Refactored TTS extension code so that the platform-specific TTS...

chrome/browser/extensions/extension_tts_api_win.cc

Index: chrome/browser/extensions/extension_tts_api_win.cc
===================================================================
--- chrome/browser/extensions/extension_tts_api_win.cc	(revision 62145)
+++ chrome/browser/extensions/extension_tts_api_win.cc	(working copy)
@@ -11,113 +11,112 @@
 #include "base/scoped_comptr_win.h"
 #include "base/singleton.h"
 #include "base/string_number_conversions.h"
+#include "base/utf_string_conversions.h"
 #include "base/values.h"
 
 namespace util = extension_tts_api_util;
 
-class SpeechSynthesizerWrapper {
+class ExtensionTtsPlatformImplWin : public ExtensionTtsPlatformImpl {
  public:
-  SpeechSynthesizerWrapper() : speech_synthesizer_(NULL),
-                               paused_(false),
-                               permanent_failure_(false) {
-    InitializeSpeechSynthesizer();
-  }
+  virtual bool Speak(
+      const std::string& utterance,
+      const std::string& language,
+      const std::string& gender,
+      double rate,
+      double pitch,
+      double volume);
 
-  bool InitializeSpeechSynthesizer() {
-    if (!SUCCEEDED(CoCreateInstance(CLSID_SpVoice,
-                                    NULL,
-                                    CLSCTX_SERVER,
-                                    IID_ISpVoice,
-                                    reinterpret_cast<void**>(
-                                        &speech_synthesizer_)))) {
-      permanent_failure_ = true;
-      return false;
-    }
+  virtual bool StopSpeaking();
 
-    if (paused_)
-      speech_synthesizer_->Resume();
-    return true;
-  }
+  virtual bool IsSpeaking();
 
-  ScopedComPtr<ISpVoice> speech_synthesizer() {
-    return speech_synthesizer_;
-  }
+  // Get the single instance of this class.
+  static ExtensionTtsPlatformImplWin* GetInstance();
 
-  bool paused() {
-    return paused_;
-  }
-
-  void paused(bool state) {
-    paused_ = state;
-  }
-
  private:
+  ExtensionTtsPlatformImplWin();
+  virtual ~ExtensionTtsPlatformImplWin() {}
+
   ScopedComPtr<ISpVoice> speech_synthesizer_;
   bool paused_;
-  // Indicates an error retrieving the SAPI COM interface.
-  bool permanent_failure_;
+
+  friend struct DefaultSingletonTraits<ExtensionTtsPlatformImplWin>;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionTtsPlatformImplWin);
 };
 
-typedef Singleton<SpeechSynthesizerWrapper> SpeechSynthesizerSingleton;
+// static
+ExtensionTtsPlatformImpl* ExtensionTtsPlatformImpl::GetInstance() {
+  return ExtensionTtsPlatformImplWin::GetInstance();
+}
 
-bool ExtensionTtsSpeakFunction::RunImpl() {
-  ScopedComPtr<ISpVoice> speech_synthesizer =
-      SpeechSynthesizerSingleton::get()->speech_synthesizer();
-  if (speech_synthesizer) {
-    std::wstring utterance;
-    EXTENSION_FUNCTION_VALIDATE(args_->GetString(0, &utterance));
+bool ExtensionTtsPlatformImplWin::Speak(
+    const std::string& src_utterance,
+    const std::string& language,
+    const std::string& gender,
+    double rate,
+    double pitch,
+    double volume) {
+  std::wstring utterance = UTF8ToUTF16(src_utterance);
 
-    std::string options = "";
-    DictionaryValue* speak_options = NULL;
+  if (!speech_synthesizer_)
+    return false;
 
-    // Parse speech properties.
-    if (args_->GetDictionary(1, &speak_options)) {
-      std::string str_value;
-      double real_value;
-      // Speech API equivalents for kGenderKey and kLanguageNameKey do not
-      // exist and thus are not supported.
-      if (util::ReadNumberByKey(speak_options, util::kRateKey, &real_value)) {
-        // The TTS api allows a range of -10 to 10 for speech rate.
-        speech_synthesizer->SetRate(static_cast<int32>(real_value*20 - 10));
-      }
-      if (util::ReadNumberByKey(speak_options, util::kPitchKey, &real_value)) {
-        // The TTS api allows a range of -10 to 10 for speech pitch.
-        // TODO(dtseng): cleanup if we ever
-        // use any other properties that require xml.
-        std::wstring pitch_value =
-            base::IntToString16(static_cast<int>(real_value*20 - 10));
-        utterance = L"<pitch absmiddle=\"" + pitch_value + L"\">" +
-            utterance + L"</pitch>";
-      }
-      if (util::ReadNumberByKey(
-          speak_options, util::kVolumeKey, &real_value)) {
-        // The TTS api allows a range of 0 to 100 for speech volume.
-        speech_synthesizer->SetVolume(static_cast<uint16>(real_value * 100));
-      }
-    }
+  // Speech API equivalents for kGenderKey and kLanguageNameKey do not
+  // exist and thus are not supported.
 
-    if (SpeechSynthesizerSingleton::get()->paused())
-      speech_synthesizer->Resume();
-    speech_synthesizer->Speak(
-        utterance.c_str(), SPF_ASYNC | SPF_PURGEBEFORESPEAK, NULL);
-    return true;
+  if (rate >= 0.0) {
+    // The TTS api allows a range of -10 to 10 for speech rate.
+    speech_synthesizer_->SetRate(static_cast<int32>(rate * 20 - 10));
   }
 
-  return false;
+  if (pitch >= 0.0) {
+    // The TTS api allows a range of -10 to 10 for speech pitch.
+    // TODO(dtseng): cleanup if we ever use any other properties that
+    // require xml.
+    std::wstring pitch_value =
+        base::IntToString16(static_cast<int>(pitch * 20 - 10));
+    utterance = L"<pitch absmiddle=\"" + pitch_value + L"\">" +
+        utterance + L"</pitch>";
+  }
+
+  if (volume >= 0.0) {
+    // The TTS api allows a range of 0 to 100 for speech volume.
+    speech_synthesizer_->SetVolume(static_cast<uint16>(volume * 100));
+  }
+
+  if (paused_)
+    speech_synthesizer_->Resume();
+  speech_synthesizer_->Speak(
+      utterance.c_str(), SPF_ASYNC | SPF_PURGEBEFORESPEAK, NULL);
+
+  return true;
 }
 
-bool ExtensionTtsStopSpeakingFunction::RunImpl() {
-  // We need to keep track of the paused state since SAPI doesn't have a stop
-  // method.
-  ScopedComPtr<ISpVoice> speech_synthesizer =
-      SpeechSynthesizerSingleton::get()->speech_synthesizer();
-  if (speech_synthesizer && !SpeechSynthesizerSingleton::get()->paused()) {
-    speech_synthesizer->Pause();
-    SpeechSynthesizerSingleton::get()->paused(true);
+bool ExtensionTtsPlatformImplWin::StopSpeaking() {
+  if (!speech_synthesizer_ && !paused_) {
+    speech_synthesizer_->Pause();
+    paused_ = true;
   }
   return true;
 }
 
-bool ExtensionTtsIsSpeakingFunction::RunImpl() {
+bool ExtensionTtsPlatformImplWin::IsSpeaking() {
   return false;
 }
+
+ExtensionTtsPlatformImplWin::ExtensionTtsPlatformImplWin()
+  : speech_synthesizer_(NULL),
+    paused_(false) {
+  CoCreateInstance(
+      CLSID_SpVoice,
+      NULL,
+      CLSCTX_SERVER,
+      IID_ISpVoice,
+      reinterpret_cast<void**>(&speech_synthesizer_));
+}
+
+// static
+ExtensionTtsPlatformImplWin* ExtensionTtsPlatformImplWin::GetInstance() {
+  return Singleton<ExtensionTtsPlatformImplWin>::get();
+}