[Chrome OS] Change layout of the launcher.

ui/app_list/views/start_page_view.cc

Index: ui/app_list/views/start_page_view.cc
diff --git a/ui/app_list/views/start_page_view.cc b/ui/app_list/views/start_page_view.cc
index cb2ca80a7818a516caed007b39c02a3a457b513c..5112e3ee3a5fa783f182add3fd4b0e254a034f29 100644
--- a/ui/app_list/views/start_page_view.cc
+++ b/ui/app_list/views/start_page_view.cc
@@ -4,6 +4,7 @@
 
 #include "ui/app_list/views/start_page_view.h"
 
+#include <algorithm>
 #include <string>
 
 #include "base/i18n/rtl.h"
@@ -30,6 +31,7 @@
 #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 {
@@ -46,8 +48,10 @@ 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;
 
@@ -131,7 +135,10 @@ class StartPageView::StartPageTilesContainer
   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_;
@@ -143,30 +150,12 @@ 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() {
@@ -194,10 +183,19 @@ int StartPageView::StartPageTilesContainer::Update() {
   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);
@@ -236,6 +234,42 @@ int StartPageView::StartPageTilesContainer::GetYSize() {
   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,