[CRX] Add a pageAction to omnibox showing PDF URL

In Chromium extensions, the viewer's URL looks like this:
chrome-extension://oemmndcbldboiebfnladdacbdfmadadm/http://example.com/file.pdf

Furthermore, the PDF Viewer itself can also add something to the reference fragment:
chrome-extension://oemmndcbldboiebfnladdacbdfmadadm/http://example.com/file.pdf#page=2

Consequently, it is difficult to copy a clean URL (e.g. for sharing over mail)
without having to tidy-up the URL manually.

This commit solves this issue by adding a button to the omnibox,
which shows the clean PDF URL on click.

extensions/chromium/extension-router.js

@@ -22,6 +22,55 @@ limitations under the License.
   var VIEWER_URL = chrome.extension.getURL('content/web/viewer.html');
   var CRX_BASE_URL = chrome.extension.getURL('/');
 
+  /**
+   * @param {string} url The URL prefixed with chrome-extension://.../
+   * @return {string|undefined} The percent-encoded URL of the (PDF) file.
+   */
+  function parseExtensionURL(url) {
+    url = url.substring(CRX_BASE_URL.length);
+    var matchingUrl = /^(?:https?|file|ftp|chrome-extension)(:|%3A)/i.exec(url);
+    if (matchingUrl) {
+      url = url.split('#')[0];
+      if (matchingUrl[1] === ':') {
+        url = encodeURIComponent(url);
+      }
+      return url;
+    }
+  }
+
+  /**
+   * @param {string} url URL of PDF Viewer.
+   * @return {string|undefined} The percent-encoded URL of the (PDF) file.
+   */
+  function parseViewerURL(url) {
+    if (url.lastIndexOf(VIEWER_URL, 0) !== 0) {
+      // Does not even start with the correct URL. Bye!
+      return;
+    }
+    url = url.match(/[&?]file=([^&#]+)/);
+    if (url) {
+      url = url[1];
+      return url;
+    }
+  }
+
+  /**
+   * @param {number} tabId ID of tab where the page action will be shown
+   * @param {string} url URL to be displayed in page action
+   */
+  function showPageAction(tabId, displayUrl) {
+    var url = parseExtensionURL(displayUrl) || parseViewerURL(displayUrl);
+    if (url) {
+      chrome.pageAction.setPopup({
+        tabId: tabId,
+        popup: 'pageActionPopup.html?file=' + url
+      });
+      chrome.pageAction.show(tabId);
+    } else {
+      console.log('Unable to get PDF url from ' + displayUrl);
+    }
+  }
+
   // TODO(rob): Use declarativeWebRequest once declared URL-encoding is
   //            supported, see http://crbug.com/273589
   //            (or rewrite the query string parser in viewer.js to get it to
@@ -29,14 +78,8 @@ limitations under the License.
   chrome.webRequest.onBeforeRequest.addListener(function(details) {
     // This listener converts chrome-extension://.../http://...pdf to
     // chrome-extension://.../content/web/viewer.html?file=http%3A%2F%2F...pdf
-    var url = details.url.substring(CRX_BASE_URL.length);
-    var matchingUrl = /^(?:https?|file|ftp|chrome-extension)(:|%3A)/.exec(url);
-    if (matchingUrl) {
-      // location.hash is restored when "#" is missing from URL.
-      url = url.split('#')[0];
-      if (matchingUrl[1] === ':') {
-        url = encodeURIComponent(url);
-      }
+    var url = parseExtensionURL(details.url);
+    if (url) {
       url = VIEWER_URL + '?file=' + url;
       console.log('Redirecting ' + details.url + ' to ' + url);
       return { redirectUrl: url };
@@ -51,6 +94,15 @@ limitations under the License.
       ]
   }, ['blocking']);
 
+  chrome.runtime.onMessage.addListener(function(message, sender) {
+    if (message === 'showPageAction' && sender.tab) {
+      if (sender.tab.url === sender.url) {
+        // Only respond to messages from the top-level frame
+        showPageAction(sender.tab.id, sender.url);
+      }
+    }
+  });
+
   // When session restore is used, viewer pages may be loaded before the
   // webRequest event listener is attached (= page not found).
   // Reload these tabs.

extensions/chromium/manifest.json

@@ -21,6 +21,14 @@
   "background": {
     "page": "pdfHandler.html"
   },
+  "page_action": {
+    "default_icon": {
+      "19": "icon19.png",
+      "38": "icon38.png"
+    },
+    "default_title": "Show PDF URL",
+    "default_popup": "pageActionPopup.html"
+  },
   "incognito": "split",
   "web_accessible_resources": [
     "getFrameId",

extensions/chromium/pageActionPopup.html

@@ -0,0 +1,43 @@
+<!doctype html>
+<!--
+Copyright 2012 Mozilla Foundation
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+-->
+<!DOCTYPE html>
+<head>
+<title></title>
+<style>
+html {
+    /* maximum width of popup as defined in Chromium's source code as kMaxWidth
+       //src/chrome/browser/ui/views/extensions/extension_popup.cc
+       //src/chrome/browser/ui/gtk/extensions/extension_popup_gtk.cc
+     */
+    width: 800px;
+    /* in case Chromium decides to lower the value of kMaxWidth */
+    max-width: 100%;
+    margin: 0;
+    padding: 0;
+}
+body {
+    box-sizing: border-box;
+    margin: 0;
+    padding: 5px;
+    width: 100%;
+}
+</style>
+</head>
+<body contentEditable="plaintext-only">
+<script src="pageActionPopup.js"></script>
+</body>
+</html>

extensions/chromium/pageActionPopup.js

@@ -0,0 +1,22 @@
+/* Copyright 2012 Mozilla Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+var url = location.search.match(/[&?]file=([^&]+)/i);
+if (url) {
+  url = decodeURIComponent(url[1]);
+  document.body.textContent = url;
+  // Set cursor to end of the content-editable section.
+  getSelection().selectAllChildren(document.body);
+  getSelection().collapseToEnd();
+}

web/pdf_history.js

@@ -143,6 +143,9 @@ var PDFHistory = {
       window.history.pushState(stateObj, '', document.URL);
 //#else
 //    window.history.pushState(stateObj, '');
+//#endif
+//#if CHROME
+//    chrome.runtime.sendMessage('showPageAction');
 //#endif
     }
   },

web/viewer.js

@@ -1530,6 +1530,7 @@ var DocumentOutlineView = function documentOutlineView(outline) {
 //    // Example: chrome-extension://.../http://example.com/file.pdf
 //    var humanReadableUrl = '/' + DEFAULT_URL + location.hash;
 //    history.replaceState(history.state, '', humanReadableUrl);
+//    chrome.runtime.sendMessage('showPageAction');
 //  }
 //})();
 //#endif