Implement urgency flag matcher

Currently it supports the following options:
"oldest": match the first window that triggered an urgent event
"latest": match the last window that triggered an urgent event

docs/userguide

@@ -1092,6 +1092,10 @@ id::
 	Compares the X11 window ID, which you can get via +xwininfo+ for example.
 title::
 	Compares the X11 window title (_NET_WM_NAME or WM_NAME as fallback).
+urgent::
+	Compares the urgent state of the window. Can be "latest" or "oldest".
+	Matches the latest or oldest urgent window, respectively.
+	(The following aliases are also available: newest, last, recent, first)
 con_mark::
 	Compares the mark set for this container, see <<vim_like_marks>>.
 con_id::

include/data.h

@@ -304,6 +304,9 @@ struct Window {
     /** Whether the application needs to receive WM_TAKE_FOCUS */
     bool needs_take_focus;
 
+    /** When this window was marked urgent. 0 means not urgent */
+    time_t urgent;
+
     /** Whether this window accepts focus. We store this inverted so that the
      * default will be 'accepts focus'. */
     bool doesnt_accept_focus;
@@ -335,6 +338,11 @@ struct Match {
     struct regex *instance;
     struct regex *mark;
     struct regex *role;
+    enum {
+        U_DONTCHECK = -1,
+        U_LATEST = 0,
+        U_OLDEST = 1
+    } urgent;
     enum {
         M_DONTCHECK = -1,
         M_NODOCK = 0,

parser-specs/commands.spec

@@ -43,6 +43,7 @@ state CRITERIA:
   ctype = 'id' -> CRITERION
   ctype = 'con_mark' -> CRITERION
   ctype = 'title' -> CRITERION
+  ctype = 'urgent' -> CRITERION
   ']' -> call cmd_criteria_match_windows(); INITIAL
 
 state CRITERION:

src/cfgparse.l

@@ -250,6 +250,7 @@ id                              { yy_push_state(WANT_QSTRING); return TOK_ID; }
 con_id                          { yy_push_state(WANT_QSTRING); return TOK_CON_ID; }
 con_mark                        { yy_push_state(WANT_QSTRING); return TOK_MARK; }
 title                           { yy_push_state(WANT_QSTRING); return TOK_TITLE; }
+urgent                          { yy_push_state(WANT_QSTRING); return TOK_URGENT; }
 
 <*>{EOL}                        {
                                   FREE(context->line_copy);

src/cfgparse.y

@@ -740,6 +740,7 @@ void parse_file(const char *f) {
 %token              TOK_ID              "id"
 %token              TOK_CON_ID          "con_id"
 %token              TOK_TITLE           "title"
+%token              TOK_URGENT          "urgent"
 
 %type   <binding>       binding
 %type   <binding>       bindcode
@@ -953,6 +954,20 @@ criterion:
         current_match.title = regex_new($3);
         free($3);
     }
+    | TOK_URGENT '=' STR
+    {
+        printf("criteria: urgent = %s\n", $3);
+        if (strcasecmp($3, "latest") == 0 ||
+            strcasecmp($3, "newest") == 0 ||
+            strcasecmp($3, "recent") == 0 ||
+            strcasecmp($3, "last") == 0) {
+            current_match.urgent = U_LATEST;
+        } else if (strcasecmp($3, "oldest") == 0 ||
+                   strcasecmp($3, "first") == 0) {
+            current_match.urgent = U_OLDEST;
+        }
+        free($3);
+    }
     ;
 
 qstring_or_number:

src/commands.c

@@ -307,6 +307,19 @@ char *cmd_criteria_add(Match *current_match, char *ctype, char *cvalue) {
         return NULL;
     }
 
+    if (strcmp(ctype, "urgent") == 0) {
+        if (strcasecmp(cvalue, "latest") == 0 ||
+            strcasecmp(cvalue, "newest") == 0 ||
+            strcasecmp(cvalue, "recent") == 0 ||
+            strcasecmp(cvalue, "last") == 0) {
+            current_match->urgent = U_LATEST;
+        } else if (strcasecmp(cvalue, "oldest") == 0 ||
+                   strcasecmp(cvalue, "first") == 0) {
+            current_match->urgent = U_OLDEST;
+        }
+        return NULL;
+    }
+
     ELOG("Unknown criterion: %s\n", ctype);
 
     /* This command is internal and does not generate a JSON reply. */

src/handlers.c

@@ -841,12 +841,20 @@ static bool handle_hints(void *data, xcb_connection_t *conn, uint8_t state, xcb_
 
     if (!con->urgent && focused == con) {
         DLOG("Ignoring urgency flag for current client\n");
+        con->window->urgent = 0;
         goto end;
     }
 
     /* Update the flag on the client directly */
     con->urgent = (xcb_icccm_wm_hints_get_urgency(&hints) != 0);
     //CLIENT_LOG(con);
+    if (con->window) {
+        if (con->urgent) {
+            con->window->urgent = time(NULL);
+        } else {
+            con->window->urgent = 0;
+        }
+    }
     LOG("Urgency flag changed to %d\n", con->urgent);
 
     Con *ws;

src/match.c

@@ -22,6 +22,7 @@
 void match_init(Match *match) {
     memset(match, 0, sizeof(Match));
     match->dock = -1;
+    match->urgent = U_DONTCHECK;
 }
 
 /*
@@ -39,6 +40,7 @@ bool match_is_empty(Match *match) {
             match->class == NULL &&
             match->instance == NULL &&
             match->role == NULL &&
+            match->urgent == U_DONTCHECK &&
             match->id == XCB_NONE &&
             match->con_id == NULL &&
             match->dock == -1 &&
@@ -120,6 +122,38 @@ bool match_matches_window(Match *match, i3Window *window) {
         }
     }
 
+    Con *con = NULL;
+    if (match->urgent == U_LATEST) {
+        /* if the window isn't urgent, no sense in searching */
+        if (window->urgent == 0) {
+            return false;
+        }
+        /* if we find a window that is newer than this one, bail */
+        TAILQ_FOREACH(con, &all_cons, all_cons) {
+            if ((con->window != NULL) &&
+                (con->window->urgent > window->urgent)) {
+                return false;
+            }
+        }
+        LOG("urgent matches latest\n");
+    }
+
+    if (match->urgent == U_OLDEST) {
+        /* if the window isn't urgent, no sense in searching */
+        if (window->urgent == 0) {
+            return false;
+        }
+        /* if we find a window that is older than this one (and not 0), bail */
+        TAILQ_FOREACH(con, &all_cons, all_cons) {
+            if ((con->window != NULL) &&
+                (con->window->urgent != 0) &&
+                (con->window->urgent < window->urgent)) {
+                return false;
+            }
+        }
+        LOG("urgent matches oldest\n");
+    }
+
     if (match->dock != -1) {
         if ((window->dock == W_DOCK_TOP && match->dock == M_DOCK_TOP) ||
          (window->dock == W_DOCK_BOTTOM && match->dock == M_DOCK_BOTTOM) ||