1 files changed, 96 insertions, 0 deletions
diff --git a/toolkit/components/reader/Readerable.js b/toolkit/components/reader/Readerable.js
new file mode 100644
index 000000000..cee8adc08
--- /dev/null
+++ b/toolkit/components/reader/Readerable.js
@@ -0,0 +1,96 @@
+// -*- 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/. */
+"use strict";
+
+// This file and Readability-readerable.js are merged together into
+// Readerable.jsm.
+
+/* exported Readerable */
+/* import-globals-from Readability-readerable.js */
+
+const { classes: Cc, interfaces: Ci, utils: Cu } = Components;
+
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+
+function isNodeVisible(node) {
+  return node.clientHeight > 0 && node.clientWidth > 0;
+}
+
+var Readerable = {
+  DEBUG: 0,
+
+  get isEnabledForParseOnLoad() {
+    return this.isEnabled || this.isForceEnabled;
+  },
+
+  log(msg) {
+    if (this.DEBUG)
+      dump("Reader: " + msg);
+  },
+
+  /**
+   * Decides whether or not a document is reader-able without parsing the whole thing.
+   *
+   * @param doc A document to parse.
+   * @return boolean Whether or not we should show the reader mode button.
+   */
+  isProbablyReaderable(doc) {
+    // Only care about 'real' HTML documents:
+    if (doc.mozSyntheticDocument || !(doc instanceof doc.defaultView.HTMLDocument)) {
+      return false;
+    }
+
+    let uri = Services.io.newURI(doc.location.href);
+    if (!this.shouldCheckUri(uri)) {
+      return false;
+    }
+
+    return isProbablyReaderable(doc, isNodeVisible);
+  },
+
+  _blockedHosts: [
+    "amazon.com",
+    "basilisk-browser.org",
+    "github.com",
+    "mail.google.com",
+    "palemoon.org",
+    "pinterest.com",
+    "reddit.com",
+    "twitter.com",
+    "youtube.com",
+  ],
+
+  shouldCheckUri(uri, isBaseUri = false) {
+    if (!(uri.schemeIs("http") || uri.schemeIs("https"))) {
+      this.log("Not parsing URI scheme: " + uri.scheme);
+      return false;
+    }
+
+    try {
+      uri.QueryInterface(Ci.nsIURL);
+    } catch (ex) {
+      // If this doesn't work, presumably the URL is not well-formed or something
+      return false;
+    }
+    // Sadly, some high-profile pages have false positives, so bail early for those:
+    let asciiHost = uri.asciiHost;
+    if (!isBaseUri && this._blockedHosts.some(blockedHost => asciiHost.endsWith(blockedHost))) {
+      return false;
+    }
+
+    if (!isBaseUri && (!uri.filePath || uri.filePath == "/")) {
+      this.log("Not parsing home page: " + uri.spec);
+      return false;
+    }
+
+    return true;
+  },
+};
+
+XPCOMUtils.defineLazyPreferenceGetter(
+  Readerable, "isEnabled", "reader.parse-on-load.enabled", true);
+XPCOMUtils.defineLazyPreferenceGetter(
+  Readerable, "isForceEnabled", "reader.parse-on-load.force-enabled", false);