core: add bar item "lag"

This bar item is overridden by the irc bar item with the same name, but it used
on relay remote buffers, so that the lag is visible as well.

ChangeLog.adoc

@@ -15,6 +15,7 @@ For a list of important changes that require manual actions, please look at rele
 
 New features::
 
+  * core: add bar item "lag"
   * core: add buffer properties "input_prompt" and "modes"
   * core: send signal "buffer_line_added" on buffers with free content
   * core: add support of XDG "state" directory (issue #2106, issue #1747)

src/gui/gui-bar-item.c

@@ -66,8 +66,8 @@ char *gui_bar_item_names[GUI_BAR_NUM_ITEMS] =
   "buffer_name", "buffer_short_name", "buffer_modes", "buffer_filter",
   "buffer_zoom", "buffer_nicklist_count", "buffer_nicklist_count_groups",
   "buffer_nicklist_count_all", "scroll", "hotlist", "completion",
-  "buffer_title", "buffer_nicklist", "window_number", "mouse_status", "away",
+  "buffer_title", "buffer_nicklist", "window_number", "mouse_status", "lag",
-  "spacer"
+  "away", "spacer"
 };
 struct t_gui_bar_item_hook *gui_bar_item_hooks = NULL;
 struct t_hook *gui_bar_item_timer = NULL;
@@ -2042,6 +2042,38 @@ gui_bar_item_mouse_status_cb (const void *pointer, void *data,
     return strdup (str_mouse);
 }
 
+/*
+ * Bar item with buffer lag.
+ */
+
+char *
+gui_bar_item_lag_cb (const void *pointer, void *data,
+                     struct t_gui_bar_item *item,
+                     struct t_gui_window *window,
+                     struct t_gui_buffer *buffer,
+                     struct t_hashtable *extra_info)
+{
+    const char *lag;
+    char str_lag[1024];
+
+    /* make C compiler happy */
+    (void) pointer;
+    (void) data;
+    (void) item;
+    (void) window;
+    (void) extra_info;
+
+    if (!buffer)
+        return NULL;
+
+    lag = (const char *)hashtable_get (buffer->local_variables, "lag");
+    if (!lag)
+        return NULL;
+
+    snprintf (str_lag, sizeof (str_lag), "%s: %s", _("Lag"), lag);
+    return strdup (str_lag);
+}
+
 /*
  * Bar item with away message.
  */
@@ -2489,6 +2521,13 @@ gui_bar_item_init ()
     gui_bar_item_hook_signal ("mouse_enabled;mouse_disabled",
                               gui_bar_item_names[GUI_BAR_ITEM_MOUSE_STATUS]);
 
+    /* lag */
+    gui_bar_item_new (NULL,
+                      gui_bar_item_names[GUI_BAR_ITEM_LAG],
+                      &gui_bar_item_lag_cb, NULL, NULL);
+    gui_bar_item_hook_signal ("window_switch;buffer_switch;buffer_localvar_*",
+                              gui_bar_item_names[GUI_BAR_ITEM_LAG]);
+
     /* away message */
     gui_bar_item_new (NULL,
                       gui_bar_item_names[GUI_BAR_ITEM_AWAY],

src/gui/gui-bar-item.h

@@ -46,6 +46,7 @@ enum t_gui_bar_item_weechat
     GUI_BAR_ITEM_BUFFER_NICKLIST,
     GUI_BAR_ITEM_WINDOW_NUMBER,
     GUI_BAR_ITEM_MOUSE_STATUS,
+    GUI_BAR_ITEM_LAG,
     GUI_BAR_ITEM_AWAY,
     GUI_BAR_ITEM_SPACER,
     /* number of bar items */