Merge remote-tracking branch 'origin/dev' into little-zen

# Conflicts:
#	src/zen/kbs/ZenKeyboardShortcuts.sys.mjs

Co-authored-by: mr-cheffy <91018726+mr-cheffy@users.noreply.github.com>

locales/en-US/browser/browser/zen-general.ftl

@@ -151,3 +151,5 @@ zen-window-sync-migration-dialog-accept = Got It
 zen-appmenu-new-blank-window =
     .label = New blank window
 
+zen-spaces-search-placeholder =
+    .placeholder = Search your spaces...

prefs/zen/kbs.yaml

@@ -7,3 +7,6 @@
 
 - name: zen.keyboard.shortcuts.disable-mainkeyset-clear
   value: false # for debugging
+
+- name: zen.keyboard.shortcuts.global.enabled
+  value: true

src/browser/base/content/zen-assets.inc.xhtml

@@ -28,6 +28,8 @@
 <link rel="stylesheet" type="text/css" href="chrome://browser/content/zen-styles/zen-welcome.css" />
 <link rel="stylesheet" type="text/css" href="chrome://browser/content/zen-styles/zen-media-controls.css" />
 <link rel="stylesheet" type="text/css" href="chrome://browser/content/zen-styles/zen-download-box-animation.css" />
+
+<link rel="stylesheet" type="text/css" href="chrome://browser/content/zen-styles/zen-little-window.css" />
 </linkset>
 
 # Startup "preloaded" scripts that requre globals such as gBrowser and gURLBar

src/browser/base/content/zen-assets.jar.inc.mn

@@ -9,7 +9,6 @@
 #include ../../../zen/mods/jar.inc.mn
 #include ../../../zen/spaces/jar.inc.mn
 #include ../../../zen/tabs/jar.inc.mn
-#include ../../../zen/kbs/jar.inc.mn
 #include ../../../zen/glance/jar.inc.mn
 #include ../../../zen/folders/jar.inc.mn
 #include ../../../zen/welcome/jar.inc.mn
@@ -20,3 +19,4 @@
 #include ../../../zen/fonts/jar.inc.mn
 #include ../../../zen/boosts/jar.inc.mn
 #include ../../../zen/live-folders/jar.inc.mn
+#include ../../../zen/little-window/jar.inc.mn

src/browser/base/content/zen-commands.inc.xhtml

@@ -68,4 +68,6 @@
   <command id="cmd_zenNewLiveFolder" />
 
   <command id="cmd_zenDuplicateTab" />
+
+  <command id="cmd_zenNewLittleWindow" />
 </commandset>

src/browser/base/content/zen-panels/spaces-search.inc

@@ -0,0 +1,23 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+<panel id="zen-spaces-popup"
+    nonnativepopover="true"
+    type="arrow"
+    orient="vertical"
+    side="bottom"
+    hidden="true"
+    consumeoutsideclicks="never">
+  <hbox class="zen-spaces-list-header" flex="1">
+    <image class="zen-spaces-list-search-icon" src="chrome://global/skin/icons/search-glass.svg"/>
+    <html:input id="zen-spaces-list-search"
+      data-l10n-id="zen-spaces-search-placeholder"
+      type="search" />
+  </hbox>
+  <scrollbox class="zen-spaces-list-scrollbox" flex="1">
+    <vbox id="zen-spaces-list"></vbox>
+    <hbox id="zen-spaces-search-no-results" hidden="true" flex="1"
+      data-l10n-id="zen-spaces-search-no-results" />
+  </scrollbox>
+</panel>

src/browser/base/content/zen-popupset.inc.xhtml

@@ -5,6 +5,7 @@
 #include zen-panels/theme-picker.inc
 #include zen-panels/emojis-picker.inc
 #include zen-panels/folders-search.inc
+#include zen-panels/spaces-search.inc
 #include zen-panels/site-data.inc
 
 #include zen-panels/popups.inc

src/browser/components/preferences/zen-settings.js

@@ -8,13 +8,16 @@ const { nsZenMultiWindowFeature } = ChromeUtils.importESModule(
   { global: "current" }
 );
 
-const { nsKeyShortcutModifiers } = ChromeUtils.importESModule(
-  "chrome://browser/content/zen-components/ZenKeyboardShortcuts.mjs",
-  {
-    global: "current",
-  }
+const {
+  nsKeyShortcutModifiers,
+  ZenKeyboardShortcuts,
+  VALID_SHORTCUT_GROUPS,
+} = ChromeUtils.importESModule(
+  "resource:///modules/zen/ZenKeyboardShortcuts.sys.mjs"
 );
 
+const gZenKeyboardShortcutsManager = ZenKeyboardShortcuts.manager;
+
 var gZenMarketplaceManager = {
   async init() {
     const checkForUpdates = document.getElementById("zenThemeMarketplaceCheckForUpdates");

src/browser/components/urlbar/content/UrlbarInput-mjs.patch

@@ -1,5 +1,5 @@
 diff --git a/browser/components/urlbar/content/UrlbarInput.mjs b/browser/components/urlbar/content/UrlbarInput.mjs
-index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f5c811a82 100644
+index b23244f9d3278918b016bb3fcab19687bc2e292a..e5de81b3060a1ee76b1a6aff2e4ae1ca50f2caa9 100644
 --- a/browser/components/urlbar/content/UrlbarInput.mjs
 +++ b/browser/components/urlbar/content/UrlbarInput.mjs
 @@ -90,6 +90,13 @@ const lazy = XPCOMUtils.declareLazy({
@@ -75,7 +75,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
      }
  
      if (isCanonized) {
-@@ -2696,6 +2728,42 @@ export class UrlbarInput extends HTMLElement {
+@@ -2696,6 +2728,45 @@ export class UrlbarInput extends HTMLElement {
      await this.#updateLayoutBreakoutDimensions();
    }
  
@@ -84,7 +84,10 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
 +  }
 +
 +  get zenUrlbarBehavior() {
-+    if (this.document.documentElement.hasAttribute("inDOMFullscreen")) {
++    if (
++      this.document.documentElement.hasAttribute("inDOMFullscreen") ||
++      this.document.documentElement.hasAttribute("zen-little-window")
++    ) {
 +      return "float";
 +    }
 +    return lazy.ZEN_URLBAR_BEHAVIOR;
@@ -118,7 +121,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
    startLayoutExtend() {
      if (!this.#allowBreakout || this.hasAttribute("breakout-extend")) {
        // Do not expand if the Urlbar does not support being expanded or it is
-@@ -2710,6 +2778,13 @@ export class UrlbarInput extends HTMLElement {
+@@ -2710,6 +2781,13 @@ export class UrlbarInput extends HTMLElement {
  
      this.setAttribute("breakout-extend", "true");
  
@@ -132,7 +135,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
      // Enable the animation only after the first extend call to ensure it
      // doesn't run when opening a new window.
      if (!this.hasAttribute("breakout-extend-animate")) {
-@@ -2729,6 +2804,27 @@ export class UrlbarInput extends HTMLElement {
+@@ -2729,6 +2807,27 @@ export class UrlbarInput extends HTMLElement {
        return;
      }
  
@@ -160,7 +163,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
      this.removeAttribute("breakout-extend");
      this.#updateTextboxPosition();
    }
-@@ -2759,7 +2855,7 @@ export class UrlbarInput extends HTMLElement {
+@@ -2759,7 +2858,7 @@ export class UrlbarInput extends HTMLElement {
      forceUnifiedSearchButtonAvailable = false
    ) {
      let prevState = this.getAttribute("pageproxystate");
@@ -169,7 +172,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
      this.setAttribute("pageproxystate", state);
      this._inputContainer.setAttribute("pageproxystate", state);
      this._identityBox?.setAttribute("pageproxystate", state);
-@@ -3031,10 +3127,12 @@ export class UrlbarInput extends HTMLElement {
+@@ -3031,10 +3130,12 @@ export class UrlbarInput extends HTMLElement {
        return;
      }
      this.style.top = px(
@@ -182,7 +185,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
      );
    }
  
-@@ -3093,9 +3191,10 @@ export class UrlbarInput extends HTMLElement {
+@@ -3093,9 +3194,10 @@ export class UrlbarInput extends HTMLElement {
            return;
          }
  
@@ -194,7 +197,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
          );
          this.style.setProperty(
            "--urlbar-height",
-@@ -3597,6 +3696,7 @@ export class UrlbarInput extends HTMLElement {
+@@ -3597,6 +3699,7 @@ export class UrlbarInput extends HTMLElement {
    }
  
    _toggleActionOverride(event) {
@@ -202,7 +205,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
      if (
        event.keyCode == KeyEvent.DOM_VK_SHIFT ||
        event.keyCode == KeyEvent.DOM_VK_ALT ||
-@@ -3709,8 +3809,8 @@ export class UrlbarInput extends HTMLElement {
+@@ -3709,8 +3812,8 @@ export class UrlbarInput extends HTMLElement {
      if (!this.#isAddressbar) {
        return val;
      }
@@ -213,7 +216,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
        : val;
      // Only trim value if the directionality doesn't change to RTL and we're not
      // showing a strikeout https protocol.
-@@ -4006,6 +4106,7 @@ export class UrlbarInput extends HTMLElement {
+@@ -4006,6 +4109,7 @@ export class UrlbarInput extends HTMLElement {
      resultDetails = null,
      browser = this.window.gBrowser.selectedBrowser
    ) {
@@ -221,7 +224,19 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
      if (this.#isAddressbar) {
        this.#prepareAddressbarLoad(
          url,
-@@ -4117,6 +4218,10 @@ export class UrlbarInput extends HTMLElement {
+@@ -4088,6 +4192,11 @@ export class UrlbarInput extends HTMLElement {
+    * @returns {"current" | "tabshifted" | "tab" | "save" | "window"}
+    */
+   _whereToOpen(event) {
++    if (this.document.documentElement.hasAttribute("zen-little-window")) {
++      // Little windows are single-tab popups -- never spawn extra tabs
++      // or new windows from the urlbar.
++      return "current";
++    }
+     let isKeyboardEvent = KeyboardEvent.isInstance(event);
+     let reuseEmpty = isKeyboardEvent;
+     let where = undefined;
+@@ -4117,6 +4226,10 @@ export class UrlbarInput extends HTMLElement {
        }
        reuseEmpty = true;
      }
@@ -232,7 +247,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
      if (
        where == "tab" &&
        reuseEmpty &&
-@@ -4124,6 +4229,9 @@ export class UrlbarInput extends HTMLElement {
+@@ -4124,6 +4237,9 @@ export class UrlbarInput extends HTMLElement {
      ) {
        where = "current";
      }
@@ -242,7 +257,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
      return where;
    }
  
-@@ -4378,6 +4486,7 @@ export class UrlbarInput extends HTMLElement {
+@@ -4378,6 +4494,7 @@ export class UrlbarInput extends HTMLElement {
        this.setResultForCurrentValue(null);
        this.handleCommand();
        this.controller.clearLastQueryContextCache();
@@ -250,7 +265,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
  
        this._suppressStartQuery = false;
      });
-@@ -4385,7 +4494,6 @@ export class UrlbarInput extends HTMLElement {
+@@ -4385,7 +4502,6 @@ export class UrlbarInput extends HTMLElement {
      contextMenu.addEventListener("popupshowing", () => {
        // Close the results pane when the input field contextual menu is open,
        // because paste and go doesn't want a result selection.
@@ -258,7 +273,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
  
        let controller =
          this.document.commandDispatcher.getControllerForCommand("cmd_paste");
-@@ -4541,7 +4649,11 @@ export class UrlbarInput extends HTMLElement {
+@@ -4541,7 +4657,11 @@ export class UrlbarInput extends HTMLElement {
      if (!engineName && !source && !this.hasAttribute("searchmode")) {
        return;
      }
@@ -271,7 +286,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
      if (this._searchModeIndicatorTitle) {
        this._searchModeIndicatorTitle.textContent = "";
        this._searchModeIndicatorTitle.removeAttribute("data-l10n-id");
-@@ -4851,6 +4963,7 @@ export class UrlbarInput extends HTMLElement {
+@@ -4851,6 +4971,7 @@ export class UrlbarInput extends HTMLElement {
  
      this.document.l10n.setAttributes(
        this.inputField,
@@ -279,7 +294,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
        l10nId,
        l10nId == "urlbar-placeholder-with-name"
          ? { name: engineName }
-@@ -4964,6 +5077,11 @@ export class UrlbarInput extends HTMLElement {
+@@ -4964,6 +5085,11 @@ export class UrlbarInput extends HTMLElement {
    }
  
    _on_click(event) {
@@ -291,7 +306,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
      switch (event.target) {
        case this.inputField:
        case this._inputContainer:
-@@ -5042,7 +5160,7 @@ export class UrlbarInput extends HTMLElement {
+@@ -5042,7 +5168,7 @@ export class UrlbarInput extends HTMLElement {
        }
      }
  
@@ -300,7 +315,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
        this.view.autoOpen({ event });
      } else {
        if (this._untrimOnFocusAfterKeydown) {
-@@ -5082,9 +5200,16 @@ export class UrlbarInput extends HTMLElement {
+@@ -5082,9 +5208,16 @@ export class UrlbarInput extends HTMLElement {
    }
  
    _on_mousedown(event) {
@@ -318,7 +333,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
          if (
            event.composedTarget != this.inputField &&
            event.composedTarget != this._inputContainer
-@@ -5094,6 +5219,10 @@ export class UrlbarInput extends HTMLElement {
+@@ -5094,6 +5227,10 @@ export class UrlbarInput extends HTMLElement {
  
          this.focusedViaMousedown = !this.focused;
          this._preventClickSelectsAll = this.focused;
@@ -329,7 +344,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
  
          // Keep the focus status, since the attribute may be changed
          // upon calling this.focus().
-@@ -5129,7 +5258,7 @@ export class UrlbarInput extends HTMLElement {
+@@ -5129,7 +5266,7 @@ export class UrlbarInput extends HTMLElement {
          }
          // Don't close the view when clicking on a tab; we may want to keep the
          // view open on tab switch, and the TabSelect event arrived earlier.
@@ -338,7 +353,7 @@ index b23244f9d3278918b016bb3fcab19687bc2e292a..ade1f031bbb68202a37e6c9d3071a73f
            break;
          }
  
-@@ -5411,7 +5540,7 @@ export class UrlbarInput extends HTMLElement {
+@@ -5411,7 +5548,7 @@ export class UrlbarInput extends HTMLElement {
      // When we are in actions search mode we can show more results so
      // increase the limit.
      let maxResults =

src/browser/modules/BrowserWindowTracker-sys-mjs.patch

@@ -1,22 +1,37 @@
 diff --git a/browser/modules/BrowserWindowTracker.sys.mjs b/browser/modules/BrowserWindowTracker.sys.mjs
-index 9aecab66d8f23fac9f16cea2120a5fe903ae1122..692f2bfe3899a58925789503a6bb2a547cdbf7f3 100644
+index 9aecab66d8f23fac9f16cea2120a5fe903ae1122..e023c27bcb027d29ba9b3469eca5957d42040c46 100644
 --- a/browser/modules/BrowserWindowTracker.sys.mjs
 +++ b/browser/modules/BrowserWindowTracker.sys.mjs
-@@ -330,6 +330,7 @@ export const BrowserWindowTracker = {
+@@ -210,7 +210,8 @@ export const BrowserWindowTracker = {
+         !win.closed &&
+         (options.allowPopups || win.toolbar.visible) &&
+         (options.allowTaskbarTabs ||
+-          !win.document.documentElement.hasAttribute("taskbartab")) &&
++          (!win.document.documentElement.hasAttribute("taskbartab") &&
++            !win.document.documentElement.hasAttribute("zen-little-window"))) &&
+         (!("private" in options) ||
+           lazy.PrivateBrowsingUtils.permanentPrivateBrowsing ||
+           lazy.PrivateBrowsingUtils.isWindowPrivate(win) == options.private)
+@@ -330,6 +331,8 @@ export const BrowserWindowTracker = {
        args = null,
        remote = undefined,
        fission = undefined,
 +    zenSyncedWindow = true,
++    zenLittleWindow = false,
      } = options;
  
      args = lazy.AIWindow.handleAIWindowOptions(options);
-@@ -386,6 +387,12 @@ export const BrowserWindowTracker = {
+@@ -386,6 +389,16 @@ export const BrowserWindowTracker = {
        windowFeatures,
        args
      );
 +    win._zenStartupSyncFlag = Services.prefs.getBoolPref("zen.window-sync.prefer-unsynced-windows")
 +      ? (zenSyncedWindow ? 'unsynced' : 'synced')
 +      : (zenSyncedWindow ? 'synced' : 'unsynced');
++    if (zenLittleWindow) {
++      win._zenStartupLittleWindow = true;
++      win._zenStartupSyncFlag = 'unsynced';
++    }
 +    if (win._zenStartupSyncFlag === 'unsynced' && openerWindow) {
 +      win._zenStartupUnsyncedUserContextId = openerWindow.gZenWorkspaces.getCurrentSpaceContainerId();
 +    }

src/browser/modules/URILoadingHelper-sys-mjs.patch

@@ -1,5 +1,5 @@
 diff --git a/browser/modules/URILoadingHelper.sys.mjs b/browser/modules/URILoadingHelper.sys.mjs
-index a005dbdf84609622ef8054f73f78c0c290e76125..d5bf6fb51c9af5e60f69a73612ee91598080730a 100644
+index a005dbdf84609622ef8054f73f78c0c290e76125..2d347ac12d53ae97b61750d421a489ce10af3376 100644
 --- a/browser/modules/URILoadingHelper.sys.mjs
 +++ b/browser/modules/URILoadingHelper.sys.mjs
 @@ -224,6 +224,7 @@ function openInWindow(url, params, sourceWindow) {
@@ -19,7 +19,17 @@ index a005dbdf84609622ef8054f73f78c0c290e76125..d5bf6fb51c9af5e60f69a73612ee9159
          where = "tab";
          targetBrowser = null;
        } else if (
-@@ -974,7 +975,7 @@ export const URILoadingHelper = {
+@@ -724,7 +725,8 @@ export const URILoadingHelper = {
+         "navigator:browser" &&
+       (!skipPopups || top.toolbar.visible) &&
+       (!skipTaskbarTabs ||
+-        !top.document.documentElement.hasAttribute("taskbartab")) &&
++        (!top.document.documentElement.hasAttribute("taskbartab") &&
++          !top.document.documentElement.hasAttribute("zen-little-window"))) &&
+       (!forceNonPrivate || !PrivateBrowsingUtils.isWindowPrivate(top))
+     ) {
+       return top;
+@@ -974,7 +976,7 @@ export const URILoadingHelper = {
          ignoreQueryString || replaceQueryString,
          ignoreFragmentWhenComparing
        );
@@ -28,7 +38,7 @@ index a005dbdf84609622ef8054f73f78c0c290e76125..d5bf6fb51c9af5e60f69a73612ee9159
        for (let i = 0; i < browsers.length; i++) {
          let browser = browsers[i];
          let browserCompare = cleanURL(
-@@ -1030,7 +1031,7 @@ export const URILoadingHelper = {
+@@ -1030,7 +1032,7 @@ export const URILoadingHelper = {
                );
                aSplitView.ownerGlobal.focus();
              } else {

src/widget/cocoa/nsCocoaWindow-mm.patch

@@ -0,0 +1,27 @@
+diff --git a/widget/cocoa/nsCocoaWindow.mm b/widget/cocoa/nsCocoaWindow.mm
+index 515177a3a97094142593a98fb1b3023acf1ccb87..fb6f932547f9523a240f95915b7440dcdfa16975 100644
+--- a/widget/cocoa/nsCocoaWindow.mm
++++ b/widget/cocoa/nsCocoaWindow.mm
+@@ -5240,7 +5240,7 @@ static unsigned int WindowMaskForBorderStyle(BorderStyle aBorderStyle) {
+       // calls to ...orderFront: in TRY blocks.  See bmo bug 470864.
+       NS_OBJC_BEGIN_TRY_IGNORE_BLOCK;
+       mWindow.contentView.needsDisplay = YES;
+-      if (!nativeParentWindow || mPopupLevel != PopupLevel::Parent) {
++      if (!mZenShowLocked && (!nativeParentWindow || mPopupLevel != PopupLevel::Parent)) {
+         [mWindow orderFront:nil];
+       }
+       NS_OBJC_END_TRY_IGNORE_BLOCK;
+@@ -5287,7 +5287,12 @@ static unsigned int WindowMaskForBorderStyle(BorderStyle aBorderStyle) {
+       // We don't want most alwaysontop / alert windows to pull focus when
+       // they're opened, as these tend to be for peripheral indicators and
+       // displays.
+-      if ((mAlwaysOnTop && mPiPType != PiPType::DocumentPiP) || mIsAlert) {
++      if (mZenShowLocked) {
++        // Zen: window-control service has this widget locked-hidden;
++        // skip the native order-front but let the rest of Show()'s
++        // bookkeeping run normally.
++      } else if ((mAlwaysOnTop && mPiPType != PiPType::DocumentPiP) ||
++                 mIsAlert) {
+         [mWindow orderFront:nil];
+       } else {
+         [mWindow makeKeyAndOrderFront:nil];

src/widget/gtk/nsWindow-cpp.patch

@@ -0,0 +1,18 @@
+diff --git a/widget/gtk/nsWindow.cpp b/widget/gtk/nsWindow.cpp
+index 89950bd72c77ed961e59faa2fadb8f21a78fd23a..8c74bfa08af3c16cc05e11ea34902cbcdde3c64a 100644
+--- a/widget/gtk/nsWindow.cpp
++++ b/widget/gtk/nsWindow.cpp
+@@ -1076,7 +1076,12 @@ void nsWindow::Show(bool aState) {
+   }
+ #endif
+ 
+-  NativeShow(aState);
++  // Zen: skip the actual GTK show when window-control has the widget
++  // locked-hidden; mIsShown is already set above so Mozilla's
++  // bookkeeping treats the widget as shown.
++  if (!(aState && mZenShowLocked)) {
++    NativeShow(aState);
++  }
+   RefreshWindowClass();
+ }
+ 

src/widget/nsIWidget-h.patch

@@ -0,0 +1,28 @@
+diff --git a/widget/nsIWidget.h b/widget/nsIWidget.h
+index c22e055b9254ed1c8943c232a8339c574563dffc..0a0cb7cad4e878f93c03078564dac051dde1d014 100644
+--- a/widget/nsIWidget.h
++++ b/widget/nsIWidget.h
+@@ -698,6 +698,14 @@ class nsIWidget : public nsSupportsWeakReference {
+    */
+   virtual void Show(bool aState) = 0;
+ 
++  /**
++   * Zen: when set to true, Show(true) calls on this widget become
++   * no-ops until SetZenShowLocked(false) is called. Used to keep a
++   * window invisible while it's being set up.
++   */
++  void SetZenShowLocked(bool aLocked) { mZenShowLocked = aLocked; }
++  bool IsZenShowLocked() const { return mZenShowLocked; }
++
+   /**
+    * Whether or not a widget must be recreated after being hidden to show
+    * again properly.
+@@ -2419,6 +2427,8 @@ class nsIWidget : public nsSupportsWeakReference {
+   mozilla::Maybe<FullscreenSavedState> mSavedBounds;
+ 
+   bool mUpdateCursor;
++  // Zen: when true, Show(true) is a no-op. See SetZenShowLocked().
++  bool mZenShowLocked = false;
+   bool mIMEHasFocus;
+   bool mIMEHasQuit;
+   // if the window is fully occluded (rendering may be paused in response)

src/widget/windows/nsWindow-cpp.patch

@@ -0,0 +1,59 @@
+diff --git a/widget/windows/nsWindow.cpp b/widget/windows/nsWindow.cpp
+index baed7d09e31291b26a1d0a1ddfd63b57f0ce67d0..9daa1140e9538427d002c6f8ff99cd68265249cc 100644
+--- a/widget/windows/nsWindow.cpp
++++ b/widget/windows/nsWindow.cpp
+@@ -1761,28 +1761,33 @@ void nsWindow::Show(bool aState) {
+         // cursor.
+         SetCursor(Cursor{eCursor_standard});
+ 
+-        switch (mFrameState->GetSizeMode()) {
+-          case nsSizeMode_Fullscreen:
+-            ::ShowWindow(mWnd, SW_SHOW);
+-            break;
+-          case nsSizeMode_Maximized:
+-            ::ShowWindow(mWnd, SW_SHOWMAXIMIZED);
+-            break;
+-          case nsSizeMode_Minimized:
+-            ::ShowWindow(mWnd, SW_SHOWMINIMIZED);
+-            break;
+-          default:
+-            if (CanTakeFocus() &&
+-                (!mAlwaysOnTop || mPiPType == PiPType::DocumentPiP)) {
+-              ::ShowWindow(mWnd, SW_SHOWNORMAL);
+-            } else {
+-              ::ShowWindow(mWnd, SW_SHOWNOACTIVATE);
+-              // Don't flicker the window if we're restoring session
+-              if (!sIsRestoringSession) {
+-                (void)GetAttention(2);
++        // Zen: skip the actual ShowWindow() call when window-control
++        // has the widget locked-hidden; mIsVisible is already set above
++        // so Mozilla's bookkeeping treats the widget as shown.
++        if (!mZenShowLocked) {
++          switch (mFrameState->GetSizeMode()) {
++            case nsSizeMode_Fullscreen:
++              ::ShowWindow(mWnd, SW_SHOW);
++              break;
++            case nsSizeMode_Maximized:
++              ::ShowWindow(mWnd, SW_SHOWMAXIMIZED);
++              break;
++            case nsSizeMode_Minimized:
++              ::ShowWindow(mWnd, SW_SHOWMINIMIZED);
++              break;
++            default:
++              if (CanTakeFocus() &&
++                  (!mAlwaysOnTop || mPiPType == PiPType::DocumentPiP)) {
++                ::ShowWindow(mWnd, SW_SHOWNORMAL);
++              } else {
++                ::ShowWindow(mWnd, SW_SHOWNOACTIVATE);
++                // Don't flicker the window if we're restoring session
++                if (!sIsRestoringSession) {
++                  (void)GetAttention(2);
++                }
+               }
+-            }
+-            break;
++              break;
++          }
+         }
+ 
+         if (!mHasBeenShown) {

src/zen/ZenComponents.manifest

@@ -16,3 +16,5 @@ category app-startup nsBrowserGlue @mozilla.org/browser/browserglue;1 applicatio
 #include common/Components.manifest
 #include sessionstore/SessionComponents.manifest
 #include live-folders/LiveFoldersComponents.manifest
+#include kbs/KbsComponents.manifest
+#include little-window/LittleWindowComponents.manifest

src/zen/common/ZenPreloadedScripts.js

@@ -13,7 +13,6 @@
     "chrome://browser/content/zen-components/ZenCompactMode.mjs",
     "chrome://browser/content/ZenUIManager.mjs",
     "chrome://browser/content/zen-components/ZenMods.mjs",
-    "chrome://browser/content/zen-components/ZenKeyboardShortcuts.mjs",
     "chrome://browser/content/zen-components/ZenSessionStore.mjs",
     "chrome://browser/content/zen-components/ZenMediaController.mjs",
     "chrome://browser/content/zen-components/ZenGlanceManager.mjs",

src/zen/common/modules/ZenStartup.mjs

@@ -32,7 +32,6 @@ class ZenStartup {
       return;
     }
     this.#hasInitializedLayout = true;
-    gZenKeyboardShortcutsManager.beforeInit();
     try {
       const kNavbarItems = ["nav-bar", "PersonalToolbar"];
       const kNewContainerId = "zen-appcontent-navbar-container";

src/zen/common/modules/ZenUIManager.mjs

@@ -295,6 +295,7 @@ window.gZenUIManager = {
   onFloatingURLBarOpen() {
     requestAnimationFrame(() => {
       this.updateTabsToolbar();
+      window.dispatchEvent(new CustomEvent("ZenFloatingURLBarOpened"));
     });
   },
 
@@ -607,6 +608,12 @@ window.gZenUIManager = {
       gURLBar._zenHandleUrlbarClose = null;
     }
 
+    window.dispatchEvent(
+      new CustomEvent("ZenURLBarClosedEarly", {
+        detail: { onSwitch, onElementPicked },
+      })
+    );
+
     const isFocusedBefore = gURLBar.focused;
     setTimeout(() => {
       // We use this attribute on Tabbrowser::addTab
@@ -951,7 +958,9 @@ window.gZenVerticalTabsManager = {
           ?.includes("toolbar") ||
         document.documentElement
           .getAttribute("chromehidden")
-          ?.includes("menubar")
+          ?.includes("menubar") ||
+        document.documentElement.hasAttribute("zen-little-window") ||
+        window._zenStartupLittleWindow
       );
     });
 
@@ -959,7 +968,18 @@ window.gZenVerticalTabsManager = {
       this,
       "_canReplaceNewTab",
       "zen.urlbar.replace-newtab",
-      true
+      true,
+      null,
+      val => {
+        // On little windows, we always want to replace new tabs
+        if (
+          window._zenStartupLittleWindow ||
+          document.documentElement.hasAttribute("zen-little-window")
+        ) {
+          return true;
+        }
+        return val;
+      }
     );
     var updateEvent = this._updateEvent.bind(this);
     var onPrefChange = this._onPrefChange.bind(this);
@@ -1270,7 +1290,8 @@ window.gZenVerticalTabsManager = {
 
       const topButtons = document.getElementById("zen-sidebar-top-buttons");
       const isCompactMode =
-        gZenCompactModeManager.preference && !forCustomizableMode;
+        (gZenCompactModeManager.preference && !forCustomizableMode) ||
+        this.hidesTabsToolbar;
       const isVerticalTabs = this._prefsVerticalTabs || forCustomizableMode;
       const isSidebarExpanded = this._prefsSidebarExpanded || !isVerticalTabs;
       const isRightSide = this._prefsRightSide && isVerticalTabs;

src/zen/common/moz.build

@@ -5,6 +5,7 @@
 EXTRA_JS_MODULES += [
   "sys/ZenActorsManager.sys.mjs",
   "sys/ZenCustomizableUI.sys.mjs",
+  "sys/ZenSearchPopup.sys.mjs",
   "sys/ZenUIMigration.sys.mjs",
 ]
 

src/zen/common/styles/zen-browser-ui.css

@@ -20,9 +20,13 @@ body,
   position: inherit;
 }
 
-:root:is([inDOMFullscreen="true"], [chromehidden~="location"], [chromehidden~="toolbar"]) {
+:root:is(
+  [inDOMFullscreen="true"], [chromehidden~="location"], 
+  [chromehidden~="toolbar"], [zen-little-window="true"]
+) {
   #navigator-toolbox,
-  #zen-sidebar-splitter {
+  #zen-sidebar-splitter,
+  #zen-sidebar-top-buttons {
     visibility: collapse;
   }
 }

src/zen/common/styles/zen-theme.css

@@ -293,7 +293,7 @@
 }
 
 #main-window[windowtype="navigator:browser"]:not([chromehidden~='toolbar']) {
-  min-height: 495px !important;
+  min-height: var(--zen-minimum-window-height, 495px) !important;
 
   @media (-moz-windows-mica) or (-moz-platform: macos) or ((-moz-platform: linux) and
         -moz-pref('zen.widget.linux.transparency')) {

src/zen/common/sys/ZenCustomizableUI.sys.mjs

@@ -3,6 +3,7 @@
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 import { AppConstants } from "resource://gre/modules/AppConstants.sys.mjs";
+import { ZenLittleWindow } from "resource:///modules/zen/ZenLittleWindow.sys.mjs";
 
 export const ZenCustomizableUI = new (class {
   constructor() {}
@@ -38,10 +39,15 @@ export const ZenCustomizableUI = new (class {
 
   // We do not have access to the window object here
   init(window) {
+    this.#initLittleWindow(window);
     this.#addSidebarButtons(window);
     this.#modifyToolbarButtons(window);
   }
 
+  #initLittleWindow(window) {
+    ZenLittleWindow.onLittleWindow(window);
+  }
+
   #addSidebarButtons(window) {
     const kDefaultSidebarWidth =
       AppConstants.platform === "macosx" ? "230px" : "186px";

src/zen/common/sys/ZenSearchPopup.sys.mjs

@@ -0,0 +1,152 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * Generic searchable XUL <panel> driver. One instance owns one panel +
+ * its search input + list + (optional) no-results element, and exposes
+ * `populate(items)` and `open(anchor, options)`.
+ *
+ * Each item passed to `populate` is `{ label, render?, onPick }`:
+ *   - label: string used for the data-label search filter.
+ *   - render: optional () => Element factory. If omitted a bare hbox
+ *     with a <label> is created.
+ *   - onPick: callback invoked when the item is clicked or activated
+ *     via Enter on the keyboard.
+ *
+ * The driver handles:
+ *   - filtering by lowercased substring match against data-label;
+ *   - arrow-key / Tab navigation with [selected="true"] highlight;
+ *   - Enter to activate the highlighted item;
+ *   - autofocus of the search input on popupshown;
+ *   - cleanup of all listeners on popuphidden.
+ */
+export class ZenSearchPopup {
+  #panel = null;
+  #searchInput = null;
+  #list = null;
+  #noResults = null;
+  #itemSelector = ".zen-search-popup-item";
+  #items = [];
+
+  /**
+   * @param {object} aOptions
+   * @param {Element} aOptions.panel        The <panel> XUL element.
+   * @param {Element} aOptions.searchInput  The search <html:input>.
+   * @param {Element} aOptions.list         The container holding items.
+   * @param {Element} [aOptions.noResults]  Optional "no results" element.
+   * @param {string}  [aOptions.itemSelector] Per-item selector. Default
+   *   is `.zen-search-popup-item`; custom items must carry that class
+   *   or override this option.
+   */
+  constructor({ panel, searchInput, list, noResults, itemSelector }) {
+    this.#panel = panel;
+    this.#searchInput = searchInput;
+    this.#list = list;
+    this.#noResults = noResults;
+    if (itemSelector) this.#itemSelector = itemSelector;
+  }
+
+  populate(items) {
+    this.#items = items;
+    this.#list.innerHTML = "";
+    const doc = this.#panel.ownerDocument;
+    for (const item of items) {
+      let node;
+      if (typeof item.render === "function") {
+        node = item.render();
+      } else {
+        node = doc.createXULElement("hbox");
+        const label = doc.createXULElement("label");
+        label.setAttribute("value", item.label);
+        node.appendChild(label);
+      }
+      node.classList.add(this.#itemSelector.replace(/^\./, ""));
+      node.setAttribute("data-label", item.label);
+      node.addEventListener("click", () => {
+        this.#panel.hidePopup();
+        item.onPick?.(item);
+      });
+      this.#list.appendChild(node);
+    }
+  }
+
+  open(anchor, { position = "after_end", onShown, onHidden } = {}) {
+    if (!this.#panel || !this.#list) return;
+
+    this.#panel.hidden = false;
+
+    if (this.#searchInput) this.#searchInput.value = "";
+    if (this.#noResults) this.#noResults.hidden = true;
+
+    const doc = this.#panel.ownerDocument;
+    const sel = this.#itemSelector;
+
+    const onSearch = () => {
+      const query = (this.#searchInput?.value || "").toLowerCase();
+      let visible = 0;
+      for (const item of this.#list.querySelectorAll(sel)) {
+        const label = item.getAttribute("data-label")?.toLowerCase() || "";
+        const found = label.includes(query);
+        item.hidden = !found;
+        if (found) visible++;
+      }
+      if (this.#noResults) this.#noResults.hidden = visible > 0;
+    };
+    if (this.#searchInput) {
+      this.#searchInput.addEventListener("input", onSearch);
+    }
+
+    const onKeyDown = event => {
+      if (
+        event.key === "ArrowDown" ||
+        event.key === "ArrowUp" ||
+        event.key === "Tab"
+      ) {
+        event.preventDefault();
+        const isUp =
+          event.key === "ArrowUp" || (event.key === "Tab" && event.shiftKey);
+        const items = Array.from(this.#list.querySelectorAll(sel)).filter(
+          it => !it.hidden
+        );
+        if (!items.length) return;
+        let index = items.indexOf(
+          this.#list.querySelector(`${sel}[selected="true"]`)
+        );
+        index = isUp
+          ? (index - 1 + items.length) % items.length
+          : (index + 1) % items.length;
+        items.forEach(it => it.removeAttribute("selected"));
+        const target = items[index];
+        target.setAttribute("selected", "true");
+        target.scrollIntoView({ block: "nearest", behavior: "smooth" });
+      } else if (event.key === "Enter") {
+        const sel2 = this.#list.querySelector(`${sel}[selected="true"]`);
+        if (sel2) sel2.click();
+      }
+    };
+    doc.addEventListener("keydown", onKeyDown);
+
+    const onPanelShown = event => {
+      if (event.target !== this.#panel) return;
+      this.#searchInput?.focus();
+      this.#searchInput?.select?.();
+      onShown?.();
+    };
+    this.#panel.addEventListener("popupshown", onPanelShown);
+
+    const onPanelHidden = event => {
+      if (event.target !== this.#panel) return;
+      if (this.#searchInput) {
+        this.#searchInput.removeEventListener("input", onSearch);
+      }
+      doc.removeEventListener("keydown", onKeyDown);
+      this.#panel.removeEventListener("popupshown", onPanelShown);
+      this.#panel.removeEventListener("popuphidden", onPanelHidden);
+      onHidden?.();
+    };
+    this.#panel.addEventListener("popuphidden", onPanelHidden);
+
+    this.#panel.openPopup(anchor, position);
+  }
+}

src/zen/common/zen-sets.js

@@ -136,6 +136,13 @@ document.addEventListener(
           case "cmd_zenNewNavigatorUnsynced":
             OpenBrowserWindow({ zenSyncedWindow: false });
             break;
+          case "cmd_zenNewLittleWindow": {
+            const { ZenLittleWindow } = ChromeUtils.importESModule(
+              "resource:///modules/zen/ZenLittleWindow.sys.mjs"
+            );
+            ZenLittleWindow.openLittleWindow(window);
+            break;
+          }
           case "cmd_zenNewLiveFolder": {
             const { ZenLiveFoldersManager } = ChromeUtils.importESModule(
               "resource:///modules/zen/ZenLiveFoldersManager.sys.mjs"

src/zen/common/zenThemeModifier.js

@@ -158,6 +158,14 @@
       ) {
         separation = 0;
       }
+      // Little windows are visually a single floating bar; we never want
+      // chrome padding around them.
+      if (
+        document.documentElement.hasAttribute("zen-little-window") ||
+        window._zenStartupLittleWindow
+      ) {
+        separation = 0;
+      }
       // In order to still use it on fullscreen, even if it's 0px, add .1px (almost invisible)
       separation = Math.max(kMinElementSeparation, separation);
       document.documentElement.style.setProperty(

src/zen/compact-mode/ZenCompactMode.mjs

@@ -126,6 +126,9 @@ window.gZenCompactModeManager = {
   },
 
   get shouldBeCompact() {
+    if (document.documentElement.hasAttribute("zen-little-window")) {
+      return false;
+    }
     return !document.documentElement
       .getAttribute("chromehidden")
       ?.includes("toolbar");

src/zen/folders/ZenFolders.mjs

@@ -3,6 +3,7 @@
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
 import { nsZenDOMOperatedFeature } from "chrome://browser/content/zen-components/ZenCommonUtils.mjs";
+import { ZenSearchPopup } from "resource:///modules/ZenSearchPopup.sys.mjs";
 
 function formatRelativeTime(timestamp) {
   const now = Date.now();
@@ -42,6 +43,7 @@ class nsZenFolders extends nsZenDOMOperatedFeature {
   );
 
   #popup = null;
+  #searchPopup = null;
   #popupTimer = null;
   #mouseTimer = null;
   #lastHighlightedGroup = null;
@@ -188,15 +190,12 @@ class nsZenFolders extends nsZenDOMOperatedFeature {
 
   #initTabsPopup() {
     this.#popup = document.getElementById("zen-folder-tabs-popup");
-
-    const search = this.#popup.querySelector("#zen-folder-tabs-list-search");
-    const tabsList = this.#popup.querySelector("#zen-folder-tabs-list");
-
-    search.addEventListener("input", () => {
-      const query = search.value.toLowerCase();
-      for (const item of tabsList.children) {
-        item.hidden = !item.getAttribute("data-label").includes(query);
-      }
+    this.#searchPopup = new ZenSearchPopup({
+      panel: this.#popup,
+      searchInput: this.#popup.querySelector("#zen-folder-tabs-list-search"),
+      list: this.#popup.querySelector("#zen-folder-tabs-list"),
+      noResults: document.getElementById("zen-folder-tabs-search-no-results"),
+      itemSelector: ".folders-tabs-list-item",
     });
 
     this.#popup.addEventListener("mouseover", () => {
@@ -788,93 +787,18 @@ class nsZenFolders extends nsZenDOMOperatedFeature {
     document.getElementById("zen-folder-tabs-search-no-results").hidden = true;
     this.#populateTabsList(activeGroup);
 
-    const search = this.#popup.querySelector("#zen-folder-tabs-list-search");
-    document.l10n.setArgs(search, {
-      "folder-name": activeGroup.name,
-    });
-    const tabsList = this.#popup.querySelector("#zen-folder-tabs-list");
-
-    const onSearchInput = () => {
-      const query = search.value.toLowerCase();
-      let foundTabs = 0;
-      for (const item of tabsList.children) {
-        const found = item.getAttribute("data-label").includes(query);
-        item.hidden = !found;
-        if (found) {
-          foundTabs++;
-        }
-      }
-      document.getElementById("zen-folder-tabs-search-no-results").hidden =
-        foundTabs > 0;
-    };
-    search.addEventListener("input", onSearchInput);
-
-    const onKeyDown = event => {
-      // Arrow down and up to navigate through the list
-      if (
-        event.key === "ArrowDown" ||
-        event.key === "ArrowUp" ||
-        event.key === "Tab"
-      ) {
-        event.preventDefault();
-        let isUp =
-          event.key === "ArrowUp" || (event.key === "Tab" && event.shiftKey);
-        const items = Array.from(tabsList.children).filter(
-          item => !item.hidden
-        );
-        if (items.length === 0) {
-          return;
-        }
-        let index = items.indexOf(
-          tabsList.querySelector(".folders-tabs-list-item[selected]")
-        );
-        if (!isUp) {
-          index = (index + 1) % items.length;
-        } else {
-          index = (index - 1 + items.length) % items.length;
-        }
-        items.forEach(item => item.removeAttribute("selected"));
-        const targetItem = items[index];
-        targetItem.setAttribute("selected", "true");
-        targetItem.scrollIntoView({ block: "start", behavior: "smooth" });
-      } else if (event.key === "Enter") {
-        // Enter to select the currently highlighted item
-        const highlightedItem = tabsList.querySelector(
-          ".folders-tabs-list-item[selected]"
-        );
-        if (highlightedItem) {
-          highlightedItem.click();
-        }
-      }
-    };
-    document.addEventListener("keydown", onKeyDown);
+    document.l10n.setArgs(
+      this.#popup.querySelector("#zen-folder-tabs-list-search"),
+      { "folder-name": activeGroup.name }
+    );
 
     const target = event.target;
     target.setAttribute("open", true);
 
-    const handlePopupHidden = event => {
-      if (event.target !== this.#popup) {
-        return;
-      }
-      search.value = "";
-      target.removeAttribute("open");
-      search.removeEventListener("input", onSearchInput);
-      document.removeEventListener("keydown", onKeyDown);
-    };
-
-    this.#popup.addEventListener(
-      "popupshown",
-      () => {
-        search.focus();
-        search.select();
-      },
-      { once: true }
-    );
-
-    this.#popup.addEventListener("popuphidden", handlePopupHidden, {
-      once: true,
+    this.#searchPopup.open(target, {
+      position: this.#searchPopupOptions,
+      onHidden: () => target.removeAttribute("open"),
     });
-    this.#popup.openPopup(target, this.#searchPopupOptions);
   }
 
   get #searchPopupOptions() {

src/zen/kbs/KbsComponents.manifest

@@ -0,0 +1,6 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+category browser-before-ui-startup resource:///modules/zen/ZenKeyboardShortcuts.sys.mjs ZenKeyboardShortcuts.init
+category browser-quit-application-granted resource:///modules/zen/ZenKeyboardShortcuts.sys.mjs ZenKeyboardShortcuts.uninit

src/zen/kbs/global-shortcuts/ZenGlobalShortcuts.cpp

@@ -0,0 +1,134 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ZenGlobalShortcuts.h"
+
+#include "mozilla/dom/Document.h"
+#include "nsContentUtils.h"
+#include "nsGlobalWindowOuter.h"
+#include "nsIWindowMediator.h"
+#include "nsPIDOMWindow.h"
+#include "nsReadableUtils.h"
+#include "nsServiceManagerUtils.h"
+#include "nsThreadUtils.h"
+
+namespace zen {
+
+ZenGlobalShortcuts* ZenGlobalShortcuts::sInstance = nullptr;
+
+NS_IMPL_ISUPPORTS(ZenGlobalShortcuts, nsIZenGlobalShortcuts)
+
+ZenGlobalShortcuts::ZenGlobalShortcuts() {
+  MOZ_ASSERT(NS_IsMainThread());
+  MOZ_ASSERT(!sInstance);
+  sInstance = this;
+}
+
+ZenGlobalShortcuts::~ZenGlobalShortcuts() {
+  MOZ_ASSERT(NS_IsMainThread());
+  for (auto& reg : mRegistrations) {
+    NativeUnregister(reg);
+  }
+  mRegistrations.Clear();
+  NativeShutdown();
+  sInstance = nullptr;
+}
+
+NS_IMETHODIMP
+ZenGlobalShortcuts::RegisterShortcut(const nsACString& aId,
+                                     const nsACString& aKey,
+                                     uint32_t aModifiers, bool* aRetVal) {
+  MOZ_ASSERT(NS_IsMainThread());
+  *aRetVal = false;
+
+  for (const auto& reg : mRegistrations) {
+    if (reg.id.Equals(aId)) return NS_ERROR_ALREADY_INITIALIZED;
+  }
+
+  Registration reg;
+  reg.id = aId;
+  reg.internalId = mNextInternalId++;
+
+  if (NS_FAILED(NativeRegister(reg, aKey, aModifiers))) {
+    return NS_OK;
+  }
+
+  mRegistrations.AppendElement(std::move(reg));
+  *aRetVal = true;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ZenGlobalShortcuts::UnregisterShortcut(const nsACString& aId) {
+  MOZ_ASSERT(NS_IsMainThread());
+  for (size_t i = 0; i < mRegistrations.Length(); ++i) {
+    if (mRegistrations[i].id.Equals(aId)) {
+      NativeUnregister(mRegistrations[i]);
+      mRegistrations.RemoveElementAt(i);
+      return NS_OK;
+    }
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ZenGlobalShortcuts::UnregisterAll() {
+  MOZ_ASSERT(NS_IsMainThread());
+  for (auto& reg : mRegistrations) {
+    NativeUnregister(reg);
+  }
+  mRegistrations.Clear();
+  return NS_OK;
+}
+
+const ZenGlobalShortcuts::Registration* ZenGlobalShortcuts::FindByInternalId(
+    uint32_t aInternalId) const {
+  for (const auto& reg : mRegistrations) {
+    if (reg.internalId == aInternalId) return &reg;
+  }
+  return nullptr;
+}
+
+// static
+void ZenGlobalShortcuts::OnNativeShortcut(uint32_t aInternalId) {
+  if (!NS_IsMainThread()) {
+    NS_DispatchToMainThread(NS_NewRunnableFunction(
+        "ZenGlobalShortcuts::OnNativeShortcut",
+        [aInternalId]() { OnNativeShortcut(aInternalId); }));
+    return;
+  }
+  if (!sInstance) return;
+
+  const Registration* reg = sInstance->FindByInternalId(aInternalId);
+  if (!reg) return;
+  DispatchEventForId(reg->id);
+}
+
+// static
+void ZenGlobalShortcuts::DispatchEventForId(const nsACString& aId) {
+  MOZ_ASSERT(NS_IsMainThread());
+
+  nsCOMPtr<nsIWindowMediator> med = do_GetService(NS_WINDOWMEDIATOR_CONTRACTID);
+  if (!med) return;
+
+  nsCOMPtr<mozIDOMWindowProxy> mostRecent;
+  med->GetMostRecentBrowserWindow(getter_AddRefs(mostRecent));
+  if (!mostRecent) return;
+
+  nsCOMPtr<nsPIDOMWindowOuter> outer = nsPIDOMWindowOuter::From(mostRecent);
+  if (!outer) return;
+
+  RefPtr<mozilla::dom::Document> doc = outer->GetExtantDoc();
+  if (!doc) return;
+
+  nsAutoString eventName;
+  eventName.AssignLiteral(u"zen-global-shortcut-");
+  AppendUTF8toUTF16(aId, eventName);
+
+  nsContentUtils::DispatchTrustedEvent(doc, nsGlobalWindowOuter::Cast(outer),
+                                       eventName, mozilla::CanBubble::eYes,
+                                       mozilla::Cancelable::eNo);
+}
+
+}  // namespace zen

src/zen/kbs/global-shortcuts/ZenGlobalShortcuts.h

@@ -0,0 +1,61 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_ZenGlobalShortcuts_h_
+#define mozilla_ZenGlobalShortcuts_h_
+
+#include "nsIZenGlobalShortcuts.h"
+
+#include "nsCOMPtr.h"
+#include "nsString.h"
+#include "nsTArray.h"
+
+namespace zen {
+
+/**
+ * @brief Singleton XPCOM service that registers OS-level global hotkeys
+ * and dispatches a trusted DOM event on the most recently focused
+ * browser window when one fires.
+ */
+class ZenGlobalShortcuts final : public nsIZenGlobalShortcuts {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIZENGLOBALSHORTCUTS
+
+  ZenGlobalShortcuts();
+
+  // Per-shortcut record. Public so the per-OS backend can read/write its
+  // fields directly without going through accessors.
+  struct Registration {
+    nsCString id;
+    uint32_t internalId = 0;
+    void* nativeHandle = nullptr;
+  };
+
+  // Called by the per-OS layer when a registered shortcut is triggered
+  // by the system. Safe to call from any thread; bounces to the main
+  // thread before touching DOM state.
+  static void OnNativeShortcut(uint32_t aInternalId);
+
+ private:
+  ~ZenGlobalShortcuts();
+
+  static ZenGlobalShortcuts* sInstance;
+
+  const Registration* FindByInternalId(uint32_t aInternalId) const;
+  static void DispatchEventForId(const nsACString& aId);
+
+  // Per-OS implementations live in cocoa/, windows/, or the stub.
+  static nsresult NativeRegister(Registration& aReg, const nsACString& aKey,
+                                 uint32_t aModifiers);
+  static void NativeUnregister(Registration& aReg);
+  static void NativeShutdown();
+
+  nsTArray<Registration> mRegistrations;
+  uint32_t mNextInternalId = 1;
+};
+
+}  // namespace zen
+
+#endif

src/zen/kbs/global-shortcuts/ZenGlobalShortcutsStub.cpp

@@ -0,0 +1,27 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ZenGlobalShortcuts.h"
+
+// Linux/other-toolkit fallback. A real implementation needs X11
+// XGrabKey on the root window or, on Wayland, the
+// org.freedesktop.portal.GlobalShortcuts portal over D-Bus. Until one
+// is added, registrations always fail and JS-side code can fall back
+// to in-window shortcuts.
+
+namespace zen {
+
+// static
+nsresult ZenGlobalShortcuts::NativeRegister(Registration&, const nsACString&,
+                                            uint32_t) {
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+// static
+void ZenGlobalShortcuts::NativeUnregister(Registration&) {}
+
+// static
+void ZenGlobalShortcuts::NativeShutdown() {}
+
+}  // namespace zen

src/zen/kbs/global-shortcuts/cocoa/ZenGlobalShortcutsCocoa.mm

@@ -0,0 +1,210 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ZenGlobalShortcuts.h"
+
+#include "mozilla/TextEvents.h"
+#include "nsReadableUtils.h"
+#include "nsString.h"
+
+#import <Carbon/Carbon.h>
+
+namespace zen {
+namespace {
+
+using mozilla::CodeNameIndex;
+using mozilla::WidgetKeyboardEvent;
+
+constexpr FourCharCode kZenHotKeySignature = 'zen ';
+
+// Mozilla-internal aliases referenced by NativeKeyToDOMCodeName.inc but
+// not part of Carbon. Mirrors widget/cocoa/TextInputHandler.h so we
+// don't need to drag the whole header in.
+enum {
+  kVK_PC_ContextMenu = 0x6E,
+  kVK_Powerbook_KeypadEnter = 0x34,
+};
+
+class MacGlobalShortcuts final {
+ public:
+  MacGlobalShortcuts() = delete;
+
+  static nsresult Register(ZenGlobalShortcuts::Registration& aReg,
+                           const nsACString& aKey, uint32_t aModifiers);
+  static void Unregister(ZenGlobalShortcuts::Registration& aReg);
+  static void Shutdown();
+
+ private:
+  static bool EnsureHandler();
+  static OSStatus HandleHotKey(EventHandlerCallRef, EventRef, void*);
+  static bool ResolveKey(const nsACString& aKey, UInt32& aOut);
+  static UInt32 ToCarbonModifiers(uint32_t aMods);
+
+  static EventHandlerUPP sUPP;
+  static EventHandlerRef sHandler;
+};
+
+EventHandlerUPP MacGlobalShortcuts::sUPP = nullptr;
+EventHandlerRef MacGlobalShortcuts::sHandler = nullptr;
+
+// static
+OSStatus MacGlobalShortcuts::HandleHotKey(EventHandlerCallRef, EventRef inEvent,
+                                          void*) {
+  EventHotKeyID hkID;
+  if (GetEventParameter(inEvent, kEventParamDirectObject, typeEventHotKeyID,
+                        nullptr, sizeof(hkID), nullptr, &hkID) == noErr) {
+    ZenGlobalShortcuts::OnNativeShortcut(hkID.id);
+  }
+  return noErr;
+}
+
+// static
+bool MacGlobalShortcuts::EnsureHandler() {
+  if (sHandler) return true;
+
+  sUPP = NewEventHandlerUPP(HandleHotKey);
+  if (!sUPP) return false;
+
+  EventTypeSpec spec = {kEventClassKeyboard, kEventHotKeyPressed};
+  OSStatus status =
+      InstallApplicationEventHandler(sUPP, 1, &spec, nullptr, &sHandler);
+  if (status != noErr) {
+    DisposeEventHandlerUPP(sUPP);
+    sUPP = nullptr;
+    sHandler = nullptr;
+    return false;
+  }
+  return true;
+}
+
+// Convert the JS-friendly key string into a DOM code-name (e.g. "A" ->
+// "KeyA", "5" -> "Digit5", "F1"/"f1" -> "F1", "Space"/"space" -> "Space").
+// Returns false for inputs we don't accept.
+static bool ToDOMCodeName(const nsACString& aKey, nsAString& aOut) {
+  aOut.Truncate();
+  if (aKey.Length() == 1) {
+    char c = aKey[0];
+    if (c >= 'a' && c <= 'z') c = char(c - 32);
+    if (c >= 'A' && c <= 'Z') {
+      aOut.AssignLiteral(u"Key");
+    } else if (c >= '0' && c <= '9') {
+      aOut.AssignLiteral(u"Digit");
+    } else {
+      return false;
+    }
+    aOut.Append(char16_t(c));
+    return true;
+  }
+  // Multi-character: assume it's a DOM code name, normalized to leading
+  // upper-case ("space" -> "Space", "f1" -> "F1").
+  AppendUTF8toUTF16(aKey, aOut);
+  if (!aOut.IsEmpty() && aOut[0] >= 'a' && aOut[0] <= 'z') {
+    aOut.BeginWriting()[0] = char16_t(aOut[0] - 32);
+  }
+  return true;
+}
+
+struct CodeIndexToMacKey {
+  CodeNameIndex idx;
+  UInt32 keyCode;
+};
+
+// Generated from widget's mapping table. Order matches the .inc, so when
+// multiple native keys map to the same DOM code (e.g. NumpadEnter ->
+// kVK_ANSI_KeypadEnter and kVK_Powerbook_KeypadEnter), the first entry
+// wins -- which is the one we'd want to pass to RegisterEventHotKey.
+static constexpr CodeIndexToMacKey kCodeIndexToMacKeyTable[] = {
+#define NS_NATIVE_KEY_TO_DOM_CODE_NAME_INDEX(aNativeKey, aCodeNameIndex) \
+  {mozilla::aCodeNameIndex, static_cast<UInt32>(aNativeKey)},
+#include "NativeKeyToDOMCodeName.inc"
+#undef NS_NATIVE_KEY_TO_DOM_CODE_NAME_INDEX
+};
+
+// static
+bool MacGlobalShortcuts::ResolveKey(const nsACString& aKey, UInt32& aOut) {
+  nsAutoString domCode;
+  if (!ToDOMCodeName(aKey, domCode)) return false;
+
+  CodeNameIndex idx = WidgetKeyboardEvent::GetCodeNameIndex(domCode);
+  if (idx == mozilla::CODE_NAME_INDEX_USE_STRING) return false;
+
+  for (const auto& entry : kCodeIndexToMacKeyTable) {
+    if (entry.idx == idx) {
+      aOut = entry.keyCode;
+      return true;
+    }
+  }
+  return false;
+}
+
+// static
+UInt32 MacGlobalShortcuts::ToCarbonModifiers(uint32_t aMods) {
+  UInt32 m = 0;
+  if (aMods & nsIZenGlobalShortcuts::MODIFIER_SHIFT) m |= shiftKey;
+  if (aMods & nsIZenGlobalShortcuts::MODIFIER_CTRL) m |= controlKey;
+  if (aMods & nsIZenGlobalShortcuts::MODIFIER_ALT) m |= optionKey;
+  if (aMods & nsIZenGlobalShortcuts::MODIFIER_META) m |= cmdKey;
+  return m;
+}
+
+// static
+nsresult MacGlobalShortcuts::Register(ZenGlobalShortcuts::Registration& aReg,
+                                      const nsACString& aKey,
+                                      uint32_t aModifiers) {
+  if (!EnsureHandler()) return NS_ERROR_FAILURE;
+
+  UInt32 keyCode;
+  if (!ResolveKey(aKey, keyCode)) return NS_ERROR_INVALID_ARG;
+
+  EventHotKeyID hkID;
+  hkID.signature = kZenHotKeySignature;
+  hkID.id = aReg.internalId;
+
+  EventHotKeyRef ref = nullptr;
+  OSStatus status =
+      RegisterEventHotKey(keyCode, ToCarbonModifiers(aModifiers), hkID,
+                          GetApplicationEventTarget(), 0, &ref);
+  if (status != noErr || !ref) return NS_ERROR_FAILURE;
+
+  aReg.nativeHandle = static_cast<void*>(ref);
+  return NS_OK;
+}
+
+// static
+void MacGlobalShortcuts::Unregister(ZenGlobalShortcuts::Registration& aReg) {
+  if (!aReg.nativeHandle) return;
+  UnregisterEventHotKey(static_cast<EventHotKeyRef>(aReg.nativeHandle));
+  aReg.nativeHandle = nullptr;
+}
+
+// static
+void MacGlobalShortcuts::Shutdown() {
+  if (sHandler) {
+    RemoveEventHandler(sHandler);
+    sHandler = nullptr;
+  }
+  if (sUPP) {
+    DisposeEventHandlerUPP(sUPP);
+    sUPP = nullptr;
+  }
+}
+
+}  // namespace
+
+// static
+nsresult ZenGlobalShortcuts::NativeRegister(Registration& aReg,
+                                            const nsACString& aKey,
+                                            uint32_t aModifiers) {
+  return MacGlobalShortcuts::Register(aReg, aKey, aModifiers);
+}
+
+// static
+void ZenGlobalShortcuts::NativeUnregister(Registration& aReg) {
+  MacGlobalShortcuts::Unregister(aReg);
+}
+
+// static
+void ZenGlobalShortcuts::NativeShutdown() { MacGlobalShortcuts::Shutdown(); }
+
+}  // namespace zen

src/zen/kbs/global-shortcuts/cocoa/moz.build

@@ -0,0 +1,18 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+FINAL_LIBRARY = "xul"
+
+SOURCES += [
+    "ZenGlobalShortcutsCocoa.mm",
+]
+
+LOCAL_INCLUDES += [
+    "../",
+    "/widget",
+]
+
+OS_LIBS += [
+    "-framework Carbon",
+]

src/zen/kbs/global-shortcuts/components.conf

@@ -0,0 +1,14 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+Classes = [
+    {
+        'cid': '{b8e9f3a2-7c1d-4a5b-9e6f-3d8c2a1b5e74}',
+        'interfaces': ['nsIZenGlobalShortcuts'],
+        'contract_ids': ['@mozilla.org/zen/global-shortcuts;1'],
+        'type': 'zen::ZenGlobalShortcuts',
+        'headers': ['mozilla/ZenGlobalShortcuts.h'],
+        'processes': ProcessSelector.MAIN_PROCESS_ONLY,
+    },
+]

src/zen/kbs/global-shortcuts/moz.build

@@ -0,0 +1,29 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+XPIDL_SOURCES += [
+    "nsIZenGlobalShortcuts.idl",
+]
+
+EXPORTS.mozilla += [
+    "ZenGlobalShortcuts.h",
+]
+
+SOURCES += [
+    "ZenGlobalShortcuts.cpp",
+]
+
+XPCOM_MANIFESTS += [
+    "components.conf",
+]
+
+if CONFIG["MOZ_WIDGET_TOOLKIT"] == "cocoa":
+    DIRS += ["cocoa"]
+elif CONFIG["MOZ_WIDGET_TOOLKIT"] == "windows":
+    DIRS += ["windows"]
+else:
+    SOURCES += ["ZenGlobalShortcutsStub.cpp"]
+
+FINAL_LIBRARY = "xul"
+XPIDL_MODULE = "zen_global_shortcuts"

src/zen/kbs/global-shortcuts/nsIZenGlobalShortcuts.idl

@@ -0,0 +1,49 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+/**
+ * @brief OS-level global keyboard shortcut registration for Zen.
+ *
+ * Registers shortcuts with the operating system so that pressing the
+ * key combination triggers a callback even when no Zen window is
+ * focused (or the application is in the background). When a shortcut
+ * fires, a trusted DOM event is dispatched on the most recently
+ * focused browser window. The event type is
+ * "zen-global-shortcut-<id>", where <id> is the identifier passed at
+ * registration time.
+ */
+[scriptable, uuid(b8e9f3a2-7c1d-4a5b-9e6f-3d8c2a1b5e74)]
+interface nsIZenGlobalShortcuts : nsISupports {
+  const unsigned long MODIFIER_NONE  = 0;
+  const unsigned long MODIFIER_SHIFT = 1;
+  const unsigned long MODIFIER_CTRL  = 2;
+  const unsigned long MODIFIER_ALT   = 4;
+  const unsigned long MODIFIER_META  = 8;
+
+  /**
+   * @brief Register a global keyboard shortcut.
+   * @param aId Caller-chosen identifier; the dispatched event name will be
+   *   "zen-global-shortcut-" + aId. Must be unique across active
+   *   registrations.
+   * @param aKey Key name. Supported: "A".."Z", "0".."9", "F1".."F12",
+   *   "Space".
+   * @param aModifiers Bitmask of MODIFIER_* constants. On macOS, META
+   *   is Command; on Windows, META is the Windows key.
+   * @return true if the OS accepted the registration.
+   */
+  boolean registerShortcut(in ACString aId, in ACString aKey,
+                           in unsigned long aModifiers);
+
+  /**
+   * @brief Unregister a previously registered shortcut by id.
+   */
+  void unregisterShortcut(in ACString aId);
+
+  /**
+   * @brief Unregister all shortcuts registered through this service.
+   */
+  void unregisterAll();
+};

src/zen/kbs/global-shortcuts/windows/ZenGlobalShortcutsWindows.cpp

@@ -0,0 +1,166 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ZenGlobalShortcuts.h"
+
+#include "nsString.h"
+
+#include <windows.h>
+
+namespace zen {
+namespace {
+
+constexpr wchar_t kWindowClassName[] = L"ZenGlobalShortcutsWindow";
+
+class WinGlobalShortcuts final {
+ public:
+  WinGlobalShortcuts() = delete;
+
+  static nsresult Register(ZenGlobalShortcuts::Registration& aReg,
+                           const nsACString& aKey, uint32_t aModifiers);
+  static void Unregister(ZenGlobalShortcuts::Registration& aReg);
+  static void Shutdown();
+
+ private:
+  static bool EnsureWindow();
+  static LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);
+  static bool ResolveKey(const nsACString& aKey, UINT& aOut);
+  static UINT ToWinModifiers(uint32_t aMods);
+
+  static HWND sWindow;
+  static ATOM sClass;
+};
+
+HWND WinGlobalShortcuts::sWindow = nullptr;
+ATOM WinGlobalShortcuts::sClass = 0;
+
+// static
+LRESULT CALLBACK WinGlobalShortcuts::WndProc(HWND hwnd, UINT msg, WPARAM wParam,
+                                             LPARAM lParam) {
+  if (msg == WM_HOTKEY) {
+    ZenGlobalShortcuts::OnNativeShortcut(static_cast<uint32_t>(wParam));
+    return 0;
+  }
+  return DefWindowProcW(hwnd, msg, wParam, lParam);
+}
+
+// static
+bool WinGlobalShortcuts::EnsureWindow() {
+  if (sWindow) return true;
+
+  HINSTANCE module = GetModuleHandleW(nullptr);
+  if (!sClass) {
+    WNDCLASSEXW wc = {};
+    wc.cbSize = sizeof(wc);
+    wc.lpfnWndProc = WndProc;
+    wc.hInstance = module;
+    wc.lpszClassName = kWindowClassName;
+    sClass = RegisterClassExW(&wc);
+    if (!sClass) return false;
+  }
+
+  sWindow = CreateWindowExW(0, kWindowClassName, L"", 0, 0, 0, 0, 0,
+                            HWND_MESSAGE, nullptr, module, nullptr);
+  return sWindow != nullptr;
+}
+
+// static
+bool WinGlobalShortcuts::ResolveKey(const nsACString& aKey, UINT& aOut) {
+  if (aKey.Length() == 1) {
+    char c = aKey[0];
+    if (c >= 'a' && c <= 'z') c = char(c - 32);
+    if ((c >= 'A' && c <= 'Z') || (c >= '0' && c <= '9')) {
+      aOut = static_cast<UINT>(c);
+      return true;
+    }
+    return false;
+  }
+  if (aKey.LowerCaseEqualsLiteral("space")) {
+    aOut = VK_SPACE;
+    return true;
+  }
+  if ((aKey.Length() == 2 || aKey.Length() == 3) &&
+      (aKey[0] == 'F' || aKey[0] == 'f')) {
+    int n = aKey[1] - '0';
+    if (n < 0 || n > 9) return false;
+    if (aKey.Length() == 3) {
+      int d = aKey[2] - '0';
+      if (d < 0 || d > 9) return false;
+      n = n * 10 + d;
+    }
+    if (n >= 1 && n <= 12) {
+      aOut = VK_F1 + (n - 1);
+      return true;
+    }
+  }
+  return false;
+}
+
+// static
+UINT WinGlobalShortcuts::ToWinModifiers(uint32_t aMods) {
+  UINT m = MOD_NOREPEAT;
+  if (aMods & nsIZenGlobalShortcuts::MODIFIER_SHIFT) m |= MOD_SHIFT;
+  if (aMods & nsIZenGlobalShortcuts::MODIFIER_CTRL) m |= MOD_CONTROL;
+  if (aMods & nsIZenGlobalShortcuts::MODIFIER_ALT) m |= MOD_ALT;
+  if (aMods & nsIZenGlobalShortcuts::MODIFIER_META) m |= MOD_WIN;
+  return m;
+}
+
+// static
+nsresult WinGlobalShortcuts::Register(ZenGlobalShortcuts::Registration& aReg,
+                                      const nsACString& aKey,
+                                      uint32_t aModifiers) {
+  if (!EnsureWindow()) return NS_ERROR_FAILURE;
+
+  UINT vk;
+  if (!ResolveKey(aKey, vk)) return NS_ERROR_INVALID_ARG;
+
+  if (!RegisterHotKey(sWindow, static_cast<int>(aReg.internalId),
+                      ToWinModifiers(aModifiers), vk)) {
+    return NS_ERROR_FAILURE;
+  }
+  aReg.nativeHandle =
+      reinterpret_cast<void*>(static_cast<uintptr_t>(aReg.internalId));
+  return NS_OK;
+}
+
+// static
+void WinGlobalShortcuts::Unregister(ZenGlobalShortcuts::Registration& aReg) {
+  if (!sWindow || !aReg.nativeHandle) return;
+  UnregisterHotKey(
+      sWindow,
+      static_cast<int>(reinterpret_cast<uintptr_t>(aReg.nativeHandle)));
+  aReg.nativeHandle = nullptr;
+}
+
+// static
+void WinGlobalShortcuts::Shutdown() {
+  if (sWindow) {
+    DestroyWindow(sWindow);
+    sWindow = nullptr;
+  }
+  if (sClass) {
+    UnregisterClassW(kWindowClassName, GetModuleHandleW(nullptr));
+    sClass = 0;
+  }
+}
+
+}  // namespace
+
+// static
+nsresult ZenGlobalShortcuts::NativeRegister(Registration& aReg,
+                                            const nsACString& aKey,
+                                            uint32_t aModifiers) {
+  return WinGlobalShortcuts::Register(aReg, aKey, aModifiers);
+}
+
+// static
+void ZenGlobalShortcuts::NativeUnregister(Registration& aReg) {
+  WinGlobalShortcuts::Unregister(aReg);
+}
+
+// static
+void ZenGlobalShortcuts::NativeShutdown() { WinGlobalShortcuts::Shutdown(); }
+
+}  // namespace zen

src/zen/kbs/global-shortcuts/windows/moz.build

@@ -2,4 +2,12 @@
 # License, v. 2.0. If a copy of the MPL was not distributed with this
 # file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
-        content/browser/zen-components/ZenKeyboardShortcuts.mjs                 (../../zen/kbs/ZenKeyboardShortcuts.mjs)
+FINAL_LIBRARY = "xul"
+
+SOURCES += [
+    "ZenGlobalShortcutsWindows.cpp",
+]
+
+LOCAL_INCLUDES += [
+    "../",
+]

src/zen/kbs/moz.build

@@ -0,0 +1,11 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+EXTRA_JS_MODULES.zen += [
+    "ZenKeyboardShortcuts.sys.mjs",
+]
+
+DIRS += [
+    "global-shortcuts",
+]

src/zen/little-window/LittleWindowComponents.manifest

@@ -0,0 +1,6 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+category browser-before-ui-startup resource:///modules/zen/ZenLittleWindow.sys.mjs ZenLittleWindow.init
+category browser-quit-application-granted resource:///modules/zen/ZenLittleWindow.sys.mjs ZenLittleWindow.uninit

src/zen/little-window/ZenLittleWindow.sys.mjs

@@ -0,0 +1,141 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import { AppConstants } from "resource://gre/modules/AppConstants.sys.mjs";
+import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+import { ZenSpacesSearch } from "resource:///modules/zen/ZenSpacesSearch.sys.mjs";
+
+const lazy = {};
+
+XPCOMUtils.defineLazyServiceGetter(
+  lazy,
+  "ZenWindowControl",
+  "@mozilla.org/zen/window-control;1",
+  Ci.nsIZenWindowControl
+);
+
+const URLBAR_HEIGHT = 340;
+const URLBAR_WIDTH = 640;
+
+const FEATURES =
+  "titlebar,close,toolbar,location,personalbar=no,status,menubar=no," +
+  `resizable,minimizable,scrollbars,width=${URLBAR_WIDTH},height=${URLBAR_HEIGHT},centerscreen`;
+
+class nsZenLittleWindow {
+  init() {}
+  uninit() {}
+
+  /**
+   * Open a fresh little window, or focus an existing empty one if there
+   * already is a little window sitting on its empty tab.
+   *
+   * @param {Window} opener The browser window asking for the little window.
+   * @returns {Window|null} The window that received focus.
+   */
+  openLittleWindow(opener) {
+    for (const win of this.#iterLittleWindows()) {
+      if (this.#isOnEmptyTab(win)) {
+        win.focus();
+        return win;
+      }
+    }
+    let win = opener.OpenBrowserWindow({
+      zenLittleWindow: true,
+      all: false,
+      features: FEATURES,
+    });
+    win.windowUtils.suppressAnimation(true);
+      // Hide the OS-level window until the floating urlbar is ready, so the
+      // user never sees a half-laid-out chrome flash on top.
+      lazy.ZenWindowControl.hide(win);
+    return win;
+  }
+
+  #isLittleWindow(win) {
+    return (
+      !!win._zenStartupLittleWindow ||
+      win.document?.documentElement?.hasAttribute("zen-little-window")
+    );
+  }
+
+  #isOnEmptyTab(win) {
+    const tab = win.gBrowser?.selectedTab;
+    return !!tab?.hasAttribute("zen-empty-tab");
+  }
+
+  *#iterLittleWindows() {
+    const en = Services.wm.getEnumerator("navigator:browser");
+    while (en.hasMoreElements()) {
+      const win = en.getNext();
+      if (!win.closed && this.#isLittleWindow(win)) {
+        yield win;
+      }
+    }
+  }
+
+  onLittleWindow(win) {
+    if (!this.#isLittleWindow(win)) {
+      return;
+    }
+    ZenSpacesSearch.init(win);
+    const observer = new win.ResizeObserver(entries => {
+      if (win.closed) {
+        return;
+      }
+      for (const entry of entries) {
+        if (entry.target.id === "urlbar") {
+          const { width, height } = entry.target.getBoundingClientRect();
+          win.resizeTo(width, height);
+        }
+      }
+    });
+    const onClosed = event => {
+      observer.disconnect();
+      if (!win.closed && !event.detail?.onElementPicked) {
+        lazy.ZenWindowControl.hide(win);
+        win.close();
+      } else {
+        const [width, height] = [1000, 600];
+        win.setResizable(true);
+        win.resizeTo(1000, 600);
+win.docShell.treeOwner
+        .QueryInterface(Ci.nsIInterfaceRequestor)
+        .getInterface(Ci.nsIAppWindow)
+        .center(null, true, true)
+      }
+    };
+    const urlbar = win.gURLBar;
+    observer.observe(urlbar);
+    // TODO: Handle window blur event
+    win.setResizable(false);
+    win.addEventListener(
+      "ZenFloatingURLBarOpened",
+      () => {
+win.docShell.treeOwner
+        .QueryInterface(Ci.nsIInterfaceRequestor)
+        .getInterface(Ci.nsIAppWindow)
+        .center(null, true, true)
+        if (AppConstants.platform == "macosx" && !Services.focus.activeWindow) {
+          Cc["@mozilla.org/widget/macdocksupport;1"]
+            .getService(Ci.nsIMacDockSupport)
+            .activateApplication(true);
+        }
+        win.focus();
+        urlbar.focus();
+      },
+      { once: true }
+    );
+    win.addEventListener("ZenURLBarClosed", onClosed, { once: true });
+    win.addEventListener("unload", () => observer.disconnect(), { once: true });
+    // Hacky, but used to prevent flashing and still being able to render
+    lazy.ZenWindowControl.show(win);
+    lazy.ZenWindowControl.hide(win);
+    win.gZenWorkspaces.promiseInitialized.then(() => {
+      win.windowUtils.suppressAnimation(false);
+      lazy.ZenWindowControl.show(win);
+    });
+  }
+}
+
+export const ZenLittleWindow = new nsZenLittleWindow();

src/zen/little-window/ZenSpacesSearch.sys.mjs

@@ -0,0 +1,142 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+import { ZenSearchPopup } from "resource:///modules/ZenSearchPopup.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  ZenSessionStore: "resource:///modules/zen/ZenSessionManager.sys.mjs",
+});
+
+/*
+ * Owns the "send to a synced window" split-button that lives in the
+ * nav-bar of a little window. Main click opens the urlbar's current
+ * value in a fresh synced browser window using the active workspace;
+ * the dropdown opens a ZenSearchPopup over #zen-spaces-popup so the
+ * user can pick a different workspace to land in.
+ */
+class ZenSpacesSearchService {
+  /**
+   * Per-window setup.
+   * @param {Window} aWindow A little window.
+   */
+  init(aWindow) {
+    if (!aWindow || aWindow._zenSpacesSearchInited) return;
+    aWindow._zenSpacesSearchInited = true;
+
+    const doc = aWindow.document;
+    const panel = doc.getElementById("zen-spaces-popup");
+    if (!panel) return;
+
+    const popup = new ZenSearchPopup({
+      panel,
+      searchInput: doc.getElementById("zen-spaces-list-search"),
+      list: doc.getElementById("zen-spaces-list"),
+      noResults: doc.getElementById("zen-spaces-search-no-results"),
+      itemSelector: ".zen-spaces-list-item",
+    });
+
+    const parts = this.#injectButton(aWindow);
+    if (!parts) return;
+    const { button, main, dropmarker } = parts;
+
+    main.addEventListener("click", event => {
+      if (event.button !== 0) return;
+      this.#openInWorkspace(aWindow, null);
+    });
+
+    dropmarker.addEventListener("click", event => {
+      if (event.button !== 0) return;
+      event.stopPropagation();
+      this.#openSpacesPopup(aWindow, popup, button);
+    });
+  }
+
+  #injectButton(aWindow) {
+    const doc = aWindow.document;
+    const target = doc.getElementById("nav-bar-customization-target");
+    if (!target) return null;
+
+    const button = doc.createXULElement("hbox");
+    button.id = "zen-little-window-send-to-window";
+    button.setAttribute("removable", "false");
+
+    const main = doc.createXULElement("hbox");
+    main.classList.add("zen-stw-main");
+
+    const prefix = doc.createXULElement("label");
+    prefix.classList.add("zen-stw-prefix");
+    prefix.setAttribute(
+      "data-l10n-id",
+      "zen-little-window-send-to-window-prefix"
+    );
+
+    const spaceName = doc.createXULElement("label");
+    spaceName.classList.add("zen-stw-space-name");
+    spaceName.setAttribute(
+      "value",
+      aWindow.gZenWorkspaces?.getActiveWorkspaceFromCache?.()?.name || ""
+    );
+
+    main.appendChild(prefix);
+    main.appendChild(spaceName);
+
+    const separator = doc.createXULElement("hbox");
+    separator.classList.add("zen-stw-separator");
+
+    const dropmarker = doc.createXULElement("hbox");
+    dropmarker.classList.add("zen-stw-dropmarker");
+    const dropIcon = doc.createXULElement("image");
+    dropIcon.classList.add("zen-stw-dropmarker-icon");
+    dropmarker.appendChild(dropIcon);
+
+    button.appendChild(main);
+    button.appendChild(separator);
+    button.appendChild(dropmarker);
+
+    target.appendChild(button);
+    return { button, main, dropmarker, spaceName };
+  }
+
+  #openSpacesPopup(aWindow, popup, anchor) {
+    const workspaces = lazy.ZenSessionStore.getClonedSpaces();
+
+    popup.populate(
+      workspaces.map(space => ({
+        label: space.name || space.uuid,
+        render: () => {
+          const node = aWindow.document.createXULElement("hbox");
+          const label = aWindow.document.createXULElement("label");
+          label.setAttribute("value", space.name || space.uuid);
+          label.classList.add("zen-spaces-list-item-label");
+          node.appendChild(label);
+          return node;
+        },
+        onPick: () => this.#openInWorkspace(aWindow, space.uuid),
+      }))
+    );
+    popup.open(anchor);
+  }
+
+  #openInWorkspace(aWindow, workspaceUuid) {
+    const url = aWindow.gURLBar?.value?.trim();
+    if (!url) return;
+
+    const args = Cc["@mozilla.org/array;1"].createInstance(Ci.nsIMutableArray);
+    const urlString = Cc["@mozilla.org/supports-string;1"].createInstance(
+      Ci.nsISupportsString
+    );
+    urlString.data = url;
+    args.appendElement(urlString);
+
+    const opts = { args, zenSyncedWindow: true };
+    if (workspaceUuid) opts.zenInitialWorkspace = workspaceUuid;
+
+    const newWin = aWindow.OpenBrowserWindow(opts);
+    if (newWin) aWindow.close();
+  }
+}
+
+export const ZenSpacesSearch = new ZenSpacesSearchService();

src/zen/little-window/jar.inc.mn

@@ -0,0 +1,5 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+        content/browser/zen-styles/zen-little-window.css                        (../../zen/little-window/zen-little-window.css)

src/zen/little-window/moz.build

@@ -0,0 +1,8 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+EXTRA_JS_MODULES.zen += [
+    "ZenLittleWindow.sys.mjs",
+    "ZenSpacesSearch.sys.mjs",
+]

src/zen/little-window/zen-little-window.css

@@ -0,0 +1,162 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * Little-window chrome: the URL bar fills the entire window. The vertical
+ * tab strip, sidebar buttons, bookmarks toolbar, and any other chrome are
+ * suppressed so the window acts as a quick search/launch box.
+ */
+
+#zen-little-window-send-to-window {
+  align-items: stretch;
+  border-radius: var(--border-radius-small);
+  background: light-dark(white, rgba(0, 0, 0, 0.4));
+  height: 32px;
+  margin-inline: 4px;
+  overflow: hidden;
+  user-select: none;
+  align-self: center;
+  box-shadow: 0 0 1px 2px rgba(0, 0, 0, 0.01);
+
+  .zen-stw-main,
+  .zen-stw-dropmarker {
+    align-items: center;
+    padding-inline: 12px;
+    transition: background 80ms ease;
+
+    &:hover {
+      background: var(--toolbarbutton-active-background, color-mix(in srgb, currentColor 12%, transparent));
+    }
+  }
+
+  .zen-stw-prefix {
+    color: color-mix(in srgb, currentColor 60%, transparent);
+    margin-inline-end: 6px;
+  }
+
+  .zen-stw-space-name {
+    color: var(--zen-primary-color, currentColor);
+    font-weight: 600;
+  }
+
+  .zen-stw-separator {
+    width: 1px;
+    background: color-mix(in srgb, currentColor 18%, transparent);
+    margin-block: 6px;
+  }
+
+  .zen-stw-dropmarker {
+    padding-inline: 8px;
+  }
+
+  .zen-stw-dropmarker-icon {
+    width: 12px;
+    height: 12px;
+    -moz-context-properties: fill;
+    fill: color-mix(in srgb, currentColor 65%, transparent);
+    list-style-image: url("chrome://global/skin/icons/arrow-down.svg");
+  }
+}
+
+#zen-spaces-popup {
+  --arrowpanel-padding: 0;
+  --zen-spaces-list-padding: 6px;
+  padding: var(--zen-spaces-list-padding);
+  min-width: 250px;
+
+  .zen-spaces-list-header {
+    display: flex;
+    flex-direction: row;
+    padding: 6px;
+    border-bottom: 1px solid color-mix(in srgb, currentColor, transparent 90%);
+  }
+
+  .zen-spaces-list-search-icon {
+    width: 14px;
+    height: 14px;
+    margin-inline: 4px 6px;
+    -moz-context-properties: fill;
+    fill: currentColor;
+    opacity: 0.6;
+  }
+
+  #zen-spaces-list-search {
+    flex: 1;
+    background: transparent;
+    border: none;
+    outline: none;
+    color: inherit;
+    font: inherit;
+  }
+
+  .zen-spaces-list-item {
+    padding: 6px 10px;
+    border-radius: 6px;
+    cursor: pointer;
+
+    &:hover,
+    &[selected="true"] {
+      background: var(--toolbarbutton-hover-background);
+    }
+    &[active="true"]::after {
+      content: "•";
+      margin-inline-start: auto;
+      opacity: 0.7;
+    }
+  }
+
+  #zen-spaces-search-no-results {
+    padding: 12px;
+    opacity: 0.7;
+    justify-content: center;
+  }
+}
+
+:root[zen-little-window="true"] {
+  toolbarspring[cui-areatype="toolbar"],
+  #nav-bar-customization-target > .toolbarbutton-1[disabled="true"] {
+    display: none;
+  }
+
+  &[zen-has-empty-tab="true"] {
+    /* Keep in sync with URLBAR_HEIGHT in ZenLittleWindow.sys.mjs */
+    --zen-minimum-window-height: 40px;
+    min-width: unset !important;
+
+    #zen-appcontent-wrapper {
+      visibility: hidden;
+    }
+
+    #urlbar[breakout-extend] {
+      min-width: 600px !important;
+      max-width: 600px !important;
+      left: 50% !important;
+      top: 0 !important;
+      transform: translate(10px, 0) !important;
+      visibility: visible;
+
+      & .urlbar-background {
+        outline: none !important;
+      }
+
+      & .urlbar-input-container {
+        -moz-window-dragging: drag;
+      }
+
+      & .urlbar-input-box {
+        -moz-window-dragging: no-drag;
+      }
+    }
+  }
+
+  @media (-moz-platform: macos) {
+    #nav-bar {
+      padding-inline-start: 6px;
+    }
+  }
+
+  #urlbar-container {
+    --border-radius-medium: var(--border-radius-small);
+  }
+}

src/zen/moz.build

@@ -11,6 +11,8 @@ DIRS += [
     "common",
     "drag-and-drop",
     "glance",
+    "kbs",
+    "little-window",
     "live-folders",
     "mods",
     "tests",

src/zen/sessionstore/ZenWindowSync.sys.mjs

@@ -206,6 +206,13 @@ class nsZenWindowSync {
    * @param {Window} aWindow - The browser window that is about to be shown.
    */
   #onWindowBeforeShow(aWindow) {
+    if (aWindow._zenStartupLittleWindow) {
+      aWindow.document.documentElement.setAttribute(
+        "zen-little-window",
+        "true"
+      );
+      delete aWindow._zenStartupLittleWindow;
+    }
     if (
       aWindow.gZenWindowSync ||
       aWindow.document.documentElement.hasAttribute("zen-unsynced-window")

src/zen/toolkit/moz.build

@@ -4,4 +4,5 @@
 
 DIRS += [
   "common",
+  "window-control",
 ]

src/zen/toolkit/window-control/ZenWindowControl.cpp

@@ -0,0 +1,47 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ZenWindowControl.h"
+
+#include "WidgetUtils.h"
+#include "nsCOMPtr.h"
+#include "nsIWidget.h"
+#include "nsPIDOMWindow.h"
+
+namespace zen {
+
+NS_IMPL_ISUPPORTS(ZenWindowControl, nsIZenWindowControl)
+
+namespace {
+
+static nsCOMPtr<nsIWidget> WidgetFor(mozIDOMWindowProxy* aWindow) {
+  if (!aWindow) return nullptr;
+  nsPIDOMWindowOuter* outer = nsPIDOMWindowOuter::From(aWindow);
+  if (!outer) return nullptr;
+  return mozilla::widget::WidgetUtils::DOMWindowToWidget(outer);
+}
+
+}  // namespace
+
+NS_IMETHODIMP
+ZenWindowControl::Hide(mozIDOMWindowProxy* aWindow) {
+  nsCOMPtr<nsIWidget> widget = WidgetFor(aWindow);
+  if (!widget) return NS_ERROR_FAILURE;
+  // Hide first, then arm the lock so any subsequent Show(true) called
+  // from anywhere in the tree is rejected by the widget itself.
+  widget->Show(false);
+  widget->SetZenShowLocked(true);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+ZenWindowControl::Show(mozIDOMWindowProxy* aWindow) {
+  nsCOMPtr<nsIWidget> widget = WidgetFor(aWindow);
+  if (!widget) return NS_ERROR_FAILURE;
+  widget->SetZenShowLocked(false);
+  widget->Show(true);
+  return NS_OK;
+}
+
+}  // namespace zen

src/zen/toolkit/window-control/ZenWindowControl.h

@@ -0,0 +1,25 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_ZenWindowControl_h_
+#define mozilla_ZenWindowControl_h_
+
+#include "nsIZenWindowControl.h"
+
+namespace zen {
+
+class ZenWindowControl final : public nsIZenWindowControl {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIZENWINDOWCONTROL
+
+  ZenWindowControl() = default;
+
+ private:
+  ~ZenWindowControl() = default;
+};
+
+}  // namespace zen
+
+#endif

src/zen/toolkit/window-control/components.conf

@@ -0,0 +1,14 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+Classes = [
+    {
+        'cid': '{c1d2e3f4-9abc-4def-8123-456789abcdef}',
+        'interfaces': ['nsIZenWindowControl'],
+        'contract_ids': ['@mozilla.org/zen/window-control;1'],
+        'type': 'zen::ZenWindowControl',
+        'headers': ['mozilla/ZenWindowControl.h'],
+        'processes': ProcessSelector.MAIN_PROCESS_ONLY,
+    },
+]

src/zen/toolkit/window-control/moz.build

@@ -0,0 +1,26 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+XPIDL_SOURCES += [
+    "nsIZenWindowControl.idl",
+]
+
+EXPORTS.mozilla += [
+    "ZenWindowControl.h",
+]
+
+SOURCES += [
+    "ZenWindowControl.cpp",
+]
+
+XPCOM_MANIFESTS += [
+    "components.conf",
+]
+
+LOCAL_INCLUDES += [
+    "/widget",
+]
+
+FINAL_LIBRARY = "xul"
+XPIDL_MODULE = "zen_window_control"

src/zen/toolkit/window-control/nsIZenWindowControl.idl

@@ -0,0 +1,34 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "nsISupports.idl"
+
+interface mozIDOMWindowProxy;
+
+/**
+ * @brief Toggle the OS-level visibility of a chrome window without
+ * destroying it. Used by little-window flow to keep a window off-screen
+ * while the urlbar is wired up.
+ *
+ * Hide() locks the widget at the component level; once locked, the
+ * widget remains hidden until Show() is called. Calling Show() on a
+ * widget that is not currently locked is a no-op so external paths
+ * can't accidentally un-hide a widget that wasn't hidden through this
+ * service.
+ */
+[scriptable, uuid(c1d2e3f4-9abc-4def-8123-456789abcdef)]
+interface nsIZenWindowControl : nsISupports {
+  /**
+   * Hide the window at the widget level
+   * (NSWindow.orderOut / ShowWindow(SW_HIDE) / gtk_widget_hide) and
+   * mark its widget as locked-hidden. Idempotent.
+   */
+  void hide(in mozIDOMWindowProxy aWindow);
+
+  /**
+   * If the window's widget is currently locked-hidden by this service,
+   * un-hide it and clear the lock. Otherwise no-op.
+   */
+  void show(in mozIDOMWindowProxy aWindow);
+};