Refactoring of code by moving navigate_() to separate file.

chrome/browser/resources/pdf/navigator.js

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+'use strict';
+
+/**
+ * Creates a new Navigator for navigating to links inside or outside the PDF.
+ * @param {string} originalUrl The original page URL.
+ * @param {Object} viewport The viewport info of the page.
+ * @param {Object} paramsParser The object for URL parsing.
+ */
+function Navigator(originalUrl, viewport, paramsParser) {
+  this.originalUrl_ = originalUrl;
+  this.viewport_ = viewport;
+  this.paramsParser_ = paramsParser;
+}
+
+Navigator.prototype = {
+   /**
+   * @private
+   * Function to navigate to the given URL. This might involve navigating
+   * within the PDF page or opening a new url (in the same tab or a new tab).
+   * @param {string} url The URL to navigate to.
+   * @param {boolean} newTab Whether to perform the navigation in a new tab or
+   *    in the current tab.
+   */
+  navigate: function(url, newTab) {
+    if (url.length == 0)
+      return;
+    // If |urlFragment| starts with '#', then it's for the same URL with a
+    // different URL fragment.
+    if (url.charAt(0) == '#') {
+      // if '#' is already present in |originalUrl| then remove old fragment
+      // and add new url fragment.
+      var hashIndex = this.originalUrl_.search('#');
+      if (hashIndex != -1)
+        url = this.originalUrl_.substring(0, hashIndex) + url;
+      else
+        url = this.originalUrl_ + url;
+    }
+
+    // If there's no scheme, add http.
+    if (url.indexOf('://') == -1 && url.indexOf('mailto:') == -1)
+      url = 'http://' + url;
+
+    // Make sure inputURL starts with a valid scheme.
+    if (url.indexOf('http://') != 0 &&
+        url.indexOf('https://') != 0 &&
+        url.indexOf('ftp://') != 0 &&
+        url.indexOf('file://') != 0 &&
+        url.indexOf('mailto:') != 0) {
+      return;
+    }
+    // Make sure inputURL is not only a scheme.
+    if (url == 'http://' ||
+        url == 'https://' ||
+        url == 'ftp://' ||
+        url == 'file://' ||
+        url == 'mailto:') {
+      return;
+    }
+
+    if (newTab) {
+      // Prefer the tabs API because it guarantees we can just open a new tab.
+      // window.open doesn't have this guarantee.
+      if (chrome.tabs)
+        chrome.tabs.create({ url: url });
+      else
+        window.open(url);
+    } else {
+      var pageNumber =
+          this.paramsParser_.getViewportFromUrlParams(url).page;
+      if (pageNumber != undefined)
+        this.viewport_.goToPage(pageNumber);
+      else
+        window.location.href = url;
+    }
+  }
+};