Experiment to hide close buttons of inactive tabs when using touch

chrome/browser/ui/views/tabs/tab_strip.cc

 // Copyright (c) 2012 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 "chrome/browser/ui/views/tabs/tab_strip.h"
 
 #if defined(OS_WIN)
 #include <windowsx.h>
 #endif
 
 #include <algorithm>
 #include <iterator>
 #include <string>
 #include <vector>
 
+#include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/metrics/histogram.h"
 #include "base/stl_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/defaults.h"
 #include "chrome/browser/ui/host_desktop.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/view_ids.h"
 #include "chrome/browser/ui/views/tabs/stacked_tab_strip_layout.h"
 #include "chrome/browser/ui/views/tabs/tab.h"
 #include "chrome/browser/ui/views/tabs/tab_drag_controller.h"
 #include "chrome/browser/ui/views/tabs/tab_strip_controller.h"
 #include "chrome/browser/ui/views/tabs/tab_strip_observer.h"
 #include "chrome/browser/ui/views/touch_uma/touch_uma.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/grit/generated_resources.h"
 #include "content/public/browser/user_metrics.h"
 #include "grit/theme_resources.h"
 #include "ui/accessibility/ax_view_state.h"
 #include "ui/base/default_theme_provider.h"
 #include "ui/base/dragdrop/drag_drop_types.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/models/list_selection_model.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/animation/animation_container.h"
@@ skipping 920 matching lines @@
 
 const ui::ListSelectionModel& TabStrip::GetSelectionModel() {
   return controller_->GetSelectionModel();
 }
 
 bool TabStrip::SupportsMultipleSelection() {
   // TODO: currently only allow single selection in touch layout mode.
   return touch_layout_ == NULL;
 }
 
+// TODO(tdanderson): Modify this logic and clean up related code once a
+//                   decision has been made on the experimental
+//                   flag --tab-close-buttons-hidden-with-touch.
+bool TabStrip::ShouldHideCloseButtonForInactiveTab(const Tab* tab) {
+  DCHECK(!tab->IsActive());
+
+  // Do not force the close button to hide if mouse was used as
+  // the last input type to interact with the tab strip.
+  if (!stacked_layout_)
+    return false;
+
+  std::string switch_value =
+      base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+          switches::kTabCloseButtonsHiddenWithTouch);
+  int width = tab->width();
+  if (switch_value == "always" ||
+      (switch_value == "narrow" && width < Tab::GetStandardSize().width()) ||
+      (switch_value == "stacked" && width <= Tab::GetTouchWidth())) {
+    return true;
+  }
+
+  return false;
+}
+
 void TabStrip::SelectTab(Tab* tab) {
   int model_index = GetModelIndexOfTab(tab);
   if (IsValidModelIndex(model_index))
     controller_->SelectTab(model_index);
 }
 
 void TabStrip::ExtendSelectionTo(Tab* tab) {
   int model_index = GetModelIndexOfTab(tab);
   if (IsValidModelIndex(model_index))
     controller_->ExtendSelectionTo(model_index);
@@ skipping 1760 matching lines @@
           ConvertPointToViewAndGetEventHandler(this, newtab_button_, point);
       if (view)
         return view;
     }
     Tab* tab = FindTabForEvent(point);
     if (tab)
       return ConvertPointToViewAndGetEventHandler(this, tab, point);
   }
   return this;
 }