add vbi_get_next_pgno

5 files changed, 140 insertions, 0 deletions

diff --git a/src/cache-priv.h b/src/cache-priv.h
index 2501536..a60ed37 100644
--- a/src/cache-priv.h
+++ b/src/cache-priv.h
@@ -470,6 +470,18 @@ _vbi_ttx_charset_init		(const vbi_ttx_charset *charset[2],
 				 const struct ttx_extension *ext,
 				 const cache_page *	cp);
 
+extern cache_page *
+_vbi_cache_find_next_page       (vbi_cache * ca,
+				 int dir,
+				 vbi_subno pgno,
+				 vbi_subno subno);
+
+extern cache_page *
+_vbi_cache_find_page            (vbi_cache * ca,
+				 int dir,
+				 vbi_subno pgno);
+
+
 #endif /* CACHE_PRIV_H */
 
 /*
diff --git a/src/cache.c b/src/cache.c
index 19a27a7..7a82bab 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -1337,6 +1337,82 @@ _vbi_cache_get_page		(vbi_cache *		ca,
 	return cache_page_ref (cp);
 }
 
+cache_page *
+_vbi_cache_find_next_page       (vbi_cache * ca,
+				 int dir,
+				 vbi_subno pgno,
+				 vbi_subno subno)
+{
+	struct node *hash_list;
+	cache_page *cp, *cp1, *ret = NULL;
+
+	assert (NULL != ca);
+
+	if (pgno < 0x100 || pgno > 0x8FF || 0xFF == (pgno & 0xFF)) {
+		warning (&ca->log,
+			 "Invalid pgno 0x%x.", pgno);
+		return NULL;
+	}
+
+	hash_list = ca->hash + hash (pgno);
+
+	FOR_ALL_NODES (cp, cp1, hash_list, hash_node) {
+		if (cp->pgno == pgno) {
+			if(dir > 0){
+				if((cp->subno > subno) && (!ret || (ret->subno > cp->subno)))
+					ret = cp;
+			}else if(dir < 0){
+				if((cp->subno < subno) && (!ret || (ret->subno < cp->subno)))
+					ret = cp;
+			}
+		}
+	}
+
+	if(ret){
+		return cache_page_ref(ret);
+	}
+
+	return NULL;
+}
+
+cache_page *
+_vbi_cache_find_page            (vbi_cache * ca,
+				 int dir,
+				 vbi_subno pgno)
+{
+	struct node *hash_list;
+	cache_page *cp, *cp1, *ret = NULL;
+
+	assert (NULL != ca);
+
+	if (pgno < 0x100 || pgno > 0x8FF || 0xFF == (pgno & 0xFF)) {
+		warning (&ca->log,
+			 "Invalid pgno 0x%x.", pgno);
+		return NULL;
+	}
+
+	hash_list = ca->hash + hash (pgno);
+
+	FOR_ALL_NODES (cp, cp1, hash_list, hash_node) {
+		if (cp->pgno == pgno) {
+			if(dir > 0){
+				if(!ret || (ret->subno > cp->subno))
+					ret = cp;
+			}else if(dir < 0){
+				if(!ret || (ret->subno < cp->subno))
+					ret = cp;
+			}
+		}
+	}
+
+	if(ret){
+		return cache_page_ref(ret);
+	}
+
+	return NULL;
+
+}
+
 /**
  * @internal
  * For vbi_search.
diff --git a/src/libzvbi.h b/src/libzvbi.h
index fa422db..28c3dc7 100644
--- a/src/libzvbi.h
+++ b/src/libzvbi.h
@@ -1836,6 +1836,7 @@ extern void		vbi_resolve_link(vbi_page *pg, int column, int row,
 					 vbi_link *ld);
 extern void		vbi_resolve_home(vbi_page *pg, vbi_link *ld);
 
+extern vbi_bool         vbi_get_next_pgno(vbi_decoder *vbi, int dir, vbi_pgno *pgno, vbi_pgno *subno);
 
 /* tables.h */
 
diff --git a/src/teletext.c b/src/teletext.c
index f9165a9..803cf5f 100644
--- a/src/teletext.c
+++ b/src/teletext.c
@@ -2872,6 +2872,55 @@ vbi_fetch_vt_page(vbi_decoder *vbi, vbi_page *pg,
 	}
 }
 
+vbi_bool
+vbi_get_next_pgno(vbi_decoder *vbi, int dir, vbi_pgno *pgno, vbi_pgno *subno)
+{
+	cache_page *vtp;
+	vbi_pgno pg, sub;
+
+	assert(pgno && subno && (pgno>0x899 || pgno < 0x100));
+
+	pg  = *pgno;
+	sub = *subno;
+
+	vtp = _vbi_cache_find_next_page (vbi->ca, dir, pg, sub);
+
+	if (!vtp) {
+		int start, no;
+		
+		start = no = vbi_bcd2dec(pg);
+
+		if(dir > 0){
+			do{
+				no++;
+				if(no > 899)
+					no = 0;
+				vtp = _vbi_cache_find_page(vbi->ca, dir, vbi_dec2bcd(no));
+				if(vtp)
+					break;
+			}while(no != start);
+		}else if(dir < 0){
+			do {
+				no--;
+				if(no < 100)
+					no = 899;
+				vtp = _vbi_cache_find_page(vbi->ca, dir, vbi_dec2bcd(no));
+				if(vtp)
+					break;
+			}while(no != start);
+		}
+	}
+
+	if(vtp) {
+		*pgno  = vtp->pgno;
+		*subno = vtp->subno;
+		cache_page_unref (vtp);
+		return TRUE;
+	}
+
+	return FALSE;
+}
+
 /*
 Local variables:
 c-set-style: K&R
diff --git a/src/teletext_decoder.h b/src/teletext_decoder.h
index aa06bf4..f31548f 100644
--- a/src/teletext_decoder.h
+++ b/src/teletext_decoder.h
@@ -119,6 +119,8 @@ extern vbi_bool		vbi_format_vt_page(vbi_decoder *, vbi_page *,
 					   int display_rows,
 					   vbi_bool navigation);
 
+extern vbi_bool         vbi_get_next_pgno(vbi_decoder *vbi, int dir, vbi_pgno *pgno, vbi_pgno *subno);
+
 #endif
 
 /*