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 #include <algorithm>
   8
   9 namespace app_list {
  10
  11 namespace {
  12
  13 // The default sound level, just gotten from the developer device.
  14 const int16 kDefaultSoundLevel = 200;
  15
  16 }  // namespace
  17
  18 SpeechUIModel::SpeechUIModel()
  19     : is_final_(false),
  20       sound_level_(0),
  21       state_(app_list::SPEECH_RECOGNITION_OFF),
  22       minimum_sound_level_(kDefaultSoundLevel),
  23       maximum_sound_level_(kDefaultSoundLevel) {
  24 }
  25
  26 SpeechUIModel::~SpeechUIModel() {}
  27
  28 void SpeechUIModel::SetSpeechResult(const base::string16& result,
  29                                     bool is_final) {
  30   if (result_ == result && is_final_ == is_final)
  31     return;
  32
  33   result_ = result;
  34   is_final_ = is_final;
  35   FOR_EACH_OBSERVER(SpeechUIModelObserver,
  36                     observers_,
  37                     OnSpeechResult(result, is_final));
  38 }
  39
  40 void SpeechUIModel::UpdateSoundLevel(int16 level) {
  41   if (sound_level_ == level)
  42     return;
  43
  44   sound_level_ = level;
  45
  46   // Tweak the sound level limits adaptively.
  47   // - min is the minimum value during the speech recognition starts but speech
  48   //   itself hasn't started.
  49   // - max is the maximum value when the user speaks.
  50   if (state_ == SPEECH_RECOGNITION_IN_SPEECH)
  51     maximum_sound_level_ = std::max(level, maximum_sound_level_);
  52   else
  53     minimum_sound_level_ = std::min(level, minimum_sound_level_);
  54
  55   if (maximum_sound_level_ < minimum_sound_level_) {
  56     maximum_sound_level_ = std::max(
  57         static_cast<int16>(minimum_sound_level_ + kDefaultSoundLevel),
  58         kint16max);
  59   }
  60
  61   int16 range = maximum_sound_level_ - minimum_sound_level_;
  62   uint8 visible_level = 0;
  63   if (range > 0) {
  64     int16 visible_level_in_range =
  65         std::min(std::max(minimum_sound_level_, sound_level_),
  66                  maximum_sound_level_);
  67     visible_level =
  68         (visible_level_in_range - minimum_sound_level_) * kuint8max / range;
  69   }
  70
  71   FOR_EACH_OBSERVER(SpeechUIModelObserver,
  72                     observers_,
  73                     OnSpeechSoundLevelChanged(visible_level));
  74 }
  75
  76 void SpeechUIModel::SetSpeechRecognitionState(
  77     SpeechRecognitionState new_state) {
  78   if (state_ == new_state)
  79     return;
  80
  81   state_ = new_state;
  82   // Revert the min/max sound level to the default.
  83   if (state_ != SPEECH_RECOGNITION_RECOGNIZING &&
  84       state_ != SPEECH_RECOGNITION_IN_SPEECH) {
  85     minimum_sound_level_ = kDefaultSoundLevel;
  86     maximum_sound_level_ = kDefaultSoundLevel;
  87   }
  88
  89   FOR_EACH_OBSERVER(SpeechUIModelObserver,
  90                     observers_,
  91                     OnSpeechRecognitionStateChanged(new_state));
  92 }
  93
  94 void SpeechUIModel::AddObserver(SpeechUIModelObserver* observer) {
  95   observers_.AddObserver(observer);
  96 }
  97
  98 void SpeechUIModel::RemoveObserver(SpeechUIModelObserver* observer) {
  99   observers_.RemoveObserver(observer);
 100 }
 101
 102 }  // namespace app_list