feat(niri/workspaces): add window icons via window-rewrite

Adds format-window-separator, window-rewrite and window-rewrite-default
options plus the {windows} format replacement to the niri/workspaces
module (rebased onto master; coexists with ignore-workspaces).

include/modules/niri/workspaces.hpp

@@ -9,6 +9,7 @@
 #include "AModule.hpp"
 #include "bar.hpp"
 #include "modules/niri/backend.hpp"
+#include "util/regex_collection.hpp" // Added for rewrite rules
 
 namespace waybar::modules::niri {
 
@@ -26,6 +27,10 @@ class Workspaces : public AModule, public EventHandler {
   std::string getIcon(const std::string& value, const Json::Value& ws);
   bool isWorkspaceIgnored(const std::string& name);
   bool handleScroll(GdkEventScroll* /*unused*/) override;
+  // Added for window rewrite
+  void populateWindowRewriteConfig();
+  void populateFormatWindowSeparatorConfig();
+  std::string getRewrite(const std::string& app_id, const std::string& title);
 
   const Bar& bar_;
   Gtk::Box box_;
@@ -37,6 +42,12 @@ class Workspaces : public AModule, public EventHandler {
   bool sort_by_id_ = false;
   bool sort_by_name_ = false;
   bool sort_by_coordinates_ = false;
+
+  // Added for window rewrite
+  util::RegexCollection m_windowRewriteRules;
+  std::string m_windowRewriteDefault;
+  std::string m_formatWindowSeparator;
+ 
 };
 
 }  // namespace waybar::modules::niri

man/waybar-niri-workspaces.5.scd

@@ -97,6 +97,21 @@ If none of the sorting options are enabled, workspaces keep their output/index o
 	default: [] ++
 	Regexes to match against workspaces names and index's. If there's a match, the workspace will not be shown.
 
+*format-window-separator*: ++
+	typeof: string ++
+	default: " " ++
+	Separator used between window representations generated by *window-rewrite*.
+
+*window-rewrite*: ++
+	typeof: object ++
+	default: {} ++
+	Rules to map window app_id and/or title to a specific string representation (e.g., an icon). Keys are regular expressions matching `app_id<regex>` and/or `title<regex>`. Values are the replacement strings, which can contain `{app_id}` and `{title}` placeholders.
+
+*window-rewrite-default*: ++
+	typeof: string ++
+	default: "?" ++
+	The default representation for windows that don't match any rule in *window-rewrite*.
+
 # FORMAT REPLACEMENTS
 
 *{value}*: Name of the workspace, or index for unnamed workspaces,
@@ -112,6 +127,8 @@ as defined by niri.
 
 *{total}*: The total number of workspaces.
 
+*{windows}*: Concatenated representation of windows in the workspace, using *window-rewrite* rules and *format-window-separator*.
+
 # ICONS
 
 Additional to workspace name matching, the following *format-icons* can be set.
@@ -126,7 +143,15 @@ Additional to workspace name matching, the following *format-icons* can be set.
 
 ```
 "niri/workspaces": {
-	"format": "{icon}",
+    "format": "{icon} {windows}",
+    "format-window-separator": "|",
+    "window-rewrite-default": "",
+    "window-rewrite": {
+        "app_id<firefox>": "",
+        "app_id<foot>": "",
+        "app_id<org.gnome.Nautilus> title<.*Downloads.*>": "",
+        "app_id<org.gnome.Nautilus>": ""
+    },
     "format-icons": {
         // Named workspaces
         // (you need to configure them in niri)

resources/config.jsonc

@@ -50,6 +50,27 @@
     //         "default": ""
     //     }
     // },
+    "niri/workspaces": {
+        "format": "{icon} {windows}",
+        "format-window-separator": " ",
+        "window-rewrite-default": "",
+        "window-rewrite": {
+            "app_id<firefox>": "",
+            "app_id<dolphin>": "",
+            "app_id<org.gnome.Nautilus>": "",
+            "app_id<thunar>": "",
+            "app_id<foot>": ""
+        },
+        "format-icons": {
+            "1": "1",
+            "2": "2",
+            "3": "3",
+            "4": "4",
+            "5": "5",
+            "active": "",
+            "default": ""
+        }
+    },
     "keyboard-state": {
         "numlock": true,
         "capslock": true,

src/modules/niri/workspaces.cpp

@@ -1,5 +1,6 @@
 #include "modules/niri/workspaces.hpp"
 
+#include <fmt/ranges.h>  // Needed for joining window representations
 #include <gtkmm/button.h>
 #include <gtkmm/label.h>
 #include <spdlog/spdlog.h>
@@ -7,6 +8,8 @@
 #include <algorithm>
 #include <cctype>
 
+#include "util/rewrite_string.hpp"  // Needed for rewrite logic
+
 namespace waybar::modules::niri {
 
 Workspaces::Workspaces(const std::string& id, const Bar& bar, const Json::Value& config)
@@ -59,6 +62,12 @@ Workspaces::Workspaces(const std::string& id, const Bar& bar, const Json::Value&
 
   if (!gIPC) gIPC = std::make_unique<IPC>();
 
+  // Parse new config options first
+  populateWindowRewriteConfig();
+  populateFormatWindowSeparatorConfig();
+
+  // Niri's WorkspacesChanged event already includes window info,
+  // so no need to register for separate window events like in Hyprland.
   gIPC->registerForIPC("WorkspacesChanged", this);
   gIPC->registerForIPC("WorkspaceActivated", this);
   gIPC->registerForIPC("WorkspaceActiveWindowChanged", this);
@@ -80,6 +89,10 @@ void Workspaces::onEvent(const Json::Value& ev) { dp.emit(); }
 void Workspaces::doUpdate() {
   auto ipcLock = gIPC->lockData();
 
+  // Debug: log global IPC lists
+  spdlog::debug("[niri/workspaces] gIPC workspaces count: {}", gIPC->workspaces().size());
+  spdlog::debug("[niri/workspaces] gIPC windows count: {}", gIPC->windows().size());
+
   const auto alloutputs = config_["all-outputs"].asBool();
   const auto display_cond = config_["display-condition"].asString();
   std::vector<Json::Value> my_workspaces;
@@ -123,6 +136,10 @@ void Workspaces::doUpdate() {
 
   // Add buttons for new workspaces, update existing ones.
   for (const auto& ws : my_workspaces) {
+    // Debug: print workspace JSON
+    spdlog::debug("[niri/workspaces] workspace id={} json={} ", ws["id"].asUInt64(),
+                  ws.toStyledString());
+
     auto bit = buttons_.find(ws["id"].asUInt64());
     auto& button = bit == buttons_.end() ? addButton(ws) : bit->second;
     auto style_context = button.get_style_context();
@@ -156,6 +173,52 @@ void Workspaces::doUpdate() {
     else
       style_context->remove_class("empty");
 
+    // --- Start Window Rewrite Logic ---
+    std::vector<std::string> window_reps;
+    if (ws.isMember("windows") && ws["windows"].isArray()) {
+      spdlog::debug("[niri/workspaces] workspace id={} has {} windows", ws["id"].asUInt64(),
+                    ws["windows"].size());
+      for (const auto& win : ws["windows"]) {
+        spdlog::debug("[niri/workspaces] window json: {}", win.toStyledString());
+        std::string app_id =
+            win.isMember("app_id") && win["app_id"].isString() ? win["app_id"].asString() : "";
+        std::string title =
+            win.isMember("title") && win["title"].isString() ? win["title"].asString() : "";
+        if (!app_id.empty() || !title.empty()) {  // Only add if we have some identifier
+          auto rep = getRewrite(app_id, title);
+          spdlog::debug("[niri/workspaces] rewrite: app_id='{}' title='{}' => '{}'", app_id, title,
+                        rep);
+          window_reps.push_back(rep);
+        }
+      }
+    } else {
+      spdlog::debug(
+          "[niri/workspaces] workspace id={} has no 'windows' array, collecting from global "
+          "windows",
+          ws["id"].asUInt64());
+      // Fallback: collect from global windows list by matching workspace_id
+      for (const auto& win : gIPC->windows()) {
+        if (!win.isMember("workspace_id")) continue;
+        if (win["workspace_id"].asUInt64() != ws["id"].asUInt64()) continue;
+        spdlog::debug("[niri/workspaces] global window json: {}", win.toStyledString());
+        std::string app_id =
+            win.isMember("app_id") && win["app_id"].isString() ? win["app_id"].asString() : "";
+        std::string title =
+            win.isMember("title") && win["title"].isString() ? win["title"].asString() : "";
+        if (!app_id.empty() || !title.empty()) {
+          auto rep = getRewrite(app_id, title);
+          spdlog::debug("[niri/workspaces] rewrite (global): app_id='{}' title='{}' => '{}'",
+                        app_id, title, rep);
+          window_reps.push_back(rep);
+        }
+      }
+    }
+    // Join representations with the separator
+    auto windows_str = fmt::format("{}", fmt::join(window_reps, m_formatWindowSeparator));
+    spdlog::debug("[niri/workspaces] workspace id={} windows_str='{}'", ws["id"].asUInt64(),
+                  windows_str);
+    // --- End Window Rewrite Logic ---
+
     std::string name;
     if (ws["name"]) {
       name = ws["name"].asString();
@@ -169,7 +232,8 @@ void Workspaces::doUpdate() {
       name = fmt::format(
           fmt::runtime(format), fmt::arg("icon", getIcon(name, ws)), fmt::arg("value", name),
           fmt::arg("name", ws["name"].asString()), fmt::arg("index", ws["idx"].asUInt()),
-          fmt::arg("output", ws["output"].asString()), fmt::arg("total", my_workspaces.size()));
+          fmt::arg("output", ws["output"].asString()), fmt::arg("total", my_workspaces.size()),
+          fmt::arg("windows", windows_str));  // Added windows arg
     }
     if (!config_["disable-markup"].asBool()) {
       auto* child = gtk_bin_get_child(GTK_BIN(button.gobj()));
@@ -243,6 +307,84 @@ Gtk::Button& Workspaces::addButton(const Json::Value& ws) {
   return button;
 }
 
+// --- Start New Helper Functions ---
+void Workspaces::populateWindowRewriteConfig() {
+  // Reconstruct RegexCollection instead of clearing/adding
+  const Json::Value& rewrite_rules_config = config_["window-rewrite"];
+  if (rewrite_rules_config.isObject()) {
+    // Assuming a constructor that takes the Json::Value object exists.
+    // If Niri needs rule prioritization like Hyprland, a priority function
+    // would be needed as a second argument here.
+    try {
+      m_windowRewriteRules = util::RegexCollection(rewrite_rules_config);
+    } catch (const std::exception& e) {
+      spdlog::error("Error initializing RegexCollection: {}", e.what());
+      // Initialize with an empty collection if error occurs
+      m_windowRewriteRules = util::RegexCollection(Json::Value(Json::objectValue));
+    }
+
+  } else {
+    // Initialize with an empty collection if config is not an object
+    m_windowRewriteRules = util::RegexCollection(Json::Value(Json::objectValue));
+  }
+
+  if (config_.isMember("window-rewrite-default") && config_["window-rewrite-default"].isString()) {
+    m_windowRewriteDefault = config_["window-rewrite-default"].asString();
+  } else {
+    m_windowRewriteDefault = "?";  // Default fallback
+  }
+}
+
+void Workspaces::populateFormatWindowSeparatorConfig() {
+  if (config_.isMember("format-window-separator") &&
+      config_["format-window-separator"].isString()) {
+    m_formatWindowSeparator = config_["format-window-separator"].asString();
+  } else {
+    m_formatWindowSeparator = " ";  // Default fallback
+  }
+}
+
+std::string Workspaces::getRewrite(const std::string& app_id, const std::string& title) {
+  // Niri uses app_id, Hyprland uses class. Adapt the key format.
+  std::string lookup_key = "app_id<" + app_id + "> title<" + title + ">";
+  std::string res = m_windowRewriteRules.get(lookup_key);
+  if (!res.empty()) {
+    // Create Json::Value for substitutions
+    Json::Value substitutions(Json::objectValue);
+    substitutions["app_id"] = app_id;
+    substitutions["title"] = title;
+    return util::rewriteString(res, substitutions);
+  }
+  // Fallback to app_id only
+  lookup_key = "app_id<" + app_id + ">";
+  res = m_windowRewriteRules.get(lookup_key);
+  if (!res.empty()) {
+    // Create Json::Value for substitutions
+    Json::Value substitutions(Json::objectValue);
+    substitutions["app_id"] = app_id;
+    substitutions["title"] = title;
+    return util::rewriteString(res, substitutions);
+  }
+  // Fallback to title only
+  lookup_key = "title<" + title + ">";
+  res = m_windowRewriteRules.get(lookup_key);
+  if (!res.empty()) {
+    // Create Json::Value for substitutions
+    Json::Value substitutions(Json::objectValue);
+    substitutions["app_id"] = app_id;
+    substitutions["title"] = title;
+    return util::rewriteString(res, substitutions);
+  }
+
+  // No rule matched, return default
+  // Apply substitutions to default as well, in case it uses placeholders
+  Json::Value substitutions(Json::objectValue);
+  substitutions["app_id"] = app_id;
+  substitutions["title"] = title;
+  return util::rewriteString(m_windowRewriteDefault, substitutions);
+}
+// --- End New Helper Functions ---
+
 std::string Workspaces::getIcon(const std::string& value, const Json::Value& ws) {
   const auto& icons = config_["format-icons"];
   if (!icons) return value;