#include	<stdio.h>
#include	<stdlib.h>
#include	<string.h>
#include	<sys/fcntl.h>
#include	<unistd.h>
#include	<yz/window.h>
#include	<yz/draw.h>
#include	<yzuitk/menu.h>
#include	<yzuitk/scrollbar.h>
#include	"lkb-avm.h"
#include	"lkb-protocol.h"
#include	"embedded-view.h"
#include	<sys/time.h>
#include	"gc-list.h"

// feature structure visualization

int		init_avm_view(embedded_view_t	*view, int	id, lkb_avm	*avm, lui_list	*failures);
void	update_avm(embedded_view_t	*view, int	x1, int	y1, int	x2, int	y2);
void	event_avm(embedded_view_t	*view, event_t	ev);
void	postscript_avm(embedded_view_t	*view);
void	latex_avm(embedded_view_t	*view);
void	close_avm_view(embedded_view_t	*view);
void	mouse_avm(embedded_view_t	*view, int	x, int	y);

embedded_view_t	prototype_avm_view = {
		init:	init_avm_view,
		update:	update_avm,
		event:	event_avm,
		postscript: postscript_avm,
		latex:	latex_avm,
		close:	close_avm_view,
		mouse_moved: mouse_avm, };

struct avm_view_data
{
	void		*selected_avm;
	char		*moused_tag;
	char		*shown_path;
	int			id;
	int			dirty;
	lkb_avm		*avm;
	gc_list		gcl;
	int			fail_idx;
	lui_list	*failures;
};

lkb_avm_tag	*find_tag_usage(lkb_avm	*avm, char	*name, lkb_avm_tag	**start, int	*tt, void	**refer, int	*listoff);

extern void	*hilite_avm;
extern char	*hilite_tag;
extern char *empty_list_type;
extern gc_list	*target_gcl;

extern int	GC_ONLY_TAGS;

int	current_offset_x, current_offset_y;

void	render_avm_item(lkb_avm	*t, int	what, int	*DY, int	*DX,
							int	display, lkb_avm_tag	*tag);

#define	tvdata	((struct avm_view_data*)view->private)

int	avm_margin = 20;

font_info	avm_bar_font = {"helvetica", 12, fsRoman, {0,0,0}, 0};
extern font_info	tag_display_font;

int	init_avm_view(embedded_view_t	*view, int	id, lkb_avm	*avm, lui_list	*failures)
{
	int			now_avm_width=0, now_avm_height=0;
	int			i;

	view->private = calloc(1, sizeof(*tvdata));
	tvdata->avm = avm;
	if(!tvdata->avm)
	{
		fprintf(stderr, "Error: tried to browse a NULL avm structure!\n");
		free(tvdata);
		return -1;
	}
	tvdata->id = id;
	tvdata->selected_avm = 0;
	tvdata->shown_path = 0;
	tvdata->moused_tag = 0;
	tvdata->gcl.ngc = 0;
	tvdata->gcl.gc = 0;
	tvdata->gcl.scale = 1.0;
	tvdata->fail_idx = -1;
	tvdata->failures = failures;

	if(failures)
	{
		//printf("browsing an avm with %d failures\n", failures->length);
		for(i=0;i<failures->length;i++)
			if(record_failure(avm, failures->data[i]))
			{
				fprintf(stderr, "Error: unable to make sense of failure record\n");
				free(tvdata);
				return -1;
			}
	}

	current_offset_x = current_offset_y = avm_margin;
	hilite_avm = tvdata->selected_avm;
	reset_gc_list(&tvdata->gcl);
	target_gcl = &tvdata->gcl;
	render_avm_item(tvdata->avm, avm_structure,
					&now_avm_height, &now_avm_width, 1, 0);
	tvdata->dirty = 0;

	now_avm_width += avm_margin*2;
	now_avm_height += avm_margin*2;

	view->width = now_avm_width;
	view->height = now_avm_height;

	return 0;
}

void	prescroll_avm_view(embedded_view_t	*view)
{
	lkb_failure	*fail;

	if(!tvdata->failures || !tvdata->failures->length)return;
	fail = tvdata->failures->data[0];
	scroll_embedded_view_to(view, fail->x, fail->y);
}

extern char	*first_feature, *rest_feature;
lkb_failure	*mark_cycle = 0;

lkb_avm	*traverse_avm_list_path(lkb_avm	*root, lkb_avm_list	*list, lui_list	*pathl, int	pathi, int	*tt, int	off, int	give_tag);
lkb_avm	*recurse_path(lkb_avm	*root, lkb_avm	*avm, lui_list	*pathl, int	pathi, int	*tt, int	type, int	give_tag);
lkb_avm	*traverse_avm_path(lkb_avm	*root, lkb_avm	*avm, lui_list	*pathl, int	pathi, int	*tt, int	give_tag);

lkb_avm	*traverse_avm_tag_path(lkb_avm	*root, lkb_avm_tag	*tag, lui_list	*pathl, int	pathi, int	*tt, int	give_tag)
{
	lkb_avm_tag	*to, *start = 0;
	int	reftype, listoff;
	void	*refer;
	lkb_avm	*ret;
	char	*path = (pathi<pathl->length)?pathl->data[pathi]:0;

	if(give_tag && (!path || !path[0]))
	{
		*tt = avm_tag;
		return (lkb_avm*)tag;
	}

	fprintf(stderr, "a_tag_path: [%s]->%s\n", tag->name, path);
	//printf("should define %s\n", t->name);
	to = find_tag_usage(root, tag->name, &start, &reftype, &refer, &listoff);
	if(!to)
	{
		fprintf(stderr, "Couldn't define correference `%d' in path\n", listoff);
		return 0;
	}

	//printf(" tag resolver: ref %p reftype %d reflistoff %d\n", refer, reftype, listoff);
	if(reftype==avm_list)
		ret = traverse_avm_list_path(root, refer, pathl, pathi, tt, listoff, give_tag);
	else ret = recurse_path(root, refer, pathl, pathi, tt, reftype, give_tag);
		//ret = traverse_avm_path(root, refer, path, tt, give_tag);

	//printf(" tag returns %p\n", ret);
	return ret;
}

lkb_avm	*traverse_avm_list_path(lkb_avm	*root, lkb_avm_list	*list, lui_list	*pathl, int	pathi, int	*tt, int	off, int	give_tag)
{
	void	*ret;
	int		i;
	char	*path = (pathi<pathl->length)?pathl->data[pathi]:0;

	//printf("a_list_path(%d) %p: %s\n", off, list, path);
	//for(i=0;i<list->length;i++)printf("(%d) %p    ", list->what[i], list->items[i]);

	if(!path || !path[0])
	{
		extern char *list_type;
		char	*type = list_type;
		int		i;

		/*if(off == list->length)	// not needed anymore
		{
			// if there's no item to split off into its own "cons" cell,
			// we should return the end 'rest' of the list
			*tt = list->rest_type;
			return list->rest_weird;
		}*/

		// split the list here and stick the current node in as a structure w/ first+rest
		lkb_avm	*avm = calloc(sizeof(lkb_avm), 1);
		lkb_avm_list	*rest = calloc(sizeof(lkb_avm_list), 1);
		if(off<list->length)
		{
			for(i=0;i<=off;i++)
				if(list->type[i])type = list->type[i];
			avm->type = strdup(type);
			avm->nattr = 2;
			avm->attr_what = malloc(sizeof(int)*2); avm->attr_what[0] = list->what[off]; avm->attr_what[1] = avm_list;
			avm->attr_name = malloc(sizeof(char*)*2); avm->attr_name[0] = strdup(first_feature); avm->attr_name[1] = strdup(rest_feature);
			avm->attr_value = malloc(sizeof(void*)*2); avm->attr_value[0] = list->items[off]; avm->attr_value[1] = rest;
			avm->attr_x = calloc(sizeof(int),2); avm->attr_y = calloc(sizeof(int),2);
			avm->attr_dx = calloc(sizeof(int),2); avm->attr_dy = calloc(sizeof(int),2);
			avm->attr_ldx = calloc(sizeof(int),2); avm->attr_hide = calloc(sizeof(int),2);
			avm->attr_cycle = calloc(sizeof(lkb_failure*), 2);
			avm->attr_tag = malloc(sizeof(lkb_avm_tag*)*2); avm->attr_tag[0] = list->tags[off]; avm->attr_tag[1] = list->rtags[off];
		}
		else
		{
			avm->type = strdup(empty_list_type);
		}
		avm->expand = 1;
		avm->show_hiders = 1;
		avm->failure = 0;
		avm->path = strdup("XXX fixme");
		rest->length = list->length - off - 1; list->length = off;
		if(rest->length>0 || (avm->nattr==2 && !avm->attr_tag[1]))
		{
			rest->what = malloc(sizeof(int)*rest->length); memcpy(rest->what, list->what+off+1, sizeof(int)*rest->length);
			rest->type = malloc(sizeof(char*)*rest->length); memcpy(rest->type, list->type+off+1, sizeof(char*)*rest->length);
			rest->items = malloc(sizeof(void*)*rest->length); memcpy(rest->items, list->items+off+1, sizeof(void*)*rest->length);
			rest->tags = malloc(sizeof(lkb_avm_tag*)*rest->length); memcpy(rest->tags, list->tags+off+1, sizeof(lkb_avm_tag*)*rest->length);
			rest->rtags = malloc(sizeof(lkb_avm_tag*)*rest->length); memcpy(rest->rtags, list->rtags+off+1, sizeof(lkb_avm_tag*)*rest->length);
			rest->rest_weird = list->rest_weird;
			rest->rest_type = list->rest_type;
			rest->open_ended = list->open_ended;
		}
		else
		{
			free(rest);
			if(avm->nattr==2)
			{
				avm->attr_value[1] = 0;
				avm->attr_what[1] = avm_tag;
			}
		}
		list->rest_weird = avm;
		list->rest_type = avm_structure;
		list->open_ended = 0;
		//fprintf(stderr, "Paths cannot currently point to list.\n");
		*tt = avm_structure;
		return avm;
	}

	if(list->length<=off)
	{
		fprintf(stderr, "Error: tried to reach %d inside a list of length %d\n", off+1, list->length);
		return 0;
	}

	//dot = strchr(path, PATH_DIV);
	//if(dot)*dot++ = 0;
	if(strcasecmp(path, first_feature) && strcasecmp(path, rest_feature))
	{
		fprintf(stderr, "Path asked for feature `%s' of list `%s'\n",
							path, list->type);
		//if(dot)dot[-1] = PATH_DIV;
		return 0;
	}

	if(!strcasecmp(path, first_feature))
	{
		//if(dot)dot[-1] = PATH_DIV;
		if(list->what[off] == avm_tag)
		{
			ret = traverse_avm_tag_path(root, list->tags[off], pathl, pathi+1, tt, give_tag);
			if(ret && mark_cycle)
				list->tags[off]->failure = mark_cycle;
		}
		else ret = recurse_path(root, list->items[off], pathl, pathi+1, tt, list->what[off], give_tag);
		//printf("lfirst_ret(%d) %p	type was %d ptr %p\n", off, ret, list->what[off], list->items[off]);
		return ret;
	}
	if(!strcasecmp(path, rest_feature))
	{
		//if(dot)dot[-1] = PATH_DIV;
		if(off+1 < list->length || (!list->rest_weird && !list->rtags[off]))
		{
			if(off+1==list->length && !list->rest_weird && !list->rtags[off])
			{
				if(pathi+1==pathl->length)
				{
					// `REST' is our final destination; invent a rest_weird for it
					extern char *empty_list_type;
					struct lkb_avm *avm = calloc(sizeof(struct lkb_avm), 1);
					avm->type = strdup(empty_list_type);
					avm->path = strdup("XXX fixme");
					list->rest_weird = avm;
					list->rest_type = avm_structure;
					return avm;
				}
				else return 0; // there's no 'REST' to traverse...
			}
			ret = traverse_avm_list_path(root, list, pathl, pathi+1, tt, off+1, give_tag);
		}
		else if(list->rest_weird)ret = recurse_path(root, list->rest_weird, pathl, pathi+1, tt, list->rest_type, give_tag);
		else
		{
			ret = traverse_avm_tag_path(root, list->rtags[off], pathl, pathi+1, tt, give_tag);
			if(ret && mark_cycle)
				list->rtags[off]->failure = mark_cycle;
		}
		//printf("lrest_ret %p\n", ret);
		return ret;
	}
	fprintf(stderr, "Huh? Shouldn't get here.\n");
	exit(-1);
}

lkb_avm	*recurse_path(lkb_avm	*root, lkb_avm	*avm, lui_list	*pathl, int	pathi, int	*tt, int	type, int	give_tag)
{
	char	*path = (pathi<pathl->length)?pathl->data[pathi]:0;

	//printf("r_path: %s\n", path);
	if((!path || !path[0]) && type != avm_list)
	{
		*tt = type;
		//printf("r_path bail %p\n", avm);
		return avm;
	}

	switch(type)
	{
		case	avm_terminal:
			if(path)
			{
				fprintf(stderr, "Requested path `%s' into terminal\n", path);
				return 0;
			}
			else
			{
				fprintf(stderr, "Requested a terminal, oops!\n");
				return 0;
			}
		case	avm_tag:
			root = traverse_avm_tag_path(root, (lkb_avm_tag*)avm, pathl, pathi, tt, give_tag);
			if(root && mark_cycle)
				((lkb_avm_tag*)avm)->failure = mark_cycle;
			return root;
		case	avm_structure:
			return traverse_avm_path(root, avm, pathl, pathi, tt, give_tag);
		case	avm_list:
			return traverse_avm_list_path(root, (lkb_avm_list*)avm, pathl, pathi, tt, 0, give_tag);
		default:
			fprintf(stderr, "What is avm_type %d?\n", type);
			return 0;
	}
}

lkb_avm	*traverse_avm_path(lkb_avm	*root, lkb_avm	*avm, lui_list	*pathl, int	pathi, int	*tt, int	give_tag)
{
	lkb_avm	*res = 0;
	int		i;
	char	*path = (pathi<pathl->length)?pathl->data[pathi]:0;

	//printf("t_avm_path: %s\n", path);
	*tt = avm_structure;
	if(!path || !path[0])return avm;
	if(!pathl->length)return avm;	// root path
	//if(!strcmp(path, PATH_DIV_STR))return avm;	// root path
	*tt = -1;

	//dot = strchr(path, PATH_DIV);
	//if(dot)*dot = 0;
	for(i=0;i<avm->nattr;i++)
	{
		if(!strcasecmp(path, avm->attr_name[i]))
		{
			if(mark_cycle)
			{
				avm->attr_cycle[i]=mark_cycle;
				avm->expand = 1;
			}
			//if(dot)*dot++ = PATH_DIV;
			if(avm->attr_what[i]==avm_tag)
			{
				res = traverse_avm_tag_path(root, avm->attr_tag[i], pathl, pathi+1, tt, give_tag);
				if(res && mark_cycle)
					((lkb_avm_tag*)avm->attr_tag[i])->failure = mark_cycle;
			}
			else res = recurse_path(root, avm->attr_value[i], pathl, pathi+1, tt, avm->attr_what[i], give_tag);
			break;
		}
	}
	//if(!res && dot)dot[-1] = PATH_DIV;

	//if(!strcasecmp(path, first_feature) || !strcasecmp(path, rest_feature))
	if(i == avm->nattr)
	{
		//fprintf(stderr, "Path asked for feature `%s' of non-list `%s'\n",
		fprintf(stderr, "Path asked for nonextant feature `%s' in type `%s'\n",
						path, avm->type);
		res = 0;
	}

	//printf(" ret %p\n", res);
	return res;
}

int	expand_around(lkb_avm	*root, void	*val, int	type)
{
	int	i;
	lkb_avm_list	*list = (lkb_avm_list*)root;

	if(val==root)return 1;
	switch(type)
	{
		case	avm_structure:
			for(i=0;i<root->nattr;i++)
				if(expand_around(root->attr_value[i], val, root->attr_what[i]))
				{
					root->expand = 1;
					root->attr_hide[i] = 0;
					return 1;
				}
			break;
		case	avm_list:
			for(i=0;i<list->length;i++)
				if(expand_around(list->items[i], val, list->what[i]))
					return 1;
			if(list->rest_weird)
				if(expand_around(list->rest_weird, val, list->rest_type))
					return 1;
			break;
	}
	return 0;
}

int	record_failure(lkb_avm	*avm, lkb_failure	*fail)
{
	lkb_avm	*loc, *crc;
	int		loct, cyct, i;

	//loc = traverse_avm_path(avm, avm, fail->path, 0, &loct, (fail->what==ufail_cycle)?1:0);
	loc = traverse_avm_path(avm, avm, fail->path, 0, &loct, 0);
	if(!loc)
	{
		fprintf(stderr, "Path `");
		if(!fail->path->length)fprintf(stderr, PATH_DIV_STR);
		else for(i=0;i<fail->path->length;i++)
			fprintf(stderr, "%s%s", (i>0)?PATH_DIV_STR:"", fail->path->data[i]);
		fprintf(stderr, "' for failure didn't exist\n");
		return -1;
	}

	// make it visible
	expand_around(avm, loc, avm_structure);

	if(fail->what==ufail_cycle)
	{
		mark_cycle = fail;
		crc = recurse_path(avm, loc, fail->cycle, 0, &cyct, loct, 0);
		mark_cycle = 0;

		//printf("path `%s' followed by cycle `%s' in node %p\n", fail->path, fail->cycle, loc);
		//printf("  cycle start %p [%d] end %p [%d]\n", loc, loct, crc, cyct);
	}
	else
	{
		//printf("path `%s` -> %p type %d is AVM[%s]\n", fail->path, loc, loct, loc->type);
		loc->failure = fail;
	}
	return 0;
}

void	print_failure(lkb_failure	*fail)
{
	switch(fail->what)
	{
		case	ufail_no_glb:
			printf("No GLB for types `%s' and `%s' at path `%s'\n",
				fail->type1, fail->type2, fail->path);
			break;
		case	ufail_cycle:
			printf("Cycle introduced from path `%s'\n", fail->path);
			break;
		case	ufail_constraint:
			printf("Type-heirarchy constraint from type `%s' conflicted with types `%s' and `%s' at `%s'\n",
				fail->constraint, fail->type1, fail->type2, fail->path);
			break;
	}
}

void	close_avm_view(embedded_view_t	*view)
{
	reset_gc_list(&tvdata->gcl);
	lkb_forget_avm(tvdata->id);
	free(tvdata);
}

update_gcl(embedded_view_t	*view)
{
	int			now_avm_width = 0, now_avm_height = 0;

	current_offset_x = current_offset_y = avm_margin;
	hilite_avm = tvdata->selected_avm;
	hilite_tag = tvdata->moused_tag;
	reset_gc_list(&tvdata->gcl);
	target_gcl = &tvdata->gcl;
	render_avm_item(tvdata->avm, avm_structure,
				&now_avm_height, &now_avm_width, 1, 0);

	now_avm_width += avm_margin*2;
	now_avm_height += avm_margin*2;
	set_embedded_view_size(view, now_avm_width, now_avm_height);
	tvdata->dirty = 0;
}

void	update_avm(embedded_view_t	*view, int	x1, int	y1, int	x2, int	y2)
{
	struct timeval	tv1, tv2;
	float			secs;

	gettimeofday(&tv1, 0);

	yzBufferMode(YZ_BUFFER_BACK);

	if(!GC_ONLY_TAGS)
	{
		yzPenColor(65535,65535,65535);
		//printf("update in %d %d -> %d %d (vis %d %d)\n", x1, y1, x2, y2,
			//view->vis_width, view->vis_height);
		yzRect(x1, y1, x2, y2);
		yzPenColor(0,0,0);
	}

	hilite_avm = tvdata->selected_avm;
	hilite_tag = tvdata->moused_tag;
	draw_gc_list(&tvdata->gcl, x1, y1, x2, y2);

	gettimeofday(&tv2, 0);
	secs = tv2.tv_sec - tv1.tv_sec;
	secs += ((float)tv2.tv_usec - tv1.tv_usec) / 1000000;
	//fprintf(stderr, "display took %.5f seconds\n", secs);

	if(x2-x1+1 == view->vis_width && y2-y1+1 == view->vis_height)
		show_path(view, tvdata->shown_path, 1, 1);
}

void	event_avm(embedded_view_t	*view, event_t	ev)
{
	switch(ev.type)
	{
		case	YZ_MOUSE_DOWN:
			if(handle_avm_click(view, ev.x, ev.y, ev.button))
				return;
			break;
		case	YZ_KEY_DOWN:
			//fprintf(stderr, "key %c\n", ev.key);
			switch(ev.key)
			{
				case	'-': case	'_':
					tvdata->gcl.scale *= 0.50;
					if(tvdata->gcl.scale < 1.0 / 128)
						tvdata->gcl.scale = 1.0 / 128;
					yzUpdateScrollArea(view->scroll_area, 0, 0, view->width, view->height);
					break;
				case	'+': case	'=':
					tvdata->gcl.scale *= 2;
					if(tvdata->gcl.scale > 2)tvdata->gcl.scale = 2;
					yzUpdateScrollArea(view->scroll_area, 0, 0, view->width, view->height);
					break;
				case	YZ_KEYCODE_RIGHT_ARROW:
					if(!tvdata->failures)break;
					tvdata->fail_idx = (tvdata->fail_idx+1)%tvdata->failures->length;
					hilite_failure(view, tvdata->failures->data[tvdata->fail_idx]);
					break;
				case	YZ_KEYCODE_LEFT_ARROW:
					if(!tvdata->failures)break;
					tvdata->fail_idx = (tvdata->fail_idx+tvdata->failures->length-1)%tvdata->failures->length;
					hilite_failure(view, tvdata->failures->data[tvdata->fail_idx]);
					break;
			}
			break;
	}
}

hilite_failure(embedded_view_t	*view, lkb_failure	*fail)
{
	yzBufferMode(YZ_BUFFER_BACK);
	/*yzPenColor(65535, 65535, 65535);
	yzRect(0, 0, view->width+20, view->height+20);
	if(tvdata->dirty)
		update_gcl(view);
	update_avm(view, 0, 0, view->width+20, view->height+20);*/

	yzPushClipRect(0, 0, view->width, view->height);
	yzPushOrigin(0,0);
	do_attention_selection(view, fail->x, fail->y);
	yzPopOrigin();
	yzPopClipRect();
	yzUpdateBuffer(YZ_BUFFER_FRONT);
}

int	nullstrcmp(char	*a, char	*b)
{
	if(a==b)return 0;
	if(!a || !b)return a-b;
	return strcmp(a, b);
}

show_path(embedded_view_t	*view, char	*path, int	force, int	from_view)
{
	int	ox, oy, cx1, cy1, cx2, cy2;
	char	*tmp = tvdata->shown_path;

	if(force || nullstrcmp(tmp, path))
	{
		if(path)tvdata->shown_path = strdup(path);
		else tvdata->shown_path = 0;
		if(tmp)free(tmp);
		if(from_view)
		{
			yzPopClipRect4p(&cx1, &cy1, &cx2, &cy2);
			yzPopOrigin2p(&ox, &oy);
		}
		yzBufferMode(YZ_BUFFER_BACK);
		yzPushClipRect(0, 0, view->use_width, avm_bar_font.size*1.3 - 1);
		yzPenColor(50000, 50000, 50000);
		yzRect(0, 0, view->use_width, avm_bar_font.size*1.3 - 1);
		yzPenColor(0,0,0);
		yzOutlineRect(0, 0, view->use_width, avm_bar_font.size*1.3 - 1);
		if(tvdata->shown_path)
		{
			use_font(&avm_bar_font);
			yzText(5, avm_bar_font.size*1.1 - 1, tvdata->shown_path);
		}
		yzUpdateBuffer(YZ_BUFFER_FRONT);
		yzPopClipRect();
		if(from_view)
		{
			yzPushOrigin(ox, oy);
			yzPushClipRect(cx1, cy1, cx2, cy2);
		}
	}
	//yzQueryKey(YZ_KEYCODE_CONTROL);
}

lkb_avm	*pick_avm_item(lkb_avm	*root, int	what, int	x, int	y,
								int	*tt, lkb_avm_tag	*tag, int	full_struct, int	*which_child);
lkb_avm	*pick_avm(lkb_avm	*root, int	x, int	y, int	*tt, int	full_struct, int	*which_child);

set_hiders(lkb_avm	*t, int	v)
{
	int	i;

	for(i=0;i<t->nattr;i++)
	{
		if(t->attr_hide[i]>0)
			t->attr_hide[i] = v;
	}
}

do_avm_popup(embedded_view_t	*view, lkb_avm	*t)
{
	window_t	*par;
	menu_data_t	*md;
	int			id;

	md = yzNewMenuData("AVM Options");
	if(t->expand)yzAddMenuDataItem(md, "Collapse", 1);
	if(!t->expand)yzAddMenuDataItem(md, "Expand", 2);
	if(t->show_hiders)yzAddMenuDataItem(md, "Banish Hidden", 8);
	if(!t->show_hiders)yzAddMenuDataItem(md, "Reveal Hidden", 9);
	yzAddMenuDataItem(md, "Select", 3);
	yzAddMenuDataItem(md, "Type Hierarchy", 4);
	yzAddMenuDataItem(md, "Type Definition", 5);
	yzAddMenuDataItem(md, "Expanded Type", 6);
	yzAddMenuDataItem(md, "Show Source", 7);

	par = yzGetSelectedWindow();
	yzShowMenu(md, &id, t->x1 + par->origin_x, t->y1 + par->origin_y);

	switch(id)
	{
		case	0:	break;	// cancelled
		default:	printf("unknown item %d\n", id);	break;

		case	1:	t->expand = 0;	tvdata->dirty = 1; break;
		case	2:	t->expand = 1;	tvdata->dirty = 1; break;
		case	3:	tvdata->selected_avm = t;	tvdata->dirty = 1; break;

		case	4:	lkb_type_command(t->type, "hierarchy");	break;
		case	5:	lkb_type_command(t->type, "skeleton");	break;
		case	6:	lkb_type_command(t->type, "expansion");	break;
		case	7:	lkb_type_command(t->type, "source");	break;
		case	8:	t->show_hiders = 0;	set_hiders(t, 2); tvdata->dirty = 1; break;
		case	9:	t->show_hiders = 1;	set_hiders(t, 1); tvdata->dirty = 1; break;
	}
	// XXX should dispose memory here
}

lkb_avm_tag	*find_tag_usage_list(lkb_avm_list	*list, char	*name, lkb_avm_tag	**start, int	*tt, void	**refer, int	*listoff)
{
	lkb_avm_tag	*ret;
	int			i;

	for(i=0;i<list->length;i++)
	{
		if(list->tags[i] &&
			!strcmp(name, list->tags[i]->name))
		{
			if(*start == list->tags[i])
				*start = 0;
			else if(!*start)
			{
				*tt = list->what[i];
				*refer = list->items[i];
				*listoff = 0;
				return list->tags[i];
			}
		}
		if(list->rtags[i] &&
			!strcmp(name, list->rtags[i]->name))
		{
			if(*start == list->rtags[i])
				*start = 0;
			else if(!*start)
			{
				if(i+1 == list->length && list->rest_weird)
				{
					*tt = list->rest_type;
					*refer = list->rest_weird;
					*listoff = 0;
				}
				else
				{
					*tt = avm_list;
					*refer = list;
					*listoff = i+1;
				}
				//fprintf(stderr, "matched `%s' rtag for item %d in list %p len %d\n",
				//	name, i, list, list->length);
				return list->rtags[i];
			}
		}
		if(list->items[i])
		{
			if(list->what[i]==avm_structure)
				ret = find_tag_usage(list->items[i], name, start, tt, refer, listoff);
			else if(list->what[i]==avm_list)
				ret = find_tag_usage_list(list->items[i], name, start, tt, refer, listoff);
			else ret = 0;
			if(ret)return ret;
		}
	}
	return 0;
}

int	dirty;

lkb_avm_tag	*find_tag_usage(lkb_avm	*avm, char	*name, lkb_avm_tag	**start, int	*tt, void	**refer, int	*listoff)
{
	lkb_avm_tag	*ret;
	int			i;

	for(i=0;i<avm->nattr;i++)
	{
		// XXX I'm not sure skipping hidden nodes is really the right answer here...
		if(avm->attr_hide[i]==2)continue;

		if(avm->attr_tag[i] &&
			!strcmp(name, avm->attr_tag[i]->name))
		{
			if(*start == avm->attr_tag[i])
				*start = 0;
			else if(!*start)
			{
				if(!avm->expand)dirty = 1;
				avm->expand = 1;
				*tt = avm->attr_what[i];
				*refer = avm->attr_value[i];
				*listoff = 0;
				return avm->attr_tag[i];
			}
		}
		if(avm->attr_value[i])
		{
			if(avm->attr_what[i]==avm_structure)
				ret = find_tag_usage(avm->attr_value[i], name, start, tt, refer, listoff);
			else if(avm->attr_what[i]==avm_list)
				ret = find_tag_usage_list(avm->attr_value[i], name, start, tt, refer, listoff);
			else ret = 0;
			if(ret)
			{
				if(!avm->expand)dirty = 1;
				avm->expand = 1;
				return ret;
			}
		}
	}
	return 0;
}

int	att_x, att_y;
lkb_avm_tag	*att_tag;

select_tag_definition(embedded_view_t	*view, lkb_avm_tag	*t)
{
	lkb_avm_tag	*to, *start = 0;
	int	reftype, listoff;
	void	*refer;

	//printf("should define %s\n", t->name);
	dirty = 0;
	to = find_tag_usage(tvdata->avm, t->name, &start, &reftype, &refer, &listoff);
	//printf("should select %p\n", to);
	if(dirty)tvdata->dirty = 1;
	tvdata->selected_avm = to;
	att_tag = to;
}

select_tag_next_occurance(embedded_view_t	*view, lkb_avm_tag	*t)
{
	lkb_avm_tag	*to, *start = t;
	int	reftype, listoff;
	void	*refer;

	//printf("should chase %s\n", t->name);
	dirty = 0;
	to = find_tag_usage(tvdata->avm, t->name, &start, &reftype, &refer, &listoff);
	if(!to)
	{
		start = 0;
		to = find_tag_usage(tvdata->avm, t->name, &start, &reftype, &refer, &listoff);
		//printf("search wrapped\n");
	}
	//printf("should select %p\n", to);
	if(dirty)tvdata->dirty = 1;
	tvdata->selected_avm = to;
	att_tag = to;
}

select_tag_prev_occurance(embedded_view_t	*view, lkb_avm_tag	*t)
{
	lkb_avm_tag	*to, *prev, *start = 0;
	int	reftype, listoff;
	void	*refer;

	//printf("should chase %s\n", t->name);
	dirty = 0;

	do
	{
		prev = start;
		to = find_tag_usage(tvdata->avm, t->name, &start, &reftype, &refer, &listoff);
		start = to;
	} while(to != t && to != 0);
	if(to==0)
	{
		fprintf(stderr, "prev-occurance search found no matches for `%s'\n", t->name);
		return;
	}

	// now prev is the tag we found just before t
	if(prev==0)
	{
		// have to find *last* occurance
		//fprintf(stderr, "prev-occurance wrapped\n");
		start = t;
		do
		{
			prev = start;
			to = find_tag_usage(tvdata->avm, t->name, &start, &reftype, &refer, &listoff);
			start = to;
		} while(to != 0);
	}

	//printf("should select %p\n", to);
	if(dirty)tvdata->dirty = 1;
	tvdata->selected_avm = prev;
	att_tag = prev;
}

do_attention_selection(embedded_view_t	*view, int	x, int	y)
{
	int	i;

	scroll_embedded_view_to(view, x, y);
	yzBufferMode(YZ_BUFFER_BACK);
	update_avm(view, 0, 0, view->width, view->height);

	yzBufferMode(YZ_BUFFER_FRONT);
	for(i=80;i>10;i-=6)
	{
		yzUpdateBuffer(YZ_BUFFER_FRONT);
		yzOutlineRect(x-i, y-i, x+i, y+i);
		usleep(10000);
		yzGetUnfilteredEvent(0);	// make sure Expose events get processed
	}
	yzBufferMode(YZ_BUFFER_BACK);
}

do_avm_tag_popup(embedded_view_t	*view, lkb_avm_tag	*t)
{
	window_t	*par;
	menu_data_t	*md;
	int			id;

	md = yzNewMenuData("Tag Options");
	yzAddMenuDataItem(md, "Find Next", 1);
	yzAddMenuDataItem(md, "Find Previous", 2);
	if(!t->is_def)yzAddMenuDataItem(md, "Find Definition", 3);

	par = yzGetSelectedWindow();
	yzShowMenu(md, &id, t->x1 + par->origin_x, t->y1 + par->origin_y);

	switch(id)
	{
		case	0:	break;	// cancelled
		default:	fprintf(stderr, "unknown item %d\n", id);	break;

		case	1:	select_tag_next_occurance(view, t);	break;
		case	2:	select_tag_prev_occurance(view, t);	break;
		case	3:	select_tag_definition(view, t);		break;
	}
	// XXX should dispose memory here
}

sim_key(int	key)
{
	event_t	ev;

	ev.type = YZ_KEY_DOWN;
	ev.key = key;
	embedded_view_event(ev);
	return 0;
}

misc_avm_popup(embedded_view_t	*view, int	x, int	y)
{
	window_t	*par;
	menu_data_t	*md;
	int			id;

	md = yzNewMenuData("AVM Options");
	yzAddMenuDataItem(md, "Output Postscript", 1);
	yzAddMenuDataItem(md, "Output LaTeX", 2);
	yzAddMenuDataItem(md, "Close Window", 3);

	par = yzGetSelectedWindow();
	yzShowMenu(md, &id, x-8, y-8);

	switch(id)
	{
		case	0:	break;	// cancelled
		default:	fprintf(stderr, "unknown item %d\n", id);	break;

		case	1:	postscript_avm(view);	break;
		case	2:	latex_avm(view);	break;
		case	3:	sim_key('q');		return -1;
	}
	// XXX should dispose memory here
	return 0;
}

click_avm_tag(embedded_view_t	*view, lkb_avm_tag	*t, int	b)
{
	//if(yzQueryKey(YZ_KEYCODE_CONTROL) || b!=1)
		return do_avm_tag_popup(view, t);

	//printf("Clicked %s tag: %s\n", t->is_def?"master":"slave", t->name);
	//tvdata->selected_avm = t;
}

// a mouse-down has occured on the title/type of an avm
// decide what to do.
#define	DRAG_DIST	10
handle_avm_structure_click(embedded_view_t	*view, lkb_avm	*avm, int	x, int	y, int	b)
{
	event_t		ev;
	int			dx = 0, dy = 0;

	do
	{
		ev = yzGetUnfilteredEvent(1000);
		if(ev.type==YZ_MOUSE_DRAG)dx += ev.x2 - ev.x, dy += ev.y2 - ev.y;
	} while((dx*dx + dy*dy < DRAG_DIST*DRAG_DIST) && ev.type != YZ_MOUSE_UP);
	if(dx*dx + dy*dy < DRAG_DIST*DRAG_DIST)
	{
		// just a simple click
		avm->expand = !avm->expand;
		tvdata->dirty = 1;
	}
	else
	{
		// a full-fledged drag!
		if(!tvdata->failures)	// only produce a drag if we have no failures
			handle_avm_drag(view, avm, x, y, b);
	}
}

handle_avm_click(embedded_view_t	*view, int	x, int	y, int	b)
{
	lkb_avm	*ptr;
	int			type, which_child;
	int	cx1, cy1, cx2, cy2, ox, oy;

	att_x = att_y = 0; att_tag = 0;
	ptr = pick_avm(tvdata->avm, x, y, &type, 0, &which_child);
	//printf("clicked at %d, %d, b %d, picked up item %p of type %d\n", x, y, b, ptr, type);
	if(type==avm_structure && which_child>=0 && ptr->attr_what[which_child]==avm_tag)
		{ptr = (lkb_avm*)ptr->attr_tag[which_child]; type=avm_tag; which_child=-1;}

	if(ptr && which_child>=0)
	{
		fprintf(stderr, "clicked child %d of parent %p type %d\n", which_child, ptr, type);
	}
	else if(ptr && type == avm_structure)
	{
		if(yzQueryKey(YZ_KEYCODE_CONTROL) || b!=1)
			do_avm_popup(view, ptr);
		else handle_avm_structure_click(view, ptr, x, y, b);
	}
	else if(ptr && type == avm_tag)
	{
		click_avm_tag(view, (lkb_avm_tag*)ptr, b);
	}
	else if(!ptr && (b!=1 || yzQueryKey(YZ_KEYCODE_CONTROL)))if(misc_avm_popup(view, x, y))return -1;
	//printf("height = %d\n", view->height);
	if(tvdata->dirty)
		update_gcl(view);

/*
	// old method of redrawing after reformat
	yzBufferMode(YZ_BUFFER_BACK);
	yzPenColor(65535, 65535, 65535);
	yzRect(0, 0, view->width+20, view->height+20);
	update_avm(view, 0, 0, view->width+20, view->height+20);
*/

	// redisplay the whole view after a click
	yzPopOrigin2p(&ox, &oy);
	yzPopClipRect4p(&cx1, &cy1, &cx2, &cy2);
	yzDrawScrollArea(view->scroll_area);
	yzPushClipRect(cx1, cy1, cx2, cy2);
	yzPushOrigin(ox, oy);

	if(att_tag)
	{
		att_x = att_tag->x1, att_y = att_tag->y1;
		do_attention_selection(view, att_x, att_y);
	}

	yzUpdateBuffer(YZ_BUFFER_FRONT);
	return 0;
}

int	near_tag(int	x, int	y, lkb_avm_tag	*tag)
{
	use_font(&tag_display_font);
	if(x>=tag->x1-2 && y>=tag->y1-8*tag_display_font.size/12 &&
		x<=tag->x1+yzStringSize(tag->name, strlen(tag->name))+2 && y <= tag->y1+4*tag_display_font.size/12)
			return 1;
	else return 0;
}

lkb_avm	*pick_avm_item(lkb_avm	*root, int	what, int	x, int	y,
								int	*tt, lkb_avm_tag	*tag, int	full_struct, int	*which_child)
{
	lkb_avm_list	*l;
	lkb_avm	*t;
	int			i;

	if((!full_struct || !root) && tag && near_tag(x, y, tag))
	{
		*tt = avm_tag;
		*which_child = -1;
		return (lkb_avm*)tag;
	}
	switch(what)
	{
		case	avm_list:
			l = (lkb_avm_list*)root;
			for(i=0;i<l->length;i++)
			{
				if(l->what[i]==avm_terminal)
					continue;
				else
				{
					*which_child = -1;
					t = pick_avm_item(l->items[i], l->what[i], x, y, tt, l->tags[i], full_struct, which_child);
					if(t)return t;
				}
				if(!full_struct && l->rtags[i] && near_tag(x, y, l->rtags[i]))
				{
					*tt = avm_tag;
					return (lkb_avm*)l->rtags[i];
				}
			}
			if(l->rest_weird)
			{
				if(l->rest_type == avm_terminal)
					break;
				else
				{
					*which_child = -1;
					t = pick_avm_item(l->rest_weird, l->rest_type, x, y, tt, 0, full_struct, which_child);
					if(t)return t;
				}
			}
			break;
		case	avm_structure:
			*tt = what;
			*which_child = -1;
			return pick_avm(root, x, y, tt, full_struct, which_child);
		case	avm_tag:
			//fprintf(stderr, "avm_tag root = %p, tag = %p\n", root, tag);
			break;
		case	avm_terminal:
			fprintf(stderr, "pick reached a terminal - bad!\n");
			return 0;
	}
	return 0;
}

lkb_avm	*pick_avm(lkb_avm	*root, int	x, int	y, int	*tt, int	full_struct, int	*which_child)
{
	int			i;
	lkb_avm	*t;

	if(!full_struct && x >= root->x1-2 && x <= root->x1+root->type_dx &&
		y >= root->y1-14 && y <= root->y1 + root->type_dy - 14)
	{
		*tt = avm_structure;
		*which_child = -1;
		return root;
	}

	if(root->expand)	// don't allow checking subitems of a closed structure
	{
		for(i=0;i<root->nattr;i++)
		{
			if(root->attr_hide[i]==2)continue;
			if(root->attr_what[i]==avm_terminal)
			{
				/*printf("terminal %s at %d %d %d %d ; x %d y %d\n",
						root->attr_value[i],
						root->attr_x[i],
						root->attr_y[i],
						root->attr_dx[i],
						root->attr_dy[i], x, y);*/
				// if we're in the tag and we're allowed to return tags...
				if(!full_struct && root->attr_tag[i] && near_tag(x, y, root->attr_tag[i]))
				{
					*tt = avm_tag;
					*which_child = -1;
					return (lkb_avm*)root->attr_tag[i];
				}
				// or if we're inside the terminal...
				if(x>root->attr_x[i] && y>root->attr_y[i] &&
					x<root->attr_x[i]+root->attr_dx[i] && y<root->attr_y[i]+root->attr_dy[i])
				{
					*which_child = i;
					*tt = avm_structure;
					return root;
				}
			}
			else
			{
				// this is a big substructure, recurse on it
				*which_child = -1;
				t = pick_avm_item(root->attr_value[i], root->attr_what[i], x, y, tt,
									root->attr_tag[i], full_struct && (root->attr_what[i]!=avm_tag), which_child);
				if(t)
				{
					if(root->attr_what[i] == avm_tag)
					{
						*which_child = i;
						*tt = avm_structure;
						return root;
					}
					else return t;
				}
			}
		}
	}

	if(full_struct)
	{
		if(x >= root->x1-4 && x <= root->x1+root->dx-4 &&
			y >= root->y1-12 && y <= root->y1+root->dy-14)
		{
			*tt = avm_structure;
			*which_child = -1;
			return root;
		}
	}
	return 0;
}

void	show_failure(embedded_view_t	*view, lkb_failure	*fail)
{
	//print_failure(fail);
	switch(fail->what)
	{
		case	ufail_no_glb:
			show_path(view, "Unification Failure: No GLB Exists", 0, 0);
			break;
		case	ufail_cycle:
			show_path(view, "Unification Failure: Cycle Introduced", 0, 0);
			break;
		case	ufail_constraint:
			show_path(view, "Unification Failure: GLB Type Constraint Violated", 0, 0);
			break;
	}
}

void	mouse_avm(embedded_view_t	*view, int	x, int	y)
{
	lkb_avm		*avm;
	lkb_avm_tag	*tag;
	int			type, which_child;
	char		*omt = tvdata->moused_tag;
	char		path[1024];

	//printf("mouse moved to %d %d\n", x, y);
	tvdata->moused_tag = 0;

	tag = (lkb_avm_tag*)pick_avm(tvdata->avm, x, y, &type, 0, &which_child);
	if(type==avm_structure && which_child>=0 && ((lkb_avm*)tag)->attr_what[which_child]==avm_tag)
		{tag = ((lkb_avm*)tag)->attr_tag[which_child]; type=avm_tag; which_child=-1;}
	if(tag && type==avm_tag)
		tvdata->moused_tag = tag->name;
	avm = pick_avm(tvdata->avm, x, y, &type, 1, &which_child);
	if(!avm)show_path(view, 0, 0, 0);
	else
	{
		if(type == avm_structure)
		{
			//printf("mouse over %p path %s\n", avm, avm->path);
			if(which_child>=0)
			{
				//printf("subitem %d of structure %p %s\n", which_child, avm, avm->path);
				snprintf(path, 1023, "%s%s%s",
					avm->path?avm->path:"", avm->path?" ":"", avm->attr_name[which_child]);
				path[1023] = 0;
				show_path(view, path, 0, 0);
			}
			else
			{
				if(avm->failure)show_failure(view, avm->failure);
				else show_path(view, avm->path, 0, 0);
			}
		}
		else if(type != avm_tag) show_path(view, "Not an AVM", 0, 0);
	}

	if(omt != tvdata->moused_tag)
	{
		// redraw all tags in the gc-list
		GC_ONLY_TAGS = 1;
		yzDrawScrollArea(view->scroll_area);
		GC_ONLY_TAGS = 0;
	}
}

char	drop_target_path[1024];
int		drop_target_id;
lkb_avm	*dropping_avm;
window_t	*dropping_window;
int		drop_x1, drop_y1, drop_x2, drop_y2;

display_avm_child_background(embedded_view_t	*view, gc_list	*gcl, color_t	col, lkb_avm	*avm, int	child,
									lkb_avm	*replacer, int	replacer_child)
{
	int				avm_x, avm_y, avm_dx, avm_dy, cx1, cy1, cx2, cy2;
	int				rep_x, rep_y, rep_dx, rep_dy;
	color_t			drop_color={65535,55000,55000}, rep_color={55000,55000,65535};

	if(child>=0)
	{
		avm_x = avm->attr_x[child]-2;
		avm_y = avm->attr_y[child]+2;
		avm_dx = avm->attr_dx[child]+2;
		avm_dy = avm->attr_dy[child]-2;
	}
	else { avm_x = avm->x1-4; avm_y = avm->y1-12;
			avm_dx = avm->dx; avm_dy = avm->dy-2; }

	if(replacer)
	{
		if(replacer_child>=0)
		{
			rep_x = replacer->attr_x[replacer_child]-2;
			rep_y = replacer->attr_y[replacer_child]+2;
			rep_dx = replacer->attr_dx[replacer_child]+2;
			rep_dy = replacer->attr_dy[replacer_child]-2;
		}
		else { rep_x = replacer->x1-4; rep_y = replacer->y1-12;
				rep_dx = replacer->dx; rep_dy = replacer->dy-2; }
	}

	yzBufferMode(YZ_BUFFER_BACK);

	yzRecomputeScrollAreaClipping(view->scroll_area);
	yzPushClipRect(avm_x, avm_y, avm_x+avm_dx-1, avm_y+avm_dy-1);
	yzPopClipRect4p(&cx1, &cy1, &cx2, &cy2);
	yzPushClipRect(cx1, cy1, cx2, cy2);
	/*printf("passed %d %d %d %d, got %d %d %d %d\n",
				avm_x, avm_y, avm_x+avm_dx-1, avm_y+avm_dy-1,
				cx1, cy1, cx2, cy2);*/

	if(dropping_avm && dropping_window==yzGetSelectedWindow() && avm_x>=drop_x1 && avm_x<=drop_x2 && avm_y>=drop_y1 && avm_y<=drop_y2)
	{
		// avm is inside drop
		yzPenColor1c(drop_color);
		yzRect(drop_x1, drop_y1, drop_x2, drop_y2);
		// draw avm second, if nonwhite background
		if(col.r != 65535 || col.g != 65535 || col.b != 65535)
		{
			yzPenColor1c(col);
			yzRect(avm_x, avm_y, avm_x+avm_dx-1, avm_y+avm_dy-1);
		}
		if(replacer)
		{
			yzPenColor1c(rep_color);
			yzRect(rep_x, rep_y, rep_x+rep_dx-1, rep_y+rep_dy-1);
		}
	}
	else
	{
		// avm is outside drop
		yzPenColor1c(col);
		yzRect(avm_x, avm_y, avm_x+avm_dx-1, avm_y+avm_dy-1);
		if(replacer)
		{
			yzPenColor1c(rep_color);
			yzRect(rep_x, rep_y, rep_x+rep_dx-1, rep_y+rep_dy-1);
		}
		// draw drop second
		if(dropping_avm && dropping_window==yzGetSelectedWindow())
		{
			yzPenColor1c(drop_color);
			yzRect(drop_x1, drop_y1, drop_x2, drop_y2);
		}
	}
	draw_gc_list(gcl, cx1, cy1, cx2, cy2);//avm_x, avm_y, avm_x+avm_dx-1, avm_y+avm_dy-1);
	yzUpdateBuffer(YZ_BUFFER_FRONT);
	yzPopClipRect();
	yzPopClipRect();
	yzPopOrigin();
}

handle_avm_drag(embedded_view_t	*view, lkb_avm	*avm, int	x, int	y, int	b)
{
	event_t		ev;
	window_t	*w, *prevw = 0;
	int			relx, rely, acc = 0;
	color_t	white = {65535, 65535, 65535, 65535}, hicolor = {65535, 55000, 55000};

	dropping_window = yzGetSelectedWindow();
	dropping_avm = avm;
	drop_x1 = avm->x1-4; drop_x2 = avm->x1+avm->dx-4;
	drop_y1 = avm->y1-12; drop_y2 = avm->y1+avm->dy-14;

	yzPopOrigin();
	yzPopClipRect();

	display_avm_child_background(view, &tvdata->gcl, hicolor, avm, -1, 0, 0);

	do
	{
		ev = yzGetUnfilteredEvent(10);
		if(ev.type == YZ_MOUSE_DRAG)
		{
			w = (window_t*)yzLocateWindow(ev.x2, ev.y2, &relx, &rely);
			if(w != prevw)
			{
				if(prevw)notify_drag(prevw, "avm", -1, -1);
				prevw = w;
			}
			if(w)acc = notify_drag(w, "avm", relx, rely);
		}
	} while(ev.type != YZ_MOUSE_UP);
	if(prevw)notify_drag(prevw, "avm", -1, -1);	// end the drag

	dropping_avm = 0;
	display_avm_child_background(view, &tvdata->gcl, white, avm, -1, 0, 0);
	yzRecomputeScrollAreaClipping(view->scroll_area);

#define	ROOT_AVM_PATH	PATH_DIV_STR
	if(prevw && acc) lkb_send_unify( tvdata->id, (avm->path==0)?ROOT_AVM_PATH:avm->path,
								drop_target_id, drop_target_path);
}

int		avm_view_drag(struct embedded_view_t	*view, char	*type, int	x, int	y)
{
	static lkb_avm	*hilite = 0;
	static int		hilite_child = -1;
	lkb_avm	*avm;
	int		atype, which_child, hx, hy, replaced = 0;
	color_t	white = {65535, 65535, 65535, 65535}, hicolor = {55000, 55000, 65535};

	if(tvdata->failures)
		return 0;	// do not accept drags if we have failures

	//printf("drag is at %d %d\n", x, y);
	if(strcmp(type, "avm"))
	{
		//printf("drag is unknown type `%s'\n", type);
		return 0;
	}

	if(x==-1 && y==-1) { avm = 0; which_child = -1; }
	else avm = pick_avm(tvdata->avm, x, y, &atype, 1, &which_child);

	if(!avm || atype != avm_structure)
	{
		//printf(" drag is not over an AVM\n");
		avm = 0;
		which_child = -1;
	}
	else if(avm == dropping_avm && which_child==-1)avm = 0;	// can't drop onto itself!
	else
	{
		if(which_child>=0) snprintf(drop_target_path, 1023, "%s%s%s",
			avm->path?avm->path:"", avm->path?PATH_DIV_STR:"", avm->attr_name[which_child]);
		else if(avm->path)strncpy(drop_target_path, avm->path, 1023);
		else strcpy(drop_target_path, ROOT_AVM_PATH);
		drop_target_path[1023] = 0;
		drop_target_id = tvdata->id;
		//printf("drag %d %d	path `%s'\n", x, y, drop_target_path);
	}

	if(hilite != avm || hilite_child != which_child)
	{
		// erase old hilite, if it is not contained in new hilite
		if(hilite)
		{
			hx = (hilite_child>=0)?hilite->attr_x[hilite_child]:hilite->x1;
			hy = (hilite_child>=0)?hilite->attr_y[hilite_child]:hilite->y1;
			if(!avm || which_child>=0 ||
				hx < avm->x1 || hx >= avm->x1+avm->dx ||
				hy < avm->y1 || hy >= avm->y1+avm->dy)
			{
				// old is not contained in new
				// check if new is contained in old
				if(avm)
				{
					hx = (which_child>=0)?avm->attr_x[which_child]:avm->x1;
					hy = (which_child>=0)?avm->attr_y[which_child]:avm->y1;
					if(hilite_child==-1 && hx>=hilite->x1 && hx<hilite->x1+hilite->dx &&
							hy>=hilite->y1 && hy<hilite->y1+hilite->dy)
					{
						replaced = 1;
						display_avm_child_background(view, &tvdata->gcl, white, hilite, hilite_child, avm, which_child);
						//printf("culled SHOW_NEW\n");
					}
				}
				if(!replaced)display_avm_child_background(view, &tvdata->gcl, white, hilite, hilite_child, 0, 0);
			}
			//else printf("culled CLEAR_OLD\n");
		}
		hilite = avm;
		hilite_child = which_child;
		if(hilite && !replaced)display_avm_child_background(view, &tvdata->gcl, hicolor, hilite, hilite_child, 0, 0);
	}

	return hilite?1:0;
}

void	do_postscript_avm(embedded_view_t	*view, int	width, int	height)
{
	window_t	*avm_ps, *old;
	int			dy, dx, fd;
	float		scale;
	struct timeval	tv1, tv2;
	float			secs;
	char	foo[1024], fname[768] = "avm-print.ps";

	sprintf(fname, "/tmp/avm.%d.ps", tvdata->id);

	gettimeofday(&tv1, 0);
	unlink(fname);
	fd = open(fname, O_WRONLY | O_CREAT, 0664);
	avm_ps = (window_t*)yzPostScriptWindow("Feature Structure", 800, 555, fd);
	old = yzSelectWindow(avm_ps);

	if(width > height)
	{
		scale = 660.0 / width;
		if((540.0 / height) < scale)
			scale = 540.0 / height;
		yzPostScriptSetLandscape();
	}
	else
	{
		scale = 540.0 / width;
		if((660.0 / height) < scale)
			scale = 660.0 / height;
		yzSetOrigin(0,350);
	}
extern int yzPostScriptSetScale(float);
	yzPostScriptSetScale(scale);

	current_offset_x = current_offset_y = 20;
	//render_avm(avm, &dy, &dx, 2);
	draw_gc_list(&tvdata->gcl, 0, 0, width, height);
	yzPostScriptEndPage();
	close(fd);
	gettimeofday(&tv2, 0);
	secs = tv2.tv_sec - tv1.tv_sec;
	secs += ((float)tv2.tv_usec - tv1.tv_usec) / 1000000;
	//fprintf(stderr, "printing took %.2f seconds\n", secs);

	sprintf(foo, "Printed AVM to '%s' at scale %.1f%%\n", fname, 100*scale);
	yzSelectWindow(old);
	console_add(foo);
}

void	postscript_avm(embedded_view_t	*view)
{
	do_postscript_avm(view, view->width, view->height);
}

void	latex_avm(embedded_view_t	*view)
{
	char	fname[768], message[1024];

	sprintf(fname, "/tmp/avm.%d.tex", tvdata->id);
	do_latex_avm(tvdata->avm, view->width, view->height, fname);
	sprintf(message, "Output AVM to `%s'\n", fname);
	console_add(message);
}