command: add dropped-file property

This adds dropped-file property which contains a list of dropped files
and the type of the drop. This allows clients to implement custom drag
and drop handling.

DOCS/interface-changes/dnd.txt

@@ -1 +1,2 @@
 add `--input-builtin-drag-and-drop` option
+add `dropped-file` property

DOCS/man/input.rst

@@ -3231,6 +3231,39 @@ Property list
             "pad-btns"           MPV_FORMAT_NODE_MAP
                (key and string value for each pad-btn entry)
 
+``dropped-files``
+    Information of the most recent drag-and-drop event mpv received. This
+    property is only updated when ``--input-builtin-drag-and-drop=no``.
+    A client can observe this property to detect when a drag-and-drop event
+    happens. This property is unavailable if no drag-and-drop event has
+    happened.
+
+    Has the following sub-properties:
+
+    ``dropped-files/time``
+        The timestamp of the last drag-and-drop event mpv received, in
+        nanoseconds. This uses the same clock as ``mpv_get_time_ns()``.
+
+    ``dropped-files/action``
+        The action of the drag-and-drop event, can be one of ``replace``,
+        ``append``, or ``insert-next``. This is affected by the
+        ``--drag-and-drop`` option.
+
+    ``dropped-files/files``
+        The dropped file names of the drag-and-drop event.
+
+    When querying the property with the client API using ``MPV_FORMAT_NODE``,
+    or with Lua ``mp.get_property_native``, this will return a mpv_node with
+    the following contents:
+
+    ::
+
+        MPV_FORMAT_NODE_MAP
+            "time"    MPV_FORMAT_INT64
+            "action"  MPV_FORMAT_STRING
+            "files"   MPV_FORMAT_NODE_ARRAY
+                MPV_FORMAT_STRING
+
 ``sub-ass-extradata``
     The current ASS subtitle track's extradata. There is no formatting done.
     The extradata is returned as a string as-is. This property is not

DOCS/man/options.rst

@@ -4454,7 +4454,8 @@ Input
 
 ``--input-builtin-drag-and-drop=<yes|no>``
     Enable the built-in drag-and-drop behavior (default: yes). Setting it to no
-    disables the built-in drag-and-drop handling.
+    disables the built-in drag-and-drop handling and enables the ``dropped-files``
+    property, which can be used to retrieve information about dropped files.
 
 ``--input-cmdlist``
     Prints all commands that can be bound to keys.

input/event.h

@@ -25,6 +25,7 @@ enum mp_dnd_action {
     DND_REPLACE,
     DND_APPEND,
     DND_INSERT_NEXT,
+    DND_NONE,
 };
 
 // Drop data in a specific format (identified by the mimetype).

input/input.c

@@ -160,6 +160,12 @@ struct input_ctx {
     struct touch_point *touch_points;
     int num_touch_points;
 
+    // List of last dropped files
+    int64_t dnd_ts;
+    enum mp_dnd_action dnd_action;
+    bstr *dropped_files;
+    int num_dropped_files;
+
     int tablet_x, tablet_y;
     // Indicates tablet tools in proximity / close to tablet surface
     bool tablet_tool_in_proximity;
@@ -1286,6 +1292,15 @@ void mp_input_drop_files(struct input_ctx *ictx, int num_files, char **files,
 {
     input_lock(ictx);
     if (!ictx->opts->builtin_dnd) {
+        TA_FREEP(&ictx->dropped_files);
+        ictx->dropped_files = talloc_zero_array(ictx, bstr, num_files);
+        ictx->num_dropped_files = num_files;
+        ictx->dnd_ts = mp_time_ns();
+        ictx->dnd_action = action;
+        for (int i = 0; i < num_files; i++)
+            ictx->dropped_files[i] = bstrdup(ictx->dropped_files, bstr0(files[i]));
+
+        notify_event_update(ictx);
         input_unlock(ictx);
         return;
     }
@@ -1336,6 +1351,23 @@ void mp_input_drop_files(struct input_ctx *ictx, int num_files, char **files,
     input_unlock(ictx);
 }
 
+void mp_input_get_dropped_files(struct input_ctx *ictx, void *talloc_ctx,
+                                int64_t *dnd_ts,
+                                enum mp_dnd_action *dnd_action,
+                                char ***dropped_files)
+{
+    input_lock(ictx);
+    *dnd_ts = ictx->dnd_ts;
+    *dnd_action = ictx->dnd_action;
+    *dropped_files = NULL;
+    int num = 0;
+    for (int i = 0; i < ictx->num_dropped_files; i++)
+        MP_TARRAY_APPEND(talloc_ctx, *dropped_files, num,
+                         bstrto0(talloc_ctx, ictx->dropped_files[i]));
+    MP_TARRAY_APPEND(talloc_ctx, *dropped_files, num, NULL);
+    input_unlock(ictx);
+}
+
 unsigned int mp_input_get_mouse_event_counter(struct input_ctx *ictx)
 {
     // Make the frontend always display the mouse cursor (as long as it's not
@@ -1746,6 +1778,7 @@ struct input_ctx *mp_input_init(struct mpv_global *global,
         .wakeup_ctx = wakeup_ctx,
         .active_sections = talloc_array(ictx, struct active_section, 0),
         .touch_points = talloc_array(ictx, struct touch_point, 0),
+        .dnd_action = DND_NONE,
     };
 
     ictx->opts = ictx->opts_cache->opts;

input/input.h

@@ -209,6 +209,11 @@ bool mp_input_test_dragging(struct input_ctx *ictx, int x, int y);
 // Enqueue files for playback after drag and drop
 void mp_input_drop_files(struct input_ctx *ictx, int num_files, char **files,
                          enum mp_dnd_action action);
+// Last dropped files
+void mp_input_get_dropped_files(struct input_ctx *ictx, void *talloc_ctx,
+                                int64_t *dnd_ts,
+                                enum mp_dnd_action *dnd_action,
+                                char ***dropped_files);
 
 // Initialize the input system
 struct mpv_global;

player/command.c

@@ -3267,6 +3267,44 @@ static int mp_property_tablet_pos(void *ctx, struct m_property *prop,
     return M_PROPERTY_NOT_IMPLEMENTED;
 }
 
+static int mp_property_dropped_files(void *ctx, struct m_property *prop,
+                                     int action, void *arg)
+{
+    MPContext *mpctx = ctx;
+
+    int valid = m_property_read_sub_validate(ctx, prop, action, arg);
+    if (valid != M_PROPERTY_VALID)
+        return valid;
+
+    int64_t dnd_ts;
+    enum mp_dnd_action dnd_action;
+    char **dropped_files;
+    void *talloc_ctx = talloc_new(NULL);
+    mp_input_get_dropped_files(mpctx->input, talloc_ctx, &dnd_ts,
+                               &dnd_action, &dropped_files);
+    int r = M_PROPERTY_UNAVAILABLE;
+    if (dnd_action == DND_NONE)
+        goto done;
+
+    char *actionstr = dnd_action == DND_REPLACE ? "replace" :
+                      dnd_action == DND_APPEND ? "append" :
+                      dnd_action == DND_INSERT_NEXT ? "insert-next" :
+                      "none";
+
+    struct m_sub_property props[] = {
+        {"time",   SUB_PROP_INT64(dnd_ts)},
+        {"action", SUB_PROP_STR(actionstr)},
+        {"files",  SUB_PROP_STRING_LIST(dropped_files)},
+        {0}
+    };
+
+    r = m_property_read_sub(props, action, arg);
+
+done:
+    talloc_free(talloc_ctx);
+    return r;
+}
+
 /// Video fps (RO)
 static int mp_property_fps(void *ctx, struct m_property *prop,
                            int action, void *arg)
@@ -4666,6 +4704,7 @@ static const struct m_property mp_properties_base[] = {
     {"mouse-pos", mp_property_mouse_pos},
     {"touch-pos", mp_property_touch_pos},
     {"tablet-pos", mp_property_tablet_pos},
+    {"dropped-files", mp_property_dropped_files},
 
     // Subs
     {"sid", mp_property_switch_track, .priv = (void *)(const int[]){0, STREAM_SUB}},
@@ -4810,7 +4849,7 @@ static const char *const *const mp_event_property_change[] = {
     E(MP_EVENT_CHANGE_PLAYLIST, "playlist", "playlist-pos", "playlist-pos-1",
       "playlist-count", "playlist/count", "playlist-current-pos",
       "playlist-playing-pos"),
-    E(MP_EVENT_INPUT_PROCESSED, "mouse-pos", "touch-pos", "tablet-pos"),
+    E(MP_EVENT_INPUT_PROCESSED, "mouse-pos", "touch-pos", "tablet-pos", "dropped-files"),
     E(MP_EVENT_CORE_IDLE, "core-idle", "eof-reached"),
 };
 #undef E