Add signal strength indicator icon to WebBluetooth chooser on non-Mac desktops

chrome/browser/ui/views/chooser_content_view.cc

Index: chrome/browser/ui/views/chooser_content_view.cc
diff --git a/chrome/browser/ui/views/chooser_content_view.cc b/chrome/browser/ui/views/chooser_content_view.cc
index 6ae3d32f4a50e61d2ff570234140d02958829013..91d56ba1bbe2c53268a561aa5300aac1205347de 100644
--- a/chrome/browser/ui/views/chooser_content_view.cc
+++ b/chrome/browser/ui/views/chooser_content_view.cc
@@ -4,8 +4,12 @@
 
 #include "chrome/browser/ui/views/chooser_content_view.h"
 
+#include "base/numerics/safe_conversions.h"
 #include "chrome/grit/generated_resources.h"
+#include "grit/ui_resources.h"
 #include "ui/base/l10n/l10n_util.h"
+#include "ui/base/resource/resource_bundle.h"
+#include "ui/gfx/image/image_skia.h"
 #include "ui/views/controls/link.h"
 #include "ui/views/controls/styled_label.h"
 #include "ui/views/controls/table/table_view.h"
@@ -20,6 +24,11 @@ const int kChooserHeight = 220;
 
 const int kThrobberDiameter = 24;
 
+// The lookup table for strength bar image.
+const int strength_bar_ids[5] = {IDR_SIGNAL_0_BAR, IDR_SIGNAL_1_BAR,
+                                 IDR_SIGNAL_2_BAR, IDR_SIGNAL_3_BAR,
+                                 IDR_SIGNAL_4_BAR};
+
 }  // namespace
 
 ChooserContentView::ChooserContentView(
@@ -29,8 +38,11 @@ ChooserContentView::ChooserContentView(
   chooser_controller_->set_view(this);
   std::vector<ui::TableColumn> table_columns;
   table_columns.push_back(ui::TableColumn());
-  table_view_ =
-      new views::TableView(this, table_columns, views::TEXT_ONLY, true);
+  table_view_ = new views::TableView(
+      this, table_columns,
+      chooser_controller_->ShouldShowIconBeforeText() ? views::ICON_AND_TEXT
+                                                      : views::TEXT_ONLY,
+      true /* single_selection */);
   table_view_->set_select_on_remove(false);
   table_view_->SetObserver(table_view_observer);
   table_view_->SetEnabled(chooser_controller_->NumOptions() > 0);
@@ -63,11 +75,12 @@ gfx::Size ChooserContentView::GetPreferredSize() const {
 int ChooserContentView::RowCount() {
   // When there are no devices, the table contains a message saying there
   // are no devices, so the number of rows is always at least 1.
-  return std::max(static_cast<int>(chooser_controller_->NumOptions()), 1);
+  return std::max(base::checked_cast<int>(chooser_controller_->NumOptions()),
+                  1);
 }
 
 base::string16 ChooserContentView::GetText(int row, int column_id) {
-  int num_options = static_cast<int>(chooser_controller_->NumOptions());
+  int num_options = base::checked_cast<int>(chooser_controller_->NumOptions());
   if (num_options == 0) {
     DCHECK_EQ(0, row);
     return chooser_controller_->GetNoOptionsText();
@@ -80,13 +93,35 @@ base::string16 ChooserContentView::GetText(int row, int column_id) {
 
 void ChooserContentView::SetObserver(ui::TableModelObserver* observer) {}
 
+gfx::ImageSkia ChooserContentView::GetIcon(int row) {
+  DCHECK(chooser_controller_->ShouldShowIconBeforeText());
+
+  int num_options = base::checked_cast<int>(chooser_controller_->NumOptions());

[msw, 2016/08/16 16:51:18]

nit: Avoid casting to compare with 0. Instead, you could inline |if
(chooser_controller_->NumOptions() == 0) {| below or make |num_options| a
size_t, then cast (if needed) in the DCHECK, which will be debug-only.

[juncai, 2016/08/16 17:49:52]

Done.

+  if (num_options == 0) {
+    DCHECK_EQ(0, row);
+    return gfx::ImageSkia();
+  }
+
+  DCHECK_GE(row, 0);
+  DCHECK_LT(row, num_options);
+
+  int level =
+      chooser_controller_->GetSignalStrengthLevel(static_cast<size_t>(row));
+
+  if (level == -1)
+    return gfx::ImageSkia();
+
+  return *ResourceBundle::GetSharedInstance().GetImageSkiaNamed(
+      strength_bar_ids[level]);

[msw, 2016/08/16 16:51:18]

nit: CHECK that the level is in the range of the array.

[juncai, 2016/08/16 17:49:52]

Done.

+}
+
 void ChooserContentView::OnOptionsInitialized() {
   table_view_->OnModelChanged();
   UpdateTableView();
 }
 
 void ChooserContentView::OnOptionAdded(size_t index) {
-  table_view_->OnItemsAdded(static_cast<int>(index), 1);
+  table_view_->OnItemsAdded(base::checked_cast<int>(index), 1);
   UpdateTableView();
   table_view_->SetVisible(true);
   throbber_->SetVisible(false);
@@ -94,7 +129,7 @@ void ChooserContentView::OnOptionAdded(size_t index) {
 }
 
 void ChooserContentView::OnOptionRemoved(size_t index) {
-  table_view_->OnItemsRemoved(static_cast<int>(index), 1);
+  table_view_->OnItemsRemoved(base::checked_cast<int>(index), 1);
   UpdateTableView();
 }