Implement support for swaymsg -t SUBSCRIBE [-m]

In `i3 4.16`, `i3-msg` can be used with the message type `subscribe`
and has the ability to monitor for responses until killed. This adds
support for both to swaymsg.

If the JSON array of event types is malformed or contains an invalid
event, sway will send a response with `success` set to `false`. If
swaymsg sees this, it will not display the failure and exit.

If the `subscribe` event is successful, swaymsg will wait for the first
response and display that instead of the success message. If
`-m/--monitor` is given, swaymsg will continue monitor for responses
until killed or a malformed response is received.

For the `subscribe` event, the responses will always be printed as JSON.
If `-r/--raw` is given, the JSON will not be pretty printed, which may
be preferred when monitoring due to there being multiple responses.

Example: `swaymsg -t SUBSCRIBE -m "['window']"`

1 files changed, 8 insertions, 5 deletions

diff --git a/sway/ipc-server.c b/sway/ipc-server.c
index 95433d97..e3d73522 100644
--- a/sway/ipc-server.c
+++ b/sway/ipc-server.c
@@ -668,7 +668,8 @@ void ipc_client_handle_command(struct ipc_client *client) {
                 // TODO: Check if they're permitted to use these events
                 struct json_object *request = json_tokener_parse(buf);
                 if (request == NULL) {
-                        client_valid = ipc_send_reply(client, "{\"success\": false}", 18);
+                        const char msg[] = "[{\"success\": false}]";
+                        client_valid = ipc_send_reply(client, msg, strlen(msg));
                         wlr_log(WLR_INFO, "Failed to parse subscribe request");
                         goto exit_cleanup;
                 }
@@ -695,8 +696,8 @@ void ipc_client_handle_command(struct ipc_client *client) {
                                 client->subscribed_events |= event_mask(IPC_EVENT_TICK);
                                 is_tick = true;
                         } else {
-                                client_valid =
-                                        ipc_send_reply(client, "{\"success\": false}", 18);
+                                const char msg[] = "[{\"success\": false}]";
+                                client_valid = ipc_send_reply(client, msg, strlen(msg));
                                 json_object_put(request);
                                 wlr_log(WLR_INFO, "Unsupported event type in subscribe request");
                                 goto exit_cleanup;
@@ -704,10 +705,12 @@ void ipc_client_handle_command(struct ipc_client *client) {
                 }
 
                 json_object_put(request);
-                client_valid = ipc_send_reply(client, "{\"success\": true}", 17);
+                const char msg[] = "[{\"success\": true}]";
+                client_valid = ipc_send_reply(client, msg, strlen(msg));
                 if (is_tick) {
                         client->current_command = IPC_EVENT_TICK;
-                        ipc_send_reply(client, "{\"first\": true, \"payload\": \"\"}", 30);
+                        const char tickmsg[] = "{\"first\": true, \"payload\": \"\"}";
+                        ipc_send_reply(client, tickmsg, strlen(tickmsg));
                 }
                 goto exit_cleanup;
         }