| // Copyright 2013 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/keyboard_uma_event_filter.h" |
| |
| #include "base/metrics/histogram.h" |
| #include "ui/events/event.h" |
| |
| namespace { |
| |
| // This threshold is used to drop keystrokes that are more than some time apart. |
| // These keystrokes are dropped to avoid recording outliers, as well as pauses |
| // between actual segments of typing. |
| const int kKeystrokeThresholdInSeconds = 5; |
| |
| } |
| |
| namespace ash { |
| |
| KeyboardUMAEventFilter::KeyboardUMAEventFilter() {} |
| |
| KeyboardUMAEventFilter::~KeyboardUMAEventFilter() {} |
| |
| void KeyboardUMAEventFilter::OnKeyEvent(ui::KeyEvent* event) { |
| // This is a rough approximation, so assume that each key release is the |
| // result of a typed key. |
| if (event->type() != ui::ET_KEY_RELEASED) |
| return; |
| |
| // Reset the timer on non-character keystrokes. |
| if (!isprint(event->GetCharacter())) { |
| last_keystroke_time_ = base::TimeDelta(); |
| return; |
| } |
| |
| if (last_keystroke_time_.ToInternalValue() == 0) { |
| last_keystroke_time_ = event->time_stamp(); |
| return; |
| } |
| |
| base::TimeDelta delta = event->time_stamp() - last_keystroke_time_; |
| if (delta < base::TimeDelta::FromSeconds(kKeystrokeThresholdInSeconds)) |
| UMA_HISTOGRAM_TIMES("Keyboard.KeystrokeDeltas", delta); |
| |
| last_keystroke_time_ = event->time_stamp(); |
| } |
| |
| } // namespace ash |