launcher-menu: closeOnLaunch and launchDebounce options

Stock, clicking a program in the VR dashboard's "+" menu only calls
SteamClient.Apps.LaunchNonSteamApp; the menu stays open until the
program's window appears, so users click again and launch it twice.

New launch/ patch (SharedJSContext) wraps LaunchNonSteamApp, whose only
caller is this menu: closeOnLaunch closes the menu through the "+" bar
button's own popup handle right after a launch; launchDebounce ignores
repeated launches of the same command line within N seconds (logged to
the steam-ui-patches journal). Both opt-in, like the other launcherMenu
options.

modules/launcher-menu.nix

@@ -7,7 +7,12 @@
 # - pinned-desktop/: hides Desktop in the scrolling list and pins a copy above
 #   or below it, with a separator; clicking the copy clicks the hidden
 #   original. The position is passed by calling the patch's function.
-# Both are reverted when turned off (next switch).
+# - launch/: wraps SteamClient.Apps.LaunchNonSteamApp (only called by this
+#   menu) to close the menu right after a program is started, and/or to
+#   ignore repeated launches of the same program within a few seconds (stock,
+#   the menu stays open until the program's window appears, inviting double
+#   launches). Options are passed by calling the patch's function.
+# All are reverted when turned off (next switch).
 # Depends on Steam UI internals; tested with Steam client 1790377368.
 { config, lib, pkgs, ... }:
 let
@@ -38,6 +43,29 @@ in {
         patch of Steam's UI (steamFrame.uiPatches).
       '';
     };
+    closeOnLaunch = lib.mkOption {
+      type = lib.types.bool;
+      default = false;
+      description = ''
+        Close the "+" menu as soon as a program in it is activated (pointer,
+        controller or the pinned Desktop entry). Stock, it stays open until the
+        program's window appears, so it looks as if the click did nothing and
+        programs get launched twice. Runtime patch of Steam's UI
+        (steamFrame.uiPatches); off by default like the other launcherMenu
+        options, so nothing is injected unless asked for.
+      '';
+    };
+    launchDebounce = lib.mkOption {
+      type = lib.types.ints.unsigned;
+      default = 0;
+      example = 10;
+      description = ''
+        Seconds during which another launch of the same program (same command
+        line) from the "+" menu is ignored, counted from the last launch that
+        went through; ignored launches are logged (steam-ui-patches journal).
+        0 disables it. Runtime patch of Steam's UI (steamFrame.uiPatches).
+      '';
+    };
   };
 
   config.steamFrame.uiPatches.patches =
@@ -54,5 +82,16 @@ in {
         (${builtins.readFile ./launcher-menu/pinned-desktop/patch.js})(${builtins.toJSON { position = cfg.pinDesktop; }})
       '';
       unpatch = ./launcher-menu/pinned-desktop/unpatch.js;
+    }
+    ++ lib.optional (cfg.closeOnLaunch || cfg.launchDebounce > 0) {
+      name = "launcher-menu-launch";
+      target = sharedJSContext;
+      patch = pkgs.writeText "launcher-menu-launch.js" ''
+        (${builtins.readFile ./launcher-menu/launch/patch.js})(${builtins.toJSON {
+          inherit (cfg) closeOnLaunch;
+          debounceSeconds = cfg.launchDebounce;
+        }})
+      '';
+      unpatch = ./launcher-menu/launch/unpatch.js;
     };
 }

modules/launcher-menu/launch/patch.js

@@ -0,0 +1,89 @@
+// launch: what happens when a program of the VR dashboard's "+" menu
+// (#VRDashboard_LaunchNonSteamApp) is activated.
+//
+// This file is a function expression; launcher-menu.nix calls it with the
+// options: (<this file>)({ closeOnLaunch: true, debounceSeconds: 10 }).
+//
+// Stock, an item's onActivate only calls
+// SteamClient.Apps.LaunchNonSteamApp(strCmdline) (plus the nav sound); the
+// "+" popup stays open until the new window takes over, so users click again
+// and start the program twice. That call is the only use of
+// LaunchNonSteamApp in Steam's UI and is looked up at call time, so this
+// patch wraps it in SharedJSContext (the dashboard bar's realm):
+// - debounceSeconds > 0: a launch of the same command line within that many
+//   seconds of the last accepted one is ignored (console.info, and reported
+//   in the steam-ui-patches journal on the next re-injection);
+// - closeOnLaunch: after a launch (ignored or not), the "+" popup is closed
+//   through the bar button's own popup handle (closePopup(), what stock does
+//   after adding a desktop window). The handle is found in the dashboard bar
+//   document: the button's React fiber ancestors include the "+" component
+//   (prop allowLaunchProgram) and the bar button (prop refBarPopopHandle).
+// Works for every activation path (pointer, controller, the pinned Desktop
+// copy, which clicks the stock item). The original is kept as __sfuiOrig
+// (unpatch.js restores it). Idempotent; bump VERSION when changing the
+// wrapper.
+((opts) => {
+  const VERSION = 1;
+  const NAME = 'launcher-menu-launch';
+  const CLOSE = opts.closeOnLaunch === true;
+  const DEBOUNCE_MS = Math.max(0, Number(opts.debounceSeconds) || 0) * 1000;
+  const Apps = window.SteamClient?.Apps;
+  const cur = Apps?.LaunchNonSteamApp;
+  if (typeof cur !== 'function') return 'SteamClient.Apps.LaunchNonSteamApp missing';
+  const st = cur.__sfuiPatch === NAME ? cur.__sfuiState : null;
+  if (st && cur.__sfuiVersion === VERSION && st.close === CLOSE && st.debounceMs === DEBOUNCE_MS) {
+    // Report ignored launches since the last evaluation (the injector logs
+    // results that differ from the previous one).
+    const msgs = st.log.splice(0);
+    return msgs.length ? msgs.join('; ') : 'unchanged';
+  }
+  const orig = cur.__sfuiPatch === NAME ? cur.__sfuiOrig : cur;
+
+  const fiberOf = (el) => { const k = Object.keys(el).find((k) => k.startsWith('__reactFiber$')); return k && el[k]; };
+  // Popup handles of the "+" bar button(s) (normally one).
+  const plusHandles = () => {
+    const hs = [];
+    for (const p of window.g_PopupManager?.GetPopups() ?? []) {
+      if (!/gamepadui\.bar\./.test(p.m_strName ?? '')) continue;
+      let d;
+      try { d = p.window?.document; } catch { continue; }
+      for (const el of d?.querySelectorAll('.VRDashboardBarSmallButton') ?? []) {
+        let h = null;
+        for (let f = fiberOf(el), i = 0; f && i < 20; f = f.return, i++) {
+          const mp = f.memoizedProps;
+          if (!mp || typeof mp !== 'object') continue;
+          if ('refBarPopopHandle' in mp) h = mp.refBarPopopHandle?.current ?? null;
+          if ('allowLaunchProgram' in mp) { if (h && !hs.includes(h)) hs.push(h); break; }
+        }
+      }
+    }
+    return hs;
+  };
+  const closeMenu = () => {
+    for (const h of plusHandles()) if (h.BPopupOpen?.()) h.closePopup();
+  };
+
+  const state = { close: CLOSE, debounceMs: DEBOUNCE_MS, last: new Map(), log: [], plusHandles, closeMenu };
+  const f = function LaunchNonSteamApp(cmdline, ...rest) {
+    let result;
+    const now = Date.now();
+    const key = String(cmdline);
+    const prev = state.last.get(key);
+    if (DEBOUNCE_MS > 0 && prev !== undefined && now - prev < DEBOUNCE_MS) {
+      const msg = `ignored repeated launch of ${JSON.stringify(key)} (${((now - prev) / 1000).toFixed(1)} s after the last one, at ${new Date(now).toLocaleTimeString()})`;
+      console.info(`sfui ${NAME}: ${msg}`);
+      state.log.push(msg);
+      if (state.log.length > 20) state.log.shift();
+    } else {
+      state.last.set(key, now);
+      for (const [k, t] of state.last) if (now - t >= DEBOUNCE_MS && k !== key) state.last.delete(k);
+      result = orig.call(this, cmdline, ...rest);
+    }
+    if (CLOSE) { try { closeMenu(); } catch (e) { console.error(`sfui ${NAME}:`, e); } }
+    return result;
+  };
+  f.__sfuiPatch = NAME; f.__sfuiVersion = VERSION; f.__sfuiOrig = orig; f.__sfuiState = state;
+  Apps.LaunchNonSteamApp = f;
+  const what = [CLOSE && 'close on launch', DEBOUNCE_MS > 0 && `debounce ${DEBOUNCE_MS / 1000} s`].filter(Boolean);
+  return `patched (${what.join(', ') || 'no-op'})`;
+})

modules/launcher-menu/launch/unpatch.js

@@ -0,0 +1,9 @@
+// Reverts launch/patch.js (restores the original
+// SteamClient.Apps.LaunchNonSteamApp). Safe when not patched.
+(() => {
+  const Apps = window.SteamClient?.Apps;
+  const f = Apps?.LaunchNonSteamApp;
+  if (f?.__sfuiPatch !== 'launcher-menu-launch') return 'not patched';
+  Apps.LaunchNonSteamApp = f.__sfuiOrig;
+  return 'unpatched';
+})()