input: add a catch-all "unmapped" command

This can be used to grab all unmapped keys.

Fixes #2612.

4 files changed, 14 insertions, 1 deletions

diff --git a/DOCS/man/input.rst b/DOCS/man/input.rst
index e3fbddd778..cfe179c06f 100644
--- a/DOCS/man/input.rst
+++ b/DOCS/man/input.rst
@@ -546,6 +546,12 @@ Input Commands that are Possibly Subject to Change
         Always bind a key. (The input section that was made active most recently
         wins if there are ambiguities.)
 
+    This command can be used to dispatch arbitrary keys to a script or a client
+    API user. If the input section defines ``script-binding`` commands, it is
+    also possible to get separate events on key up/down, and relatively detailed
+    information about the key state. The special key name ``unmapped`` can be
+    used to match any unmapped key.
+
 ``overlay-add <id> <x> <y> "<file>" <offset> "<fmt>" <w> <h> <stride>``
     Add an OSD overlay sourced from raw data. This might be useful for scripts
     and applications controlling mpv, and which want to display things on top
diff --git a/input/input.c b/input/input.c
index 58907ccd50..24281fe99e 100644
--- a/input/input.c
+++ b/input/input.c
@@ -446,7 +446,9 @@ static mp_cmd_t *get_cmd_from_keys(struct input_ctx *ictx, char *force_section,
         return handle_test(ictx, code);
 
     struct cmd_bind *cmd = find_any_bind_for_key(ictx, force_section, code);
-    if (cmd == NULL) {
+    if (!cmd)
+        cmd = find_any_bind_for_key(ictx, force_section, MP_KEY_UNMAPPED);
+    if (!cmd) {
         if (code == MP_KEY_CLOSE_WIN)
             return mp_input_parse_cmd_strv(ictx->log, (const char*[]){"quit", 0});
         int msgl = MSGL_WARN;
diff --git a/input/keycodes.c b/input/keycodes.c
index 21a3c10e64..d6c07288c2 100644
--- a/input/keycodes.c
+++ b/input/keycodes.c
@@ -171,6 +171,8 @@ static const struct key_name key_names[] = {
   { MP_KEY_MOUSE_LEAVE, "MOUSE_LEAVE" },
   { MP_KEY_MOUSE_ENTER, "MOUSE_ENTER" },
 
+  { MP_KEY_UNMAPPED,    "UNMAPPED" },
+
   { 0, NULL }
 };
 
diff --git a/input/keycodes.h b/input/keycodes.h
index d95edb1f45..da88d52c37 100644
--- a/input/keycodes.h
+++ b/input/keycodes.h
@@ -200,6 +200,9 @@
 #define MP_KEY_IS_MOUSE(code) \
     (MP_KEY_IS_MOUSE_CLICK(code) || MP_KEY_IS_MOUSE_MOVE(code))
 
+// No input source should generate this.
+#define MP_KEY_UNMAPPED (MP_KEY_INTERN+4)
+
 // Emit a command even on key-up (normally key-up is ignored). This means by
 // default they binding will be triggered on key-up instead of key-down.
 // This is a fixed part of the keycode, not a modifier than can change.