xclip_provide_selection(RDPCLIENT * This, XSelectionRequestEvent * req, Atom type, unsigned int format, uint8 * data,
			uint32 length)
{
	XEvent xev;

	DEBUG_CLIPBOARD(("xclip_provide_selection: requestor=0x%08x, target=%s, property=%s, length=%u\n", (unsigned) req->requestor, XGetAtomName(This->display, req->target), XGetAtomName(This->display, req->property), (unsigned) length));

	XChangeProperty(This->display, req->requestor, req->property,
			type, format, PropModeReplace, data, length);

	xev.xselection.type = SelectionNotify;
	xev.xselection.serial = 0;
	xev.xselection.send_event = True;
	xev.xselection.requestor = req->requestor;
	xev.xselection.selection = req->selection;
	xev.xselection.target = req->target;
	xev.xselection.property = req->property;
	xev.xselection.time = req->time;
	XSendEvent(This->display, req->requestor, False, NoEventMask, &xev);
}

/* Replies a clipboard requestor, telling that we're unable to satisfy his request for whatever reason.
   This has the benefit of finalizing the clipboard negotiation and thus not leaving our requestor
   lingering (and, potentially, stuck). */
static void
xclip_refuse_selection(RDPCLIENT * This, XSelectionRequestEvent * req)
{
	XEvent xev;

	DEBUG_CLIPBOARD(("xclip_refuse_selection: requestor=0x%08x, target=%s, property=%s\n",
			 (unsigned) req->requestor, XGetAtomName(This->display, req->target),
			 XGetAtomName(This->display, req->property)));

	xev.xselection.type = SelectionNotify;
	xev.xselection.serial = 0;
	xev.xselection.send_event = True;
	xev.xselection.requestor = req->requestor;
	xev.xselection.selection = req->selection;
	xev.xselection.target = req->target;
	xev.xselection.property = None;
	xev.xselection.time = req->time;
	XSendEvent(This->display, req->requestor, False, NoEventMask, &xev);
}

/* Wrapper for cliprdr_send_data which also cleans the request state. */
static void
helper_cliprdr_send_response(RDPCLIENT * This, uint8 * data, uint32 length)
{
	if (This->xclip.rdp_clipboard_request_format != 0)
	{
		cliprdr_send_data(This, data, length);
		This->xclip.rdp_clipboard_request_format = 0;
		if (!This->xclip.rdesktop_is_selection_owner)
			cliprdr_send_simple_native_format_announce(This, RDP_CF_TEXT);
	}
}

/* Last resort, when we have to provide clipboard data but for whatever
   reason couldn't get any.
 */
static void
helper_cliprdr_send_empty_response(RDPCLIENT * This)
{
	helper_cliprdr_send_response(This, NULL, 0);
}

/* Replies with clipboard data to RDP, converting it from the target format
   to the expected RDP format as necessary. Returns true if data was sent.
 */
static Bool
xclip_send_data_with_convert(RDPCLIENT * This, uint8 * source, size_t source_size, Atom target)
{
	DEBUG_CLIPBOARD(("xclip_send_data_with_convert: target=%s, size=%u\n",
			 XGetAtomName(This->display, target), (unsigned) source_size));

#ifdef USE_UNICODE_CLIPBOARD
	if (target == This->xclip.format_string_atom ||
	    target == This->xclip.format_unicode_atom || target == This->xclip.format_utf8_string_atom)
	{
		size_t unicode_buffer_size;
		char *unicode_buffer;
		iconv_t cd;
		size_t unicode_buffer_size_remaining;
		char *unicode_buffer_remaining;
		char *data_remaining;
		size_t data_size_remaining;
		uint32 translated_data_size;
		uint8 *translated_data;

		if (This->xclip.rdp_clipboard_request_format != RDP_CF_TEXT)
			return False;

		/* Make an attempt to convert any string we send to Unicode.
		   We don't know what the RDP server's ANSI Codepage is, or how to convert
		   to it, so using CF_TEXT is not safe (and is unnecessary, since all
		   WinNT versions are Unicode-minded).
		 */
		if (target == This->xclip.format_string_atom)
		{
			char *locale_charset = nl_langinfo(CODESET);
			cd = iconv_open(WINDOWS_CODEPAGE, locale_charset);
			if (cd == (iconv_t) - 1)
			{
				DEBUG_CLIPBOARD(("Locale charset %s not found in iconv. Unable to convert clipboard text.\n", locale_charset));
				return False;
			}
			unicode_buffer_size = source_size * 4;
		}
		else if (target == This->xclip.format_unicode_atom)
		{
			cd = iconv_open(WINDOWS_CODEPAGE, "UCS-2");
			if (cd == (iconv_t) - 1)
			{
				return False;
			}
			unicode_buffer_size = source_size;
		}
		else if (target == This->xclip.format_utf8_string_atom)
		{
			cd = iconv_open(WINDOWS_CODEPAGE, "UTF-8");
			if (cd == (iconv_t) - 1)
			{
				return False;
			}
			/* UTF-8 is guaranteed to be less or equally compact
			   as UTF-16 for all Unicode chars >=2 bytes.
			 */
			unicode_buffer_size = source_size * 2;
		}
		else
		{
			return False;
		}

		unicode_buffer = xmalloc(unicode_buffer_size);
		unicode_buffer_size_remaining = unicode_buffer_size;
		unicode_buffer_remaining = unicode_buffer;
		data_remaining = (char *) source;
		data_size_remaining = source_size;
		iconv(cd, (ICONV_CONST char **) &data_remaining, &data_size_remaining,
		      &unicode_buffer_remaining, &unicode_buffer_size_remaining);
		iconv_close(cd);

		/* translate linebreaks */
		translated_data_size = unicode_buffer_size - unicode_buffer_size_remaining;
		translated_data = utf16_lf2crlf((uint8 *) unicode_buffer, &translated_data_size);
		if (translated_data != NULL)
		{
			DEBUG_CLIPBOARD(("Sending Unicode string of %d bytes\n",
					 translated_data_size));
			helper_cliprdr_send_response(This, translated_data, translated_data_size);
			xfree(translated_data);	/* Not the same thing as XFree! */
		}

		xfree(unicode_buffer);

		return True;
	}
#else
	if (target == This->xclip.format_string_atom)
	{
		uint8 *translated_data;
		uint32 length = source_size;

		if (This->xclip.rdp_clipboard_request_format != RDP_CF_TEXT)
			return False;

		DEBUG_CLIPBOARD(("Translating linebreaks before sending data\n"));
		translated_data = lf2crlf(source, &length);
		if (translated_data != NULL)
		{
			helper_cliprdr_send_response(This, translated_data, length);
			xfree(translated_data);	/* Not the same thing as XFree! */
		}

		return True;
	}
#endif
	else if (target == This->xclip.rdesktop_native_atom)
	{
		helper_cliprdr_send_response(This, source, source_size + 1);

		return True;
	}
	else
	{
		return False;
	}
}

static void
xclip_clear_target_props(RDPCLIENT * This)
{
	XDeleteProperty(This->display, This->wnd, This->xclip.rdesktop_clipboard_target_atom);
	XDeleteProperty(This->display, This->wnd, This->xclip.rdesktop_primary_timestamp_target_atom);
	XDeleteProperty(This->display, This->wnd, This->xclip.rdesktop_clipboard_timestamp_target_atom);
}

static void
xclip_notify_change(RDPCLIENT * This)
{
	XChangeProperty(This->display, DefaultRootWindow(This->display),
			This->xclip.rdesktop_selection_notify_atom, XA_INTEGER, 32, PropModeReplace, NULL, 0);
}

static void
xclip_probe_selections(RDPCLIENT * This)
{
	Window primary_owner, clipboard_owner;

	if (This->xclip.probing_selections)
	{
		DEBUG_CLIPBOARD(("Already probing selections. Scheduling reprobe.\n"));
		This->xclip.reprobe_selections = True;
		return;
	}

	DEBUG_CLIPBOARD(("Probing selections.\n"));

	This->xclip.probing_selections = True;
	This->xclip.reprobe_selections = False;

	xclip_clear_target_props(This);

	if (This->xclip.auto_mode)
		primary_owner = XGetSelectionOwner(This->display, This->xclip.primary_atom);
	else
		primary_owner = None;

	clipboard_owner = XGetSelectionOwner(This->display, This->xclip.clipboard_atom);

	/* If we own all relevant selections then don't do anything. */
	if (((primary_owner == This->wnd) || !This->xclip.auto_mode) && (clipboard_owner == This->wnd))
		goto end;