1 files changed, 92 insertions, 0 deletions
diff --git a/browser/base/content/browser-tabsintitlebar.js b/browser/base/content/browser-tabsintitlebar.js
new file mode 100644
index 0000000000..caf9986b2f
--- /dev/null
+++ b/browser/base/content/browser-tabsintitlebar.js
@@ -0,0 +1,92 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*-
+ * 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/. */
+
+var TabsInTitlebar = {
+  init() {
+    this._readPref();
+    Services.prefs.addObserver(this._prefName, this);
+
+    this._initialized = true;
+    this._update();
+  },
+
+  allowedBy(condition, allow) {
+    if (allow) {
+      if (condition in this._disallowed) {
+        delete this._disallowed[condition];
+        this._update();
+      }
+    } else if (!(condition in this._disallowed)) {
+      this._disallowed[condition] = null;
+      this._update();
+    }
+  },
+
+  get systemSupported() {
+    let isSupported = false;
+    switch (AppConstants.MOZ_WIDGET_TOOLKIT) {
+      case "windows":
+      case "cocoa":
+        isSupported = true;
+        break;
+      case "gtk":
+        isSupported = window.matchMedia("(-moz-gtk-csd-available)").matches;
+        break;
+    }
+    delete this.systemSupported;
+    return (this.systemSupported = isSupported);
+  },
+
+  get enabled() {
+    return document.documentElement.getAttribute("tabsintitlebar") == "true";
+  },
+
+  observe(subject, topic, data) {
+    if (topic == "nsPref:changed") {
+      this._readPref();
+    }
+  },
+
+  _initialized: false,
+  _disallowed: {},
+  _prefName: "browser.tabs.inTitlebar",
+
+  _readPref() {
+    let hiddenTitlebar = Services.appinfo.drawInTitlebar;
+    this.allowedBy("pref", hiddenTitlebar);
+  },
+
+  _update() {
+    if (!this._initialized) {
+      return;
+    }
+
+    let allowed =
+      this.systemSupported &&
+      !window.fullScreen &&
+      !Object.keys(this._disallowed).length;
+    if (allowed) {
+      document.documentElement.setAttribute("tabsintitlebar", "true");
+      if (AppConstants.platform == "macosx") {
+        document.documentElement.setAttribute("chromemargin", "0,-1,-1,-1");
+        document.documentElement.removeAttribute("drawtitle");
+      } else {
+        document.documentElement.setAttribute("chromemargin", "0,2,2,2");
+      }
+    } else {
+      document.documentElement.removeAttribute("tabsintitlebar");
+      document.documentElement.removeAttribute("chromemargin");
+      if (AppConstants.platform == "macosx") {
+        document.documentElement.setAttribute("drawtitle", "true");
+      }
+    }
+
+    ToolbarIconColor.inferFromText("tabsintitlebar", allowed);
+  },
+
+  uninit() {
+    Services.prefs.removeObserver(this._prefName, this);
+  },
+};