Implement the window_role criterion (checks WM_WINDOW_ROLE)

Closes: #446

This is handy for matching specific windows of a multi-window application, for
example only Pidgin’s buddy list window.

include/atoms.xmacro

@@ -21,5 +21,6 @@ xmacro(UTF8_STRING)
 xmacro(WM_STATE)
 xmacro(WM_CLIENT_LEADER)
 xmacro(WM_TAKE_FOCUS)
+xmacro(WM_WINDOW_ROLE)
 xmacro(I3_SOCKET_PATH)
 xmacro(I3_CONFIG_PATH)

include/data.h

@@ -264,6 +264,11 @@ struct Window {
      * application supports _NET_WM_NAME, in COMPOUND_TEXT otherwise). */
     char *name_x;
 
+    /** The WM_WINDOW_ROLE of this window (for example, the pidgin buddy window
+     * sets "buddy list"). Useful to match specific windows in assignments or
+     * for_window. */
+    char *role;
+
     /** Flag to force re-rendering the decoration upon changes */
     bool name_x_changed;
 
@@ -298,6 +303,7 @@ struct Match {
     struct regex *class;
     struct regex *instance;
     struct regex *mark;
+    struct regex *role;
     enum {
         M_DONTCHECK = -1,
         M_NODOCK = 0,

include/window.h

@@ -42,4 +42,10 @@ void window_update_transient_for(i3Window *win, xcb_get_property_reply_t *prop);
  */
 void window_update_strut_partial(i3Window *win, xcb_get_property_reply_t *prop);
 
+/**
+ * Updates the WM_WINDOW_ROLE
+ *
+ */
+void window_update_role(i3Window *win, xcb_get_property_reply_t *prop, bool before_mgmt);
+
 #endif

src/cfgparse.l

@@ -170,6 +170,7 @@ shift                           { return TOKSHIFT; }
 
 class                           { yy_push_state(WANT_QSTRING); return TOK_CLASS; }
 instance                        { yy_push_state(WANT_QSTRING); return TOK_INSTANCE; }
+window_role                     { yy_push_state(WANT_QSTRING); return TOK_WINDOW_ROLE; }
 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; }

src/cfgparse.y

@@ -632,6 +632,7 @@ void parse_file(const char *f) {
 %token              TOK_MARK            "mark"
 %token              TOK_CLASS           "class"
 %token              TOK_INSTANCE        "instance"
+%token              TOK_WINDOW_ROLE     "window_role"
 %token              TOK_ID              "id"
 %token              TOK_CON_ID          "con_id"
 %token              TOK_TITLE           "title"
@@ -792,6 +793,12 @@ criterion:
         current_match.instance = regex_new($3);
         free($3);
     }
+    | TOK_WINDOW_ROLE '=' STR
+    {
+        printf("criteria: window_role = %s\n", $3);
+        current_match.role = regex_new($3);
+        free($3);
+    }
     | TOK_CON_ID '=' STR
     {
         printf("criteria: id = %s\n", $3);

src/cmdparse.l

@@ -155,6 +155,7 @@ no                              { return TOK_DISABLE; }
 
 class                           { BEGIN(WANT_QSTRING); return TOK_CLASS; }
 instance                        { BEGIN(WANT_QSTRING); return TOK_INSTANCE; }
+window_role                     { BEGIN(WANT_QSTRING); return TOK_WINDOW_ROLE; }
 id                              { BEGIN(WANT_QSTRING); return TOK_ID; }
 con_id                          { BEGIN(WANT_QSTRING); return TOK_CON_ID; }
 con_mark                        { BEGIN(WANT_QSTRING); return TOK_MARK; }

src/cmdparse.y

@@ -177,6 +177,7 @@ bool definitelyGreaterThan(float a, float b, float epsilon) {
 
 %token              TOK_CLASS           "class"
 %token              TOK_INSTANCE        "instance"
+%token              TOK_WINDOW_ROLE     "window_role"
 %token              TOK_ID              "id"
 %token              TOK_CON_ID          "con_id"
 %token              TOK_TITLE           "title"
@@ -308,6 +309,12 @@ criterion:
         current_match.instance = regex_new($3);
         free($3);
     }
+    | TOK_WINDOW_ROLE '=' STR
+    {
+        printf("criteria: window_role = %s\n", $3);
+        current_match.role = regex_new($3);
+        free($3);
+    }
     | TOK_CON_ID '=' STR
     {
         printf("criteria: id = %s\n", $3);

src/handlers.c

@@ -557,6 +557,21 @@ static bool handle_windowname_change_legacy(void *data, xcb_connection_t *conn,
     return true;
 }
 
+/*
+ * Called when a window changes its WM_WINDOW_ROLE.
+ *
+ */
+static bool handle_windowrole_change(void *data, xcb_connection_t *conn, uint8_t state,
+                                     xcb_window_t window, xcb_atom_t atom, xcb_get_property_reply_t *prop) {
+    Con *con;
+    if ((con = con_by_window_id(window)) == NULL || con->window == NULL)
+        return false;
+
+    window_update_role(con->window, prop, false);
+
+    return true;
+}
+
 #if 0
 /*
  * Updates the client’s WM_CLASS property
@@ -933,7 +948,8 @@ static struct property_handler_t property_handlers[] = {
     { 0, 128, handle_windowname_change_legacy },
     { 0, UINT_MAX, handle_normal_hints },
     { 0, UINT_MAX, handle_clientleader_change },
-    { 0, UINT_MAX, handle_transient_for }
+    { 0, UINT_MAX, handle_transient_for },
+    { 0, 128, handle_windowrole_change }
 };
 #define NUM_HANDLERS (sizeof(property_handlers) / sizeof(struct property_handler_t))
 
@@ -949,6 +965,7 @@ void property_handlers_init() {
     property_handlers[3].atom = XCB_ATOM_WM_NORMAL_HINTS;
     property_handlers[4].atom = A_WM_CLIENT_LEADER;
     property_handlers[5].atom = XCB_ATOM_WM_TRANSIENT_FOR;
+    property_handlers[6].atom = A_WM_WINDOW_ROLE;
 }
 
 static void property_notify(uint8_t state, xcb_window_t window, xcb_atom_t atom) {

src/manage.c

@@ -83,7 +83,8 @@ void manage_window(xcb_window_t window, xcb_get_window_attributes_cookie_t cooki
 
     xcb_get_property_cookie_t wm_type_cookie, strut_cookie, state_cookie,
                               utf8_title_cookie, title_cookie,
-                              class_cookie, leader_cookie, transient_cookie;
+                              class_cookie, leader_cookie, transient_cookie,
+                              role_cookie;
 
 
     geomc = xcb_get_geometry(conn, d);
@@ -145,6 +146,7 @@ void manage_window(xcb_window_t window, xcb_get_window_attributes_cookie_t cooki
     transient_cookie = GET_PROPERTY(XCB_ATOM_WM_TRANSIENT_FOR, UINT32_MAX);
     title_cookie = GET_PROPERTY(XCB_ATOM_WM_NAME, 128);
     class_cookie = GET_PROPERTY(XCB_ATOM_WM_CLASS, 128);
+    role_cookie = GET_PROPERTY(A_WM_WINDOW_ROLE, 128);
     /* TODO: also get wm_normal_hints here. implement after we got rid of xcb-event */
 
     DLOG("reparenting!\n");
@@ -171,6 +173,7 @@ void manage_window(xcb_window_t window, xcb_get_window_attributes_cookie_t cooki
     window_update_leader(cwindow, xcb_get_property_reply(conn, leader_cookie, NULL));
     window_update_transient_for(cwindow, xcb_get_property_reply(conn, transient_cookie, NULL));
     window_update_strut_partial(cwindow, xcb_get_property_reply(conn, strut_cookie, NULL));
+    window_update_role(cwindow, xcb_get_property_reply(conn, role_cookie, NULL), true);
 
     /* check if the window needs WM_TAKE_FOCUS */
     cwindow->needs_take_focus = window_supports_protocol(cwindow->id, A_WM_TAKE_FOCUS);

src/match.c

@@ -39,6 +39,7 @@ bool match_is_empty(Match *match) {
             match->application == NULL &&
             match->class == NULL &&
             match->instance == NULL &&
+            match->role == NULL &&
             match->id == XCB_NONE &&
             match->con_id == NULL &&
             match->dock == -1 &&
@@ -65,6 +66,7 @@ void match_copy(Match *dest, Match *src) {
     DUPLICATE_REGEX(application);
     DUPLICATE_REGEX(class);
     DUPLICATE_REGEX(instance);
+    DUPLICATE_REGEX(role);
 }
 
 /*
@@ -113,6 +115,16 @@ bool match_matches_window(Match *match, i3Window *window) {
         }
     }
 
+    if (match->role != NULL) {
+        if (window->role != NULL &&
+            regex_matches(match->role, window->role)) {
+            LOG("window_role matches (%s)\n", window->role);
+        } else {
+            LOG("window_role does not match\n");
+            return false;
+        }
+    }
+
     if (match->dock != -1) {
         LOG("match->dock = %d, window->dock = %d\n", match->dock, window->dock);
         if ((window->dock == W_DOCK_TOP && match->dock == M_DOCK_TOP) ||
@@ -148,6 +160,7 @@ void match_free(Match *match) {
     regex_free(match->class);
     regex_free(match->instance);
     regex_free(match->mark);
+    regex_free(match->role);
 
     /* Second step: free the regex helper struct itself */
     FREE(match->title);
@@ -155,4 +168,5 @@ void match_free(Match *match) {
     FREE(match->class);
     FREE(match->instance);
     FREE(match->mark);
+    FREE(match->role);
 }

src/window.c

@@ -215,3 +215,36 @@ void window_update_strut_partial(i3Window *win, xcb_get_property_reply_t *prop)
 
     free(prop);
 }
+
+/*
+ * Updates the WM_WINDOW_ROLE
+ *
+ */
+void window_update_role(i3Window *win, xcb_get_property_reply_t *prop, bool before_mgmt) {
+    if (prop == NULL || xcb_get_property_value_length(prop) == 0) {
+        DLOG("prop == NULL\n");
+        FREE(prop);
+        return;
+    }
+
+    char *new_role;
+    if (asprintf(&new_role, "%.*s", xcb_get_property_value_length(prop),
+                 (char*)xcb_get_property_value(prop)) == -1) {
+        perror("asprintf()");
+        DLOG("Could not get WM_WINDOW_ROLE\n");
+        free(prop);
+        return;
+    }
+    FREE(win->role);
+    win->role = new_role;
+    LOG("WM_WINDOW_ROLE changed to \"%s\"\n", win->role);
+
+    if (before_mgmt) {
+        free(prop);
+        return;
+    }
+
+    run_assignments(win);
+
+    free(prop);
+}