desktop: showing currently active windows in eww

- successfully showing the icons for the currently active windows
  running in the current workspace

6 files changed, 209 insertions, 79 deletions

diff --git a/modules/desktop/eww/activate-windows.py b/modules/desktop/eww/activate-windows.py
new file mode 100644
index 0000000..b0dba4a
--- /dev/null
+++ b/modules/desktop/eww/activate-windows.py
@@ -0,0 +1,108 @@
+#!/usr/bin/env python3
+"""active-windows: emit icons for windows on the currently active
+niri workspace, driven by niri's event-stream instead of polling."""
+import json
+import subprocess
+import gi
+from gi.repository import Gio, Gtk
+
+gi.require_version("Gtk", "3.0")
+
+icon_theme = Gtk.IconTheme.get_default()
+_icon_cache: dict[str, str] = {}
+
+
+def resolve_icon_path(app_id: str) -> str:
+    if not app_id:
+        return ""
+    if app_id in _icon_cache:
+        return _icon_cache[app_id]
+
+    app_info = Gio.DesktopAppInfo.new(f"{app_id}.desktop") \
+        or Gio.DesktopAppInfo.new(f"{app_id.lower()}.desktop")
+
+    # fall back: scan installed .desktop files for a matching StartupWMClass
+    if app_info is None:
+        for info in Gio.AppInfo.get_all():
+            if isinstance(info, Gio.DesktopAppInfo):
+                wm_class = info.get_startup_wm_class()
+                if wm_class and wm_class.lower() == app_id.lower():
+                    app_info = info
+                    break
+
+    icon_path = ""
+    gicon = app_info.get_icon() if app_info else None
+    if gicon is not None:
+        lookup = icon_theme.lookup_by_gicon(gicon,
+                                            32,
+                                            Gtk.IconLookupFlags.FORCE_SIZE)
+        if lookup:
+            icon_path = lookup.get_filename() or ""
+
+    if not icon_path:
+        # last resort: treat app_id itself as an icon-theme name
+        lookup = icon_theme.lookup_icon(app_id,
+                                        32,
+                                        Gtk.IconLookupFlags.FORCE_SIZE)
+        if lookup:
+            icon_path = lookup.get_filename() or ""
+
+    _icon_cache[app_id] = icon_path
+    return icon_path
+
+
+def niri_json(*args):
+    out = subprocess.run(["niri", "msg", "-j", *args],
+                         capture_output=True,
+                         text=True,
+                         check=True)
+    return json.loads(out.stdout)
+
+
+def emit_active_windows():
+    workspaces = niri_json("workspaces")
+    windows = niri_json("windows")
+
+    active_ws = next((w for w in workspaces if w.get("is_active")), None)
+    active_id = active_ws["id"] if active_ws else None
+
+    result = [
+        {
+            "id": w["id"],
+            "title": w.get("title", ""),
+            "app_id": w.get("app_id") or "",
+            "is_focused": w.get("is_focused", False),
+            "icon": resolve_icon_path(w.get("app_id") or ""),
+        }
+        for w in windows
+        if w.get("workspace_id") == active_id
+    ]
+    print(json.dumps(result), flush=True)
+
+
+RELEVANT_EVENTS = {
+    "WindowOpenedOrChanged", "WindowClosed", "WindowFocusChanged",
+    "WorkspaceActivated", "WorkspacesChanged", "WindowsChanged",
+}
+
+
+def main():
+    emit_active_windows()
+    proc = subprocess.Popen(
+        ["niri", "msg", "-j", "event-stream"],
+        stdout=subprocess.PIPE, text=True, bufsize=1,
+    )
+    for line in proc.stdout:
+        try:
+            key = next(iter(json.loads(line)))
+        except (json.JSONDecodeError, StopIteration):
+            continue
+        if key in RELEVANT_EVENTS:
+            try:
+                emit_active_windows()
+            except subprocess.CalledProcessError:
+                pass
+
+
+if __name__ == "__main__":
+    main()
diff --git a/modules/desktop/eww/eww.mustache.scss b/modules/desktop/eww/eww.mustache.scss
new file mode 100644
index 0000000..a24b71e
--- /dev/null
+++ b/modules/desktop/eww/eww.mustache.scss
@@ -0,0 +1,39 @@
+* {
+  font-family: "Fira Code Nerd Font";
+  font-size: 18px;
+  min-height: 0;
+}
+
+window#eww-bar {
+  background: transparent;
+}
+
+.bar-container {
+  background: #{{base00}};
+  margin: 3px 5px;
+  border: 1px solid #{{base07}};
+  color: #{{base07}};
+  padding: 5px;
+}
+
+.workspaces {
+  background: #{{base00}};
+  padding: 0;
+  margin: 0;
+}
+
+.workspace-btn {
+  padding: 8px;
+  color: #{{base07}};
+  font-size: 24px;
+  background-color: #{{base00}};
+  border: 1px solid #{{base03}};
+  background-image: none;
+  box-shadow: none;
+  text-shadow: none;
+  outline: none;
+}
+
+.workspace-btn.active {
+  border-color: #{{base07}};
+}
diff --git a/modules/desktop/eww/eww.scss.mustache b/modules/desktop/eww/eww.scss.mustache
deleted file mode 100644
index a791633..0000000
--- a/modules/desktop/eww/eww.scss.mustache
+++ /dev/null
@@ -1,56 +0,0 @@
-* {
-  font-family: "Fira Code Nerd Font";
-  font-size: 18px;
-  min-height: 0;
-}
-
-window#eww-bar {
-  background: transparent;
-}
-
-.bar-container {
-  background: #{{base00}};
-  border: 1px solid #{{base07}};
-  padding: 5px 0;
-  margin: 5px;
-}
-
-.workspaces {
-  background: transparent;
-  padding: 0;
-  margin: 0;
-}
-
-.workspaces button {
-  background-image: none;
-  box-shadow: none;
-  text-shadow: none;
-  outline: none;
-  border: none;
-  padding: 5px 10px;
-  color: #{{base07}};
-  border: 1px solid #{{base07}};
-  border-color: #{{base07}};
-  border-radius: 0;
-  min-width: 0;
-  min-height: 0;
-  margin: 0 5px;
-  font-size: 24px;
-  background: transparent;
-}
-
-.workspaces button:hover {
-  background: #{{base00}};
-  border: 1px solid #{{base07}};
-  box-shadow: none;
-}
-
-.workspaces button:active {
-  background-image: none;
-  box-shadow: none;
-}
-
-.workspaces button:hover {
-  background: #{{base00}};
-  border-color: #{{base07}};
-}
diff --git a/modules/desktop/eww/scss.nix b/modules/desktop/eww/scss.nix
index b535c3a..408ff64 100644
--- a/modules/desktop/eww/scss.nix
+++ b/modules/desktop/eww/scss.nix
@@ -3,5 +3,5 @@
   ...
 }:
 config.scheme {
-  template = builtins.readFile ./eww.scss.mustache;
+  template = builtins.readFile ./eww.mustache.scss;
 }
diff --git a/modules/desktop/eww/workspaces.sh b/modules/desktop/eww/workspaces.sh
new file mode 100644
index 0000000..18193fa
--- /dev/null
+++ b/modules/desktop/eww/workspaces.sh
@@ -0,0 +1,16 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+print_workspaces() {
+  niri msg -j workspaces | jq -c --unbuffered 'sort_by(.idx)'
+}
+
+print_workspaces
+
+niri msg -j event-stream | while IFS= read -r line; do
+  case "$line" in
+    *WorkspacesChanged*|*WorkspaceActivated*|*WorkspaceUrgencyChanged*|*WorkspaceActiveWindowChanged*)
+      print_workspaces
+      ;;
+  esac
+done
diff --git a/modules/desktop/eww/yuck.nix b/modules/desktop/eww/yuck.nix
index d61f70a..df688fe 100644
--- a/modules/desktop/eww/yuck.nix
+++ b/modules/desktop/eww/yuck.nix
@@ -6,46 +6,65 @@
 }:
 {
   config = lib.mkIf config.desktop.enable {
-    home.file.".config/eww/icons/fallback.svg".text = ''
-      <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 24 24" width="24" height="24">
-        <rect x="2" y="2" width="20" height="20" rx="3" fill="none" stroke="#c8ccd4" stroke-width="2"/>
-      </svg>
-    '';
-
     programs.eww.yuckConfig =
       let
         workspaces = pkgs.writeShellApplication {
           name = "eww-workspaces";
-          # This automatically adds these packages to the script's PATH
           runtimeInputs = with pkgs; [
-            niri
+            config.desktop.niri.package
             jq
           ];
 
-          text = ''
-            #!/usr/bin/env bash
-            # Outputs JSON array of workspaces for eww bar
-            niri msg -j workspaces | jq -c 'sort_by(.idx)'
-          '';
+          text = builtins.readFile ./workspaces.sh;
         };
+
+        activate-windows =
+          let
+            pythonEnv = pkgs.python3.withPackages (ps: [ ps.pygobject3 ]);
+          in
+          pkgs.stdenv.mkDerivation {
+            pname = "eww-activate-windows";
+            version = "0.1.0";
+            src = ./activate-windows.py;
+            dontUnpack = true;
+            meta.mainProgram = "eww-activate-windows";
+
+            nativeBuildInputs = [
+              pkgs.wrapGAppsHook3
+              pkgs.gobject-introspection
+            ];
+            buildInputs = [ pkgs.gtk3 ];
+
+            installPhase = ''
+              mkdir -p $out/bin
+              install -m755 $src $out/bin/eww-activate-windows
+              patchShebangs $out/bin/eww-activate-windows
+            '';
+
+            # wrapGAppsHook3 wraps every executable in $out/bin automatically,
+            # setting GI_TYPELIB_PATH etc. from buildInputs' closure.
+            preFixup = ''
+              gappsWrapperArgs+=(--prefix PATH : "${pythonEnv}/bin")
+            '';
+          };
       in
       ''
         (defpoll time :interval "10s" "date '+%H:%M'")
         (defpoll date :interval "60s" "date '+%d/%m'")
-        (defpoll workspaces :interval "1s" :initial "[]" "${lib.getExe workspaces}")
-        (defpoll active-windows :interval "1s" "${lib.getExe config.scripts.eww-active-windows.package}")
+        (deflisten workspaces :initial "[]" "${lib.getExe workspaces}")
+        (deflisten active-windows :initial "[]" "${lib.getExe activate-windows}")
 
         (defwindow bar
           :monitor 0
           :geometry (geometry
                       :x "0px"
                       :y "0px"
-                      :width "50px"
+                      :width "60px"
                       :height "100%"
                       :anchor "top right")
           :stacking "fg"
           :focusable "none"
-          :reserve (struts :distance "50px" :side "right")
+          :reserve (struts :distance "60px" :side "right")
           (bar-content))
 
         (defwidget bar-content []
@@ -55,15 +74,19 @@
               (windows-widget))))
 
         (defwidget workspaces-widget []
-          (box :orientation "v" :space-evenly false :spacing 4 :halign "center" :class "workspaces"
+          (box :orientation "v" :space-evenly false :spacing 4 :halign "fill" :class "workspaces"
             (for ws in workspaces
-              (button :class {ws.is_active ? "ws-active" : "ws-inactive"}
-                      :onclick "niri msg action focus-workspace ''${ws.idx}"
-                (label :text "''${ws.idx}")))))
+              (eventbox :onclick "niri msg action focus-workspace ''${ws.idx}"
+                        :cursor "pointer"
+                        :halign "fill"
+                (box :halign "fill" :class "workspace-btn ''${ws.is_active ? 'active' : '''}"
+                  (label :text "''${ws.idx}"))))))
 
         (defwidget windows-widget []
           (box :orientation "v" :space-evenly false :spacing 4 :halign "center" :class "windows"
-            (image :class "win-icon" :path "/tmp/test-icon.svg" :image-width 20 :image-height 20)))
+
+            (for w in active-windows
+              (image :class "win-icon" :path "''${w.icon != ''' ? w.icon : '${../../../assets/icons/obs.svg}'}" :image-width 20 :image-height 20))))
       '';
   };
 }