Add an optional 'page_index' preference to apps and 'setPageIndex' message which can be used to set it.

This doesn't actually modify the behavior of the NTP whatsoever.  It's a small extension which will be used by a future alternate NTP front-end that shares the same WebUI back-end code.  Any NTP front-end that doesn't support pagination of apps will simply ignore this.

This also includes a simple unit test to verify the functioning of this preference.

BUG=73437
TEST=new test in unit_tests ('ExtensionPrefsPageIndex')

Review URL: http://codereview.chromium.org/6546017

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@76916 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 77 insertions, 1 deletions

diff --git a/chrome/browser/extensions/extension_prefs.cc b/chrome/browser/extensions/extension_prefs.cc
index 2f6a31a..2022c11 100644
--- a/chrome/browser/extensions/extension_prefs.cc
+++ b/chrome/browser/extensions/extension_prefs.cc
@@ -79,6 +79,9 @@ const char kPrefLaunchType[] = "launchType";
 // A preference determining the order of which the apps appear on the NTP.
 const char kPrefAppLaunchIndex[] = "app_launcher_index";
 
+// A preference determining the page on which an app appears in the NTP.
+const char kPrefPageIndex[] = "page_index";
+
 // A preference specifying if the user dragged the app on the NTP.
 const char kPrefUserDraggedApp[] = "user_dragged_app_ntp";
 
@@ -1129,6 +1132,23 @@ void ExtensionPrefs::SetAppLauncherOrder(
       NotificationService::NoDetails());
 }
 
+int ExtensionPrefs::GetPageIndex(const std::string& extension_id)
+{
+  int value;
+  if (ReadExtensionPrefInteger(extension_id, kPrefPageIndex, &value))
+    return value;
+
+  return -1;
+}
+
+void ExtensionPrefs::SetPageIndex(const std::string& extension_id, int index)
+{
+  CHECK_GE(index, 0);
+  UpdateExtensionPref(extension_id, kPrefPageIndex,
+                      Value::CreateIntegerValue(index));
+  SavePrefsAndNotify();
+}
+
 bool ExtensionPrefs::WasAppDraggedByUser(const std::string& extension_id) {
   DictionaryValue* dictionary = GetExtensionPref(extension_id);
   if (!dictionary) {
diff --git a/chrome/browser/extensions/extension_prefs.h b/chrome/browser/extensions/extension_prefs.h
index 611d4b1..d672ce3 100644
--- a/chrome/browser/extensions/extension_prefs.h
+++ b/chrome/browser/extensions/extension_prefs.h
@@ -260,6 +260,14 @@ class ExtensionPrefs {
   // Sets the order the apps should be displayed in the app launcher.
   void SetAppLauncherOrder(const std::vector<std::string>& extension_ids);
 
+  // Get the application page index for an extension with |extension_id|.  This
+  // determines which page an app will appear on in page-based NTPs.  If
+  // the app has no page specified, -1 is returned.
+  int GetPageIndex(const std::string& extension_id);
+
+  // Sets a specific page index for an extension with |extension_id|.
+  void SetPageIndex(const std::string& extension_id, int index);
+
   // Returns true if the user repositioned the app on the app launcher via drag
   // and drop.
   bool WasAppDraggedByUser(const std::string& extension_id);
diff --git a/chrome/browser/extensions/extension_prefs_unittest.cc b/chrome/browser/extensions/extension_prefs_unittest.cc
index e6bd0a5..fd83f56 100644
--- a/chrome/browser/extensions/extension_prefs_unittest.cc
+++ b/chrome/browser/extensions/extension_prefs_unittest.cc
@@ -550,6 +550,33 @@ class ExtensionPrefsAppLaunchIndex : public ExtensionPrefsTest {
 };
 TEST_F(ExtensionPrefsAppLaunchIndex, ExtensionPrefsAppLaunchIndex) {}
 
+class ExtensionPrefsPageIndex : public ExtensionPrefsTest {
+ public:
+  virtual void Initialize() {
+    extension_id_ = prefs_.AddExtensionAndReturnId("page_index");
+
+    int page_index = prefs()->GetPageIndex(extension_id_);
+    // Extension should not have been assigned a page
+    EXPECT_EQ(page_index, -1);
+
+    // Set the page index
+    prefs()->SetPageIndex(extension_id_, 2);
+  }
+
+  virtual void Verify() {
+    // Verify the page index.
+    int page_index = prefs()->GetPageIndex(extension_id_);
+    EXPECT_EQ(page_index, 2);
+
+    // This extension doesn't exist, so it should return -1.
+    EXPECT_EQ(-1, prefs()->GetPageIndex("foo"));
+  }
+
+ private:
+  std::string extension_id_;
+};
+TEST_F(ExtensionPrefsPageIndex, ExtensionPrefsPageIndex) {}
+
 class ExtensionPrefsAppDraggedByUser : public ExtensionPrefsTest {
  public:
   virtual void Initialize() {
diff --git a/chrome/browser/ui/webui/app_launcher_handler.cc b/chrome/browser/ui/webui/app_launcher_handler.cc
index 955e8f9..51cd4ac 100644
--- a/chrome/browser/ui/webui/app_launcher_handler.cc
+++ b/chrome/browser/ui/webui/app_launcher_handler.cc
@@ -107,6 +107,12 @@ void AppLauncherHandler::CreateAppInfo(const Extension* extension,
     prefs->SetAppLaunchIndex(extension->id(), app_launch_index);
   }
   value->SetInteger("app_launch_index", app_launch_index);
+
+  int page_index = prefs->GetPageIndex(extension->id());
+  if (page_index >= 0) {
+    // Only provide a value if one is stored
+    value->SetInteger("page_index", page_index);
+  }
 }
 
 // static
@@ -170,6 +176,8 @@ void AppLauncherHandler::RegisterMessages() {
       NewCallback(this, &AppLauncherHandler::HandleCreateAppShortcut));
   web_ui_->RegisterMessageCallback("reorderApps",
       NewCallback(this, &AppLauncherHandler::HandleReorderApps));
+  web_ui_->RegisterMessageCallback("setPageIndex",
+      NewCallback(this, &AppLauncherHandler::HandleSetPageIndex));
 }
 
 void AppLauncherHandler::Observe(NotificationType type,
@@ -463,6 +471,16 @@ void AppLauncherHandler::HandleReorderApps(const ListValue* args) {
   extensions_service_->extension_prefs()->SetAppLauncherOrder(extension_ids);
 }
 
+void AppLauncherHandler::HandleSetPageIndex(const ListValue* args) {
+  std::string extension_id;
+  double page_index;
+  CHECK(args->GetString(0, &extension_id));
+  CHECK(args->GetDouble(1, &page_index));
+
+  extensions_service_->extension_prefs()->SetPageIndex(extension_id,
+      static_cast<int>(page_index));
+}
+
 // static
 void AppLauncherHandler::RecordWebStoreLaunch(bool promo_active) {
   UMA_HISTOGRAM_ENUMERATION(extension_misc::kAppLaunchHistogram,
diff --git a/chrome/browser/ui/webui/app_launcher_handler.h b/chrome/browser/ui/webui/app_launcher_handler.h
index ba058ca..50a3ebb 100644
--- a/chrome/browser/ui/webui/app_launcher_handler.h
+++ b/chrome/browser/ui/webui/app_launcher_handler.h
@@ -72,9 +72,12 @@ class AppLauncherHandler
   // Callback for the "createAppShortcut" message.
   void HandleCreateAppShortcut(const ListValue* args);
 
-  // Callback for the 'reorderApps" message.
+  // Callback for the "reorderApps" message.
   void HandleReorderApps(const ListValue* args);
 
+  // Callback for the "setPageIndex" message.
+  void HandleSetPageIndex(const ListValue* args);
+
  private:
   // Records a web store launch in the appropriate histograms. |promo_active|
   // specifies if the web store promotion was active.