[Chrome OS] Change layout of the launcher.

ui/app_list/views/start_page_view.cc

 // Copyright 2014 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/start_page_view.h"
 
+#include <algorithm>
 #include <string>
 
 #include "base/i18n/rtl.h"
 #include "base/macros.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/utf_string_conversions.h"
 #include "ui/accessibility/ax_view_state.h"
 #include "ui/app_list/app_list_constants.h"
 #include "ui/app_list/app_list_item.h"
 #include "ui/app_list/app_list_model.h"
 #include "ui/app_list/app_list_view_delegate.h"
 #include "ui/app_list/search_result.h"
 #include "ui/app_list/views/all_apps_tile_item_view.h"
 #include "ui/app_list/views/app_list_main_view.h"
 #include "ui/app_list/views/contents_view.h"
 #include "ui/app_list/views/custom_launcher_page_view.h"
 #include "ui/app_list/views/search_box_view.h"
 #include "ui/app_list/views/search_result_container_view.h"
 #include "ui/app_list/views/search_result_tile_item_view.h"
 #include "ui/app_list/views/tile_item_view.h"
 #include "ui/gfx/canvas.h"
 #include "ui/views/background.h"
 #include "ui/views/controls/image_view.h"
 #include "ui/views/controls/label.h"
 #include "ui/views/controls/textfield/textfield.h"
 #include "ui/views/layout/box_layout.h"
+#include "ui/views/layout/grid_layout.h"
 #include "ui/views/widget/widget.h"
 
 namespace app_list {
 
 namespace {
 
 // Layout constants.
 const int kInstantContainerSpacing = 24;
 const int kSearchBoxAndTilesSpacing = 35;
 const int kStartPageSearchBoxWidth = 480;
 
 // WebView constants.
 const int kWebViewWidth = 700;
 const int kWebViewHeight = 244;
 
 // Tile container constants.
-const size_t kNumStartPageTiles = 4;
+const int kNumStartPageTiles = 9;

[xiyuan, 2016/08/08 18:02:15]

nit: do we have to replace size_t with int?

[xdai1, 2016/08/08 21:25:38]

Reverted it back. Not necessarily... I just thought it might be good to be
consistent with other variables.

 const int kTileSpacing = 7;
+const int kNumStartPageTilesCols = 5;
+const int kTilesHorizontalMarginLeft = 145;
 
 const int kLauncherPageBackgroundWidth = 400;
 
 // An invisible placeholder view which fills the space for the search box view
 // in a box layout. The search box view itself is a child of the AppListView
 // (because it is visible on many different pages).
 class SearchBoxSpacerView : public views::View {
  public:
   explicit SearchBoxSpacerView(const gfx::Size& search_box_size)
       : size_(kStartPageSearchBoxWidth, search_box_size.height()) {}
@@ skipping 63 matching lines @@
 
   // Overridden from SearchResultContainerView:
   int Update() override;
   void UpdateSelectedIndex(int old_selected, int new_selected) override;
   void OnContainerSelected(bool from_bottom,
                            bool directional_movement) override;
   void NotifyFirstResultYIndex(int y_index) override;
   int GetYSize() override;
 
  private:
+  void CreateAppsGrid(int apps_num);
+
   ContentsView* contents_view_;
+  AppListViewDelegate* view_delegate_;
 
   std::vector<SearchResultTileItemView*> search_result_tile_views_;
   AllAppsTileItemView* all_apps_button_;
 
   DISALLOW_COPY_AND_ASSIGN(StartPageTilesContainer);
 };
 
 StartPageView::StartPageTilesContainer::StartPageTilesContainer(
     ContentsView* contents_view,
     AllAppsTileItemView* all_apps_button,
     AppListViewDelegate* view_delegate)
-    : contents_view_(contents_view), all_apps_button_(all_apps_button) {
-  views::BoxLayout* tiles_layout_manager =
-      new views::BoxLayout(views::BoxLayout::kHorizontal, 0, 0, kTileSpacing);
-  tiles_layout_manager->set_main_axis_alignment(
-      views::BoxLayout::MAIN_AXIS_ALIGNMENT_CENTER);
-  SetLayoutManager(tiles_layout_manager);
+    : contents_view_(contents_view),
+      view_delegate_(view_delegate),
+      all_apps_button_(all_apps_button) {
   set_background(
       views::Background::CreateSolidBackground(kLabelBackgroundColor));
-
-  // Add SearchResultTileItemViews to the container.
-  for (size_t i = 0; i < kNumStartPageTiles; ++i) {
-    SearchResultTileItemView* tile_item =
-        new SearchResultTileItemView(this, view_delegate);
-    AddChildView(tile_item);
-    tile_item->SetParentBackgroundColor(kLabelBackgroundColor);
-    tile_item->SetHoverStyle(TileItemView::HOVER_STYLE_ANIMATE_SHADOW);
-    search_result_tile_views_.push_back(tile_item);
-  }
-
-  // Also add a special "all apps" button to the end of the container.
-  all_apps_button_->SetHoverStyle(TileItemView::HOVER_STYLE_ANIMATE_SHADOW);
-  all_apps_button_->UpdateIcon();
-  all_apps_button_->SetParentBackgroundColor(kLabelBackgroundColor);
-  AddChildView(all_apps_button_);
+  CreateAppsGrid(kNumStartPageTiles);
 }
 
 StartPageView::StartPageTilesContainer::~StartPageTilesContainer() {
 }
 
 TileItemView* StartPageView::StartPageTilesContainer::GetTileItemView(
     int index) {
   DCHECK_GT(num_results(), index);
   if (index == num_results() - 1)
     return all_apps_button_;
 
   return search_result_tile_views_[index];
 }
 
 int StartPageView::StartPageTilesContainer::Update() {
   // Ignore updates and disable buttons when transitioning to a different
   // state.
   if (contents_view_->GetActiveState() != AppListModel::STATE_START) {
     for (auto* view : search_result_tile_views_)
       view->SetEnabled(false);
 
     return num_results();
   }
 
   std::vector<SearchResult*> display_results =
       AppListModel::FilterSearchResultsByDisplayType(
           results(), SearchResult::DISPLAY_RECOMMENDATION, kNumStartPageTiles);
+  if (display_results.size() < kNumStartPageTiles &&
+      display_results.size() > 0) {

[xiyuan, 2016/08/08 18:02:15]

Think we need to update the gird when display_results.size() !=
search_result_tile_views_.size().

And handle the size constraint in the branch, i.e. in line 193
  CreateAppsGrid(std::min(kNumStartPageTiles, display_results.size()));

[xdai1, 2016/08/08 21:25:38]

Done.

+    // We should recreate the grid layout in this case.
+    for (size_t i = 0; i < search_result_tile_views_.size(); i++)
+      RemoveChildView(search_result_tile_views_[i]);
+    search_result_tile_views_.clear();

[xiyuan, 2016/08/08 18:02:15]

Would this leak? That is, RemoveChildView() does not delete the child view and
just removes it from view hierarchy. And when the reference in vector is removed
here. Who is going to release the actual view? We probably should do a "delete
search_result_tile_views_[i]" in the loop.

[xdai1, 2016/08/08 21:25:38]

You're right. I think we should manually delete the child views.

+    RemoveChildView(all_apps_button_);
+    CreateAppsGrid(display_results.size());
+  }
 
   // Update the tile item results.
   for (size_t i = 0; i < search_result_tile_views_.size(); ++i) {
-    SearchResult* item = NULL;
+    SearchResult* item = nullptr;
     if (i < display_results.size())
       item = display_results[i];
     search_result_tile_views_[i]->SetSearchResult(item);
     search_result_tile_views_[i]->SetEnabled(true);
   }
 
   Layout();
   parent()->Layout();
   // Add 1 to the results size to account for the all apps button.
   return display_results.size() + 1;
@@ skipping 18 matching lines @@
 void StartPageView::StartPageTilesContainer::NotifyFirstResultYIndex(
     int /*y_index*/) {
   NOTREACHED();
 }
 
 int StartPageView::StartPageTilesContainer::GetYSize() {
   NOTREACHED();
   return 0;
 }
 
+void StartPageView::StartPageTilesContainer::CreateAppsGrid(int apps_num) {
+  views::GridLayout* tiles_layout_manager = new views::GridLayout(this);

[xiyuan, 2016/08/08 18:02:15]

nit: DCHECK(search_result_tile_views_.empty()) to ensure it is empty when
calling into this function.

[xdai1, 2016/08/08 21:25:38]

Done.

+  SetLayoutManager(tiles_layout_manager);
+
+  views::ColumnSet* column_set = tiles_layout_manager->AddColumnSet(0);
+  column_set->AddPaddingColumn(0, kTilesHorizontalMarginLeft);
+  for (int col = 0; col < kNumStartPageTilesCols; col++) {
+    column_set->AddColumn(views::GridLayout::FILL, views::GridLayout::FILL, 0,
+                          views::GridLayout::USE_PREF, 0, 0);
+    column_set->AddPaddingColumn(0, kTileSpacing);
+  }
+
+  // Add SearchResultTileItemViews to the container.
+  int i = 0;
+  for (; i < apps_num; i++) {
+    SearchResultTileItemView* tile_item =
+        new SearchResultTileItemView(this, view_delegate_);
+    if (i % kNumStartPageTilesCols == 0)
+      tiles_layout_manager->StartRow(0, 0);
+    tiles_layout_manager->AddView(tile_item);
+    AddChildView(tile_item);
+    tile_item->SetParentBackgroundColor(kLabelBackgroundColor);
+    tile_item->SetHoverStyle(TileItemView::HOVER_STYLE_ANIMATE_SHADOW);
+    search_result_tile_views_.push_back(tile_item);
+  }
+
+  // Also add a special "all apps" button to the end of the container.
+  all_apps_button_->SetHoverStyle(TileItemView::HOVER_STYLE_ANIMATE_SHADOW);
+  all_apps_button_->UpdateIcon();
+  all_apps_button_->SetParentBackgroundColor(kLabelBackgroundColor);

[xiyuan, 2016/08/08 18:02:15]

nit: hover style in line 264 and this background color can stay in ctor since we
don't need to set them every time when creating the grid.

[xdai1, 2016/08/08 21:25:38]

Done.

+  if (i % kNumStartPageTilesCols == 0)
+    tiles_layout_manager->StartRow(0, 0);
+  tiles_layout_manager->AddView(all_apps_button_);
+  AddChildView(all_apps_button_);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // StartPageView implementation:
 StartPageView::StartPageView(AppListMainView* app_list_main_view,
                              AppListViewDelegate* view_delegate)
     : app_list_main_view_(app_list_main_view),
       view_delegate_(view_delegate),
       search_box_spacer_view_(new SearchBoxSpacerView(
           app_list_main_view->search_box_view()->GetPreferredSize())),
       instant_container_(new views::View),
       custom_launcher_page_background_(new CustomLauncherPageBackgroundView(
@@ skipping 247 matching lines @@
   // is enabled).
   if (event->type() == ui::ET_SCROLL && event->y_offset() < 0)
     MaybeOpenCustomLauncherPage();
 }
 
 TileItemView* StartPageView::GetTileItemView(size_t index) {
   return tiles_container_->GetTileItemView(index);
 }
 
 }  // namespace app_list