Update the list of apps when installed/uninstalled for Athena.

BUG=425810
R=oshima@chromium.org
TEST=athena_unittests, manually

Review URL: https://codereview.chromium.org/665403005

Cr-Commit-Position: refs/heads/master@{#300768}

9 files changed, 204 insertions, 49 deletions

diff --git a/athena/extensions/extension_app_model_builder.cc b/athena/extensions/extension_app_model_builder.cc
index 92ee81f..411c8b8 100644
--- a/athena/extensions/extension_app_model_builder.cc
+++ b/athena/extensions/extension_app_model_builder.cc
@@ -8,6 +8,8 @@
 #include "athena/activity/public/activity_manager.h"
 #include "athena/extensions/public/extensions_delegate.h"
 #include "extensions/browser/extension_icon_image.h"
+#include "extensions/browser/extension_registry.h"
+#include "extensions/browser/extension_registry_factory.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/extension_set.h"
 #include "extensions/common/manifest_handlers/icons_handler.h"
@@ -29,17 +31,22 @@ class AppItem : public app_list::AppListItem {
   AppItem(scoped_refptr<const extensions::Extension> extension,
           content::BrowserContext* browser_context)
       : app_list::AppListItem(extension->id()),
-        extension_(extension),
-        browser_context_(browser_context),
-        icon_image_(browser_context_,
-                    extension.get(),
-                    extensions::IconsInfo::GetIcons(extension.get()),
-                    extension_misc::EXTENSION_ICON_MEDIUM,
-                    *ui::ResourceBundle::GetSharedInstance().GetImageSkiaNamed(
-                        IDR_APP_DEFAULT_ICON),
-                    NULL) {
-    icon_image_.image_skia().EnsureRepsForSupportedScales();
-    SetIcon(icon_image_.image_skia(), false);
+        browser_context_(browser_context) {
+    Reload(extension);
+  }
+
+  void Reload(scoped_refptr<const extensions::Extension> extension) {
+    extension_ = extension;
+    icon_image_.reset(new extensions::IconImage(
+        browser_context_,
+        extension.get(),
+        extensions::IconsInfo::GetIcons(extension.get()),
+        extension_misc::EXTENSION_ICON_MEDIUM,
+        *ui::ResourceBundle::GetSharedInstance().GetImageSkiaNamed(
+            IDR_APP_DEFAULT_ICON),
+        NULL));
+    icon_image_->image_skia().EnsureRepsForSupportedScales();
+    SetIcon(icon_image_->image_skia(), false);
     SetName(extension->name());
   }
 
@@ -51,7 +58,7 @@ class AppItem : public app_list::AppListItem {
 
   scoped_refptr<const extensions::Extension> extension_;
   content::BrowserContext* browser_context_;
-  extensions::IconImage icon_image_;
+  scoped_ptr<extensions::IconImage> icon_image_;
 
   DISALLOW_COPY_AND_ASSIGN(AppItem);
 };
@@ -60,27 +67,57 @@ class AppItem : public app_list::AppListItem {
 
 ExtensionAppModelBuilder::ExtensionAppModelBuilder(
     content::BrowserContext* browser_context)
-    : browser_context_(browser_context) {
+    : browser_context_(browser_context), model_(nullptr) {
+  extensions::ExtensionRegistryFactory::GetForBrowserContext(browser_context_)
+      ->AddObserver(this);
 }
 
 ExtensionAppModelBuilder::~ExtensionAppModelBuilder() {
+  extensions::ExtensionRegistryFactory::GetForBrowserContext(browser_context_)
+      ->RemoveObserver(this);
 }
 
-void ExtensionAppModelBuilder::PopulateApps(app_list::AppListModel* model) {
+void ExtensionAppModelBuilder::RegisterAppListModel(
+    app_list::AppListModel* model) {
+  DCHECK(!model_);
+  model_ = model;
+
   ExtensionsDelegate* bridge = ExtensionsDelegate::Get(browser_context_);
   const extensions::ExtensionSet& extensions = bridge->GetInstalledExtensions();
   for (extensions::ExtensionSet::const_iterator iter = extensions.begin();
        iter != extensions.end();
        ++iter) {
-    // Chrome icon is currently disabled for homecard since it's not meaningful.
-    // http://crbug.com/421677
-    // TODO(mukai): use chrome/browser/extension_ui_util.
-    if ((*iter)->ShouldDisplayInAppLauncher() &&
-        (*iter)->id() != kChromeAppId) {
-      model->AddItem(scoped_ptr<app_list::AppListItem>(
-          new AppItem(*iter, browser_context_)));
-    }
+    AddItem(*iter);
+  }
+}
+
+void ExtensionAppModelBuilder::AddItem(
+    scoped_refptr<const extensions::Extension> extension) {
+  // Chrome icon is currently disabled for homecard since it's not meaningful.
+  // http://crbug.com/421677
+  // TODO(mukai): use chrome/browser/extension_ui_util.
+  if (extension->ShouldDisplayInAppLauncher() &&
+      extension->id() != kChromeAppId) {
+    model_->AddItem(make_scoped_ptr(new AppItem(extension, browser_context_)));
   }
 }
 
+void ExtensionAppModelBuilder::OnExtensionInstalled(
+    content::BrowserContext* browser_context,
+    const extensions::Extension* extension,
+    bool is_update) {
+  app_list::AppListItem* item = model_->FindItem(extension->id());
+  if (item)
+    static_cast<AppItem*>(item)->Reload(make_scoped_refptr(extension));
+  else
+    AddItem(make_scoped_refptr(extension));
+}
+
+void ExtensionAppModelBuilder::OnExtensionUninstalled(
+    content::BrowserContext* browser_context,
+    const extensions::Extension* extension,
+    extensions::UninstallReason reason) {
+  model_->DeleteItem(extension->id());
+}
+
 }  // namespace athena
diff --git a/athena/extensions/public/extension_app_model_builder.h b/athena/extensions/public/extension_app_model_builder.h
index 0906add..abd8972 100644
--- a/athena/extensions/public/extension_app_model_builder.h
+++ b/athena/extensions/public/extension_app_model_builder.h
@@ -7,23 +7,45 @@
 
 #include "athena/home/public/app_model_builder.h"
 #include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "extensions/browser/extension_registry_observer.h"
 
 namespace content {
 class BrowserContext;
 }
 
+namespace extensions {
+class Extension;
+}
+
 namespace athena {
 
-class ATHENA_EXPORT ExtensionAppModelBuilder : public AppModelBuilder {
+class ATHENA_EXPORT ExtensionAppModelBuilder
+    : public AppModelBuilder,
+      public extensions::ExtensionRegistryObserver {
  public:
   explicit ExtensionAppModelBuilder(content::BrowserContext* browser_context);
   virtual ~ExtensionAppModelBuilder();
 
-  virtual void PopulateApps(app_list::AppListModel* model) override;
+  virtual void RegisterAppListModel(app_list::AppListModel* model) override;
 
  private:
+  void AddItem(scoped_refptr<const extensions::Extension> extension);
+
+  // extensions::ExtensionRegistryObserver:
+  virtual void OnExtensionInstalled(content::BrowserContext* browser_context,
+                                    const extensions::Extension* extension,
+                                    bool is_update) override;
+  virtual void OnExtensionUninstalled(
+      content::BrowserContext* browser_context,
+      const extensions::Extension* extension,
+      extensions::UninstallReason reason) override;
+
   content::BrowserContext* browser_context_;
 
+  // Unowned pointer to the app list model.
+  app_list::AppListModel* model_;
+
   DISALLOW_COPY_AND_ASSIGN(ExtensionAppModelBuilder);
 };
 
diff --git a/athena/home/app_list_view_delegate.cc b/athena/home/app_list_view_delegate.cc
index bb1e0be..eead245 100644
--- a/athena/home/app_list_view_delegate.cc
+++ b/athena/home/app_list_view_delegate.cc
@@ -34,7 +34,7 @@ AppListViewDelegate::AppListViewDelegate(
     SearchControllerFactory* search_factory)
     : model_(new app_list::AppListModel),
       speech_ui_(new app_list::SpeechUIModel) {
-  model_builder->PopulateApps(model_.get());
+  model_builder->RegisterAppListModel(model_.get());
   model_->search_box()->SetHintText(
       l10n_util::GetStringUTF16(IDS_ATHENA_SEARCH_BOX_HINT));
   if (search_factory) {
diff --git a/athena/home/athena_start_page_view.cc b/athena/home/athena_start_page_view.cc
index 0891487..72ba721 100644
--- a/athena/home/athena_start_page_view.cc
+++ b/athena/home/athena_start_page_view.cc
@@ -84,8 +84,12 @@ class AppIconButton : public views::ImageButton,
                       public views::ButtonListener {
  public:
   explicit AppIconButton(app_list::AppListItem* item)
-      : ImageButton(this),
-        item_(item) {
+      : ImageButton(this), item_(nullptr) {
+    SetItem(item);
+  }
+
+  void SetItem(app_list::AppListItem* item) {
+    item_ = item;
     // TODO(mukai): icon should be resized.
     SetImage(STATE_NORMAL, &item->icon());
   }
@@ -209,11 +213,9 @@ AthenaStartPageView::AthenaStartPageView(
   app_icon_container_->layer()->SetFillsBoundsOpaquely(false);
   app_icon_container_->SetLayoutManager(new views::BoxLayout(
       views::BoxLayout::kHorizontal, 0, 0, kIconMargin));
-  app_list::AppListItemList* top_level =
-      view_delegate->GetModel()->top_level_item_list();
-  for (size_t i = 0; i < std::min(top_level->item_count(), kMaxIconNum); ++i)
-    app_icon_container_->AddChildView(new AppIconButton(top_level->item_at(i)));
   app_icon_container_->SetSize(GetIconContainerSize());
+  UpdateAppIcons();
+  view_delegate->GetModel()->top_level_item_list()->AddObserver(this);
 
   control_icon_container_ = new views::View();
   control_icon_container_->SetPaintToLayer(true);
@@ -235,7 +237,9 @@ AthenaStartPageView::AthenaStartPageView(
   AddChildView(search_box_container_);
 }
 
-AthenaStartPageView::~AthenaStartPageView() {}
+AthenaStartPageView::~AthenaStartPageView() {
+  delegate_->GetModel()->top_level_item_list()->RemoveObserver(this);
+}
 
 void AthenaStartPageView::RequestFocusOnSearchBox() {
   search_box_view_->search_box()->RequestFocus();
@@ -324,6 +328,28 @@ AthenaStartPageView::LayoutData AthenaStartPageView::CreateCenteredBounds(
   return state;
 }
 
+void AthenaStartPageView::UpdateAppIcons() {
+  app_list::AppListItemList* top_level =
+      delegate_->GetModel()->top_level_item_list();
+  size_t max_items = std::min(top_level->item_count(), kMaxIconNum);
+  for (size_t i = 0; i < max_items; ++i) {
+    if (i < static_cast<size_t>(app_icon_container_->child_count())) {
+      AppIconButton* button =
+          static_cast<AppIconButton*>(app_icon_container_->child_at(i));
+      button->SetItem(top_level->item_at(i));
+    } else {
+      app_icon_container_->AddChildView(
+          new AppIconButton(top_level->item_at(i)));
+    }
+  }
+
+  while (max_items < static_cast<size_t>(app_icon_container_->child_count())) {
+    scoped_ptr<views::View> remover(
+        app_icon_container_->child_at(app_icon_container_->child_count() - 1));
+    app_icon_container_->RemoveChildView(remover.get());
+  }
+}
+
 void AthenaStartPageView::LayoutSearchResults(bool should_show_search_results) {
   if (should_show_search_results ==
       search_results_view_->layer()->GetTargetVisibility()) {
@@ -445,4 +471,25 @@ void AthenaStartPageView::QueryChanged(app_list::SearchBoxView* sender) {
   LayoutSearchResults(!query.empty());
 }
 
+void AthenaStartPageView::OnListItemAdded(size_t index,
+                                          app_list::AppListItem* item) {
+  UpdateAppIcons();
+}
+
+void AthenaStartPageView::OnListItemRemoved(size_t index,
+                                            app_list::AppListItem* item) {
+  UpdateAppIcons();
+}
+
+void AthenaStartPageView::OnListItemMoved(size_t from_index,
+                                          size_t to_index,
+                                          app_list::AppListItem* item) {
+  UpdateAppIcons();
+}
+
+// static
+size_t AthenaStartPageView::GetMaxIconNumForTest() {
+  return kMaxIconNum;
+}
+
 }  // namespace athena
diff --git a/athena/home/athena_start_page_view.h b/athena/home/athena_start_page_view.h
index f92a73f..4e0f19d 100644
--- a/athena/home/athena_start_page_view.h
+++ b/athena/home/athena_start_page_view.h
@@ -8,11 +8,13 @@
 #include "athena/athena_export.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
+#include "ui/app_list/app_list_item_list_observer.h"
 #include "ui/app_list/views/search_box_view_delegate.h"
 #include "ui/gfx/animation/tween.h"
 #include "ui/views/view.h"
 
 namespace app_list {
+class AppListModelObserver;
 class AppListViewDelegate;
 class SearchBoxView;
 class SearchResultListView;
@@ -22,7 +24,8 @@ namespace athena {
 
 class ATHENA_EXPORT AthenaStartPageView
     : public views::View,
-      public app_list::SearchBoxViewDelegate {
+      public app_list::SearchBoxViewDelegate,
+      public app_list::AppListItemListObserver {
  public:
   class Observer {
    public:
@@ -51,6 +54,8 @@ class ATHENA_EXPORT AthenaStartPageView
 
   static const char kViewClassName[];
 
+  static size_t GetMaxIconNumForTest();
+
   // A struct which bundles the layout data of subviews.
   struct LayoutData {
     gfx::Rect search_box;
@@ -69,6 +74,8 @@ class ATHENA_EXPORT AthenaStartPageView
   // Returns the bounds for |VISIBLE_CENTERED|.
   LayoutData CreateCenteredBounds(int width);
 
+  void UpdateAppIcons();
+
   // Schedules the animation for the layout the search box and the search
   // results.
   void LayoutSearchResults(bool should_show_search_results);
@@ -84,6 +91,15 @@ class ATHENA_EXPORT AthenaStartPageView
   // app_list::SearchBoxViewDelegate:
   virtual void QueryChanged(app_list::SearchBoxView* sender) override;
 
+  // app_list::AppListItemListObserver:
+  virtual void OnListItemAdded(size_t index,
+                               app_list::AppListItem* item) override;
+  virtual void OnListItemRemoved(size_t index,
+                                 app_list::AppListItem* item) override;
+  virtual void OnListItemMoved(size_t from_index,
+                               size_t to_index,
+                               app_list::AppListItem* item) override;
+
   // Not owned.
   app_list::AppListViewDelegate* delegate_;
 
diff --git a/athena/home/athena_start_page_view_unittest.cc b/athena/home/athena_start_page_view_unittest.cc
index c91177e..d611c3b 100644
--- a/athena/home/athena_start_page_view_unittest.cc
+++ b/athena/home/athena_start_page_view_unittest.cc
@@ -19,13 +19,6 @@
 
 namespace athena {
 
-namespace {
-
-// The number of dummy applications in this tetst.
-const size_t kNumApps = 10;
-
-}
-
 class AthenaTestViewDelegate : public app_list::test::AppListTestViewDelegate {
  public:
   AthenaTestViewDelegate() {}
@@ -48,11 +41,8 @@ class AthenaStartPageViewTest : public test::AthenaTestBase {
   // testing::Test:
   virtual void SetUp() override {
     test::AthenaTestBase::SetUp();
-    app_list::test::AppListTestModel* model = view_delegate_.GetTestModel();
-    for (size_t i = 0; i < kNumApps; ++i) {
-      model->AddItem(new app_list::test::AppListTestModel::AppListTestItem(
-          base::StringPrintf("id-%" PRIuS, i), model));
-    }
+    for (size_t i = 0; i < GetMaxIconNum(); ++i)
+      AddTestItem(i);
 
     view_.reset(new AthenaStartPageView(&view_delegate_));
     SetSize(gfx::Size(1280, 800));
@@ -68,6 +58,24 @@ class AthenaStartPageViewTest : public test::AthenaTestBase {
     view_->Layout();
   }
 
+  void AddTestItem(size_t index) {
+    app_list::test::AppListTestModel* model = view_delegate_.GetTestModel();
+    model->AddItem(new app_list::test::AppListTestModel::AppListTestItem(
+        GetAppIdFor(index), model));
+  }
+
+  static size_t GetMaxIconNum() {
+    return AthenaStartPageView::GetMaxIconNumForTest();
+  }
+
+  static std::string GetAppIdFor(size_t index) {
+    return base::StringPrintf("id-%" PRIuS, index);
+  }
+
+  app_list::AppListModel* GetModel() { return view_delegate_.GetTestModel(); }
+
+  views::View* GetIconsContainer() { return view_->app_icon_container_; }
+
   gfx::Rect GetIconsBounds() const {
     return view_->app_icon_container_->layer()->GetTargetBounds();
   }
@@ -244,4 +252,28 @@ TEST_F(AthenaStartPageViewTest, SearchFromBottom) {
   EXPECT_EQ(1.0f, layout_state());
 }
 
+TEST_F(AthenaStartPageViewTest, AppAddRemove) {
+  gfx::Rect icons_bounds = GetIconsBounds();
+  EXPECT_EQ(GetMaxIconNum(),
+            static_cast<size_t>(GetIconsContainer()->child_count()));
+
+  GetModel()->DeleteItem(GetAppIdFor(1));
+
+  // The removed icon disappear, however its bound should not change.
+  EXPECT_EQ(GetMaxIconNum() - 1,
+            static_cast<size_t>(GetIconsContainer()->child_count()));
+  EXPECT_EQ(icons_bounds.size().ToString(), GetIconsBounds().size().ToString());
+
+  AddTestItem(GetMaxIconNum() + 1);
+  EXPECT_EQ(GetMaxIconNum(),
+            static_cast<size_t>(GetIconsContainer()->child_count()));
+  EXPECT_EQ(icons_bounds.size().ToString(), GetIconsBounds().size().ToString());
+
+  // Adding more doesn't cause any effects.
+  AddTestItem(GetMaxIconNum() + 2);
+  EXPECT_EQ(GetMaxIconNum(),
+            static_cast<size_t>(GetIconsContainer()->child_count()));
+  EXPECT_EQ(icons_bounds.size().ToString(), GetIconsBounds().size().ToString());
+}
+
 }  // namespace athena
diff --git a/athena/home/public/app_model_builder.h b/athena/home/public/app_model_builder.h
index 5cfa890..50c38bf 100644
--- a/athena/home/public/app_model_builder.h
+++ b/athena/home/public/app_model_builder.h
@@ -20,8 +20,9 @@ class ATHENA_EXPORT AppModelBuilder {
  public:
   virtual ~AppModelBuilder() {}
 
-  // Fills |model| with the currently available app_list::AppListItems.
-  virtual void PopulateApps(app_list::AppListModel* model) = 0;
+  // Registers |model| to the builder so that the builder can fill the currently
+  // available app_list::AppListItems.
+  virtual void RegisterAppListModel(app_list::AppListModel* model) = 0;
 };
 
 }  // namespace athena
diff --git a/athena/test/base/test_app_model_builder.cc b/athena/test/base/test_app_model_builder.cc
index 6f2c37e..beaa846 100644
--- a/athena/test/base/test_app_model_builder.cc
+++ b/athena/test/base/test_app_model_builder.cc
@@ -96,7 +96,7 @@ TestAppModelBuilder::TestAppModelBuilder() {
 TestAppModelBuilder::~TestAppModelBuilder() {
 }
 
-void TestAppModelBuilder::PopulateApps(app_list::AppListModel* model) {
+void TestAppModelBuilder::RegisterAppListModel(app_list::AppListModel* model) {
   for (int i = 0; i < static_cast<int>(DummyItem::LAST_TYPE); ++i) {
     model->AddItem(scoped_ptr<app_list::AppListItem>(
         new DummyItem(static_cast<DummyItem::Type>(i))));
diff --git a/athena/test/base/test_app_model_builder.h b/athena/test/base/test_app_model_builder.h
index 262ce25..e7a7e4b 100644
--- a/athena/test/base/test_app_model_builder.h
+++ b/athena/test/base/test_app_model_builder.h
@@ -16,7 +16,7 @@ class TestAppModelBuilder : public AppModelBuilder {
   virtual ~TestAppModelBuilder();
 
   // Overridden from AppModelBuilder:
-  virtual void PopulateApps(app_list::AppListModel* model) override;
+  virtual void RegisterAppListModel(app_list::AppListModel* model) override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TestAppModelBuilder);