App Launcher: Preload the correct number of icons (don't assume 4x4).

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"
 #include "base/files/file_path.h"
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string_util.h"
 #include "ui/app_list/app_list_constants.h"
 #include "ui/app_list/app_list_folder_item.h"
 #include "ui/app_list/app_list_item.h"
 #include "ui/app_list/app_list_model.h"
 #include "ui/app_list/app_list_switches.h"
 #include "ui/app_list/app_list_view_delegate.h"
 #include "ui/app_list/pagination_model.h"
 #include "ui/app_list/search_box_model.h"
 #include "ui/app_list/views/app_list_item_view.h"
 #include "ui/app_list/views/apps_container_view.h"
+#include "ui/app_list/views/apps_grid_view.h"
 #include "ui/app_list/views/contents_switcher_view.h"
 #include "ui/app_list/views/contents_view.h"
 #include "ui/app_list/views/search_box_view.h"
 #include "ui/views/controls/textfield/textfield.h"
 #include "ui/views/layout/box_layout.h"
 #include "ui/views/widget/widget.h"
 
 namespace app_list {
 
 namespace {
@@ skipping 50 matching lines @@
 
 AppListMainView::AppListMainView(AppListViewDelegate* delegate,
                                  PaginationModel* pagination_model,
                                  gfx::NativeView parent)
     : delegate_(delegate),
       pagination_model_(pagination_model),
       model_(delegate->GetModel()),
       search_box_view_(NULL),
       contents_view_(NULL),
       weak_ptr_factory_(this) {
-  // Starts icon loading early.
-  PreloadIcons(parent);
-
   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_));
+
+  // Starts icon loading early.
+  PreloadIcons(parent);
 }
 
 void AppListMainView::AddContentsView() {
   contents_view_ = new ContentsView(
       this, pagination_model_, model_, delegate_);
   AddChildViewAt(contents_view_, kContentsViewIndex);
 
   search_box_view_->set_contents_view(contents_view_);
 
 #if defined(USE_AURA)
@@ skipping 72 matching lines @@
 
 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
   // 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 tiles_per_page = kPreferredCols * kPreferredRows;
+  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);
 
   pending_icon_loaders_.clear();
   for (int i = start_model_index; i < end_model_index; ++i) {
     AppListItem* item = model_->top_level_item_list()->item_at(i);
     if (item->icon().HasRepresentation(scale_factor))
       continue;
@@ skipping 61 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