ui/app_list/speech_ui_model.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "ui/app_list/speech_ui_model.h"
   6
   7 namespace app_list {
   8
   9 namespace {
  10
  11 // The default sound level, just gotten from the developer device.
  12 const int16 kDefaultSoundLevel = 200;
  13
  14 }  // namespace
  15
  16 SpeechUIModel::SpeechUIModel(SpeechRecognitionState initial_state)
  17     : state_(initial_state),
  18       minimum_sound_level_(kDefaultSoundLevel),
  19       maximum_sound_level_(kDefaultSoundLevel) {}
  20
  21 SpeechUIModel::~SpeechUIModel() {}
  22
  23 void SpeechUIModel::SetSpeechResult(const base::string16& result,
  24                                     bool is_final) {
  25   if (result_ == result && is_final_ == is_final)
  26     return;
  27
  28   result_ = result;
  29   is_final_ = is_final;
  30   FOR_EACH_OBSERVER(SpeechUIModelObserver,
  31                     observers_,
  32                     OnSpeechResult(result, is_final));
  33 }
  34
  35 void SpeechUIModel::UpdateSoundLevel(int16 level) {
  36   if (sound_level_ == level)
  37     return;
  38
  39   sound_level_ = level;
  40
  41   // Tweak the sound level limits adaptively.
  42   // - min is the minimum value during the speech recognition starts but speech
  43   //   itself hasn't started.
  44   // - max is the maximum value when the user speaks.
  45   if (state_ == SPEECH_RECOGNITION_IN_SPEECH)
  46     maximum_sound_level_ = std::max(level, maximum_sound_level_);
  47   else
  48     minimum_sound_level_ = std::min(level, minimum_sound_level_);
  49
  50   if (maximum_sound_level_ < minimum_sound_level_) {
  51     maximum_sound_level_ = std::max(
  52         static_cast<int16>(minimum_sound_level_ + kDefaultSoundLevel),
  53         kint16max);
  54   }
  55
  56   int16 range = maximum_sound_level_ - minimum_sound_level_;
  57   uint8 visible_level = 0;
  58   if (range > 0) {
  59     int16 visible_level_in_range =
  60         std::min(std::max(minimum_sound_level_, sound_level_),
  61                  maximum_sound_level_);
  62     visible_level =
  63         (visible_level_in_range - minimum_sound_level_) * kuint8max / range;
  64   }
  65
  66   FOR_EACH_OBSERVER(SpeechUIModelObserver,
  67                     observers_,
  68                     OnSpeechSoundLevelChanged(visible_level));
  69 }
  70
  71 void SpeechUIModel::SetSpeechRecognitionState(
  72     SpeechRecognitionState new_state) {
  73   if (state_ == new_state)
  74     return;
  75
  76   state_ = new_state;
  77   // Revert the min/max sound level to the default.
  78   if (state_ != SPEECH_RECOGNITION_RECOGNIZING &&
  79       state_ != SPEECH_RECOGNITION_IN_SPEECH) {
  80     minimum_sound_level_ = kDefaultSoundLevel;
  81     maximum_sound_level_ = kDefaultSoundLevel;
  82   }
  83
  84   FOR_EACH_OBSERVER(SpeechUIModelObserver,
  85                     observers_,
  86                     OnSpeechRecognitionStateChanged(new_state));
  87 }
  88
  89 void SpeechUIModel::AddObserver(SpeechUIModelObserver* observer) {
  90   observers_.AddObserver(observer);
  91 }
  92
  93 void SpeechUIModel::RemoveObserver(SpeechUIModelObserver* observer) {
  94   observers_.RemoveObserver(observer);
  95 }
  96
  97 }  // namespace app_list