ash:Shelf - Added UMA stats for ShelfAlignment

ash/shelf/shelf_view.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 "ash/shelf/shelf_view.h"
 
 #include <algorithm>
 
 #include "ash/ash_constants.h"
 #include "ash/ash_switches.h"
 #include "ash/drag_drop/drag_image_view.h"
 #include "ash/launcher/launcher_button.h"
 #include "ash/launcher/launcher_delegate.h"
 #include "ash/launcher/launcher_icon_observer.h"
 #include "ash/launcher/launcher_item_delegate.h"
 #include "ash/launcher/launcher_item_delegate_manager.h"
 #include "ash/launcher/launcher_model.h"
 #include "ash/root_window_controller.h"
 #include "ash/scoped_target_root_window.h"
 #include "ash/shelf/alternate_app_list_button.h"
 #include "ash/shelf/app_list_button.h"
 #include "ash/shelf/overflow_bubble.h"
 #include "ash/shelf/overflow_button.h"
 #include "ash/shelf/shelf_layout_manager.h"
 #include "ash/shelf/shelf_tooltip_manager.h"
 #include "ash/shelf/shelf_widget.h"
 #include "ash/shell_delegate.h"
 #include "base/auto_reset.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/metrics/histogram.h"
 #include "grit/ash_resources.h"
 #include "grit/ash_strings.h"
 #include "ui/aura/client/screen_position_client.h"
 #include "ui/aura/root_window.h"
 #include "ui/aura/window.h"
 #include "ui/base/accessibility/accessible_view_state.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/models/simple_menu_model.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/compositor/layer.h"
@@ skipping 11 matching lines @@
 #include "ui/views/view_model.h"
 #include "ui/views/view_model_utils.h"
 #include "ui/views/widget/widget.h"
 
 using gfx::Animation;
 using views::View;
 
 namespace ash {
 namespace internal {
 
+const int SHELF_ALIGNMENT_UMA_ENUM_VALUE_BOTTOM = 0;
+const int SHELF_ALIGNMENT_UMA_ENUM_VALUE_LEFT = 1;
+const int SHELF_ALIGNMENT_UMA_ENUM_VALUE_RIGHT = 2;
+const int SHELF_ALIGNMENT_UMA_ENUM_VALUE_COUNT = 3;
+
 // Default amount content is inset on the left edge.
 const int kDefaultLeadingInset = 8;
 
 // Minimum distance before drag starts.
 const int kMinimumDragDistance = 8;
 
 // Size between the buttons.
 const int kButtonSpacing = 4;
 const int kAlternateButtonSpacing = 10;
 
@@ skipping 1448 matching lines @@
     return;
 
   int index = view_model_->GetIndexOfView(view);
   if (index == -1)
     return;
 
   LauncherItemDelegate* item_delegate = item_manager_->GetLauncherItemDelegate(
       model_->items()[index].id);
   if (view_model_->view_size() <= 1 || !item_delegate->IsDraggable())
     return;  // View is being deleted or not draggable, ignore request.
-
   drag_view_ = view;
   drag_offset_ = layout_manager_->PrimaryAxisValue(event.x(), event.y());
+  RecordCurrentAlignmentForUMAHistogram("Ash.ShelfAlignmentUsage");
 }
 
 void ShelfView::PointerDraggedOnButton(views::View* view,
                                        Pointer pointer,
                                        const ui::LocatedEvent& event) {
   if (!dragging() && drag_view_ &&
       layout_manager_->PrimaryAxisValue(abs(event.x() - drag_offset_),
                                         abs(event.y() - drag_offset_)) >=
       kMinimumDragDistance) {
     PrepareForDrag(pointer, event);
@@ skipping 335 matching lines @@
     case ash::SHELF_ALIGNMENT_RIGHT:
       distance = bounds.x() - coordinate.x();
       break;
     case ash::SHELF_ALIGNMENT_TOP:
       distance = coordinate.y() - bounds.bottom();
       break;
   }
   return distance > 0 ? distance : 0;
 }
 
+void ShelfView::RecordCurrentAlignmentForUMAHistogram(
+    const char* histogram_name) {
+  UMA_HISTOGRAM_ENUMERATION(histogram_name,

[James Cook, 2013/10/30 16:49:12]

This won't work. UMA_HISTOGRAM_ENUMERATION does some magic with the current
file/line name to create a cached value - it needs a literal string at the call
site.  This is why ChromeShellDelegate::RecordUserMetricsAction() has a huge
switch.  It might be better to pull out the shelf alignment into the sites that
are recording it and put the strings there.

If you really need to build histograms out of a string see
RecordLinearHistogram() in oom_priority_manager.cc for an example.

+      layout_manager_->SelectValueForShelfAlignment(
+          SHELF_ALIGNMENT_UMA_ENUM_VALUE_BOTTOM,
+          SHELF_ALIGNMENT_UMA_ENUM_VALUE_LEFT,
+          SHELF_ALIGNMENT_UMA_ENUM_VALUE_RIGHT,
+          -1),
+      SHELF_ALIGNMENT_UMA_ENUM_VALUE_COUNT);
+}
+
 }  // namespace internal
 }  // namespace ash