Extensions: create a simple model for the browser action buttons toolstrip and use it on Linux.

TODO: persist the order of buttons
TODO: use the model on windows, mac
TODO: let the view change the order of buttons

My plan for persisting the order is just to write/read a simple text file to/from disk, one extension id per line. Similar to the bookmark model, except that is structured data (because they try to hold more information).

BUG=26990

Review URL: http://codereview.chromium.org/462026

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@34005 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 185 insertions, 44 deletions

diff --git a/chrome/browser/extensions/extension_toolbar_model.cc b/chrome/browser/extensions/extension_toolbar_model.cc
new file mode 100644
index 0000000..39856cf
--- /dev/null
+++ b/chrome/browser/extensions/extension_toolbar_model.cc
@@ -0,0 +1,79 @@
+// Copyright (c) 2009 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.
+
+#include "chrome/browser/extensions/extension_toolbar_model.h"
+
+#include "chrome/browser/extensions/extensions_service.h"
+#include "chrome/common/extensions/extension.h"
+#include "chrome/common/notification_service.h"
+
+ExtensionToolbarModel::ExtensionToolbarModel(ExtensionsService* service)
+    : service_(service) {
+  DCHECK(service_);
+
+  registrar_.Add(this, NotificationType::EXTENSION_LOADED,
+                 Source<Profile>(service_->profile()));
+  registrar_.Add(this, NotificationType::EXTENSION_UNLOADED,
+                 Source<Profile>(service_->profile()));
+  registrar_.Add(this, NotificationType::EXTENSION_UNLOADED_DISABLED,
+                 Source<Profile>(service_->profile()));
+  registrar_.Add(this, NotificationType::EXTENSIONS_READY,
+                 Source<Profile>(service_->profile()));
+}
+
+ExtensionToolbarModel::~ExtensionToolbarModel() {
+}
+
+void ExtensionToolbarModel::AddObserver(Observer* observer) {
+  observers_.AddObserver(observer);
+}
+
+void ExtensionToolbarModel::RemoveObserver(Observer* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+void ExtensionToolbarModel::Observe(NotificationType type,
+                                    const NotificationSource& source,
+                                    const NotificationDetails& details) {
+  if (type == NotificationType::EXTENSIONS_READY) {
+    for (size_t i = 0; i < service_->extensions()->size(); ++i) {
+      Extension* extension = service_->GetExtensionById(
+          service_->extensions()->at(i)->id(), false);
+      AddExtension(extension);
+    }
+    return;
+  }
+
+  if (!service_->is_ready())
+    return;
+
+  Extension* extension = Details<Extension>(details).ptr();
+  if (type == NotificationType::EXTENSION_LOADED) {
+    AddExtension(extension);
+  } else if (type == NotificationType::EXTENSION_UNLOADED ||
+             type == NotificationType::EXTENSION_UNLOADED_DISABLED) {
+    RemoveExtension(extension);
+  } else {
+    NOTREACHED() << "Received unexpected notification";
+  }
+}
+
+void ExtensionToolbarModel::AddExtension(Extension* extension) {
+  // We only care about extensions with browser actions.
+  if (!extension->browser_action())
+    return;
+
+  toolitems_.push_back(extension);
+  FOR_EACH_OBSERVER(Observer, observers_,
+                    BrowserActionAdded(extension, toolitems_.size() - 1));
+}
+
+void ExtensionToolbarModel::RemoveExtension(Extension* extension) {
+  ExtensionList::iterator pos = std::find(begin(), end(), extension);
+  if (pos != end()) {
+    toolitems_.erase(pos);
+    FOR_EACH_OBSERVER(Observer, observers_,
+                      BrowserActionRemoved(extension));
+  }
+}
diff --git a/chrome/browser/extensions/extension_toolbar_model.h b/chrome/browser/extensions/extension_toolbar_model.h
new file mode 100644
index 0000000..d02dc0f
--- /dev/null
+++ b/chrome/browser/extensions/extension_toolbar_model.h
@@ -0,0 +1,64 @@
+// Copyright (c) 2009 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.
+
+#ifndef CHROME_BROWSER_EXTENSIONS_EXTENSION_TOOLBAR_MODEL_H_
+#define CHROME_BROWSER_EXTENSIONS_EXTENSION_TOOLBAR_MODEL_H_
+
+#include "base/observer_list.h"
+#include "chrome/common/extensions/extension.h"
+#include "chrome/common/notification_observer.h"
+#include "chrome/common/notification_registrar.h"
+
+class ExtensionsService;
+
+// Model for the browser actions toolbar.
+class ExtensionToolbarModel : public NotificationObserver {
+ public:
+  explicit ExtensionToolbarModel(ExtensionsService* service);
+  ~ExtensionToolbarModel();
+
+  // A class which is informed of changes to the model; represents the view of
+  // MVC.
+  class Observer {
+   public:
+    // An extension with a browser action button has been added, and should go
+    // in the toolbar at |index|.
+    virtual void BrowserActionAdded(Extension* extension, int index) {}
+
+    // The browser action button for |extension| should no longer show.
+    virtual void BrowserActionRemoved(Extension* extension) {}
+  };
+
+  void AddObserver(Observer* observer);
+  void RemoveObserver(Observer* observer);
+
+  ExtensionList::iterator begin() {
+    return toolitems_.begin();
+  }
+
+  ExtensionList::iterator end() {
+    return toolitems_.end();
+  }
+
+ private:
+  // NotificationObserver implementation.
+  virtual void Observe(NotificationType type,
+                       const NotificationSource& source,
+                       const NotificationDetails& details);
+
+  // Our observers.
+  ObserverList<Observer> observers_;
+
+  void AddExtension(Extension* extension);
+  void RemoveExtension(Extension* extension);
+
+  // Our ExtensionsService, guaranteed to outlive us.
+  ExtensionsService* service_;
+
+  // Ordered list of browser action buttons.
+  ExtensionList toolitems_;
+
+  NotificationRegistrar registrar_;
+};
+#endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_TOOLBAR_MODEL_H_
diff --git a/chrome/browser/extensions/extensions_service.cc b/chrome/browser/extensions/extensions_service.cc
index 7af9133..2ae7f5e 100644
--- a/chrome/browser/extensions/extensions_service.cc
+++ b/chrome/browser/extensions/extensions_service.cc
@@ -91,7 +91,8 @@ ExtensionsService::ExtensionsService(Profile* profile,
       install_directory_(install_directory),
       extensions_enabled_(true),
       show_extensions_prompts_(true),
-      ready_(false) {
+      ready_(false),
+      ALLOW_THIS_IN_INITIALIZER_LIST(toolbar_model_(this)) {
   // Figure out if extension installation should be enabled.
   if (command_line->HasSwitch(switches::kDisableExtensions)) {
     extensions_enabled_ = false;
diff --git a/chrome/browser/extensions/extensions_service.h b/chrome/browser/extensions/extensions_service.h
index 79fdc10..0492538 100644
--- a/chrome/browser/extensions/extensions_service.h
+++ b/chrome/browser/extensions/extensions_service.h
@@ -20,6 +20,7 @@
 #include "chrome/browser/chrome_thread.h"
 #include "chrome/browser/extensions/extension_prefs.h"
 #include "chrome/browser/extensions/extension_process_manager.h"
+#include "chrome/browser/extensions/extension_toolbar_model.h"
 #include "chrome/browser/extensions/extensions_quota_service.h"
 #include "chrome/browser/extensions/external_extension_provider.h"
 #include "chrome/browser/extensions/sandboxed_extension_unpacker.h"
@@ -32,6 +33,7 @@ class Browser;
 class DictionaryValue;
 class Extension;
 class ExtensionsServiceBackend;
+class ExtensionToolbarModel;
 class ExtensionUpdater;
 class GURL;
 class PrefService;
@@ -213,6 +215,8 @@ class ExtensionsService
   // Note that this may return NULL if autoupdate is not turned on.
   ExtensionUpdater* updater() { return updater_.get(); }
 
+  ExtensionToolbarModel* toolbar_model() { return &toolbar_model_; }
+
   ExtensionsQuotaService* quota_service() { return &quota_service_; }
 
   // Notify the frontend that there was an error loading an extension.
@@ -292,6 +296,9 @@ class ExtensionsService
   // Our extension updater, if updates are turned on.
   scoped_refptr<ExtensionUpdater> updater_;
 
+  // The model that tracks extensions with BrowserAction buttons.
+  ExtensionToolbarModel toolbar_model_;
+
   // Map of inspector cookies that are detached, waiting for an extension to be
   // reloaded.
   typedef std::map<std::string, int> OrphanedDevTools;
diff --git a/chrome/browser/gtk/browser_actions_toolbar_gtk.cc b/chrome/browser/gtk/browser_actions_toolbar_gtk.cc
index 4399923..91ea423 100644
--- a/chrome/browser/gtk/browser_actions_toolbar_gtk.cc
+++ b/chrome/browser/gtk/browser_actions_toolbar_gtk.cc
@@ -203,18 +203,20 @@ class BrowserActionButton : public NotificationObserver,
 BrowserActionsToolbarGtk::BrowserActionsToolbarGtk(Browser* browser)
     : browser_(browser),
       profile_(browser->profile()),
+      model_(NULL),
       hbox_(gtk_hbox_new(FALSE, kBrowserActionButtonPadding)) {
-  registrar_.Add(this, NotificationType::EXTENSION_LOADED,
-                 Source<Profile>(profile_));
-  registrar_.Add(this, NotificationType::EXTENSION_UNLOADED,
-                 Source<Profile>(profile_));
-  registrar_.Add(this, NotificationType::EXTENSION_UNLOADED_DISABLED,
-                 Source<Profile>(profile_));
-
-  CreateAllButtons();
+  ExtensionsService* extension_service = profile_->GetExtensionsService();
+  // The |extension_service| can be NULL in Incognito.
+  if (extension_service) {
+    model_ = extension_service->toolbar_model();
+    model_->AddObserver(this);
+    CreateAllButtons();
+  }
 }
 
 BrowserActionsToolbarGtk::~BrowserActionsToolbarGtk() {
+  if (model_)
+    model_->RemoveObserver(this);
   hbox_.Destroy();
 }
 
@@ -233,38 +235,14 @@ void BrowserActionsToolbarGtk::Update() {
   }
 }
 
-void BrowserActionsToolbarGtk::Observe(NotificationType type,
-                                       const NotificationSource& source,
-                                       const NotificationDetails& details) {
-  Extension* extension = Details<Extension>(details).ptr();
-
-  if (type == NotificationType::EXTENSION_LOADED) {
-    CreateButtonForExtension(extension);
-  } else if (type == NotificationType::EXTENSION_UNLOADED ||
-             type == NotificationType::EXTENSION_UNLOADED_DISABLED) {
-    RemoveButtonForExtension(extension);
-  } else {
-    NOTREACHED() << "Received unexpected notification";
-  }
-}
-
 void BrowserActionsToolbarGtk::CreateAllButtons() {
-  ExtensionsService* extension_service = profile_->GetExtensionsService();
-  if (!extension_service)  // The |extension_service| can be NULL in Incognito.
-    return;
-
-  for (size_t i = 0; i < extension_service->extensions()->size(); ++i) {
-    Extension* extension = extension_service->GetExtensionById(
-        extension_service->extensions()->at(i)->id(), false);
-    CreateButtonForExtension(extension);
+  for (ExtensionList::iterator iter = model_->begin();
+       iter != model_->end(); ++iter) {
+    CreateButtonForExtension(*iter);
   }
 }
 
 void BrowserActionsToolbarGtk::CreateButtonForExtension(Extension* extension) {
-  // Only show extensions with browser actions.
-  if (!extension->browser_action())
-    return;
-
   RemoveButtonForExtension(extension);
   linked_ptr<BrowserActionButton> button(
       new BrowserActionButton(this, extension));
@@ -286,3 +264,13 @@ void BrowserActionsToolbarGtk::UpdateVisibility() {
   else
     gtk_widget_show(widget());
 }
+
+void BrowserActionsToolbarGtk::BrowserActionAdded(Extension* extension,
+                                                  int index) {
+  // TODO(estade): respect |index|.
+  CreateButtonForExtension(extension);
+}
+
+void BrowserActionsToolbarGtk::BrowserActionRemoved(Extension* extension) {
+  RemoveButtonForExtension(extension);
+}
diff --git a/chrome/browser/gtk/browser_actions_toolbar_gtk.h b/chrome/browser/gtk/browser_actions_toolbar_gtk.h
index 015b5c9..ceee599b 100644
--- a/chrome/browser/gtk/browser_actions_toolbar_gtk.h
+++ b/chrome/browser/gtk/browser_actions_toolbar_gtk.h
@@ -9,6 +9,7 @@
 #include <string>
 
 #include "base/linked_ptr.h"
+#include "chrome/browser/extensions/extension_toolbar_model.h"
 #include "chrome/common/notification_observer.h"
 #include "chrome/common/notification_registrar.h"
 #include "chrome/common/owned_widget_gtk.h"
@@ -20,7 +21,7 @@ class Profile;
 
 typedef struct _GtkWidget GtkWidget;
 
-class BrowserActionsToolbarGtk : public NotificationObserver {
+class BrowserActionsToolbarGtk : public ExtensionToolbarModel::Observer {
  public:
   explicit BrowserActionsToolbarGtk(Browser* browser);
   ~BrowserActionsToolbarGtk();
@@ -37,11 +38,6 @@ class BrowserActionsToolbarGtk : public NotificationObserver {
   // Update the display of all buttons.
   void Update();
 
-  // NotificationObserver implementation.
-  void Observe(NotificationType type,
-               const NotificationSource& source,
-               const NotificationDetails& details);
-
  private:
   // Query the extensions service for all extensions with browser actions,
   // and create the UI for them.
@@ -60,13 +56,17 @@ class BrowserActionsToolbarGtk : public NotificationObserver {
   // to show.
   void UpdateVisibility();
 
+  // ExtensionToolbarModel::Observer implementation.
+  virtual void BrowserActionAdded(Extension* extension, int index);
+  virtual void BrowserActionRemoved(Extension* extension);
+
   Browser* browser_;
 
   Profile* profile_;
 
-  OwnedWidgetGtk hbox_;
+  ExtensionToolbarModel* model_;
 
-  NotificationRegistrar registrar_;
+  OwnedWidgetGtk hbox_;
 
   // Map from extension ID to BrowserActionButton, which is a wrapper for
   // a chrome button and related functionality. There should be one entry
diff --git a/chrome/chrome_browser.gypi b/chrome/chrome_browser.gypi
index 5999495..8a88319 100755
--- a/chrome/chrome_browser.gypi
+++ b/chrome/chrome_browser.gypi
@@ -686,6 +686,8 @@
         'browser/extensions/extension_tabs_module_constants.h',
         'browser/extensions/extension_test_api.cc',
         'browser/extensions/extension_test_api.h',
+        'browser/extensions/extension_toolbar_model.cc',
+        'browser/extensions/extension_toolbar_model.h',
         'browser/extensions/extension_toolstrip_api.cc',
         'browser/extensions/extension_toolstrip_api.h',
         'browser/extensions/extension_updater.cc',