Send IPC modifier event on bar_modifier up/down

Detects when a bar modifier key is pressed/released and sends a modifier
IPC event to any listeners (usually swaybars).

This way a swaybar can listen on the modifier event and hide/show the
bar accordingly (not implemented yet)

The modifier event looks like this:

    {
      "change": "pressed", // or released
      "modifier": "Mod4"
    }

1 files changed, 39 insertions, 0 deletions

diff --git a/sway/ipc-server.c b/sway/ipc-server.c
index ed3977d5..da3d52e3 100644
--- a/sway/ipc-server.c
+++ b/sway/ipc-server.c
@@ -35,6 +35,22 @@ struct ipc_client {
         enum ipc_command_type subscribed_events;
 };
 
+static struct modifier_key {
+        char *name;
+        uint32_t mod;
+} modifiers[] = {
+        { XKB_MOD_NAME_SHIFT, WLC_BIT_MOD_SHIFT },
+        { XKB_MOD_NAME_CAPS, WLC_BIT_MOD_CAPS },
+        { XKB_MOD_NAME_CTRL, WLC_BIT_MOD_CTRL },
+        { "Ctrl", WLC_BIT_MOD_CTRL },
+        { XKB_MOD_NAME_ALT, WLC_BIT_MOD_ALT },
+        { "Alt", WLC_BIT_MOD_ALT },
+        { XKB_MOD_NAME_NUM, WLC_BIT_MOD_MOD2 },
+        { "Mod3", WLC_BIT_MOD_MOD3 },
+        { XKB_MOD_NAME_LOGO, WLC_BIT_MOD_LOGO },
+        { "Mod5", WLC_BIT_MOD_MOD5 },
+};
+
 struct sockaddr_un *ipc_user_sockaddr(void);
 int ipc_handle_connection(int fd, uint32_t mask, void *data);
 int ipc_client_handle_readable(int client_fd, uint32_t mask, void *data);
@@ -295,6 +311,8 @@ void ipc_client_handle_command(struct ipc_client *client) {
                                 client->subscribed_events |= IPC_EVENT_BARCONFIG_UPDATE;
                         } else if (strcmp(event_type, "mode") == 0) {
                                 client->subscribed_events |= IPC_EVENT_MODE;
+                        } else if (strcmp(event_type, "modifier") == 0) {
+                                client->subscribed_events |= IPC_EVENT_MODIFIER;
                         } else {
                                 ipc_send_reply(client, "{\"success\": false}", 18);
                                 ipc_client_disconnect(client);
@@ -617,3 +635,24 @@ void ipc_event_mode(const char *mode) {
 
         json_object_put(obj); // free
 }
+
+void ipc_event_modifier(uint32_t modifier, const char *state) {
+        json_object *obj = json_object_new_object();
+        json_object_object_add(obj, "change", json_object_new_string(state));
+
+        const char *modifier_name = NULL;
+        int i;
+        for (i = 0; i < (int)(sizeof(modifiers) / sizeof(struct modifier_key)); ++i) {
+                if (modifiers[i].mod == modifier) {
+                        modifier_name = modifiers[i].name;
+                        break;
+                }
+        }
+
+        json_object_object_add(obj, "modifier", json_object_new_string(modifier_name));
+
+        const char *json_string = json_object_to_json_string(obj);
+        ipc_send_event(json_string, IPC_EVENT_MODIFIER);
+
+        json_object_put(obj); // free
+}