Refactor app list so AppsGridView owns the PaginationModel.

ui/app_list/views/app_list_main_view.cc

 // Copyright 2013 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 "ui/app_list/views/app_list_main_view.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/callback.h"
@@ skipping 66 matching lines @@
   AppListMainView* owner_;
   AppListItem* item_;
 
   DISALLOW_COPY_AND_ASSIGN(IconLoader);
 };
 
 ////////////////////////////////////////////////////////////////////////////////
 // AppListMainView:
 
 AppListMainView::AppListMainView(AppListViewDelegate* delegate,
-                                 PaginationModel* pagination_model,
+                                 int initial_apps_page,
                                  gfx::NativeView parent)
     : delegate_(delegate),
-      pagination_model_(pagination_model),
       model_(delegate->GetModel()),
       search_box_view_(NULL),
       contents_view_(NULL),
       weak_ptr_factory_(this) {
   SetLayoutManager(new views::BoxLayout(views::BoxLayout::kVertical,
                                         kInnerPadding,
                                         kInnerPadding,
                                         kInnerPadding));
 
   search_box_view_ = new SearchBoxView(this, delegate);
   AddChildView(search_box_view_);
   AddContentsView();
   if (app_list::switches::IsExperimentalAppListEnabled())
     AddChildView(new ContentsSwitcherView(contents_view_));
 
+  // Switch the apps grid view to the specified page.
+  app_list::PaginationModel* pagination_model = GetAppsPaginationModel();
+  if (pagination_model->is_valid_page(initial_apps_page))
+    pagination_model->SelectPage(initial_apps_page, false);
+
   // Starts icon loading early.
   PreloadIcons(parent);
 }
 
 void AppListMainView::AddContentsView() {
-  contents_view_ = new ContentsView(
-      this, pagination_model_, model_, delegate_);
+  contents_view_ = new ContentsView(this, model_, delegate_);
   AddChildViewAt(contents_view_, kContentsViewIndex);
 
   search_box_view_->set_contents_view(contents_view_);
 
 #if defined(USE_AURA)
   contents_view_->SetPaintToLayer(true);
   contents_view_->SetFillsBoundsOpaquely(false);
   contents_view_->layer()->SetMasksToBounds(true);
 #endif
 }
@@ skipping 33 matching lines @@
 void AppListMainView::Prerender() {
   contents_view_->Prerender();
 }
 
 void AppListMainView::ModelChanged() {
   pending_icon_loaders_.clear();
   model_ = delegate_->GetModel();
   search_box_view_->ModelChanged();
   delete contents_view_;
   contents_view_ = NULL;
-  pagination_model_->SelectPage(0, false /* animate */);
   AddContentsView();
   Layout();
 }
 
 void AppListMainView::OnContentsViewShowStateChanged() {
   search_box_view_->SetVisible(contents_view_->show_state() !=
                                ContentsView::SHOW_START_PAGE);
 }
 
 void AppListMainView::OnStartPageSearchButtonPressed() {
   search_box_view_->SetVisible(true);
   search_box_view_->search_box()->SetText(base::string16());
   search_box_view_->RequestFocus();
 }
 
 void AppListMainView::SetDragAndDropHostOfCurrentAppList(
     ApplicationDragAndDropHost* drag_and_drop_host) {
   contents_view_->SetDragAndDropHostOfCurrentAppList(drag_and_drop_host);
 }
 
 bool AppListMainView::ShouldCenterWindow() const {
   return delegate_->ShouldCenterWindow();
 }
 
+PaginationModel* AppListMainView::GetAppsPaginationModel() {
+  return contents_view_->apps_container_view()
+      ->apps_grid_view()
+      ->pagination_model();
+}
+
 void AppListMainView::PreloadIcons(gfx::NativeView parent) {
   float scale_factor = 1.0f;
   if (parent)
     scale_factor = ui::GetScaleFactorForNativeView(parent);
 
-  // |pagination_model| could have -1 as the initial selected page and
+  // The PaginationModel could have -1 as the initial selected page and
   // assumes first page (i.e. index 0) will be used in this case.
-  const int selected_page = std::max(0, pagination_model_->selected_page());
+  const int selected_page =
+      std::max(0, GetAppsPaginationModel()->selected_page());
 
   const AppsGridView* const apps_grid_view =
       contents_view_->apps_container_view()->apps_grid_view();
   const int tiles_per_page =
       apps_grid_view->cols() * apps_grid_view->rows_per_page();
 
   const int start_model_index = selected_page * tiles_per_page;
   const int end_model_index =
       std::min(static_cast<int>(model_->top_level_item_list()->item_count()),
                start_model_index + tiles_per_page);
@@ skipping 67 matching lines @@
   // Resubmit the query via a posted task so that all observers for the
   // uninstall notification are notified.
   base::MessageLoop::current()->PostTask(
       FROM_HERE,
       base::Bind(&AppListMainView::QueryChanged,
                  weak_ptr_factory_.GetWeakPtr(),
                  search_box_view_));
 }
 
 }  // namespace app_list