Alert for using network-only-tts with no network.

If TTS requires network for selected language, we will
show dialog informing why we can't synthesize an example
if user have no internet connectivity.

Bug: 7398316
Change-Id: I01b033a9a8b8538b322ed3639b671f90f849ae29

res/values/strings.xml

@@ -3438,6 +3438,9 @@
     all the text that will be spoken, including personal data like passwords and credit
     card numbers. It comes from the <xliff:g id="tts_plugin_engine_name">%s</xliff:g> engine.
     Enable the use of this speech synthesis engine?</string>
+    <!-- Warning message about required internet conectivity for TTS synthesis, displayed as a dialog
+         message when the user selects to play an example for network only locale and there's no internet connectivity. -->
+    <string name="tts_engine_network_required">This language requires a working network connection for text-to-speech output.</string>
     <!-- On main TTS Settings screen, text for divider under which all TTS engines are listed -->
     <string name="tts_engines_section">Engines</string>
     <!-- On main TTS Settings screen, text preceded by the TTS engine name, clicking this button will launch the engine settings -->

src/com/android/settings/tts/TextToSpeechSettings.java

@@ -36,14 +36,17 @@ import android.preference.PreferenceCategory;
 import android.provider.Settings;
 import android.provider.Settings.SettingNotFoundException;
 import android.speech.tts.TextToSpeech;
+import android.speech.tts.UtteranceProgressListener;
 import android.speech.tts.TextToSpeech.EngineInfo;
 import android.speech.tts.TtsEngines;
 import android.text.TextUtils;
 import android.util.Log;
 import android.widget.Checkable;
 
+import java.util.HashMap;
 import java.util.List;
 import java.util.Locale;
+import java.util.Set;
 
 public class TextToSpeechSettings extends SettingsPreferenceFragment implements
         Preference.OnPreferenceChangeListener, Preference.OnPreferenceClickListener,
@@ -137,9 +140,28 @@ public class TextToSpeechSettings extends SettingsPreferenceFragment implements
         mTts = new TextToSpeech(getActivity().getApplicationContext(), mInitListener);
         mEnginesHelper = new TtsEngines(getActivity().getApplicationContext());
 
+        setTtsUtteranceProgressListener();
         initSettings();
     }
 
+    private void setTtsUtteranceProgressListener() {
+        if (mTts == null) {
+            return;
+        }
+        mTts.setOnUtteranceProgressListener(new UtteranceProgressListener() {
+            @Override
+            public void onStart(String utteranceId) {}
+
+            @Override
+            public void onDone(String utteranceId) {}
+
+            @Override
+            public void onError(String utteranceId) {
+                Log.e(TAG, "Error while trying to synthesize sample text");
+            }
+        });
+    }
+
     @Override
     public void onDestroy() {
         super.onDestroy();
@@ -258,6 +280,12 @@ public class TextToSpeechSettings extends SettingsPreferenceFragment implements
         return null;
     }
 
+    private boolean isNetworkRequiredForSynthesis() {
+        Set<String> features = mTts.getFeatures(mTts.getLanguage());
+        return features.contains(TextToSpeech.Engine.KEY_FEATURE_NETWORK_SYNTHESIS) &&
+                !features.contains(TextToSpeech.Engine.KEY_FEATURE_EMBEDDED_SYNTHESIS);
+    }
+
     private void onSampleTextReceived(int resultCode, Intent data) {
         String sample = getDefaultSampleString();
 
@@ -273,7 +301,18 @@ public class TextToSpeechSettings extends SettingsPreferenceFragment implements
         if (sample != null && mTts != null) {
             // The engine is guaranteed to have been initialized here
             // because this preference is not enabled otherwise.
-            mTts.speak(sample, TextToSpeech.QUEUE_FLUSH, null);
+
+            final boolean networkRequired = isNetworkRequiredForSynthesis();
+            if (!networkRequired || networkRequired &&
+                    (mTts.isLanguageAvailable(mTts.getLanguage()) >= TextToSpeech.LANG_AVAILABLE)) {
+                HashMap<String, String> params = new HashMap<String, String>();
+                params.put(TextToSpeech.Engine.KEY_PARAM_UTTERANCE_ID, "Sample");
+
+                mTts.speak(sample, TextToSpeech.QUEUE_FLUSH, params);
+            } else {
+                Log.w(TAG, "Network required for sample synthesis for requested language");
+                displayNetworkAlert();
+            }
         } else {
             // TODO: Display an error here to the user.
             Log.e(TAG, "Did not have a sample string for the requested language");
@@ -340,6 +379,18 @@ public class TextToSpeechSettings extends SettingsPreferenceFragment implements
         dialog.show();
     }
 
+    private void displayNetworkAlert() {
+        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
+        builder.setTitle(android.R.string.dialog_alert_title);
+        builder.setIconAttribute(android.R.attr.alertDialogIcon);
+        builder.setMessage(getActivity().getString(R.string.tts_engine_network_required));
+        builder.setCancelable(false);
+        builder.setPositiveButton(android.R.string.ok, null);
+
+        AlertDialog dialog = builder.create();
+        dialog.show();
+    }
+
     private void updateDefaultEngine(String engine) {
         if (DBG) Log.d(TAG, "Updating default synth to : " + engine);
 
@@ -369,6 +420,7 @@ public class TextToSpeechSettings extends SettingsPreferenceFragment implements
         // the app binds successfully to the engine.
         if (DBG) Log.d(TAG, "Updating engine : Attempting to connect to engine: " + engine);
         mTts = new TextToSpeech(getActivity().getApplicationContext(), mUpdateListener, engine);
+        setTtsUtteranceProgressListener();
     }
 
     /*
@@ -390,6 +442,7 @@ public class TextToSpeechSettings extends SettingsPreferenceFragment implements
                 // null if the previous bind to this engine failed.
                 mTts = new TextToSpeech(getActivity().getApplicationContext(), mInitListener,
                         mPreviousEngine);
+                setTtsUtteranceProgressListener();
             }
             mPreviousEngine = null;
         }