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