Introduce GET_BINDING_STATE IPC command

fixes #3892

AnyEvent-I3/lib/AnyEvent/I3.pm

@@ -101,11 +101,13 @@ use constant TYPE_GET_BINDING_MODES => 8;
 use constant TYPE_GET_CONFIG => 9;
 use constant TYPE_SEND_TICK => 10;
 use constant TYPE_SYNC => 11;
+use constant TYPE_GET_BINDING_STATE => 12;
 
 our %EXPORT_TAGS = ( 'all' => [
     qw(i3 TYPE_RUN_COMMAND TYPE_COMMAND TYPE_GET_WORKSPACES TYPE_SUBSCRIBE TYPE_GET_OUTPUTS
        TYPE_GET_TREE TYPE_GET_MARKS TYPE_GET_BAR_CONFIG TYPE_GET_VERSION
-       TYPE_GET_BINDING_MODES TYPE_GET_CONFIG TYPE_SEND_TICK TYPE_SYNC)
+       TYPE_GET_BINDING_MODES TYPE_GET_CONFIG TYPE_SEND_TICK TYPE_SYNC
+       TYPE_GET_BINDING_STATE)
 ] );
 
 our @EXPORT_OK = ( @{ $EXPORT_TAGS{all} } );

docs/ipc

@@ -66,6 +66,7 @@ to do that).
 | 9 | +GET_CONFIG+ | <<_config_reply,CONFIG>> | Returns the last loaded i3 config.
 | 10 | +SEND_TICK+ | <<_tick_reply,TICK>> | Sends a tick event with the specified payload.
 | 11 | +SYNC+ | <<_sync_reply,SYNC>> | Sends an i3 sync event with the specified random value to the specified window.
+| 12 | +GET_BINDING_STATE+ | <<_binding_state_reply,BINDING_STATE>> | Request the current binding state, e.g. the currently active binding mode name.
 |======================================================
 
 So, a typical message could look like this:
@@ -131,6 +132,8 @@ GET_CONFIG (9)::
 	Reply to the GET_CONFIG message.
 TICK (10)::
 	Reply to the SEND_TICK message.
+GET_BINDING_STATE (12)::
+	Reply to the GET_BINDING_STATE message.
 
 [[_command_reply]]
 === COMMAND reply
@@ -709,6 +712,17 @@ responded to.
 { "success": true }
 -------------------
 
+[[_binding_state_reply]]
+=== GET_BINDING_STATE reply
+
+The binding_state reply is a map which currently only contains the "name"
+member, which is the name of the currently active binding mode as a string.
+
+*Example:*
+-------------------
+{ "name": "default" }
+-------------------
+
 == Events
 
 [[events]]

include/i3.h

@@ -58,6 +58,7 @@ extern char **start_argv;
 extern Display *xlibdpy, *xkbdpy;
 extern int xkb_current_group;
 extern TAILQ_HEAD(bindings_head, Binding) * bindings;
+extern const char *current_binding_mode;
 extern TAILQ_HEAD(autostarts_head, Autostart) autostarts;
 extern TAILQ_HEAD(autostarts_always_head, Autostart) autostarts_always;
 extern TAILQ_HEAD(ws_assignments_head, Workspace_Assignment) ws_assignments;

include/i3/ipc.h

@@ -66,6 +66,9 @@ typedef struct i3_ipc_header {
 /** Trigger an i3 sync protocol message via IPC. */
 #define I3_IPC_MESSAGE_TYPE_SYNC 11
 
+/** Request the current binding state. */
+#define I3_IPC_MESSAGE_TYPE_GET_BINDING_STATE 12
+
 /*
  * Messages from i3 to clients
  *
@@ -82,6 +85,7 @@ typedef struct i3_ipc_header {
 #define I3_IPC_REPLY_TYPE_CONFIG 9
 #define I3_IPC_REPLY_TYPE_TICK 10
 #define I3_IPC_REPLY_TYPE_SYNC 11
+#define I3_IPC_REPLY_TYPE_GET_BINDING_STATE 12
 
 /*
  * Events from i3 to clients. Events have the first bit set high.

src/bindings.c

@@ -628,6 +628,7 @@ void switch_mode(const char *new_mode) {
 
         ungrab_all_keys(conn);
         bindings = mode->bindings;
+        current_binding_mode = mode->name;
         translate_keysyms();
         grab_all_keys(conn);
 

src/config.c

@@ -174,6 +174,7 @@ bool load_configuration(const char *override_configpath, config_load_t load_type
     SLIST_INSERT_HEAD(&modes, default_mode, modes);
 
     bindings = default_mode->bindings;
+    current_binding_mode = default_mode->name;
 
     /* Clear the old config or initialize the data structure */
     memset(&config, 0, sizeof(config));

src/ipc.c

@@ -1337,9 +1337,27 @@ IPC_HANDLER(sync) {
     ipc_send_client_message(client, strlen(reply), I3_IPC_REPLY_TYPE_SYNC, (const uint8_t *)reply);
 }
 
+IPC_HANDLER(get_binding_state) {
+    yajl_gen gen = ygenalloc();
+
+    y(map_open);
+
+    ystr("name");
+    ystr(current_binding_mode);
+
+    y(map_close);
+
+    const unsigned char *payload;
+    ylength length;
+    y(get_buf, &payload, &length);
+
+    ipc_send_client_message(client, length, I3_IPC_REPLY_TYPE_GET_BINDING_STATE, payload);
+    y(free);
+}
+
 /* The index of each callback function corresponds to the numeric
  * value of the message type (see include/i3/ipc.h) */
-handler_t handlers[12] = {
+handler_t handlers[13] = {
     handle_run_command,
     handle_get_workspaces,
     handle_subscribe,
@@ -1352,6 +1370,7 @@ handler_t handlers[12] = {
     handle_get_config,
     handle_send_tick,
     handle_sync,
+    handle_get_binding_state,
 };
 
 /*

src/main.c

@@ -79,6 +79,7 @@ const int default_shmlog_size = 25 * 1024 * 1024;
 
 /* The list of key bindings */
 struct bindings_head *bindings;
+const char *current_binding_mode = NULL;
 
 /* The list of exec-lines */
 struct autostarts_head autostarts = TAILQ_HEAD_INITIALIZER(autostarts);

testcases/t/311-get-binding-modes.t

@@ -0,0 +1,41 @@
+#!perl
+# vim:ts=4:sw=4:expandtab
+#
+# Please read the following documents before working on tests:
+# • https://build.i3wm.org/docs/testsuite.html
+#   (or docs/testsuite)
+#
+# • https://build.i3wm.org/docs/lib-i3test.html
+#   (alternatively: perldoc ./testcases/lib/i3test.pm)
+#
+# • https://build.i3wm.org/docs/ipc.html
+#   (or docs/ipc)
+#
+# • http://onyxneon.com/books/modern_perl/modern_perl_a4.pdf
+#   (unless you are already familiar with Perl)
+#
+# Verifies the GET_BINDING_MODE IPC command
+# Ticket: #3892
+# Bug still in: 4.18-318-g50160eb1
+use i3test i3_config => <<EOT;
+# i3 config file (v4)
+font -misc-fixed-medium-r-normal--13-120-75-75-C-70-iso10646-1
+
+mode "extra" {
+    bindsym Mod1+x nop foo
+}
+EOT
+
+my $i3 = i3(get_socket_path());
+$i3->connect->recv;
+# TODO: use the symbolic name for the command/reply type instead of the
+# numerical 12:
+my $binding_state = $i3->message(12, "")->recv;
+is($binding_state->{name}, 'default', 'at startup, binding mode is default');
+
+cmd 'mode extra';
+
+$binding_state = $i3->message(12, "")->recv;
+is($binding_state->{name}, 'extra', 'after switching, binding mode is extra');
+
+done_testing;