command, input: add input-bindings property

Read-only information about all bindings. Somewhat hoping someone can
make a nice GUI-like overlay thing for it, which provides information
about mapped keys.

DOCS/man/input.rst

@@ -2641,6 +2641,43 @@ Property list
     information, but it's a valid feature request to extend this property if
     needed.)
 
+``input-bindings``
+    Return list of current input key bindings. This returns an array of maps,
+    where each map node represents a binding for a single key/command. This map
+    has the following entries:
+
+    ``key``
+        The key name. This is normalized and may look slightly different from
+        how it was specified in the source (e.g. in input.conf).
+
+    ``cmd``
+        The command mapped to the key. (Currently, this is exactly the same
+        string as specified in the source. It's possible that it will be
+        normalized in the future.)
+
+    ``is_weak``
+        If set to true, any existing and active user bindings will take priority.
+
+    ``owner``
+        If this entry exists, the name of the script (or similar) which added
+        this binding.
+
+    ``section``
+        Name of the section this binding is part of. This is a rarely used
+        mechanism. This entry may be removed or change meaning in the future.
+
+    ``priority``
+        A number. Bindings with a higher value are preferred over bindings
+        with a lower value. If the value is negative, this binding is inactive
+        and will not be triggered by input. Note that mpv does not use this
+        value internally, and matching of bindings may work slightly differently
+        in some cases. In addition, this value is dynamic and can change around
+        at runtime.
+
+    This property is read-only, and change notification is not supported.
+    Currently, there is no mechanism to change key bindings at runtime, other
+    than scripts adding or removing their own bindings.
+
 Inconsistencies between options and properties
 ----------------------------------------------
 

input/input.c

@@ -46,6 +46,7 @@
 #include "mpv_talloc.h"
 #include "options/options.h"
 #include "misc/bstr.h"
+#include "misc/node.h"
 #include "stream/stream.h"
 #include "common/common.h"
 
@@ -1487,6 +1488,53 @@ void mp_input_bind_key(struct input_ctx *ictx, int key, bstr command)
     }
 }
 
+struct mpv_node mp_input_get_bindings(struct input_ctx *ictx)
+{
+    input_lock(ictx);
+    struct mpv_node root;
+    node_init(&root, MPV_FORMAT_NODE_ARRAY, NULL);
+
+    for (struct cmd_bind_section *s = ictx->cmd_bind_sections; s; s = s->next) {
+        int priority = -1;
+
+        for (int i = 0; i < ictx->num_active_sections; i++) {
+            struct active_section *as = &ictx->active_sections[i];
+            if (strcmp(as->name, s->section) == 0) {
+                priority = i;
+                break;
+            }
+        }
+
+        for (int n = 0; n < s->num_binds; n++) {
+            struct cmd_bind *b = &s->binds[n];
+            struct mpv_node *entry = node_array_add(&root, MPV_FORMAT_NODE_MAP);
+
+            int b_priority = priority;
+            if (b->is_builtin && !ictx->opts->default_bindings)
+                b_priority = -1;
+
+            // Try to fixup the weird logic so consumer of this bindings list
+            // does not get too confused.
+            if (b_priority >= 0 && !b->is_builtin)
+                b_priority += ictx->num_active_sections;
+
+            node_map_add_string(entry, "section", s->section);
+            if (s->owner)
+                node_map_add_string(entry, "owner", s->owner);
+            node_map_add_string(entry, "cmd", b->cmd);
+            node_map_add_flag(entry, "is_weak", b->is_builtin);
+            node_map_add_int64(entry, "priority", b_priority);
+
+            char *key = mp_input_get_key_combo_name(b->keys, b->num_keys);
+            node_map_add_string(entry, "key", key);
+            talloc_free(key);
+        }
+    }
+
+    input_unlock(ictx);
+    return root;
+}
+
 struct mp_input_src_internal {
     pthread_t thread;
     bool thread_running;

input/input.h

@@ -205,6 +205,8 @@ void mp_input_bind_key(struct input_ctx *ictx, int key, bstr command);
 
 void mp_input_set_repeat_info(struct input_ctx *ictx, int rate, int delay);
 
+struct mpv_node mp_input_get_bindings(struct input_ctx *ictx);
+
 void mp_input_pipe_add(struct input_ctx *ictx, const char *filename);
 
 void mp_input_sdl_gamepad_add(struct input_ctx *ictx);

player/command.c

@@ -3505,6 +3505,22 @@ static int mp_property_commands(void *ctx, struct m_property *prop,
     return M_PROPERTY_NOT_IMPLEMENTED;
 }
 
+static int mp_property_bindings(void *ctx, struct m_property *prop,
+                                int action, void *arg)
+{
+    MPContext *mpctx = ctx;
+    switch (action) {
+    case M_PROPERTY_GET_TYPE:
+        *(struct m_option *)arg = (struct m_option){.type = CONF_TYPE_NODE};
+        return M_PROPERTY_OK;
+    case M_PROPERTY_GET: {
+        *(struct mpv_node *)arg = mp_input_get_bindings(mpctx->input);
+        return M_PROPERTY_OK;
+    }
+    }
+    return M_PROPERTY_NOT_IMPLEMENTED;
+}
+
 // Redirect a property name to another
 #define M_PROPERTY_ALIAS(name, real_property) \
     {(name), mp_property_alias, .priv = (real_property)}
@@ -3691,6 +3707,7 @@ static const struct m_property mp_properties_base[] = {
     {"property-list", mp_property_list},
     {"profile-list", mp_profile_list},
     {"command-list", mp_property_commands},
+    {"input-bindings", mp_property_bindings},
 
     {"play-dir", mp_property_play_direction},
 
@@ -5806,7 +5823,7 @@ static void cmd_dump_cache_ab(void *p)
  * command has an arbitrary number of arguments, all using the type indicated by
  * the last argument (they are appended to mp_cmd.args[] starting at the last
  * argument's index).
- * Arguments have named, which can be used by named argument functions, e.g. in
+ * Arguments have names, which can be used by named argument functions, e.g. in
  * Lua with mp.command_native().
  */