UMA stats for stylus usage

chrome/browser/ui/ash/metrics/stylus_metrics_recorder_chromeos.cc

+// Copyright 2016 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/ash/metrics/stylus_metrics_recorder_chromeos.h"
+
+#include "ash/common/shell_window_ids.h"
+#include "ash/common/wm/container_finder.h"
+#include "ash/common/wm/maximize_mode/maximize_mode_controller.h"
+#include "ash/common/wm_lookup.h"
+#include "ash/common/wm_shell.h"
+#include "ash/common/wm_window.h"
+#include "base/metrics/histogram_macros.h"
+#include "chrome/browser/apps/app_window_registry_util.h"
+#include "chrome/browser/chromeos/note_taking_app_utils.h"
+#include "components/exo/shell_surface.h"
+#include "extensions/browser/app_window/app_window.h"
+#include "ui/aura/window_property.h"
+#include "ui/events/event_constants.h"
+#include "ui/views/widget/widget.h"
+
+DECLARE_WINDOW_PROPERTY_TYPE(chromeos::StylusWindowType);
+
+namespace chromeos {
+
+DEFINE_WINDOW_PROPERTY_KEY(StylusWindowType,
+                           kStylusWindowTypeBucket,
+                           StylusWindowType::WINDOW_TYPE_OTHERS);
+
+namespace {
+
+// Form factor of the down event. This enum is used to back an UMA histogram
+// and should be treated as append-only.
+enum DownEventFormFactor {

[sky, 2016/09/16 23:20:16]

enum class, and avoid duplicating the name, e.g.
DownEventFormFactor::CLAM_SHELL.

[xiaoyinh(OOO Sep 11-29), 2016/09/19 21:19:52]

Done.

+  DOWN_EVENT_FORMFACTOR_CLAMSHELL = 0,
+  DOWN_EVENT_FORMFACTOR_TOUCHVIEW,
+  DOWN_EVENT_FORMFACTOR_COUNT
+};
+
+// Input type of the down event. This enum is used to back an UMA
+// histogram and should be treated as append-only.
+enum DownEventSource {
+  DOWN_EVENT_SOURCE_UNKNOWN = 0,
+  DOWN_EVENT_SOURCE_MOUSE,
+  DOWN_EVENT_SOURCE_STYLUS,
+  DOWN_EVENT_SOURCE_TOUCH,
+  DOWN_EVENT_SOURCE_COUNT
+};
+
+// Destination of the down event. This enum is used to back
+// an UMA histogram and should be treated as append-only.
+enum DownEventDestination {
+  DOWN_EVENT_DESTINATION_OTHERS = 0,
+  DOWN_EVENT_DESTINATION_BROWSER,
+  DOWN_EVENT_DESTINATION_CHROME_APP,
+  DOWN_EVENT_DESTINATION_ARC_APP,
+  DOWN_EVENT_DESTINATION_NOTE_TAKING_APP,
+  DOWN_EVENT_DESTINATION_COUNT
+};
+
+DownEventDestination GetDownEventDestination(views::Widget* target) {
+  DownEventDestination dest = DOWN_EVENT_DESTINATION_OTHERS;

[sky, 2016/09/16 23:20:16]

dest is never changed. The code would be cleaner if you returned
DOWN_EVENT_DESTINATION_OTHERS rather than having dest.

[xiaoyinh(OOO Sep 11-29), 2016/09/19 21:19:53]

Done.

+  if (!target)
+    return dest;
+
+  aura::Window* window = target->GetNativeWindow();
+
+  if (!window)

[sky, 2016/09/16 23:20:16]

This shouldn't be possible. DCHECK?

[xiaoyinh(OOO Sep 11-29), 2016/09/19 21:19:52]

Done.

+    return dest;
+
+  if (exo::ShellSurface::GetMainSurface(window))
+    return DOWN_EVENT_DESTINATION_ARC_APP;
+
+  StylusWindowType window_type = window->GetProperty(kStylusWindowTypeBucket);
+
+  if (window_type == StylusWindowType::WINDOW_TYPE_BROWSER_WINDOW)
+    return DownEventDestination::DOWN_EVENT_DESTINATION_BROWSER;
+
+  if (window_type == StylusWindowType::WINDOW_TYPE_APP) {
+    extensions::AppWindow* app_window =
+        AppWindowRegistryUtil::GetAppWindowForNativeWindowAnyProfile(window);
+    if (app_window && chromeos::IsNoteTakingApp(app_window))
+      return DOWN_EVENT_DESTINATION_NOTE_TAKING_APP;
+    else

[sky, 2016/09/16 23:20:16]

no else (see chromium style guide for details)

[xiaoyinh(OOO Sep 11-29), 2016/09/19 21:19:53]

Done.

+      return DOWN_EVENT_DESTINATION_CHROME_APP;
+  }
+
+  return dest;
+}
+
+void RecordUMA(ui::EventPointerType type, views::Widget* target) {
+  DownEventFormFactor form_factor = DOWN_EVENT_FORMFACTOR_CLAMSHELL;
+  if (ash::WmShell::Get()
+          ->maximize_mode_controller()
+          ->IsMaximizeModeWindowManagerEnabled()) {
+    form_factor = DOWN_EVENT_FORMFACTOR_TOUCHVIEW;
+  }
+  UMA_HISTOGRAM_ENUMERATION("Event.DownEventCount.PerFormFactor", form_factor,
+                            DownEventFormFactor::DOWN_EVENT_FORMFACTOR_COUNT);
+
+  DownEventSource input_type = DownEventSource::DOWN_EVENT_SOURCE_UNKNOWN;
+  switch (type) {
+    case ui::EventPointerType::POINTER_TYPE_UNKNOWN:
+      input_type = DOWN_EVENT_SOURCE_UNKNOWN;
+      break;
+    case ui::EventPointerType::POINTER_TYPE_MOUSE:
+      input_type = DOWN_EVENT_SOURCE_MOUSE;
+      break;
+    case ui::EventPointerType::POINTER_TYPE_PEN:
+      input_type = DOWN_EVENT_SOURCE_STYLUS;
+      break;
+    case ui::EventPointerType::POINTER_TYPE_TOUCH:
+      input_type = DOWN_EVENT_SOURCE_TOUCH;
+      break;
+    case ui::EventPointerType::POINTER_TYPE_ERASER:
+      input_type = DOWN_EVENT_SOURCE_STYLUS;
+      break;
+  }
+
+  UMA_HISTOGRAM_ENUMERATION("Event.DownEventCount.PerInput", input_type,
+                            DOWN_EVENT_SOURCE_COUNT);
+
+  DownEventDestination dest = GetDownEventDestination(target);
+  UMA_HISTOGRAM_ENUMERATION("Event.DownEventCount.PerDestination", dest,
+                            DOWN_EVENT_DESTINATION_COUNT);
+}
+
+}  // namespace
+
+StylusMetricsRecorder::StylusMetricsRecorder() {
+  ash::WmShell::Get()->AddPointerWatcher(
+      this, views::PointerWatcherEventTypes::BASIC);
+}
+
+StylusMetricsRecorder::~StylusMetricsRecorder() {
+  ash::WmShell::Get()->RemovePointerWatcher(this);
+}
+
+void StylusMetricsRecorder::OnPointerEventObserved(
+    const ui::PointerEvent& event,
+    const gfx::Point& location_in_screen,
+    views::Widget* target) {
+  if (event.type() != ui::ET_POINTER_DOWN)
+    return;
+  RecordUMA(event.pointer_details().pointer_type, target);
+}
+
+}  // namespace chromeos