command: add properties for playlist position

playlist-pos can set/get the current playlist index. playlist-count
returns the number of entries in the playlist.

DOCS/man/en/input.rst

@@ -396,9 +396,11 @@ tv-brightness               x
 tv-contrast                 x
 tv-saturation               x
 tv-hue                      x
+playlist-pos                  current position on playlist
+playlist-count                number of total playlist entries
+playlist                      playlist, current entry marked
 track-list                    list of audio/video/sub tracks, cur. entr. marked
 chapter-list                  list of chapters, current entry marked
-playlist                      playlist, current entry marked
 quvi-format                 x see ``--quvi-format``
 =========================== = ==================================================
 

core/command.c

@@ -1494,6 +1494,53 @@ static int mp_property_tv_color(m_option_t *prop, int action, void *arg,
 
 #endif
 
+static int mp_property_playlist_pos(m_option_t *prop, int action, void *arg,
+                                    MPContext *mpctx)
+{
+    struct playlist *pl = mpctx->playlist;
+    if (!pl->first)
+        return M_PROPERTY_UNAVAILABLE;
+
+    switch (action) {
+    case M_PROPERTY_GET: {
+        int pos = playlist_entry_to_index(pl, pl->current);
+        if (pos < 0)
+            return M_PROPERTY_UNAVAILABLE;
+        *(int *)arg = pos;
+        return M_PROPERTY_OK;
+    }
+    case M_PROPERTY_SET: {
+        struct playlist_entry *e = playlist_entry_from_index(pl, *(int *)arg);
+        if (!e)
+            return M_PROPERTY_ERROR;
+        mp_set_playlist_entry(mpctx, e);
+        return M_PROPERTY_OK;
+    }
+    case M_PROPERTY_GET_TYPE: {
+        struct m_option opt = {
+            .name = prop->name,
+            .type = CONF_TYPE_INT,
+            .flags = CONF_RANGE,
+            .min = 0,
+            .max = playlist_entry_count(pl) - 1,
+        };
+        *(struct m_option *)arg = opt;
+        return M_PROPERTY_OK;
+    }
+    }
+    return M_PROPERTY_NOT_IMPLEMENTED;
+}
+
+static int mp_property_playlist_count(m_option_t *prop, int action, void *arg,
+                                      MPContext *mpctx)
+{
+    if (action == M_PROPERTY_GET) {
+        *(int *)arg = playlist_entry_count(mpctx->playlist);
+        return M_PROPERTY_OK;
+    }
+    return M_PROPERTY_NOT_IMPLEMENTED;
+}
+
 static int mp_property_playlist(m_option_t *prop, int action, void *arg,
                                 MPContext *mpctx)
 {
@@ -1602,7 +1649,10 @@ static const m_option_t mp_properties[] = {
 
     { "chapter-list", mp_property_list_chapters, CONF_TYPE_STRING },
     { "track-list", property_list_tracks, CONF_TYPE_STRING },
+
     { "playlist", mp_property_playlist, CONF_TYPE_STRING },
+    { "playlist-pos", mp_property_playlist_pos, CONF_TYPE_INT },
+    { "playlist-count", mp_property_playlist_count, CONF_TYPE_INT },
 
     // Audio
     { "volume", mp_property_volume, CONF_TYPE_FLOAT,
@@ -2108,11 +2158,8 @@ void run_command(MPContext *mpctx, mp_cmd_t *cmd)
 
         playlist_add(mpctx->playlist, playlist_entry_new(filename));
 
-        if (!append) {
-            mpctx->playlist->current = mpctx->playlist->first;
-            mpctx->playlist->current_was_replaced = false;
-            mpctx->stop_play = PT_CURRENT_ENTRY;
-        }
+        if (!append)
+            mp_set_playlist_entry(mpctx, mpctx->playlist->first);
         break;
     }
 
@@ -2126,10 +2173,8 @@ void run_command(MPContext *mpctx, mp_cmd_t *cmd)
             playlist_transfer_entries(mpctx->playlist, pl);
             talloc_free(pl);
 
-            if (!append) {
-                mpctx->playlist->current = mpctx->playlist->first;
-                mpctx->stop_play = PT_CURRENT_ENTRY;
-            }
+            if (!append && mpctx->playlist->first)
+                mp_set_playlist_entry(mpctx, mpctx->playlist->first);
         } else {
             mp_tmsg(MSGT_CPLAYER, MSGL_ERR,
                     "\nUnable to load playlist %s.\n", filename);

core/mp_core.h

@@ -317,6 +317,7 @@ bool mp_remove_track(struct MPContext *mpctx, struct track *track);
 struct playlist_entry *mp_next_file(struct MPContext *mpctx, int direction);
 int mp_get_cache_percent(struct MPContext *mpctx);
 void mp_write_watch_later_conf(struct MPContext *mpctx);
+void mp_set_playlist_entry(struct MPContext *mpctx, struct playlist_entry *e);
 
 void mp_print_version(int always);
 

core/mplayer.c

@@ -4521,6 +4521,16 @@ static void play_files(struct MPContext *mpctx)
     }
 }
 
+// Abort current playback and set the given entry to play next.
+// e must be on the mpctx->playlist.
+void mp_set_playlist_entry(struct MPContext *mpctx, struct playlist_entry *e)
+{
+    assert(playlist_entry_to_index(mpctx->playlist, e) >= 0);
+    mpctx->playlist->current = e;
+    mpctx->playlist->current_was_replaced = false;
+    mpctx->stop_play = PT_CURRENT_ENTRY;
+}
+
 void mp_print_version(int always)
 {
     mp_msg(MSGT_CPLAYER, always ? MSGL_INFO : MSGL_V,

core/playlist.c

@@ -196,3 +196,36 @@ void playlist_transfer_entries(struct playlist *pl, struct playlist *source_pl)
         playlist_insert(pl, add_after, e);
     }
 }
+
+// Return number of entries between list start and e.
+// Return -1 if e is not on the list, or if e is NULL.
+int playlist_entry_to_index(struct playlist *pl, struct playlist_entry *e)
+{
+    struct playlist_entry *cur = pl->first;
+    int pos = 0;
+    if (!e)
+        return -1;
+    while (cur && cur != e) {
+        cur = cur->next;
+        pos++;
+    }
+    return cur == e ? pos : -1;
+}
+
+int playlist_entry_count(struct playlist *pl)
+{
+    return playlist_entry_to_index(pl, pl->last) + 1;
+}
+
+// Return entry for which playlist_entry_to_index() would return index.
+// Return NULL if not found.
+struct playlist_entry *playlist_entry_from_index(struct playlist *pl, int index)
+{
+    struct playlist_entry *e = pl->first;
+    for (int n = 0; ; n++) {
+        if (!e || n == index)
+            return e;
+        e = e->next;
+    }
+}
+

core/playlist.h

@@ -64,4 +64,8 @@ struct playlist_entry *playlist_get_next(struct playlist *pl, int direction);
 void playlist_add_base_path(struct playlist *pl, bstr base_path);
 void playlist_transfer_entries(struct playlist *pl, struct playlist *source_pl);
 
+int playlist_entry_to_index(struct playlist *pl, struct playlist_entry *e);
+int playlist_entry_count(struct playlist *pl);
+struct playlist_entry *playlist_entry_from_index(struct playlist *pl, int index);
+
 #endif