From 339428fdda104566cf8402b2e57a7b7fd21a4624 Mon Sep 17 00:00:00 2001
From: "khorimoto@chromium.org"
 <khorimoto@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98>
Date: Mon, 9 Apr 2012 22:16:02 +0000
Subject: [PATCH] Detects whether the current profile has a history extension.
 If it does, displays that instead of the default history when the 'History'
 navigation item is clicked.

BUG=120958
TEST=


Review URL: http://codereview.chromium.org/10019002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@131457 0039d316-1c4b-4281-b951-d872f2087c98
---
 chrome/browser/resources/uber/uber_frame.html |  2 +-
 chrome/browser/resources/uber/uber_frame.js   | 23 ++++++++++
 chrome/browser/ui/webui/uber/uber_ui.cc       | 64 ++++++++++++++++++++++++++-
 chrome/browser/ui/webui/uber/uber_ui.h        | 13 +++++-
 4 files changed, 98 insertions(+), 4 deletions(-)

diff --git a/chrome/browser/resources/uber/uber_frame.html b/chrome/browser/resources/uber/uber_frame.html
index 4ce4c1e6a9c5..ddeda8a5bdb9 100644
--- a/chrome/browser/resources/uber/uber_frame.html
+++ b/chrome/browser/resources/uber/uber_frame.html
@@ -15,7 +15,7 @@
 <h1 i18n-content="shortProductName"></h1>
 <ul>
   <li i18n-content="historyDisplayName"
-      i18n-values="controls:historyHost">
+      i18n-values="controls:historyHost;override:overridesHistory">
   </li>
   <li i18n-content="extensionsDisplayName"
       i18n-values="controls:extensionsHost">
diff --git a/chrome/browser/resources/uber/uber_frame.js b/chrome/browser/resources/uber/uber_frame.js
index ede136304890..47f950433e5e 100644
--- a/chrome/browser/resources/uber/uber_frame.js
+++ b/chrome/browser/resources/uber/uber_frame.js
@@ -39,6 +39,14 @@ cr.define('uber_frame', function() {
     if (e.target.classList.contains('selected'))
       return;
 
+    // Extensions can override Uber content (e.g., if the user has a history
+    // extension, it should display when the 'History' navigation is clicked).
+    if (e.currentTarget.getAttribute('override') == 'yes') {
+      window.open('chrome://' + e.currentTarget.getAttribute('controls'),
+          '_blank');
+      return;
+    }
+
     uber.invokeMethodOnParent('showPage',
        {pageId: e.currentTarget.getAttribute('controls')});
 
@@ -122,8 +130,23 @@ cr.define('uber_frame', function() {
     return document.querySelector('.iframe-container.selected');
   }
 
+  /**
+   * Finds the <li> element whose 'controls' attribute is |controls| and sets
+   * its 'override' attribute to |override|.
+   * @param {string} controls The value of the 'controls' attribute of the
+   *     element to change.
+   * @param {string} override The value to set for the 'override' attribute of
+   *     that element (either 'yes' or 'no').
+   */
+  function setNavigationOverride(controls, override) {
+    var navItem =
+        document.querySelector('li[controls="' + controls + '"]');
+    navItem.setAttribute('override', override);
+  }
+
   return {
     onLoad: onLoad,
+    setNavigationOverride: setNavigationOverride,
   };
 
 });
diff --git a/chrome/browser/ui/webui/uber/uber_ui.cc b/chrome/browser/ui/webui/uber/uber_ui.cc
index 59b4755bb660..873d74f78b85 100644
--- a/chrome/browser/ui/webui/uber/uber_ui.cc
+++ b/chrome/browser/ui/webui/uber/uber_ui.cc
@@ -6,15 +6,20 @@
 
 #include "base/stl_util.h"
 #include "base/utf_string_conversions.h"
+#include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/webui/chrome_url_data_manager.h"
 #include "chrome/browser/ui/webui/chrome_web_ui_data_source.h"
 #include "chrome/browser/ui/webui/chrome_web_ui_controller_factory.h"
 #include "chrome/browser/ui/webui/extensions/extensions_ui.h"
 #include "chrome/browser/ui/webui/options2/options_ui2.h"
+#include "chrome/common/chrome_notification_types.h"
+#include "chrome/common/extensions/extension.h"
+#include "chrome/common/extensions/extension_set.h"
 #include "chrome/common/url_constants.h"
 #include "content/public/browser/navigation_controller.h"
 #include "content/public/browser/navigation_entry.h"
+#include "content/public/browser/notification_source.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_ui.h"
 #include "grit/browser_resources.h"
@@ -60,7 +65,25 @@ ChromeWebUIDataSource* CreateUberHTMLSource() {
   return source;
 }
 
-ChromeWebUIDataSource* CreateUberFrameHTMLSource() {
+// Determines whether the user has an active extension of the given type.
+bool HasExtensionType(Profile* profile, const char* extensionType) {
+  const ExtensionSet* extensionSet =
+      profile->GetExtensionService()->extensions();
+
+  for (ExtensionSet::const_iterator iter = extensionSet->begin();
+       iter != extensionSet->end(); ++iter) {
+    Extension::URLOverrideMap map = (*iter)->GetChromeURLOverrides();
+    Extension::URLOverrideMap::const_iterator result =
+        map.find(std::string(extensionType));
+
+    if (result != map.end())
+      return true;
+  }
+
+  return false;
+}
+
+ChromeWebUIDataSource* CreateUberFrameHTMLSource(Profile* profile) {
   ChromeWebUIDataSource* source =
       new ChromeWebUIDataSource(chrome::kChromeUIUberFrameHost);
 
@@ -88,6 +111,10 @@ ChromeWebUIDataSource* CreateUberFrameHTMLSource() {
   source->AddString("settingsHost",
                     ASCIIToUTF16(chrome::kChromeUISettingsHost));
   source->AddLocalizedString("settingsDisplayName", IDS_SETTINGS_TITLE);
+  bool overridesHistory = HasExtensionType(profile,
+      chrome::kChromeUIHistoryHost);
+  source->AddString("overridesHistory",
+                    ASCIIToUTF16(overridesHistory ? "yes" : "no"));
 
   return source;
 }
@@ -170,8 +197,41 @@ bool UberUI::OverrideHandleWebUIMessage(const GURL& source_url,
 UberFrameUI::UberFrameUI(content::WebUI* web_ui) : WebUIController(web_ui) {
   Profile* profile = Profile::FromWebUI(web_ui);
   profile->GetChromeURLDataManager()->AddDataSource(
-      CreateUberFrameHTMLSource());
+      CreateUberFrameHTMLSource(profile));
+
+  // Register as an observer for when extensions are loaded and unloaded.
+  registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_LOADED,
+      content::Source<Profile>(profile));
+  registrar_.Add(this, chrome::NOTIFICATION_EXTENSION_UNLOADED,
+      content::Source<Profile>(profile));
 }
 
 UberFrameUI::~UberFrameUI() {
 }
+
+void UberFrameUI::Observe(int type, const content::NotificationSource& source,
+                          const content::NotificationDetails& details) {
+  switch (type) {
+    // We listen for notifications that indicate an extension has been loaded
+    // (i.e., has been installed and/or enabled) or unloaded (i.e., has been
+    // uninstalled and/or disabled). If one of these events has occurred, then
+    // we must update the behavior of the History navigation element so that
+    // it opens the history extension if one is installed and enabled or
+    // opens the default history page if one is uninstalled or disabled.
+    case chrome::NOTIFICATION_EXTENSION_LOADED:
+    case chrome::NOTIFICATION_EXTENSION_UNLOADED: {
+      Profile* profile = Profile::FromWebUI(web_ui());
+      bool overridesHistory = HasExtensionType(profile,
+          chrome::kChromeUIHistoryHost);
+      scoped_ptr<Value> controlsValue(
+          Value::CreateStringValue(chrome::kChromeUIHistoryHost));
+      scoped_ptr<Value> overrideValue(
+          Value::CreateStringValue(overridesHistory ? "yes" : "no"));
+      web_ui()->CallJavascriptFunction(
+          "uber_frame.setNavigationOverride", *controlsValue, *overrideValue);
+      break;
+    }
+    default:
+      NOTREACHED();
+  }
+}
diff --git a/chrome/browser/ui/webui/uber/uber_ui.h b/chrome/browser/ui/webui/uber/uber_ui.h
index c6e94a94b17b..1a9432b068c9 100644
--- a/chrome/browser/ui/webui/uber/uber_ui.h
+++ b/chrome/browser/ui/webui/uber/uber_ui.h
@@ -10,6 +10,9 @@
 
 #include "base/memory/scoped_vector.h"
 #include "base/values.h"
+#include "chrome/browser/profiles/profile.h"
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
 #include "content/public/browser/web_ui_controller.h"
 
 // The WebUI class for the uber page (chrome://chrome). It manages the UI for
@@ -45,12 +48,20 @@ class UberUI : public content::WebUIController {
   DISALLOW_COPY_AND_ASSIGN(UberUI);
 };
 
-class UberFrameUI : public content::WebUIController {
+class UberFrameUI : public content::NotificationObserver,
+                    public content::WebUIController {
  public:
   explicit UberFrameUI(content::WebUI* web_ui);
   virtual ~UberFrameUI();
 
  private:
+  // content::NotificationObserver implementation.
+  virtual void Observe(int type,
+                       const content::NotificationSource& source,
+                       const content::NotificationDetails& details) OVERRIDE;
+
+  content::NotificationRegistrar registrar_;
+
   DISALLOW_COPY_AND_ASSIGN(UberFrameUI);
 };
 
-- 
2.11.4.GIT