Initial revision

src/w16select.c

+/* Win16 Selection processing for emacs on MS-Windows
+   Copyright (C) 1996, 1997 Free Software Foundation.
+   
+This file is part of GNU Emacs.
+
+GNU Emacs 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, or (at your option)
+any later version.
+
+GNU Emacs 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 GNU Emacs; see the file COPYING.  If not, write to
+the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+Boston, MA 02111-1307, USA.  */
+
+/* These functions work by using WinOldAp interface.  WinOldAp
+   (WINOLDAP.MOD) is a Microsoft Windows extension supporting
+   "old" (character-mode) application access to Dynamic Data Exchange,
+   menus, and the Windows clipboard.  */
+
+/* Written by Dale P. Smith <dpsm@en.com>  */
+/* Adapted to DJGPP v1 by Eli Zaretskii <eliz@is.elta.co.il>  */
+
+#ifdef MSDOS
+
+#include <config.h>
+#include <string.h>
+#include <dpmi.h>
+#include <go32.h>
+#include <sys/farptr.h>
+#include "lisp.h"
+#include "dispextern.h"	/* frame.h seems to want this */
+#include "frame.h"	/* Need this to get the X window of selected_frame */
+#include "blockinput.h"
+
+/* If ever some function outside this file will need to call any
+   clipboard-related function, the following prototypes and constants
+   should be put on a header file.  Right now, nobody else uses them.  */
+
+#define CF_TEXT      0x01
+#define CF_BITMAP    0x02
+#define CF_METAFILE  0x03
+#define CF_SYLK	     0x04
+#define CF_DIF	     0x05
+#define CF_TIFF	     0x06
+#define CF_OEMTEXT   0x07
+#define CF_DIBBITMAP 0x08
+#define CF_WINWRITE  0x80
+#define CF_DSPTEXT   0x81
+#define CF_DSPBITMAP 0x82
+
+unsigned identify_winoldap_version (void);
+unsigned open_clipboard (void);
+unsigned empty_clipboard (void);
+unsigned set_clipboard_data (unsigned, void *, unsigned);
+unsigned get_clipboard_data_size (unsigned);
+unsigned get_clipboard_data (unsigned, void *, unsigned);
+unsigned close_clipboard (void);
+unsigned clipboard_compact (unsigned);
+
+Lisp_Object QCLIPBOARD, QPRIMARY;
+
+/* The segment address and the size of the buffer in low
+   memory used to move data between us and WinOldAp module.  */
+
+static struct {
+  unsigned long size;
+  unsigned short rm_segment;
+} clipboard_xfer_buf_info;
+
+/* Emulation of `__dpmi_int' and friends for DJGPP v1.x  */
+
+#if __DJGPP__ < 2
+
+typedef _go32_dpmi_registers __dpmi_regs;
+#define __tb      _go32_info_block.linear_address_of_transfer_buffer
+#define _dos_ds	  _go32_info_block.selector_for_linear_memory
+
+static int
+__dpmi_int (intno, regs)
+     int intno;
+     __dpmi_regs *regs;
+{
+  regs->x.ss = regs->x.sp = regs->x.flags = 0;
+  return _go32_dpmi_simulate_int (intno, regs);
+}
+
+#endif /* __DJGPP__ < 2 */
+
+/* C functions to access the Windows 3.1x clipboard from DOS apps.
+
+   The information was obtained from the Microsoft Knowledge Base,
+   article Q67675 and can be found at:
+   http://www.microsoft.com/kb/developr/win_dk/q67675.htm  */
+
+/* See also Ralf Brown's Interrupt List.
+
+   I also seem to remember reading about this in Dr. Dobbs Journal a
+   while ago, but if you knew my memory...  :-)
+
+   Dale P. Smith <dpsm@en.com> */
+
+/* Return the WinOldAp support version, or 0x1700 if not supported.  */
+unsigned
+identify_winoldap_version ()
+{
+  __dpmi_regs regs;
+
+  /* Calls Int 2Fh/AX=1700h
+     Return Values   AX == 1700H: Clipboard functions not available
+                        <> 1700H: AL = Major version number
+				  AH = Minor version number */
+  regs.x.ax = 0x1700;
+  __dpmi_int(0x2f, &regs);
+  return regs.x.ax;
+}
+
+/* Open the clipboard, return non-zero if successfull.  */
+unsigned
+open_clipboard ()
+{
+  __dpmi_regs regs;
+
+  /* Is WINOLDAP supported?  */
+  /* Kludge alert!!  If WinOldAp is not supported, we return a 0,
+     which is the same as ``Clipboard already open''.  Currently,
+     this is taken as an error by all the functions that use
+     `open_clipboard', but if somebody someday will use that ``open''
+     clipboard, they will have interesting time debugging it...  */
+  if (identify_winoldap_version () == 0x1700)
+    return 0;
+
+  /* Calls Int 2Fh/AX=1701h
+     Return Values   AX == 0: Clipboard already open
+			<> 0: Clipboard opened */
+  regs.x.ax = 0x1701;
+  __dpmi_int(0x2f, &regs);
+  return regs.x.ax;
+}
+
+/* Empty clipboard, return non-zero if successfull.  */
+unsigned
+empty_clipboard ()
+{
+  __dpmi_regs regs;
+  
+  /* Calls Int 2Fh/AX=1702h
+     Return Values   AX == 0: Error occurred
+			<> 0: OK, Clipboard emptied */
+  regs.x.ax = 0x1702;
+  __dpmi_int(0x2f, &regs);
+  return regs.x.ax;
+}
+
+/* Ensure we have a buffer in low memory with enough memory for data
+   of size WANT_SIZE.  Return the linear address of the buffer.  */
+static unsigned long
+alloc_xfer_buf (want_size)
+     unsigned want_size;
+{
+  __dpmi_regs regs;
+
+  /* If the usual DJGPP transfer buffer is large enough, use that.  */
+  if (want_size <= _go32_info_block.size_of_transfer_buffer)
+    return __tb & 0xfffff;
+
+  /* Need size rounded up to the nearest paragraph, and in
+     paragraph units (1 paragraph = 16 bytes).  */
+  clipboard_xfer_buf_info.size = (want_size + 15) >> 4;
+
+  /* The NT DPMI host crashes us if we free DOS memory via the
+     DPMI service.  Work around by calling DOS allocate/free block.  */
+  regs.h.ah = 0x48;
+  regs.x.bx = clipboard_xfer_buf_info.size;
+  __dpmi_int (0x21, &regs);
+  if (regs.x.flags & 1)
+    {
+      clipboard_xfer_buf_info.size = 0;
+      return 0;
+    }
+
+  clipboard_xfer_buf_info.rm_segment = regs.x.ax;
+  return (((int)clipboard_xfer_buf_info.rm_segment) << 4) & 0xfffff;
+}
+
+/* Free our clipboard buffer.  We always free it after use, because
+   keeping it leaves less free conventional memory for subprocesses.
+   The clipboard buffer tends to be large in size, because for small
+   clipboard data sizes we use the DJGPP transfer buffer.  */
+static void
+free_xfer_buf ()
+{
+  /* If the size is 0, we used DJGPP transfer buffer, so don't free.  */
+  if (clipboard_xfer_buf_info.size)
+    {
+      __dpmi_regs regs;
+
+      /* The NT DPMI host crashes us if we free DOS memory via
+	 the DPMI service.  Work around by calling DOS free block.  */
+      regs.h.ah = 0x49;
+      regs.x.es = clipboard_xfer_buf_info.rm_segment;
+      __dpmi_int (0x21, &regs);
+      clipboard_xfer_buf_info.size = 0;
+    }
+}
+
+/* Copy data into the clipboard, return non-zero if successfull.  */
+unsigned
+set_clipboard_data (Format, Data, Size)
+     unsigned Format;
+     void *Data;
+     unsigned Size;
+{
+  __dpmi_regs regs;
+  unsigned truelen;
+  unsigned long xbuf_addr, buf_offset;
+  unsigned char *dp = Data, *dstart = dp;
+
+  if (Format != CF_TEXT)
+    return 0;
+
+  /* need to know final size after '\r' chars are inserted (the
+     standard CF_TEXT clipboard format uses CRLF line endings,
+     while Emacs uses just LF internally).  */
+  truelen = Size;
+  /* avoid using strchr because it recomputes the length everytime */
+  while ((dp = memchr (dp, '\n', Size - (dp - dstart))) != 0)
+    {
+      truelen++;
+      dp++;
+    }
+
+  if (clipboard_compact (truelen) < truelen)
+    return 0;
+
+  if ((xbuf_addr = alloc_xfer_buf (truelen)) == 0)
+    return 0;
+
+  /* Move the buffer into the low memory, convert LF into CR-LF pairs.  */
+  dp = Data;
+  buf_offset = xbuf_addr;
+  _farsetsel (_dos_ds);
+  while (Size--)
+    {
+      if (*dp == '\n')
+	_farnspokeb (buf_offset++, '\r');
+      _farnspokeb (buf_offset++, *dp++);
+    }
+
+  /* Calls Int 2Fh/AX=1703h with:
+	             DX = WinOldAp-Supported Clipboard format
+                     ES:BX = Pointer to data
+                     SI:CX = Size of data in bytes
+     Return Values   AX == 0: Error occurred
+			<> 0: OK.  Data copied into the Clipboard.  */
+  regs.x.ax = 0x1703;
+  regs.x.dx = Format;
+  regs.x.si = truelen >> 16;
+  regs.x.cx = truelen & 0xffff;
+  regs.x.es = xbuf_addr >> 4;
+  regs.x.bx = xbuf_addr & 15;
+  __dpmi_int(0x2f, &regs);
+
+  free_xfer_buf ();
+
+  return regs.x.ax;
+}
+
+/* Return the size of the clipboard data of format FORMAT.  */
+unsigned
+get_clipboard_data_size (Format)
+     unsigned Format;
+{
+  __dpmi_regs regs;
+
+  /* Calls Int 2Fh/AX=1704h with:
+		     DX = WinOldAp-Supported Clipboard format
+     Return Values   DX:AX == Size of the data in bytes, including any
+                              headers.
+                           == 0 If data in this format is not in
+			   the clipboard.  */
+  regs.x.ax = 0x1704;
+  regs.x.dx = Format;
+  __dpmi_int(0x2f, &regs);
+  return ( (((unsigned)regs.x.dx) << 16) | regs.x.ax);
+}
+
+/* Get clipboard data, return its length.
+   Warning: this doesn't check whether DATA has enough space to hold
+   SIZE bytes.  */
+unsigned
+get_clipboard_data (Format, Data, Size)
+     unsigned Format;
+     void *Data;
+     unsigned Size;
+{
+  __dpmi_regs regs;
+  unsigned datalen = 0;
+  unsigned long xbuf_addr;
+  unsigned char *dp = Data;
+
+  if (Format != CF_TEXT)
+    return 0;
+
+  if (Size == 0)
+    return 0;
+
+  if ((xbuf_addr = alloc_xfer_buf (Size)) == 0)
+    return 0;
+
+  /* Calls Int 2Fh/AX=1705h with:
+		     DX = WinOldAp-Supported Clipboard format
+		     ES:BX = Pointer to data buffer to hold data
+     Return Values   AX == 0: Error occurred (or data in this format is not
+                              in the clipboard)
+                        <> 0: OK  */
+  regs.x.ax = 0x1705;
+  regs.x.dx = Format;
+  regs.x.es = xbuf_addr >> 4;
+  regs.x.bx = xbuf_addr & 15;
+  __dpmi_int(0x2f, &regs);
+  if (regs.x.ax != 0)
+    {
+      /* Copy data from low memory, remove CR characters if before LF.  */
+      _farsetsel (_dos_ds);
+      while (Size--)
+	{
+	  register unsigned char c = _farnspeekb (xbuf_addr++);
+
+	  if ((*dp++ = c) == '\r' && _farnspeekb (xbuf_addr) == '\n')
+	    {
+	      dp--;
+	      *dp++ = '\n';
+	      xbuf_addr++;
+	    }
+	  /* Windows reportedly rounds up the size of clipboard data
+	     (passed in SIZE) to a multiple of 32.  We therefore bail
+	     out when we see the first null character.  */
+	  else if (c == '\0')
+	    {
+	      datalen = dp - (unsigned char *)Data - 1;
+	      break;
+	    }
+	}
+    }
+
+  free_xfer_buf ();
+
+  return datalen;
+}
+
+/* Close clipboard, return non-zero if successfull.  */
+unsigned
+close_clipboard ()
+{
+  __dpmi_regs regs;
+
+  /* Calls Int 2Fh/AX=1708h
+     Return Values   AX == 0: Error occurred
+                        <> 0: OK */
+  regs.x.ax = 0x1708;
+  __dpmi_int(0x2f, &regs);
+  return regs.x.ax;
+}
+
+/* Compact clipboard data so that at least SIZE bytes is available.  */
+unsigned
+clipboard_compact (Size)
+     unsigned Size;
+{
+  __dpmi_regs regs;
+
+  /* Calls Int 2Fh/AX=1709H with:
+                     SI:CX = Desired memory size in bytes.
+     Return Values   DX:AX == Number of bytes of largest block of free memory.
+                           == 0 if error or no memory  */
+  regs.x.ax = 0x1709;
+  regs.x.si = Size >> 16;
+  regs.x.cx = Size & 0xffff;
+  __dpmi_int(0x2f, &regs);
+  return ((unsigned)regs.x.dx << 16) | regs.x.ax;
+}
+
+static char no_mem_msg[] =
+  "(Not enough DOS memory to put saved text into clipboard.)";
+
+DEFUN ("win16-set-clipboard-data", Fwin16_set_clipboard_data, Swin16_set_clipboard_data, 1, 2, 0,
+       "This sets the clipboard data to the given text.")
+    (string, frame)
+    Lisp_Object string, frame;
+{
+  int ok = 1, ok1 = 1;
+  int nbytes;
+  unsigned char *src;
+
+  CHECK_STRING (string, 0);
+  
+  if (NILP (frame))
+    frame = Fselected_frame ();
+
+  CHECK_LIVE_FRAME (frame, 0);
+  if ( !FRAME_MSDOS_P (XFRAME (frame)))
+    goto done;
+  
+  BLOCK_INPUT;
+
+  nbytes = XSTRING (string)->size + 1;
+  src = XSTRING (string)->data;
+    
+  if (!open_clipboard ())
+    goto error;
+  
+  ok = empty_clipboard () && (ok1 = set_clipboard_data (CF_TEXT, src, nbytes));
+  
+  close_clipboard ();
+  
+  if (ok) goto done;
+
+ error:
+  
+  ok = 0;
+
+  /* Notify user if the text is too large to fit into DOS memory.
+     (This will happen somewhere after 600K bytes (470K in DJGPP v1.x),
+     depending on user system configuration.)  If we just silently
+     fail the function, people might wonder why their text sometimes
+     doesn't make it to the clipboard.  */
+  if (ok1 == 0)
+    {
+      message2 (no_mem_msg, sizeof (no_mem_msg) - 1);
+      sit_for (2, 0, 0, 1);
+    }
+  
+ done:
+  UNBLOCK_INPUT;
+
+  return (ok ? string : Qnil);
+}
+
+DEFUN ("win16-get-clipboard-data", Fwin16_get_clipboard_data, Swin16_get_clipboard_data, 0, 1, 0,
+       "This gets the clipboard data in text format.")
+     (frame)
+     Lisp_Object frame;
+{
+  unsigned data_size, truelen;
+  unsigned char *htext;
+  Lisp_Object ret = Qnil;
+  
+  if (!NILP (frame))
+    CHECK_LIVE_FRAME (frame, 0);
+  
+  if (NILP (frame))
+    frame = Fselected_frame ();
+
+  CHECK_LIVE_FRAME (frame, 0);
+  if ( !FRAME_MSDOS_P (XFRAME (frame)))
+    goto done;
+  
+  BLOCK_INPUT;
+  
+  if (!open_clipboard ())
+    goto done;
+
+  if ((data_size = get_clipboard_data_size (CF_TEXT)) == 0 ||
+      (htext = (unsigned char *)xmalloc (data_size)) == 0)
+    goto closeclip;
+
+  /* need to know final size after '\r' chars are removed because
+     we can't change the string size manually, and doing an extra
+     copy is silly */
+  if ((truelen = get_clipboard_data (CF_TEXT, htext, data_size)) == 0)
+    goto closeclip;
+
+  ret = make_string (htext, truelen);
+  xfree (htext);
+
+ closeclip:
+  close_clipboard ();
+  
+ done:
+  UNBLOCK_INPUT;
+  
+  return (ret);
+}
+
+/* Support checking for a clipboard selection. */
+
+DEFUN ("x-selection-exists-p", Fx_selection_exists_p, Sx_selection_exists_p,
+  0, 1, 0,
+  "Whether there is an owner for the given X Selection.\n\
+The arg should be the name of the selection in question, typically one of\n\
+the symbols `PRIMARY', `SECONDARY', or `CLIPBOARD'.\n\
+\(Those are literal upper-case symbol names, since that's what X expects.)\n\
+For convenience, the symbol nil is the same as `PRIMARY',\n\
+and t is the same as `SECONDARY'.")
+  (selection)
+     Lisp_Object selection;
+{
+  CHECK_SYMBOL (selection, 0);
+
+  /* Return nil for SECONDARY selection.  For PRIMARY (or nil)
+     selection, check if there is some text on the kill-ring;
+     for CLIPBOARD, check if the clipboard currently has valid
+     text format contents.
+
+     The test for killed text on the kill-ring emulates the Emacs
+     behavior on X, where killed text is also put into X selection
+     by the X interface code.  (On MSDOS, killed text is only put
+     into the clipboard if we run under Windows, so we cannot check
+     the clipboard alone.)  */
+  if ((EQ (selection, Qnil) || EQ (selection, QPRIMARY))
+      && ! NILP (XSYMBOL (Fintern_soft (build_string ("kill-ring"),
+					Qnil))->value))
+    return Qt;
+
+  if (EQ (selection, QCLIPBOARD))
+    {
+      Lisp_Object val = Qnil;
+
+      if (open_clipboard ())
+	{
+	  if (get_clipboard_data_size (CF_TEXT))
+	    val = Qt;
+	  close_clipboard ();
+	}
+      return val;
+    }
+  return Qnil;
+}
+
+void 
+syms_of_win16select ()
+{
+  defsubr (&Swin16_set_clipboard_data);
+  defsubr (&Swin16_get_clipboard_data);
+  defsubr (&Sx_selection_exists_p);
+
+  QPRIMARY   = intern ("PRIMARY");	staticpro (&QPRIMARY);
+  QCLIPBOARD = intern ("CLIPBOARD");	staticpro (&QCLIPBOARD);
+}
+
+#endif /* MSDOS */