Change ContentsView::SetActivePage to use States rather than indexes.

This CL makes the ContentsView's API state-keyed rather than page index
keyed. This removes cruft from callers of SetActivePage and will
support further refactors.

BUG=455059
TBR=jamescook@chromium.org, benwells@chromium.org

Review URL: https://codereview.chromium.org/947903002

Cr-Commit-Position: refs/heads/master@{#321513}

7 files changed, 60 insertions, 73 deletions

diff --git a/ui/app_list/views/all_apps_tile_item_view.cc b/ui/app_list/views/all_apps_tile_item_view.cc
index c7e10f7..5e12ad7 100644
--- a/ui/app_list/views/all_apps_tile_item_view.cc
+++ b/ui/app_list/views/all_apps_tile_item_view.cc
@@ -32,8 +32,7 @@ void AllAppsTileItemView::ButtonPressed(views::Button* sender,
   UMA_HISTOGRAM_ENUMERATION(kPageOpenedHistogram, AppListModel::STATE_APPS,
                             AppListModel::STATE_LAST);
 
-  contents_view_->SetActivePage(
-      contents_view_->GetPageIndexForState(AppListModel::STATE_APPS));
+  contents_view_->SetActiveState(AppListModel::STATE_APPS);
 }
 
 void AllAppsTileItemView::OnFolderImageUpdated() {
diff --git a/ui/app_list/views/app_list_main_view.cc b/ui/app_list/views/app_list_main_view.cc
index 02690dc..aa45d63 100644
--- a/ui/app_list/views/app_list_main_view.cc
+++ b/ui/app_list/views/app_list_main_view.cc
@@ -144,10 +144,9 @@ void AppListMainView::ShowAppListWhenReady() {
 }
 
 void AppListMainView::ResetForShow() {
-  if (switches::IsExperimentalAppListEnabled()) {
-    contents_view_->SetActivePage(
-        contents_view_->GetPageIndexForState(AppListModel::STATE_START));
-  }
+  if (switches::IsExperimentalAppListEnabled())
+    contents_view_->SetActiveState(AppListModel::STATE_START);
+
   contents_view_->apps_container_view()->ResetForShowApps();
   // We clear the search when hiding so when app list appears it is not showing
   // search results.
@@ -262,8 +261,7 @@ void AppListMainView::UpdateCustomLauncherPageVisibility() {
                  AppListModel::STATE_CUSTOM_LAUNCHER_PAGE)) {
     // Animate to the start page if currently on the custom page view. The view
     // will hide on animation completion.
-    contents_view_->SetActivePage(
-        contents_view_->GetPageIndexForState(AppListModel::STATE_START));
+    contents_view_->SetActiveState(AppListModel::STATE_START);
   } else {
     // Hide the view immediately otherwise.
     custom_page->SetVisible(false);
diff --git a/ui/app_list/views/app_list_main_view_unittest.cc b/ui/app_list/views/app_list_main_view_unittest.cc
index accc731..547b9b3 100644
--- a/ui/app_list/views/app_list_main_view_unittest.cc
+++ b/ui/app_list/views/app_list_main_view_unittest.cc
@@ -278,8 +278,7 @@ TEST_F(AppListMainViewTest, MouseHoverToHighlight) {
 
   // If experimental launcher, switch to All Apps page
   if (app_list::switches::IsExperimentalAppListEnabled()) {
-    GetContentsView()->SetActivePage(
-        GetContentsView()->GetPageIndexForState(AppListModel::STATE_APPS));
+    GetContentsView()->SetActiveState(AppListModel::STATE_APPS);
     GetContentsView()->Layout();
   }
 
@@ -314,8 +313,7 @@ TEST_F(AppListMainViewTest, MAYBE_TapGestureToHighlight) {
 
   // If experimental launcher, switch to All Apps page
   if (app_list::switches::IsExperimentalAppListEnabled()) {
-    GetContentsView()->SetActivePage(
-        GetContentsView()->GetPageIndexForState(AppListModel::STATE_APPS));
+    GetContentsView()->SetActiveState(AppListModel::STATE_APPS);
     GetContentsView()->Layout();
   }
 
@@ -371,8 +369,7 @@ TEST_F(AppListMainViewTest, DragReparentItemOntoPageSwitcher) {
 
   // Ensure we are on the apps grid view page.
   app_list::ContentsView* contents_view = GetContentsView();
-  contents_view->SetActivePage(
-      contents_view->GetPageIndexForState(AppListModel::STATE_APPS));
+  contents_view->SetActiveState(AppListModel::STATE_APPS);
   contents_view->Layout();
 
   AppListItemView* folder_item_view = CreateAndOpenSingleItemFolder();
diff --git a/ui/app_list/views/app_list_view_unittest.cc b/ui/app_list/views/app_list_view_unittest.cc
index ded3543..dde70081 100644
--- a/ui/app_list/views/app_list_view_unittest.cc
+++ b/ui/app_list/views/app_list_view_unittest.cc
@@ -234,8 +234,7 @@ void AppListViewTestContext::CheckView(views::View* subview) {
 
 bool AppListViewTestContext::SetAppListState(AppListModel::State state) {
   ContentsView* contents_view = view_->app_list_main_view()->contents_view();
-  int index = contents_view->GetPageIndexForState(state);
-  contents_view->SetActivePage(index);
+  contents_view->SetActiveState(state);
   contents_view->Layout();
   return IsStateShown(state);
 }
@@ -509,47 +508,51 @@ void AppListViewTestContext::RunPageSwitchingAnimationTest() {
     EXPECT_NO_FATAL_FAILURE(CheckView(main_view->contents_view()));
 
     ContentsView* contents_view = main_view->contents_view();
-    // Pad the ContentsView with blank pages so we have at least 3 views.
-    while (contents_view->NumLauncherPages() < 3)
-      contents_view->AddBlankPageForTesting();
 
-    contents_view->SetActivePage(0);
+    int start_page_index =
+        contents_view->GetPageIndexForState(AppListModel::STATE_START);
+    int search_results_page_index =
+        contents_view->GetPageIndexForState(AppListModel::STATE_SEARCH_RESULTS);
+    int apps_page_index =
+        contents_view->GetPageIndexForState(AppListModel::STATE_APPS);
+
+    contents_view->SetActiveState(AppListModel::STATE_START);
     contents_view->Layout();
 
-    EXPECT_EQ(contents_view->GetOnscreenPageBounds(0),
-              contents_view->GetPageView(0)->bounds());
-    EXPECT_NE(contents_view->GetOnscreenPageBounds(1),
-              contents_view->GetPageView(1)->bounds());
-    EXPECT_NE(contents_view->GetOnscreenPageBounds(2),
-              contents_view->GetPageView(2)->bounds());
+    EXPECT_EQ(contents_view->GetOnscreenPageBounds(start_page_index),
+              contents_view->GetPageView(start_page_index)->bounds());
+    EXPECT_NE(contents_view->GetOnscreenPageBounds(search_results_page_index),
+              contents_view->GetPageView(search_results_page_index)->bounds());
+    EXPECT_NE(contents_view->GetOnscreenPageBounds(apps_page_index),
+              contents_view->GetPageView(apps_page_index)->bounds());
 
     // Change pages. View should not have moved without Layout().
-    contents_view->SetActivePage(1);
-    EXPECT_EQ(contents_view->GetOnscreenPageBounds(0),
-              contents_view->GetPageView(0)->bounds());
-    EXPECT_NE(contents_view->GetOnscreenPageBounds(1),
-              contents_view->GetPageView(1)->bounds());
-    EXPECT_NE(contents_view->GetOnscreenPageBounds(2),
-              contents_view->GetPageView(2)->bounds());
+    contents_view->SetActiveState(AppListModel::STATE_SEARCH_RESULTS);
+    EXPECT_EQ(contents_view->GetOnscreenPageBounds(start_page_index),
+              contents_view->GetPageView(start_page_index)->bounds());
+    EXPECT_NE(contents_view->GetOnscreenPageBounds(search_results_page_index),
+              contents_view->GetPageView(search_results_page_index)->bounds());
+    EXPECT_NE(contents_view->GetOnscreenPageBounds(apps_page_index),
+              contents_view->GetPageView(apps_page_index)->bounds());
 
     // Change to a third page. This queues up the second animation behind the
     // first.
-    contents_view->SetActivePage(2);
-    EXPECT_EQ(contents_view->GetOnscreenPageBounds(0),
-              contents_view->GetPageView(0)->bounds());
-    EXPECT_NE(contents_view->GetOnscreenPageBounds(1),
-              contents_view->GetPageView(1)->bounds());
-    EXPECT_NE(contents_view->GetOnscreenPageBounds(2),
-              contents_view->GetPageView(2)->bounds());
+    contents_view->SetActiveState(AppListModel::STATE_APPS);
+    EXPECT_EQ(contents_view->GetOnscreenPageBounds(start_page_index),
+              contents_view->GetPageView(start_page_index)->bounds());
+    EXPECT_NE(contents_view->GetOnscreenPageBounds(search_results_page_index),
+              contents_view->GetPageView(search_results_page_index)->bounds());
+    EXPECT_NE(contents_view->GetOnscreenPageBounds(apps_page_index),
+              contents_view->GetPageView(apps_page_index)->bounds());
 
     // Call Layout(). Should jump to the third page.
     contents_view->Layout();
-    EXPECT_NE(contents_view->GetOnscreenPageBounds(0),
-              contents_view->GetPageView(0)->bounds());
-    EXPECT_NE(contents_view->GetOnscreenPageBounds(1),
-              contents_view->GetPageView(1)->bounds());
-    EXPECT_EQ(contents_view->GetOnscreenPageBounds(2),
-              contents_view->GetPageView(2)->bounds());
+    EXPECT_NE(contents_view->GetOnscreenPageBounds(start_page_index),
+              contents_view->GetPageView(start_page_index)->bounds());
+    EXPECT_NE(contents_view->GetOnscreenPageBounds(search_results_page_index),
+              contents_view->GetPageView(search_results_page_index)->bounds());
+    EXPECT_EQ(contents_view->GetOnscreenPageBounds(apps_page_index),
+              contents_view->GetPageView(apps_page_index)->bounds());
   }
 
   Close();
diff --git a/ui/app_list/views/contents_view.cc b/ui/app_list/views/contents_view.cc
index 3c27e17..623b391 100644
--- a/ui/app_list/views/contents_view.cc
+++ b/ui/app_list/views/contents_view.cc
@@ -131,15 +131,15 @@ void ContentsView::SetDragAndDropHostOfCurrentAppList(
   apps_container_view_->SetDragAndDropHostOfCurrentAppList(drag_and_drop_host);
 }
 
-void ContentsView::SetActivePage(int page_index) {
-  SetActivePage(page_index, true);
+void ContentsView::SetActiveState(AppListModel::State state) {
+  SetActiveState(state, true);
 }
 
-void ContentsView::SetActivePage(int page_index, bool animate) {
-  if (GetActivePageIndex() == page_index)
+void ContentsView::SetActiveState(AppListModel::State state, bool animate) {
+  if (IsStateActive(state))
     return;
 
-  SetActivePageInternal(page_index, false, animate);
+  SetActiveStateInternal(GetPageIndexForState(state), false, animate);
 }
 
 int ContentsView::GetActivePageIndex() const {
@@ -180,9 +180,9 @@ int ContentsView::NumLauncherPages() const {
   return pagination_model_.total_pages();
 }
 
-void ContentsView::SetActivePageInternal(int page_index,
-                                         bool show_search_results,
-                                         bool animate) {
+void ContentsView::SetActiveStateInternal(int page_index,
+                                          bool show_search_results,
+                                          bool animate) {
   if (!GetPageView(page_index)->visible())
     return;
 
@@ -237,7 +237,7 @@ void ContentsView::ShowSearchResults(bool show) {
   int search_page = GetPageIndexForState(AppListModel::STATE_SEARCH_RESULTS);
   DCHECK_GE(search_page, 0);
 
-  SetActivePageInternal(show ? search_page : page_before_search_, show, true);
+  SetActiveStateInternal(show ? search_page : page_before_search_, show, true);
 }
 
 bool ContentsView::IsShowingSearchResults() const {
@@ -335,11 +335,6 @@ SearchBoxView* ContentsView::GetSearchBoxView() const {
   return app_list_main_view_->search_box_view();
 }
 
-void ContentsView::AddBlankPageForTesting() {
-  AddLauncherPage(new views::View);
-  pagination_model_.SetTotalPages(view_model_->view_size());
-}
-
 int ContentsView::AddLauncherPage(views::View* view) {
   int page_index = view_model_->view_size();
   AddChildView(view);
@@ -432,13 +427,13 @@ bool ContentsView::Back() {
       if (app_list_main_view_->model()->PopCustomLauncherPageSubpage())
         app_list_main_view_->view_delegate()->CustomLauncherPagePopSubpage();
       else
-        SetActivePage(GetPageIndexForState(AppListModel::STATE_START));
+        SetActiveState(AppListModel::STATE_START);
       break;
     case AppListModel::STATE_APPS:
       if (apps_container_view_->IsInFolderView())
         apps_container_view_->app_list_folder_view()->CloseFolderPage();
       else
-        SetActivePage(GetPageIndexForState(AppListModel::STATE_START));
+        SetActiveState(AppListModel::STATE_START);
       break;
     case AppListModel::STATE_SEARCH_RESULTS:
       GetSearchBoxView()->ClearSearch();
diff --git a/ui/app_list/views/contents_view.h b/ui/app_list/views/contents_view.h
index 89d8d69..e568b35 100644
--- a/ui/app_list/views/contents_view.h
+++ b/ui/app_list/views/contents_view.h
@@ -70,8 +70,8 @@ class APP_LIST_EXPORT ContentsView : public views::View,
   void ShowFolderContent(AppListFolderItem* folder);
 
   // Sets the active launcher page and animates the pages into place.
-  void SetActivePage(int page_index);
-  void SetActivePage(int page_index, bool animate);
+  void SetActiveState(AppListModel::State state);
+  void SetActiveState(AppListModel::State state, bool animate);
 
   // The index of the currently active launcher page.
   int GetActivePageIndex() const;
@@ -108,9 +108,6 @@ class APP_LIST_EXPORT ContentsView : public views::View,
 
   AppListMainView* app_list_main_view() const { return app_list_main_view_; }
 
-  // Adds a blank launcher page. For use in tests only.
-  void AddBlankPageForTesting();
-
   // Returns the pagination model for the ContentsView.
   const PaginationModel& pagination_model() { return pagination_model_; }
 
@@ -166,9 +163,9 @@ class APP_LIST_EXPORT ContentsView : public views::View,
  private:
   // Sets the active launcher page, accounting for whether the change is for
   // search results.
-  void SetActivePageInternal(int page_index,
-                             bool show_search_results,
-                             bool animate);
+  void SetActiveStateInternal(int page_index,
+                              bool show_search_results,
+                              bool animate);
 
   // Invoked when active view is changed.
   void ActivePageChanged();
diff --git a/ui/app_list/views/start_page_view.cc b/ui/app_list/views/start_page_view.cc
index 401aae1..1c62aca 100644
--- a/ui/app_list/views/start_page_view.cc
+++ b/ui/app_list/views/start_page_view.cc
@@ -279,9 +279,7 @@ void StartPageView::MaybeOpenCustomLauncherPage() {
                             AppListModel::STATE_CUSTOM_LAUNCHER_PAGE,
                             AppListModel::STATE_LAST);
 
-  int custom_page_index = contents_view->GetPageIndexForState(
-      AppListModel::STATE_CUSTOM_LAUNCHER_PAGE);
-  contents_view->SetActivePage(custom_page_index);
+  contents_view->SetActiveState(AppListModel::STATE_CUSTOM_LAUNCHER_PAGE);
 }
 
 void StartPageView::Reset() {