command: add some playlist manipulation commands

playlist_remove and playlist_move.

DOCS/man/en/input.rst

@@ -164,6 +164,17 @@ loadlist "<playlist>" [replace|append]
 playlist_clear
     Clear the playlist, except the currently played file.
 
+playlist_remove <index>
+    Remove the playlist entry at the given index. Index values start counting
+    with 0. You can't remove the entry for the currently played file.
+
+playlist_move <index1> <index2>
+    Move the playlist entry at index1, so that it takes the place of the
+    entry index2. (Paradoxically, the moved playlist entry will not have
+    the index value index2 after moving if index1 was lower than index2,
+    because index2 refers to the target entry, not the index the entry
+    will have after moving.)
+
 run "<command>"
     Run the given command with ``/bin/sh -c``. The string is expanded like in
     property_expansion_.

core/command.c

@@ -2180,6 +2180,29 @@ void run_command(MPContext *mpctx, mp_cmd_t *cmd)
         break;
     }
 
+    case MP_CMD_PLAYLIST_REMOVE: {
+        struct playlist_entry *e = playlist_entry_from_index(mpctx->playlist,
+                                                             cmd->args[0].v.i);
+        if (e) {
+            // Can't play a removed entry
+            if (mpctx->playlist->current == e)
+                mpctx->stop_play = PT_CURRENT_ENTRY;
+            playlist_remove(mpctx->playlist, e);
+        }
+        break;
+    }
+
+    case MP_CMD_PLAYLIST_MOVE: {
+        struct playlist_entry *e1 = playlist_entry_from_index(mpctx->playlist,
+                                                              cmd->args[0].v.i);
+        struct playlist_entry *e2 = playlist_entry_from_index(mpctx->playlist,
+                                                              cmd->args[1].v.i);
+        if (e1) {
+            playlist_move(mpctx->playlist, e1, e2);
+        }
+        break;
+    }
+
     case MP_CMD_STOP:
         // Go back to the starting point.
         mpctx->stop_play = PT_STOP;

core/input/input.c

@@ -183,6 +183,8 @@ static const mp_cmd_t mp_cmds[] = {
                       {"append", 1},           {"1", 1})),
   }},
   { MP_CMD_PLAYLIST_CLEAR, "playlist_clear", },
+  { MP_CMD_PLAYLIST_REMOVE, "playlist_remove", { ARG_INT } },
+  { MP_CMD_PLAYLIST_MOVE, "playlist_move", { ARG_INT, ARG_INT } },
   { MP_CMD_RUN, "run", { ARG_STRING } },
 
   { MP_CMD_KEYDOWN_EVENTS, "key_down_event", { ARG_INT } },

core/input/input.h

@@ -39,6 +39,8 @@ enum mp_command_type {
     MP_CMD_LOADFILE,
     MP_CMD_LOADLIST,
     MP_CMD_PLAYLIST_CLEAR,
+    MP_CMD_PLAYLIST_REMOVE,
+    MP_CMD_PLAYLIST_MOVE,
     MP_CMD_SUB_STEP,
     MP_CMD_TV_SET_CHANNEL,
     MP_CMD_TV_LAST_CHANNEL,

core/playlist.c

@@ -114,6 +114,20 @@ void playlist_clear(struct playlist *pl)
     pl->current_was_replaced = false;
 }
 
+// Moves entry such that entry->prev = at (even if at is NULL)
+void playlist_move(struct playlist *pl, struct playlist_entry *entry,
+                   struct playlist_entry *at)
+{
+    struct playlist_entry *save_current = pl->current;
+    bool save_replaced = pl->current_was_replaced;
+
+    playlist_unlink(pl, entry);
+    playlist_insert(pl, at ? at->prev : pl->last, entry);
+
+    pl->current = save_current;
+    pl->current_was_replaced = save_replaced;
+}
+
 void playlist_add_file(struct playlist *pl, const char *filename)
 {
     playlist_add(pl, playlist_entry_new(filename));

core/playlist.h

@@ -58,6 +58,9 @@ void playlist_add(struct playlist *pl, struct playlist_entry *add);
 void playlist_remove(struct playlist *pl, struct playlist_entry *entry);
 void playlist_clear(struct playlist *pl);
 
+void playlist_move(struct playlist *pl, struct playlist_entry *entry,
+                   struct playlist_entry *at);
+
 void playlist_add_file(struct playlist *pl, const char *filename);
 void playlist_shuffle(struct playlist *pl);
 struct playlist_entry *playlist_get_next(struct playlist *pl, int direction);