path: root/hw/xquartz/pbproxy/x-selection.m

/* x-selection.m -- proxies between NSPasteboard and X11 selections

   Copyright (c) 2002, 2008 Apple Computer, Inc. All rights reserved.

   Permission is hereby granted, free of charge, to any person
   obtaining a copy of this software and associated documentation files
   (the "Software"), to deal in the Software without restriction,
   including without limitation the rights to use, copy, modify, merge,
   publish, distribute, sublicense, and/or sell copies of the Software,
   and to permit persons to whom the Software is furnished to do so,
   subject to the following conditions:

   The above copyright notice and this permission notice shall be
   included in all copies or substantial portions of the Software.

   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
   NONINFRINGEMENT.  IN NO EVENT SHALL THE ABOVE LISTED COPYRIGHT
   HOLDER(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
   WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
   DEALINGS IN THE SOFTWARE.

   Except as contained in this notice, the name(s) of the above
   copyright holders shall not be used in advertising or otherwise to
   promote the sale, use or other dealings in this Software without
   prior written authorization. 
*/

#import "x-selection.h"

#include <stdio.h>
#include <stdlib.h>
#include <X11/Xatom.h>
#include <X11/Xutil.h>
#import <AppKit/NSGraphics.h>
#import <AppKit/NSImage.h>
#import <AppKit/NSBitmapImageRep.h>

/*
 * The basic design of the pbproxy code is as follows.
 *
 * When a client selects text, say from an xterm - we only copy it when the
 * X11 Edit->Copy menu item is pressed or the shortcut activated.  In this
 * case we take the PRIMARY selection, and set it as the NSPasteboard data.
 *
 * When an X11 client copies something to the CLIPBOARD, pbproxy greedily grabs
 * the data, sets it as the NSPasteboard data, and finally sets itself as 
 * owner of the CLIPBOARD.
 * 
 * When an X11 window is activated we check to see if the NSPasteboard has
 * changed.  If the NSPasteboard has changed, then we set pbproxy as owner
 * of the PRIMARY and CLIPBOARD and respond to requests for text and images.
 *
 * The behavior is now dynamic since the information above was written.
 * The behavior is now dependent on the pbproxy_prefs below.
 */

/*
 * TODO:
 * 1. handle MULTIPLE - I need to study the ICCCM further, and find a test app.
 * 2. Handle NSPasteboard updates immediately, not on active/inactive
 *    - Open xterm, run 'cat readme.txt | pbcopy'
 */

static struct {
    BOOL active ;
    BOOL primary_on_grab; /* This is provided as an option for people who
			   * want it and has issues that won't ever be
			   * addressed to make it *always* work.
			   */
    BOOL clipboard_to_pasteboard;
    BOOL pasteboard_to_primary;
    BOOL pasteboard_to_clipboard;
} pbproxy_prefs = { YES, NO, YES, YES, YES };

@implementation x_selection

static struct propdata null_propdata = {NULL, 0, 0};

#ifdef DEBUG
static void
dump_prefs (FILE *fp) {
    fprintf(fp, 
	    "pbproxy preferences:\n"
	    "\tactive %u\n"
	    "\tprimary_on_grab %u\n"
	    "\tclipboard_to_pasteboard %u\n"
	    "\tpasteboard_to_primary %u\n"
	    "\tpasteboard_to_clipboard %u\n",
	    pbproxy_prefs.active,
	    pbproxy_prefs.primary_on_grab,
	    pbproxy_prefs.clipboard_to_pasteboard,
	    pbproxy_prefs.pasteboard_to_primary,
	    pbproxy_prefs.pasteboard_to_clipboard);
}
#endif

extern CFStringRef app_prefs_domain_cfstr;

static BOOL
prefs_get_bool (CFStringRef key, BOOL defaultValue) {
    Boolean value, ok;
    
    value = CFPreferencesGetAppBooleanValue (key, app_prefs_domain_cfstr, &ok);
   
    return ok ? (BOOL) value : defaultValue;
}

static void
init_propdata (struct propdata *pdata)
{
    *pdata = null_propdata;
}

static void
free_propdata (struct propdata *pdata)
{
    free (pdata->data);
    *pdata = null_propdata;
}

/*
 * Return True if an error occurs.  Return False if pdata has data 
 * and we finished. 
 * The property is only deleted when bytesleft is 0 if delete is True.
 */
static Bool
get_property(Window win, Atom property, struct propdata *pdata, Bool delete, Atom *type) 
{
    long offset = 0;
    unsigned long numitems, bytesleft = 0;
#ifdef TEST
    /* This is used to test the growth handling. */
    unsigned long length = 4UL;
#else
    unsigned long length = (100000UL + 3) / 4; 
#endif
    unsigned char *buf = NULL, *chunk = NULL;
    size_t buflen = 0, chunkbytesize = 0;
    int format;

    TRACE ();
    
    if(None == property)
	return True;
    
    do 
    {
	unsigned long newbuflen = 0;
	unsigned char *newbuf = NULL;
	
#ifdef TEST   
	printf("bytesleft %lu\n", bytesleft);
#endif

	if (Success != XGetWindowProperty (xpbproxy_dpy, win, property,
					   offset, length, delete, 
					   AnyPropertyType,
					   type, &format, &numitems, 
					   &bytesleft, &chunk)) 
	{
	    DB ("Error while getting window property.\n");
	    *pdata = null_propdata;
	    free (buf);
	    return True;
	}
	
#ifdef TEST
	printf("format %d numitems %lu bytesleft %lu\n",
	       format, numitems, bytesleft);
	
	printf("type %s\n", XGetAtomName (xpbproxy_dpy, *type));
#endif
	
	/* Format is the number of bits. */
	chunkbytesize = numitems * (format / 8);

#ifdef TEST
	printf("chunkbytesize %zu\n", chunkbytesize);
#endif
 	newbuflen = buflen + chunkbytesize;
	if (newbuflen > 0) 
	{
	    newbuf = realloc (buf, newbuflen);
	    
	    if (NULL == newbuf)
	    {
		XFree (chunk);
		free (buf);
		return True;
	    }
	
	    memcpy (newbuf + buflen, chunk, chunkbytesize);
	    XFree (chunk);
	    buf = newbuf;
	    buflen = newbuflen;
	    /* offset is a multiple of 32 bits*/
	    offset += chunkbytesize / 4;
	} 
	else 
	{
	    if (chunk) 
		XFree (chunk);
	}
	
#ifdef TEST
	printf("bytesleft %lu\n", bytesleft);
#endif
    } while (bytesleft > 0);
    
    pdata->data = buf;
    pdata->length = buflen;
    pdata->format = format;

    return /*success*/ False;
}


/* Implementation methods */

/* This finds the preferred type from a TARGETS list.*/
- (Atom) find_preferred:(struct propdata *)pdata
{
    Atom a = None;
    size_t i, step;
    Bool png = False, jpeg = False, utf8 = False, string = False;

    TRACE ();

    if (pdata->format != 32)
    {
	fprintf(stderr, "Atom list is expected to be formatted as an array of 32bit values.\n");
	return None;
    }

    for (i = 0, step = pdata->format >> 3; i < pdata->length; i += step)
    {
	a = (Atom)*(uint32_t *)(pdata->data + i);

	if (a == atoms->image_png)
	{
	    png = True;
	}
	else if (a == atoms->image_jpeg)
	{
	    jpeg = True;
	}
	else if (a == atoms->utf8_string)
	{
	    utf8 = True;
        } 
	else if (a == atoms->string)
	{
	    string = True;
	}
	else
	{
	    char *type = XGetAtomName(xpbproxy_dpy, a);
	    if (type)
	    {
		DB("Unhandled X11 mime type: %s", type);
		XFree(type);
	    }
	}
    }

    /*We prefer PNG over strings, and UTF8 over a Latin-1 string.*/
    if (png)
	return atoms->image_png;

    if (jpeg)
	return atoms->image_jpeg;

    if (utf8)
	return atoms->utf8_string;

    if (string)
	return atoms->string;

    /* This is evidently something we don't know how to handle.*/
    return None;
}

/* Return True if this is an INCR-style transfer. */
- (Bool) is_incr_type:(XSelectionEvent *)e
{
    Atom seltype;
    int format;
    unsigned long numitems = 0UL, bytesleft = 0UL;
    unsigned char *chunk;
       
    TRACE ();

    if (Success != XGetWindowProperty (xpbproxy_dpy, e->requestor, e->property,
				       /*offset*/ 0L, /*length*/ 4UL,
				       /*Delete*/ False,
				       AnyPropertyType, &seltype, &format,
				       &numitems, &bytesleft, &chunk))
    {
	return False;
    }

    if(chunk)
	XFree(chunk);

    return (seltype == atoms->incr) ? True : False;
}

/* 
 * This should be called after a selection has been copied, 
 * or when the selection is unfinished before a transfer completes. 
 */
- (void) release_pending
{
    TRACE ();

    free_propdata (&pending.propdata);
    pending.requestor = None;
    pending.selection = None;
}

/* Return True if an error occurs during an append.*/
/* Return False if the append succeeds. */
- (Bool) append_to_pending:(struct propdata *)pdata requestor:(Window)requestor
{
    unsigned char *newdata;
    size_t newlength;
    
    TRACE ();
    
    if (requestor != pending.requestor)
    {
	[self release_pending];
	pending.requestor = requestor;
    }
	
    newlength = pending.propdata.length + pdata->length;
    newdata = realloc(pending.propdata.data, newlength);

    if(NULL == newdata) 
    {
	perror("realloc propdata");
	[self release_pending];
        return True;
    }

    memcpy(newdata + pending.propdata.length, pdata->data, pdata->length);
    pending.propdata.data = newdata;
    pending.propdata.length = newlength;
    
    return False;
}



/* Called when X11 becomes active (i.e. has key focus) */
- (void) x_active:(Time)timestamp
{
    static NSInteger changeCount;
    NSInteger countNow;
    NSPasteboard *pb;

    TRACE ();

    pb = [NSPasteboard generalPasteboard];

    if (nil == pb)
	return;

    countNow = [pb changeCount];

    if (countNow != changeCount)
    {
        DB ("changed pasteboard!\n");
        changeCount = countNow;
        
        if (pbproxy_prefs.pasteboard_to_primary)
        {
            XSetSelectionOwner (xpbproxy_dpy, atoms->primary, _selection_window, CurrentTime);
        }
        
        if (pbproxy_prefs.pasteboard_to_clipboard) {
            [self own_clipboard];
        }
    }

#if 0
	/*gstaplin: we should perhaps investigate something like this branch above...*/
	if ([_pasteboard availableTypeFromArray: _known_types] != nil)
	{
	    /* Pasteboard has data we should proxy; I think it makes
	       sense to put it on both CLIPBOARD and PRIMARY */

	    XSetSelectionOwner (xpbproxy_dpy, atoms->clipboard,
				_selection_window, timestamp);
	    XSetSelectionOwner (xpbproxy_dpy, atoms->primary,
				_selection_window, timestamp);
	}
#endif
}

/* Called when X11 loses key focus */
- (void) x_inactive:(Time)timestamp
{
    TRACE ();
}

/* This requests the TARGETS list from the PRIMARY selection owner. */
- (void) x_copy_request_targets
{
    TRACE ();

    request_atom = atoms->targets;
    XConvertSelection (xpbproxy_dpy, atoms->primary, atoms->targets,
		       atoms->primary, _selection_window, CurrentTime);
}

/* Called when the Edit/Copy item on the main X11 menubar is selected
 * and no appkit window claims it. */
- (void) x_copy:(Time)timestamp
{
    Window w;

    TRACE ();

    w = XGetSelectionOwner (xpbproxy_dpy, atoms->primary);

    if (None != w)
    {
	++pending_copy;
	
	if (1 == pending_copy) {
	    /*
	     * There are no other copy operations in progress, so we
	     * can proceed safely.  Otherwise the copy_completed method
	     * will see that the pending_copy is > 1, and do another copy.
	     */	    
	    [self x_copy_request_targets];
	}
    }
}

/* Set pbproxy as owner of the SELECTION_MANAGER selection.
 * This prevents tools like xclipboard from causing havoc.
 * Returns TRUE on success
 */
- (BOOL) set_clipboard_manager_status:(BOOL)value
{
    TRACE ();

    Window owner = XGetSelectionOwner (xpbproxy_dpy, atoms->clipboard_manager);

    if(value) {
        if(owner == _selection_window)
            return TRUE;

        if(owner != None) {
            fprintf (stderr, "A clipboard manager using window 0x%lx "
		     "already owns the clipboard selection.  "
		     "pbproxy will not sync clipboard to pasteboard.\n", owner);
            return FALSE;
        }
        
        XSetSelectionOwner(xpbproxy_dpy, atoms->clipboard_manager, _selection_window, CurrentTime);
        return (_selection_window == XGetSelectionOwner(xpbproxy_dpy, atoms->clipboard_manager));
    } else {
        if(owner != _selection_window)
            return TRUE;

        XSetSelectionOwner(xpbproxy_dpy, atoms->clipboard_manager, None, CurrentTime);
        return(None == XGetSelectionOwner(xpbproxy_dpy, atoms->clipboard_manager));
    }
    
    return FALSE;
}

/*
 * This occurs when we previously owned a selection, 
 * and then lost it from another client.
 */
- (void) clear_event:(XSelectionClearEvent *)e
{
    

    TRACE ();
        
    DB ("e->selection %s\n", XGetAtomName (xpbproxy_dpy, e->selection));
    
    if(e->selection == atoms->clipboard) {
        /* 
         * We lost ownership of the CLIPBOARD.
         */
        ++pending_clipboard;
        
        if (1 == pending_clipboard) {
            /* Claim the clipboard contents from the new owner. */
            [self claim_clipboard];
        }
    } else if(e->selection == atoms->clipboard_manager) {
        if(pbproxy_prefs.clipboard_to_pasteboard) {
            /* Another CLIPBOARD_MANAGER has set itself as owner.  Disable syncing
             * to avoid a race.
             */
            fprintf(stderr, "Another clipboard manager was started!  "
		    "xpbproxy is disabling syncing with clipboard.\n"); 
            pbproxy_prefs.clipboard_to_pasteboard = NO;
        }
    }
}

/* 
 * We greedily acquire the clipboard after it changes, and on startup.
 */
- (void) claim_clipboard
{
    Window owner;
    
    TRACE ();
    
    if (!pbproxy_prefs.clipboard_to_pasteboard)
        return;
    
    owner = XGetSelectionOwner (xpbproxy_dpy, atoms->clipboard);
    if (None == owner) {
        /*
         * The owner probably died or we are just starting up pbproxy.
         * Set pbproxy's _selection_window as the owner, and continue.
         */
        DB ("No clipboard owner.\n");
        [self copy_completed:atoms->clipboard];
        return;
    } else if (owner == _selection_window) {
        [self copy_completed:atoms->clipboard];
        return;
    }
    
    DB ("requesting targets\n");
    
    request_atom = atoms->targets;
    XConvertSelection (xpbproxy_dpy, atoms->clipboard, atoms->targets,
                       atoms->clipboard, _selection_window, CurrentTime);
    XFlush (xpbproxy_dpy);
    /* Now we will get a SelectionNotify event in the future. */
}

/* Greedily acquire the clipboard. */
- (void) own_clipboard
{

    TRACE ();

    /* We should perhaps have a boundary limit on the number of iterations... */
    do 
    {
	XSetSelectionOwner (xpbproxy_dpy, atoms->clipboard, _selection_window,
			    CurrentTime);
    } while (_selection_window != XGetSelectionOwner (xpbproxy_dpy,
						      atoms->clipboard));
}

- (void) init_reply:(XEvent *)reply request:(XSelectionRequestEvent *)e
{
    reply->xselection.type = SelectionNotify;
    reply->xselection.selection = e->selection;
    reply->xselection.target = e->target;
    reply->xselection.requestor = e->requestor;
    reply->xselection.time = e->time;
    reply->xselection.property = None; 
}

- (void) send_reply:(XEvent *)reply
{
    /*
     * We are supposed to use an empty event mask, and not propagate
     * the event, according to the ICCCM.
     */
    DB ("reply->xselection.requestor 0x%lx\n", reply->xselection.requestor);
  
    XSendEvent (xpbproxy_dpy, reply->xselection.requestor, False, 0, reply);
    XFlush (xpbproxy_dpy);
}

/* 
 * This responds to a TARGETS request.
 * The result is a list of a ATOMs that correspond to the types available
 * for a selection.  
 * For instance an application might provide a UTF8_STRING and a STRING
 * (in Latin-1 encoding).  The requestor can then make the choice based on
 * the list.
 */
- (void) send_targets:(XSelectionRequestEvent *)e pasteboard:(NSPasteboard *)pb
{
    XEvent reply;
    NSArray *pbtypes;

    [self init_reply:&reply request:e];

    pbtypes = [pb types];
    if (pbtypes)
    {
	long list[7]; /* Don't forget to increase this if we handle more types! */
        long count = 0;
 	
	/*
	 * I'm not sure if this is needed, but some toolkits/clients list 
	 * TARGETS in response to targets. 
	 */
	list[count] = atoms->targets;
	++count;

	if ([pbtypes containsObject:NSStringPboardType])
	{
	    /* We have a string type that we can convert to UTF8, or Latin-1... */
	    DB ("NSStringPboardType\n");
	    list[count] = atoms->utf8_string;
	    ++count;
	    list[count] = atoms->string;
	    ++count;
	    list[count] = atoms->compound_text;
	    ++count;
	}

	/* TODO add the NSPICTPboardType back again, once we have conversion
	 * functionality in send_image.
	 */

	if ([pbtypes containsObject:NSPICTPboardType] 
	    || [pbtypes containsObject:NSTIFFPboardType]) 
	{
	    /* We can convert a TIFF to a PNG or JPEG. */
	    DB ("NSTIFFPboardType\n");
	    list[count] = atoms->image_png;
	    ++count;
	    list[count] = atoms->image_jpeg;
	    ++count;
	} 

	if (count)
	{
	    /* We have a list of ATOMs to send. */
	    XChangeProperty (xpbproxy_dpy, e->requestor, e->property, atoms->atom, 32,
			 PropModeReplace, (unsigned char *) list, count);
	    
	    reply.xselection.property = e->property;
	}
    }

    [self send_reply:&reply];
}


- (void) send_string:(XSelectionRequestEvent *)e utf8:(BOOL)utf8 pasteboard:(NSPasteboard *)pb
{
    XEvent reply;
    NSArray *pbtypes;
    NSString *data;
    const char *bytes;
    NSUInteger length;

    TRACE ();

    [self init_reply:&reply request:e];

    pbtypes = [pb types];
 
    if (![pbtypes containsObject:NSStringPboardType])
    {
	[self send_reply:&reply];
	return;
    }

    DB ("pbtypes retainCount after containsObject: %u\n", [pbtypes retainCount]);

    data = [pb stringForType:NSStringPboardType];

    if (nil == data)
    {
	[self send_reply:&reply];
	return;
    }

    if (utf8) 
    {
	bytes = [data UTF8String];
	/*
	 * We don't want the UTF-8 string length here.  
	 * We want the length in bytes.
	 */
	length = strlen (bytes);
	
	if (length < 50) {
	    DB ("UTF-8: %s\n", bytes);
	    DB ("UTF-8 length: %u\n", length); 
	}
    } 
    else 
    {
	DB ("Latin-1\n");
	bytes = [data cStringUsingEncoding:NSISOLatin1StringEncoding];
	/*WARNING: bytes is not NUL-terminated. */
	length = [data lengthOfBytesUsingEncoding:NSISOLatin1StringEncoding];
    }

    DB ("e->target %s\n", XGetAtomName (xpbproxy_dpy, e->target));
    
    XChangeProperty (xpbproxy_dpy, e->requestor, e->property, e->target,
		     8, PropModeReplace, (unsigned char *) bytes, length);
    
    reply.xselection.property = e->property;

    [self send_reply:&reply];
}

- (void) send_compound_text:(XSelectionRequestEvent *)e pasteboard:(NSPasteboard *)pb
{
    XEvent reply;
    NSArray *pbtypes;
    
    TRACE ();
    
    [self init_reply:&reply request:e];
     
    pbtypes = [pb types];

    if ([pbtypes containsObject: NSStringPboardType])
    {
	NSString *data = [pb stringForType:NSStringPboardType];
	if (nil != data)
	{
	    /*
	     * Cast to (void *) to avoid a const warning. 
	     * AFAIK Xutf8TextListToTextProperty does not modify the input memory.
	     */
	    void *utf8 = (void *)[data UTF8String];
	    char *list[] = { utf8, NULL };
	    XTextProperty textprop;
	    
	    textprop.value = NULL;

	    if (Success == Xutf8TextListToTextProperty (xpbproxy_dpy, list, 1,
							XCompoundTextStyle,
							&textprop))
	    {
		
		if (8 != textprop.format)
		    DB ("textprop.format is unexpectedly not 8 - it's %d instead\n",
			textprop.format);

		XChangeProperty (xpbproxy_dpy, e->requestor, e->property, 
				 atoms->compound_text, textprop.format, 
				 PropModeReplace, textprop.value,
				 textprop.nitems);
		
		reply.xselection.property = e->property;
	    }

	    if (textprop.value)
 		XFree (textprop.value);

	}
    }
    
    [self send_reply:&reply];
}

/* Finding a test application that uses MULTIPLE has proven to be difficult. */
- (void) send_multiple:(XSelectionRequestEvent *)e
{
    XEvent reply;

    TRACE ();

    [self init_reply:&reply request:e];

    if (None != e->property) 
    {
	
    }
    
    [self send_reply:&reply];
}

/* Return nil if an error occured. */
/* DO NOT retain the encdata for longer than the length of an event response.  
 * The autorelease pool will reuse/free it.
 */ 
- (NSData *) encode_image_data:(NSData *)data type:(NSBitmapImageFileType)enctype
{
    NSBitmapImageRep *bmimage = nil; 
    NSData *encdata = nil;
    NSDictionary *dict = nil;

    bmimage = [[NSBitmapImageRep alloc] initWithData:data];

    if (nil == bmimage)
	return nil;

    dict = [[NSDictionary alloc] init];
    encdata = [bmimage representationUsingType:enctype properties:dict];

    if (nil == encdata)
    {
	[dict autorelease];
	[bmimage autorelease];
	return nil;
    }
    
    [dict autorelease];
    [bmimage autorelease];

    return encdata;
}

/* Return YES when an error has occured when trying to send the PICT. */
/* The caller should send a default reponse with a property of None when an error occurs. */
- (BOOL) send_image_pict_reply:(XSelectionRequestEvent *)e 
		    pasteboard:(NSPasteboard *)pb 
			  type:(NSBitmapImageFileType)imagetype
{
    XEvent reply;
    NSImage *img = nil;
    NSData *data = nil, *encdata = nil;
    NSUInteger length;
    const void *bytes = NULL;
    
    img = [[NSImage alloc] initWithPasteboard:pb];

    if (nil == img) 
    {
	return YES;
    }
	    
    data = [img TIFFRepresentation];

    if (nil == data)
    {
	[img autorelease];
	fprintf(stderr, "unable to convert PICT to TIFF!\n");
	return YES;
    }
        
    encdata = [self encode_image_data:data type:imagetype];
    if(nil == encdata)
    {
	[img autorelease];
	return YES;
    }

    [self init_reply:&reply request:e];

    length = [encdata length];
    bytes = [encdata bytes];
    
    XChangeProperty (xpbproxy_dpy, e->requestor, e->property, e->target,
		     8, PropModeReplace, bytes, length);
    reply.xselection.property = e->property;

    [self send_reply:&reply];

    [img autorelease];

    return NO; /*no error*/
}

/* Return YES if an error occured. */
/* The caller should send a reply with a property of None when an error occurs. */
- (BOOL) send_image_tiff_reply:(XSelectionRequestEvent *)e
		    pasteboard:(NSPasteboard *)pb 
			  type:(NSBitmapImageFileType)imagetype
{
    XEvent reply;
    NSData *data = nil;
    NSData *encdata = nil;
    NSUInteger length;
    const void *bytes = NULL;

    data = [pb dataForType:NSTIFFPboardType];

    if (nil == data)
 	return YES;
  
    encdata = [self encode_image_data:data type:imagetype];

    if(nil == encdata)
	return YES;

    [self init_reply:&reply request:e];

    length = [encdata length];
    bytes = [encdata bytes];
    
    XChangeProperty (xpbproxy_dpy, e->requestor, e->property, e->target,
		     8, PropModeReplace, bytes, length);
    reply.xselection.property = e->property;
    
    [self send_reply:&reply];

    return NO; /*no error*/
}

- (void) send_image:(XSelectionRequestEvent *)e pasteboard:(NSPasteboard *)pb
{
    NSArray *pbtypes = nil;
    NSBitmapImageFileType imagetype = NSPNGFileType;

    TRACE ();

    if (e->target == atoms->image_png)
	imagetype = NSPNGFileType;
    else if (e->target == atoms->image_jpeg)
	imagetype = NSJPEGFileType;
    else 
    {
	fprintf(stderr, "internal failure in xpbproxy!  imagetype being sent isn't PNG or JPEG.\n");
    }

    pbtypes = [pb types];

    if (pbtypes) 
    {
	if ([pbtypes containsObject:NSTIFFPboardType])
	{
	    if (NO == [self send_image_tiff_reply:e pasteboard:pb type:imagetype]) 
	  	return;
	} 
     	else if ([pbtypes containsObject:NSPICTPboardType])
	{
	    if (NO == [self send_image_pict_reply:e pasteboard:pb type:imagetype]) 
		return;

	    /* Fall through intentionally to the send_none: */
	}
    }

    [self send_none:e];
}

- (void)send_none:(XSelectionRequestEvent *)e
{
    XEvent reply;

    TRACE ();

    [self init_reply:&reply request:e];
    [self send_reply:&reply];
}


/* Another client requested the data or targets of data available from the clipboard. */
- (void)request_event:(XSelectionRequestEvent *)e
{
    NSPasteboard *pb;

    TRACE ();

    /* TODO We should also keep track of the time of the selection, and 
     * according to the ICCCM "refuse the request" if the event timestamp
     * is before we owned it.
     * What should we base the time on?  How can we get the current time just
     * before an XSetSelectionOwner?  Is it the server's time, or the clients?
     * According to the XSelectionRequestEvent manual page, the Time value
     * may be set to CurrentTime or a time, so that makes it a bit different.
     * Perhaps we should just punt and ignore races.
     */

    /*TODO we need a COMPOUND_TEXT test app*/
    /*TODO we need a MULTIPLE test app*/

    pb = [NSPasteboard generalPasteboard];
    if (nil == pb) 
    {
	[self send_none:e];
	return;
    }
    

    if (None != e->target)
	DB ("e->target %s\n", XGetAtomName (xpbproxy_dpy, e->target));

    if (e->target == atoms->targets) 
    {
	/* The paste requestor wants to know what TARGETS we support. */
	[self send_targets:e pasteboard:pb];
    }
    else if (e->target == atoms->multiple)
    {
	/*
	 * This isn't finished, and may never be, unless I can find 
	 * a good test app.
	 */
	[self send_multiple:e];
    } 
    else if (e->target == atoms->utf8_string)
    {
	[self send_string:e utf8:YES pasteboard:pb];
    } 
    else if (e->target == atoms->string)
    {
	[self send_string:e utf8:NO pasteboard:pb];
    }
    else if (e->target == atoms->compound_text)
    {
	[self send_compound_text:e pasteboard:pb];
    }
    else if (e->target == atoms->multiple)
    {
	[self send_multiple:e];
    }
    else if (e->target == atoms->image_png || e->target == atoms->image_jpeg)
    {
	[self send_image:e pasteboard:pb];
    }
    else
    {
	[self send_none:e];
    }
}

/* This handles the events resulting from an XConvertSelection request. */
- (void) notify_event:(XSelectionEvent *)e
{
    Atom type;
    struct propdata pdata;
	
    TRACE ();

    [self release_pending];
 
    if (None == e->property) {
	DB ("e->property is None.\n");
	[self copy_completed:e->selection];
	/* Nothing is selected. */
	return;
    }

#if 0
    printf ("e->selection %s\n", XGetAtomName (xpbproxy_dpy, e->selection));
    printf ("e->property %s\n", XGetAtomName (xpbproxy_dpy, e->property));
#endif

    if ([self is_incr_type:e]) 
    {
	/*
	 * This is an INCR-style transfer, which means that we 
	 * will get the data after a series of PropertyNotify events.
	 */
	DB ("is INCR\n");

	if (get_property (e->requestor, e->property, &pdata, /*Delete*/ True, &type)) 
	{
	    /* 
	     * An error occured, so we should invoke the copy_completed:, but
	     * not handle_selection:type:propdata:
	     */
	    [self copy_completed:e->selection];
	    return;
	}

	free_propdata (&pdata);

      	pending.requestor = e->requestor;
	pending.selection = e->selection;

	DB ("set pending.requestor to 0x%lx\n", pending.requestor);
    }
    else
    {
	if (get_property (e->requestor, e->property, &pdata, /*Delete*/ True, &type))
	{
	    [self copy_completed:e->selection];
	    return;
	}

	/* We have the complete selection data.*/
	[self handle_selection:e->selection type:type propdata:&pdata];
	
	DB ("handled selection with the first notify_event\n");
    }
}

/* This is used for INCR transfers.  See the ICCCM for the details. */
/* This is used to retrieve PRIMARY and CLIPBOARD selections. */
- (void) property_event:(XPropertyEvent *)e
{
    struct propdata pdata;
    Atom type;

    TRACE ();
    
    if (None != e->atom) 
    {
#ifdef DEBUG
	char *name = XGetAtomName (xpbproxy_dpy, e->atom);

	if (name) 
	{
	    DB ("e->atom %s\n", name);
	    XFree(name);
	}
#endif
    }

    if (None != pending.requestor && PropertyNewValue == e->state) 
    {
	DB ("pending.requestor 0x%lx\n", pending.requestor);

	if (get_property (e->window, e->atom, &pdata, /*Delete*/ True, &type))
        {
	    [self copy_completed:pending.selection];
	    [self release_pending];
	    return;
	}

	if (0 == pdata.length) 
	{
	    /*
	     * We completed the transfer.
	     * handle_selection will call copy_completed: for us.
	     */
	    [self handle_selection:pending.selection type:type propdata:&pending.propdata];
	    free_propdata(&pdata);
	    pending.propdata = null_propdata;
	    pending.requestor = None;
	    pending.selection = None;
	}
	else 
	{
	    [self append_to_pending:&pdata requestor:e->window];
	    free_propdata (&pdata);
	}
    }
}

- (void) xfixes_selection_notify:(XFixesSelectionNotifyEvent *)e {
    if(!pbproxy_prefs.active)
        return;
    
    switch(e->subtype) {              
        case XFixesSetSelectionOwnerNotify:
            if(e->selection == atoms->primary && pbproxy_prefs.primary_on_grab)
                [self x_copy:e->timestamp];
            break;
                
        case XFixesSelectionWindowDestroyNotify:
        case XFixesSelectionClientCloseNotify:
        default:
            fprintf(stderr, "Unhandled XFixesSelectionNotifyEvent: subtype=%d\n", e->subtype);
            break;
    }
}

- (void) handle_targets: (Atom)selection propdata:(struct propdata *)pdata
{
    /* Find a type we can handle and prefer from the list of ATOMs. */
    Atom preferred;
    char *name;

    TRACE ();

    preferred = [self find_preferred:pdata];
    
    if (None == preferred) 
    {
	/* 
	 * This isn't required by the ICCCM, but some apps apparently 
	 * don't respond to TARGETS properly.
	 */
	preferred = atoms->string;
    }

    (void)name; /* Avoid a warning with non-debug compiles. */
#ifdef DEBUG
    name = XGetAtomName (xpbproxy_dpy, preferred);

    if (name)
    {
	DB ("requesting %s\n", name);
    }
#endif
    request_atom = preferred;
    XConvertSelection (xpbproxy_dpy, selection, preferred, selection,
		       _selection_window, CurrentTime);    
}

/* This handles the image type of selection (typically in CLIPBOARD). */
/* We convert to a TIFF, so that other applications can paste more easily. */
- (void) handle_image: (struct propdata *)pdata pasteboard:(NSPasteboard *)pb
{
    NSArray *pbtypes;
    NSUInteger length;
    NSData *data, *tiff;
    NSBitmapImageRep *bmimage;

    TRACE ();

    length = pdata->length;
    data = [[NSData alloc] initWithBytes:pdata->data length:length];

    if (nil == data)
    {
	DB ("unable to create NSData object!\n");
	return;
    }

    DB ("data retainCount before NSBitmapImageRep initWithData: %u\n",
	[data retainCount]);

    bmimage = [[NSBitmapImageRep alloc] initWithData:data];

    if (nil == bmimage)
    {
	[data autorelease];
	DB ("unable to create NSBitmapImageRep!\n");
	return;
    }

    DB ("data retainCount after NSBitmapImageRep initWithData: %u\n", 
	[data retainCount]);

    @try 
    {
	tiff = [bmimage TIFFRepresentation];
    }

    @catch (NSException *e) 
    {
	DB ("NSTIFFException!\n");
	[data autorelease];
	[bmimage autorelease];
	return;
    }
    
    DB ("bmimage retainCount after TIFFRepresentation %u\n", [bmimage retainCount]);

    pbtypes = [NSArray arrayWithObjects:NSTIFFPboardType, nil];

    if (nil == pbtypes)
    {
	[data autorelease];
	[bmimage autorelease];
	return;
    }

    [pb declareTypes:pbtypes owner:nil];
    if (YES != [pb setData:tiff forType:NSTIFFPboardType])
    {
	DB ("writing pasteboard data failed!\n");
    }

    [data autorelease];

    DB ("bmimage retainCount before release %u\n", [bmimage retainCount]);
    [bmimage autorelease];
}

/* This handles the UTF8_STRING type of selection. */
- (void) handle_utf8_string:(struct propdata *)pdata pasteboard:(NSPasteboard *)pb
{
    NSString *string;
    NSArray *pbtypes;
 
    TRACE ();

    string = [[NSString alloc] initWithBytes:pdata->data length:pdata->length encoding:NSUTF8StringEncoding];
 
    if (nil == string)
	return;

    pbtypes = [NSArray arrayWithObjects:NSStringPboardType, nil];

    if (nil == pbtypes)
    {
	[string autorelease];
	return;	
    }

    [pb declareTypes:pbtypes owner:nil];
    
    if (YES != [pb setString:string forType:NSStringPboardType]) {
	fprintf(stderr, "pasteboard setString:forType: failed!\n");
    }
    [string autorelease];
    DB ("done handling utf8 string\n");
}

/* This handles the STRING type, which should be in Latin-1. */
- (void) handle_string: (struct propdata *)pdata pasteboard:(NSPasteboard *)pb
{
    NSString *string; 
    NSArray *pbtypes;

    TRACE ();

    string = [[NSString alloc] initWithBytes:pdata->data length:pdata->length encoding:NSISOLatin1StringEncoding];
    
    if (nil == string)
	return;

    pbtypes = [NSArray arrayWithObjects:NSStringPboardType, nil];

    if (nil == pbtypes)
    {
	[string autorelease];
	return;
    }

    [pb declareTypes:pbtypes owner:nil];
    if (YES != [pb setString:string forType:NSStringPboardType]) {
	fprintf(stderr, "pasteboard setString:forType failed in handle_string!\n");
    }
    [string autorelease];
}

/* This is called when the selection is completely retrieved from another client. */
/* Warning: this frees the propdata. */
- (void) handle_selection:(Atom)selection type:(Atom)type propdata:(struct propdata *)pdata
{
    NSPasteboard *pb;

    TRACE ();

    pb = [NSPasteboard generalPasteboard];

    if (nil == pb) 
    {
	[self copy_completed:selection];
	free_propdata (pdata);
	return;
    }

    /*
     * Some apps it seems set the type to TARGETS instead of ATOM, such as Eterm.
     * These aren't ICCCM compliant apps, but we need these to work... 
     */
    if (request_atom == atoms->targets
	&& (type == atoms->atom || type == atoms->targets))
    {
	[self handle_targets:selection propdata:pdata];
	free_propdata(pdata);
	return;
    } 
    else if (type == atoms->image_png)
    {
	[self handle_image:pdata pasteboard:pb];
    } 
    else if (type == atoms->image_jpeg)
    {
	[self handle_image:pdata pasteboard:pb];
    }
    else if (type == atoms->utf8_string) 
    {
	[self handle_utf8_string:pdata pasteboard:pb];
    } 
    else if (type == atoms->string)
    {
	[self handle_string:pdata pasteboard:pb];
    } 
   
    free_propdata(pdata);

    [self copy_completed:selection];
}


- (void) copy_completed:(Atom)selection
{
    TRACE ();
    char *name;

    (void)name; /* Avoid warning with non-debug compiles. */
#ifdef DEBUG
    name = XGetAtomName (xpbproxy_dpy, selection);
    if (name)
    {
	DB ("copy_completed: %s\n", name);
	XFree (name);
    }
#endif

    if (selection == atoms->primary && pending_copy > 0)
    {
	--pending_copy;
	if (pending_copy > 0)
	{
	    /* Copy PRIMARY again. */
	    [self x_copy_request_targets];
	    return;
	}
    }
    else if (selection == atoms->clipboard && pending_clipboard > 0) 
    {
	--pending_clipboard;
	if (pending_clipboard > 0) 
	{
	    /* Copy CLIPBOARD. */
	    [self claim_clipboard];
	    return;
	} 
	else 
	{
	    /* We got the final data.  Now set pbproxy as the owner. */
	    [self own_clipboard];
	    return;
	}
    }
    
    /* 
     * We had 1 or more primary in progress, and the clipboard arrived
     * while we were busy. 
     */
    if (pending_clipboard > 0)
    {
	[self claim_clipboard];
    }
}

- (void) reload_preferences
{
    /*
     * It's uncertain how we could handle the synchronization failing, so cast to void.
     * The prefs_get_bool should fall back to defaults if the org.x.X11 plist doesn't exist or is invalid.
     */
    (void)CFPreferencesAppSynchronize(app_prefs_domain_cfstr);
#ifdef STANDALONE_XPBPROXY
    if(xpbproxy_is_standalone)
        pbproxy_prefs.active = YES;
    else
#endif
    pbproxy_prefs.active = prefs_get_bool(CFSTR("sync_pasteboard"), pbproxy_prefs.active);
    pbproxy_prefs.primary_on_grab = prefs_get_bool(CFSTR("sync_primary_on_select"), pbproxy_prefs.primary_on_grab);
    pbproxy_prefs.clipboard_to_pasteboard = prefs_get_bool(CFSTR("sync_clipboard_to_pasteboard"), pbproxy_prefs.clipboard_to_pasteboard);
    pbproxy_prefs.pasteboard_to_primary = prefs_get_bool(CFSTR("sync_pasteboard_to_primary"), pbproxy_prefs.pasteboard_to_primary);
    pbproxy_prefs.pasteboard_to_clipboard =  prefs_get_bool(CFSTR("sync_pasteboard_to_clipboard"), pbproxy_prefs.pasteboard_to_clipboard);

    /* This is used for debugging. */
    //dump_prefs(stdout);

    if(pbproxy_prefs.active && pbproxy_prefs.primary_on_grab && !xpbproxy_have_xfixes) {
        fprintf(stderr, "Disabling sync_primary_on_select functionality due to missing XFixes extension.\n");
        pbproxy_prefs.primary_on_grab = NO;
    }

    /* Claim or release the CLIPBOARD_MANAGER atom */
    if(![self set_clipboard_manager_status:(pbproxy_prefs.active && pbproxy_prefs.clipboard_to_pasteboard)])
        pbproxy_prefs.clipboard_to_pasteboard = NO;
    
    if(pbproxy_prefs.active && pbproxy_prefs.clipboard_to_pasteboard)
        [self claim_clipboard];
}

- (BOOL) is_active 
{
    return pbproxy_prefs.active;
}

/* NSPasteboard-required methods */

- (void) paste:(id)sender
{
    TRACE ();
}

- (void) pasteboard:(NSPasteboard *)pb provideDataForType:(NSString *)type
{
    TRACE ();
}

- (void) pasteboardChangedOwner:(NSPasteboard *)pb
{
    TRACE ();

    /* Right now we don't care with this. */
}

/* Allocation */

- init
{
    unsigned long pixel;

    self = [super init];
    if (self == nil)
	return nil;

    atoms->primary = XInternAtom (xpbproxy_dpy, "PRIMARY", False);
    atoms->clipboard = XInternAtom (xpbproxy_dpy, "CLIPBOARD", False);
    atoms->text = XInternAtom (xpbproxy_dpy, "TEXT", False);
    atoms->utf8_string = XInternAtom (xpbproxy_dpy, "UTF8_STRING", False);
    atoms->string = XInternAtom (xpbproxy_dpy, "STRING", False);
    atoms->targets = XInternAtom (xpbproxy_dpy, "TARGETS", False);
    atoms->multiple = XInternAtom (xpbproxy_dpy, "MULTIPLE", False);
    atoms->cstring = XInternAtom (xpbproxy_dpy, "CSTRING", False);
    atoms->image_png = XInternAtom (xpbproxy_dpy, "image/png", False);
    atoms->image_jpeg = XInternAtom (xpbproxy_dpy, "image/jpeg", False);
    atoms->incr = XInternAtom (xpbproxy_dpy, "INCR", False);
    atoms->atom = XInternAtom (xpbproxy_dpy, "ATOM", False);
    atoms->clipboard_manager = XInternAtom (xpbproxy_dpy, "CLIPBOARD_MANAGER", False);
    atoms->compound_text = XInternAtom (xpbproxy_dpy, "COMPOUND_TEXT", False);
    atoms->atom_pair = XInternAtom (xpbproxy_dpy, "ATOM_PAIR", False);

    pixel = BlackPixel (xpbproxy_dpy, DefaultScreen (xpbproxy_dpy));
    _selection_window = XCreateSimpleWindow (xpbproxy_dpy, DefaultRootWindow (xpbproxy_dpy),
					     0, 0, 1, 1, 0, pixel, pixel);

    /* This is used to get PropertyNotify events when doing INCR transfers. */
    XSelectInput (xpbproxy_dpy, _selection_window, PropertyChangeMask);

    request_atom = None;

    init_propdata (&pending.propdata);
    pending.requestor = None;
    pending.selection = None;

    pending_copy = 0;
    pending_clipboard = 0;

    if(xpbproxy_have_xfixes)
        XFixesSelectSelectionInput(xpbproxy_dpy, _selection_window, atoms->primary, 
                                   XFixesSetSelectionOwnerNotifyMask);

    [self reload_preferences];
    
    return self;
}

- (void) dealloc
{
    if (None != _selection_window)
    {
	XDestroyWindow (xpbproxy_dpy, _selection_window);
	_selection_window = None;
    }

    free_propdata (&pending.propdata);

    [super dealloc];
}

@end