Implement the new TTS settings UI.

bug:5149036

Change-Id: I81a9786d20be3e9bf87550d6a0cc04191409600c

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

@@ -0,0 +1,481 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.tts;
+
+import static android.provider.Settings.Secure.TTS_DEFAULT_RATE;
+import static android.provider.Settings.Secure.TTS_DEFAULT_SYNTH;
+
+import com.android.settings.R;
+import com.android.settings.SettingsPreferenceFragment;
+import com.android.settings.tts.TtsEnginePreference.RadioButtonGroupState;
+
+import android.app.AlertDialog;
+import android.content.ActivityNotFoundException;
+import android.content.ContentResolver;
+import android.content.DialogInterface;
+import android.content.Intent;
+import android.os.Bundle;
+import android.preference.ListPreference;
+import android.preference.Preference;
+import android.preference.PreferenceActivity;
+import android.preference.PreferenceCategory;
+import android.provider.Settings;
+import android.provider.Settings.SettingNotFoundException;
+import android.speech.tts.TextToSpeech;
+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.List;
+import java.util.Locale;
+
+public class TextToSpeechSettings extends SettingsPreferenceFragment implements
+        Preference.OnPreferenceChangeListener, Preference.OnPreferenceClickListener,
+        RadioButtonGroupState {
+
+    private static final String TAG = "TextToSpeechSettings";
+    private static final boolean DBG = false;
+
+    /** Preference key for the "play TTS example" preference. */
+    private static final String KEY_PLAY_EXAMPLE = "tts_play_example";
+
+    /** Preference key for the TTS rate selection dialog. */
+    private static final String KEY_DEFAULT_RATE = "tts_default_rate";
+
+    /**
+     * Preference key for the engine selection preference.
+     */
+    private static final String KEY_ENGINE_PREFERENCE_SECTION =
+            "tts_engine_preference_section";
+
+    /**
+     * These look like birth years, but they aren't mine. I'm much younger than this.
+     */
+    private static final int GET_SAMPLE_TEXT = 1983;
+    private static final int VOICE_DATA_INTEGRITY_CHECK = 1977;
+
+    private PreferenceCategory mEnginePreferenceCategory;
+    private ListPreference mDefaultRatePref;
+    private Preference mPlayExample;
+
+    private int mDefaultRate = TextToSpeech.Engine.DEFAULT_RATE;
+
+    /**
+     * The currently selected engine.
+     */
+    private String mCurrentEngine;
+
+    /**
+     * The engine checkbox that is currently checked. Saves us a bit of effort
+     * in deducing the right one from the currently selected engine.
+     */
+    private Checkable mCurrentChecked;
+
+    /**
+     * The previously selected TTS engine. Useful for rollbacks if the users
+     * choice is not loaded or fails a voice integrity check.
+     */
+    private String mPreviousEngine;
+
+    private TextToSpeech mTts = null;
+    private TtsEngines mEnginesHelper = null;
+
+    /**
+     * The initialization listener used when we are initalizing the settings
+     * screen for the first time (as opposed to when a user changes his choice
+     * of engine).
+     */
+    private final TextToSpeech.OnInitListener mInitListener = new TextToSpeech.OnInitListener() {
+        @Override
+        public void onInit(int status) {
+            onInitEngine(status);
+        }
+    };
+
+    /**
+     * The initialization listener used when the user changes his choice of
+     * engine (as opposed to when then screen is being initialized for the first
+     * time).
+     */
+    private final TextToSpeech.OnInitListener mUpdateListener = new TextToSpeech.OnInitListener() {
+        @Override
+        public void onInit(int status) {
+            onUpdateEngine(status);
+        }
+    };
+
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        addPreferencesFromResource(R.xml.tts_settings);
+
+        getActivity().setVolumeControlStream(TextToSpeech.Engine.DEFAULT_STREAM);
+
+        mPlayExample = findPreference(KEY_PLAY_EXAMPLE);
+        mPlayExample.setOnPreferenceClickListener(this);
+
+        mEnginePreferenceCategory = (PreferenceCategory) findPreference(
+                KEY_ENGINE_PREFERENCE_SECTION);
+        mDefaultRatePref = (ListPreference) findPreference(KEY_DEFAULT_RATE);
+
+        mTts = new TextToSpeech(getActivity().getApplicationContext(), mInitListener);
+        mEnginesHelper = new TtsEngines(getActivity().getApplicationContext());
+
+        initSettings();
+    }
+
+    @Override
+    public void onDestroy() {
+        super.onDestroy();
+        if (mTts != null) {
+            mTts.shutdown();
+            mTts = null;
+        }
+    }
+
+    @Override
+    public void onPause() {
+        super.onPause();
+        if ((mDefaultRatePref != null) && (mDefaultRatePref.getDialog() != null)) {
+            mDefaultRatePref.getDialog().dismiss();
+        }
+    }
+
+    private void initSettings() {
+        final ContentResolver resolver = getContentResolver();
+
+        // Set up the default rate.
+        try {
+            mDefaultRate = Settings.Secure.getInt(resolver, TTS_DEFAULT_RATE);
+        } catch (SettingNotFoundException e) {
+            // Default rate setting not found, initialize it
+            mDefaultRate = TextToSpeech.Engine.DEFAULT_RATE;
+        }
+        mDefaultRatePref.setValue(String.valueOf(mDefaultRate));
+        mDefaultRatePref.setOnPreferenceChangeListener(this);
+
+        mCurrentEngine = mTts.getCurrentEngine();
+
+        PreferenceActivity preferenceActivity = null;
+        if (getActivity() instanceof PreferenceActivity) {
+            preferenceActivity = (PreferenceActivity) getActivity();
+        } else {
+            throw new IllegalStateException("TextToSpeechSettings used outside a " +
+                    "PreferenceActivity");
+        }
+
+        mEnginePreferenceCategory.removeAll();
+
+        List<EngineInfo> engines = mEnginesHelper.getEngines();
+        for (EngineInfo engine : engines) {
+            TtsEnginePreference enginePref = new TtsEnginePreference(getActivity(), engine,
+                    this, preferenceActivity);
+            mEnginePreferenceCategory.addPreference(enginePref);
+        }
+
+        checkVoiceData(mCurrentEngine);
+    }
+
+    /**
+     * Ask the current default engine to return a string of sample text to be
+     * spoken to the user.
+     */
+    private void getSampleText() {
+        String currentEngine = mTts.getCurrentEngine();
+        Locale currentLocale = mTts.getLanguage();
+
+        if (TextUtils.isEmpty(currentEngine)) currentEngine = mTts.getDefaultEngine();
+
+        // TODO: This is currently a hidden private API. The intent extras
+        // and the intent action should be made public if we intend to make this
+        // a public API. We fall back to using a canned set of strings if this
+        // doesn't work.
+        Intent intent = new Intent(TextToSpeech.Engine.ACTION_GET_SAMPLE_TEXT);
+
+        if (currentLocale != null) {
+            intent.putExtra("language", currentLocale.getLanguage());
+            intent.putExtra("country", currentLocale.getCountry());
+            intent.putExtra("variant", currentLocale.getVariant());
+        }
+        intent.setPackage(currentEngine);
+
+        try {
+            if (DBG) Log.d(TAG, "Getting sample text: " + intent.toUri(0));
+            startActivityForResult(intent, GET_SAMPLE_TEXT);
+        } catch (ActivityNotFoundException ex) {
+            Log.e(TAG, "Failed to get sample text, no activity found for " + intent + ")");
+            onSampleTextReceived(TextToSpeech.ERROR, null);
+        }
+    }
+
+    /**
+     * Called when the TTS engine is initialized.
+     */
+    public void onInitEngine(int status) {
+        if (status == TextToSpeech.SUCCESS) {
+            updateWidgetState(true);
+            if (DBG) Log.d(TAG, "TTS engine for settings screen initialized.");
+        } else {
+            if (DBG) Log.d(TAG, "TTS engine for settings screen failed to initialize successfully.");
+            updateWidgetState(false);
+        }
+    }
+
+    /**
+     * Called when voice data integrity check returns
+     */
+    @Override
+    public void onActivityResult(int requestCode, int resultCode, Intent data) {
+        if (requestCode == GET_SAMPLE_TEXT) {
+            onSampleTextReceived(resultCode, data);
+        } else if (requestCode == VOICE_DATA_INTEGRITY_CHECK) {
+            onVoiceDataIntegrityCheckDone(data);
+        }
+    }
+
+    private String getDefaultSampleString() {
+        if (mTts != null && mTts.getLanguage() != null) {
+            final String currentLang = mTts.getLanguage().getISO3Language();
+            String[] strings = getActivity().getResources().getStringArray(
+                    R.array.tts_demo_strings);
+            String[] langs = getActivity().getResources().getStringArray(
+                    R.array.tts_demo_string_langs);
+
+            for (int i = 0; i < strings.length; ++i) {
+                if (langs[i].equals(currentLang)) {
+                    return strings[i];
+                }
+            }
+        }
+        return null;
+    }
+
+    private void onSampleTextReceived(int resultCode, Intent data) {
+        String sample = getDefaultSampleString();
+
+        if (resultCode == TextToSpeech.LANG_AVAILABLE && data != null) {
+            if (data != null && data.getStringExtra("sampleText") != null) {
+                sample = data.getStringExtra("sampleText");
+            }
+            if (DBG) Log.d(TAG, "Got sample text: " + sample);
+        } else {
+            if (DBG) Log.d(TAG, "Using default sample text :" + sample);
+        }
+
+        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);
+        } else {
+            // TODO: Display an error here to the user.
+            Log.e(TAG, "Did not have a sample string for the requested language");
+        }
+    }
+
+    public boolean onPreferenceChange(Preference preference, Object objValue) {
+        if (KEY_DEFAULT_RATE.equals(preference.getKey())) {
+            // Default rate
+            mDefaultRate = Integer.parseInt((String) objValue);
+            try {
+                Settings.Secure.putInt(getContentResolver(), TTS_DEFAULT_RATE, mDefaultRate);
+                if (mTts != null) {
+                    mTts.setSpeechRate(mDefaultRate / 100.0f);
+                }
+                if (DBG) Log.d(TAG, "TTS default rate changed, now " + mDefaultRate);
+            } catch (NumberFormatException e) {
+                Log.e(TAG, "could not persist default TTS rate setting", e);
+            }
+        }
+
+        return true;
+    }
+
+    /**
+     * Called when mPlayExample is clicked
+     */
+    public boolean onPreferenceClick(Preference preference) {
+        if (preference == mPlayExample) {
+            // Get the sample text from the TTS engine; onActivityResult will do
+            // the actual speaking
+            getSampleText();
+            return true;
+        }
+
+        return false;
+    }
+
+    private void updateWidgetState(boolean enable) {
+        mPlayExample.setEnabled(enable);
+        mDefaultRatePref.setEnabled(enable);
+    }
+
+    private void displayDataAlert(final String key) {
+        Log.i(TAG, "Displaying data alert for :" + key);
+        AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
+        builder.setTitle(android.R.string.dialog_alert_title);
+        builder.setIcon(android.R.drawable.ic_dialog_alert);
+        builder.setMessage(getActivity().getString(
+                R.string.tts_engine_security_warning, mEnginesHelper.getEngineInfo(key).label));
+        builder.setCancelable(true);
+        builder.setPositiveButton(android.R.string.ok,
+                new DialogInterface.OnClickListener() {
+                    public void onClick(DialogInterface dialog, int which) {
+                       updateDefaultEngine(key);
+                    }
+                });
+        builder.setNegativeButton(android.R.string.cancel, null);
+
+        AlertDialog dialog = builder.create();
+        dialog.show();
+    }
+
+    private void updateDefaultEngine(String engine) {
+        if (DBG) Log.d(TAG, "Updating default synth to : " + engine);
+
+        // Disable the "play sample text" preference and the speech
+        // rate preference while the engine is being swapped.
+        updateWidgetState(false);
+
+        // Keep track of the previous engine that was being used. So that
+        // we can reuse the previous engine.
+        //
+        // Note that if TextToSpeech#getCurrentEngine is not null, it means at
+        // the very least that we successfully bound to the engine service.
+        mPreviousEngine = mTts.getCurrentEngine();
+
+        // Step 1: Shut down the existing TTS engine.
+        if (mTts != null) {
+            try {
+                mTts.shutdown();
+                mTts = null;
+            } catch (Exception e) {
+                Log.e(TAG, "Error shutting down TTS engine" + e);
+            }
+        }
+
+        // Step 2: Connect to the new TTS engine.
+        // Step 3 is continued on #onUpdateEngine (below) which is called when
+        // 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);
+    }
+
+    /*
+     * Step 3: We have now bound to the TTS engine the user requested. We will
+     * attempt to check voice data for the engine if we successfully bound to it,
+     * or revert to the previous engine if we didn't.
+     */
+    public void onUpdateEngine(int status) {
+        if (status == TextToSpeech.SUCCESS) {
+            if (DBG) {
+                Log.d(TAG, "Updating engine: Successfully bound to the engine: " +
+                        mTts.getCurrentEngine());
+            }
+            checkVoiceData(mTts.getCurrentEngine());
+        } else {
+            if (DBG) Log.d(TAG, "Updating engine: Failed to bind to engine, reverting.");
+            if (mPreviousEngine != null) {
+                // This is guaranteed to at least bind, since mPreviousEngine would be
+                // null if the previous bind to this engine failed.
+                mTts = new TextToSpeech(getActivity().getApplicationContext(), mInitListener,
+                        mPreviousEngine);
+            }
+            mPreviousEngine = null;
+        }
+    }
+
+    /*
+     * Step 4: Check whether the voice data for the engine is ok.
+     */
+    private void checkVoiceData(String engine) {
+        Intent intent = new Intent(TextToSpeech.Engine.ACTION_CHECK_TTS_DATA);
+        intent.setPackage(engine);
+        try {
+            if (DBG) Log.d(TAG, "Updating engine: Checking voice data: " + intent.toUri(0));
+            startActivityForResult(intent, VOICE_DATA_INTEGRITY_CHECK);
+        } catch (ActivityNotFoundException ex) {
+            Log.e(TAG, "Failed to check TTS data, no activity found for " + intent + ")");
+        }
+    }
+
+    /*
+     * Step 5: The voice data check is complete.
+     */
+    private void onVoiceDataIntegrityCheckDone(Intent data) {
+        final String engine = mTts.getCurrentEngine();
+
+        if (engine == null) {
+            Log.e(TAG, "Voice data check complete, but no engine bound");
+            return;
+        }
+
+        if (data == null){
+            Log.e(TAG, "Engine failed voice data integrity check (null return)" +
+                    mTts.getCurrentEngine());
+            return;
+        }
+
+        Settings.Secure.putString(getContentResolver(), TTS_DEFAULT_SYNTH, engine);
+
+        final int engineCount = mEnginePreferenceCategory.getPreferenceCount();
+        for (int i = 0; i < engineCount; ++i) {
+            final Preference p = mEnginePreferenceCategory.getPreference(i);
+            if (p instanceof TtsEnginePreference) {
+                TtsEnginePreference enginePref = (TtsEnginePreference) p;
+                if (enginePref.getKey().equals(engine)) {
+                    enginePref.setVoiceDataDetails(data);
+                    break;
+                }
+            }
+        }
+
+        updateWidgetState(true);
+    }
+
+    private boolean shouldDisplayDataAlert(String engine) {
+        final EngineInfo info = mEnginesHelper.getEngineInfo(engine);
+        return !info.system;
+    }
+
+    @Override
+    public Checkable getCurrentChecked() {
+        return mCurrentChecked;
+    }
+
+    @Override
+    public String getCurrentKey() {
+        return mCurrentEngine;
+    }
+
+    @Override
+    public void setCurrentChecked(Checkable current) {
+        mCurrentChecked = current;
+    }
+
+    @Override
+    public void setCurrentKey(String key) {
+        mCurrentEngine = key;
+        if (shouldDisplayDataAlert(mCurrentEngine)) {
+            displayDataAlert(mCurrentEngine);
+        } else {
+            updateDefaultEngine(mCurrentEngine);
+        }
+    }
+
+}

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

@@ -0,0 +1,197 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.tts;
+
+import com.android.settings.R;
+
+import android.content.Context;
+import android.content.Intent;
+import android.os.Bundle;
+import android.preference.Preference;
+import android.preference.PreferenceActivity;
+import android.speech.tts.TextToSpeech.EngineInfo;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.Checkable;
+import android.widget.CompoundButton;
+import android.widget.RadioButton;
+
+
+public class TtsEnginePreference extends Preference {
+
+    /**
+     * Key for the name of the TTS engine passed in to the engine
+     * settings fragment {@link TtsEngineSettingsFragment}.
+     */
+    static final String FRAGMENT_ARGS_NAME = "name";
+
+    /**
+     * Key for the label of the TTS engine passed in to the engine
+     * settings fragment. This is used as the title of the fragment
+     * {@link TtsEngineSettingsFragment}.
+     */
+    static final String FRAGMENT_ARGS_LABEL = "label";
+
+    /**
+     * Key for the voice data data passed in to the engine settings
+     * fragmetn {@link TtsEngineSettingsFragment}.
+     */
+    static final String FRAGMENT_ARGS_VOICES = "voices";
+
+    /**
+     * The preference activity that owns this preference. Required
+     * for instantiating the engine specific settings screen.
+     */
+    private final PreferenceActivity mPreferenceActivity;
+
+    /**
+     * The engine information for the engine this preference represents.
+     * Contains it's name, label etc. which are used for display.
+     */
+    private final EngineInfo mEngineInfo;
+
+    /**
+     * The shared radio button state, which button is checked etc.
+     */
+    private final RadioButtonGroupState mSharedState;
+
+    /**
+     * When true, the change callbacks on the radio button will not
+     * fire.
+     */
+    private volatile boolean mPreventRadioButtonCallbacks;
+
+    private View mSettingsIcon;
+    private RadioButton mRadioButton;
+    private Intent mVoiceCheckData;
+
+    private final CompoundButton.OnCheckedChangeListener mRadioChangeListener =
+        new CompoundButton.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
+                onRadioButtonClicked(buttonView, isChecked);
+            }
+        };
+
+    public TtsEnginePreference(Context context, EngineInfo info, RadioButtonGroupState state,
+            PreferenceActivity prefActivity) {
+        super(context);
+        setLayoutResource(R.layout.preference_tts_engine);
+
+        mSharedState = state;
+        mPreferenceActivity = prefActivity;
+        mEngineInfo = info;
+        mPreventRadioButtonCallbacks = false;
+
+        setKey(mEngineInfo.name);
+        setTitle(mEngineInfo.label);
+    }
+
+    @Override
+    public View getView(View convertView, ViewGroup parent) {
+        if (mSharedState == null) {
+            throw new IllegalStateException("Call to getView() before a call to" +
+                    "setSharedState()");
+        }
+
+        View view = super.getView(convertView, parent);
+        final RadioButton rb = (RadioButton) view.findViewById(R.id.tts_engine_radiobutton);
+        rb.setOnCheckedChangeListener(mRadioChangeListener);
+
+        boolean isChecked = getKey().equals(mSharedState.getCurrentKey());
+        if (isChecked) {
+            mSharedState.setCurrentChecked(rb);
+        }
+
+        mPreventRadioButtonCallbacks = true;
+        rb.setChecked(isChecked);
+        mPreventRadioButtonCallbacks = false;
+
+        mRadioButton = rb;
+
+        View textLayout = view.findViewById(R.id.tts_engine_pref_text);
+        textLayout.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                onRadioButtonClicked(rb, !rb.isChecked());
+            }
+        });
+
+        mSettingsIcon = view.findViewById(R.id.tts_engine_settings);
+        // Will be enabled only the engine has passed the voice check, and
+        // is currently enabled.
+        mSettingsIcon.setEnabled(isChecked && mVoiceCheckData != null);
+        mSettingsIcon.setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View v) {
+                Bundle args = new Bundle();
+                args.putString(FRAGMENT_ARGS_NAME, mEngineInfo.name);
+                args.putString(FRAGMENT_ARGS_LABEL, mEngineInfo.label);
+                if (mVoiceCheckData != null) {
+                    args.putParcelable(FRAGMENT_ARGS_VOICES, mVoiceCheckData);
+                }
+
+                // Note that we use this instead of the (easier to use)
+                // PreferenceActivity.startPreferenceFragment because the
+                // title will not be updated correctly in the fragment
+                // breadcrumb since it isn't inflated from the XML layout.
+                mPreferenceActivity.startPreferencePanel(
+                        TtsEngineSettingsFragment.class.getName(),
+                        args, 0, mEngineInfo.label, null, 0);
+            }
+        });
+
+        return view;
+    }
+
+    public void setVoiceDataDetails(Intent data) {
+        mVoiceCheckData = data;
+        mSettingsIcon.setEnabled(mRadioButton.isChecked());
+    }
+
+    private void onRadioButtonClicked(CompoundButton buttonView, boolean isChecked) {
+        if (mPreventRadioButtonCallbacks) {
+            return;
+        }
+
+        if (isChecked) {
+            if (mSharedState.getCurrentChecked() != null) {
+                mSharedState.getCurrentChecked().setChecked(false);
+            }
+            mSharedState.setCurrentChecked(buttonView);
+            mSharedState.setCurrentKey(getKey());
+            callChangeListener(mSharedState.getCurrentKey());
+        }
+
+        mSettingsIcon.setEnabled(isChecked);
+    }
+
+
+    /**
+     * Holds all state that is common to this group of radio buttons, such
+     * as the currently selected key and the currently checked compound button.
+     * (which corresponds to this key).
+     */
+    public interface RadioButtonGroupState {
+        String getCurrentKey();
+        Checkable getCurrentChecked();
+
+        void setCurrentKey(String key);
+        void setCurrentChecked(Checkable current);
+    }
+
+}

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

@@ -0,0 +1,200 @@
+/*
+ * Copyright (C) 2011 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.settings.tts;
+
+import com.android.settings.R;
+import com.android.settings.SettingsPreferenceFragment;
+
+import android.content.ActivityNotFoundException;
+import android.content.Intent;
+import android.os.Bundle;
+import android.preference.ListPreference;
+import android.preference.Preference;
+import android.preference.Preference.OnPreferenceChangeListener;
+import android.preference.Preference.OnPreferenceClickListener;
+import android.preference.PreferenceScreen;
+import android.speech.tts.TextToSpeech;
+import android.speech.tts.TtsEngines;
+import android.text.TextUtils;
+import android.util.Log;
+
+import java.util.ArrayList;
+import java.util.Locale;
+
+
+public class TtsEngineSettingsFragment extends SettingsPreferenceFragment implements
+        OnPreferenceClickListener, OnPreferenceChangeListener {
+    private static final String TAG = "TtsEngineSettings";
+    private static final boolean DBG = false;
+
+    private static final String KEY_ENGINE_LOCALE = "tts_default_lang";
+    private static final String KEY_ENGINE_SETTINGS = "tts_engine_settings";
+    private static final String KEY_INSTALL_DATA = "tts_install_data";
+
+    private TtsEngines mEnginesHelper;
+    private ListPreference mLocalePreference;
+    private Preference mEngineSettingsPreference;
+    private Preference mInstallVoicesPreference;
+    private Intent mEngineSettingsIntent;
+
+    public TtsEngineSettingsFragment() {
+        super();
+    }
+
+    @Override
+    public void onCreate(Bundle savedInstanceState) {
+        super.onCreate(savedInstanceState);
+        addPreferencesFromResource(R.xml.tts_engine_settings);
+        mEnginesHelper = new TtsEngines(getActivity());
+
+        final PreferenceScreen root = getPreferenceScreen();
+        mLocalePreference = (ListPreference) root.findPreference(KEY_ENGINE_LOCALE);
+        mLocalePreference.setOnPreferenceChangeListener(this);
+        mEngineSettingsPreference = root.findPreference(KEY_ENGINE_SETTINGS);
+        mEngineSettingsPreference.setOnPreferenceClickListener(this);
+        mInstallVoicesPreference = root.findPreference(KEY_INSTALL_DATA);
+        mInstallVoicesPreference.setOnPreferenceClickListener(this);
+
+        root.setTitle(getEngineLabel());
+        root.setKey(getEngineName());
+        mEngineSettingsPreference.setTitle(getResources().getString(
+                R.string.tts_engine_settings_title, getEngineLabel()));
+
+        mEngineSettingsIntent = mEnginesHelper.getSettingsIntent(getEngineName());
+        if (mEngineSettingsIntent == null) {
+            mEngineSettingsPreference.setEnabled(false);
+        }
+        mInstallVoicesPreference.setEnabled(false);
+
+        updateVoiceDetails();
+    }
+
+    private void updateVoiceDetails() {
+        final Intent voiceDataDetails = getArguments().getParcelable(
+                TtsEnginePreference.FRAGMENT_ARGS_VOICES);
+        if (DBG) Log.d(TAG, "Parsing voice data details, data: " + voiceDataDetails.toUri(0));
+        ArrayList<String> available = voiceDataDetails.getStringArrayListExtra(
+                TextToSpeech.Engine.EXTRA_AVAILABLE_VOICES);
+        ArrayList<String> unavailable = voiceDataDetails.getStringArrayListExtra(
+                TextToSpeech.Engine.EXTRA_UNAVAILABLE_VOICES);
+
+        if (available == null || unavailable == null){
+            Log.e(TAG, "TTS data check failed (available == null).");
+            return;
+        }
+
+        if (unavailable.size() > 0) {
+            mInstallVoicesPreference.setEnabled(true);
+        }
+
+        if (available.size() > 0) {
+            updateDefaultLocalePref(available);
+        } else {
+            final CharSequence[] empty = new CharSequence[0];
+            mLocalePreference.setEntries(empty);
+            mLocalePreference.setEntryValues(empty);
+        }
+    }
+
+    private void updateDefaultLocalePref(ArrayList<String> availableLangs) {
+        String currentLocale = mEnginesHelper.getLocalePrefForEngine(
+                getEngineName());
+
+        CharSequence[] entries = new CharSequence[availableLangs.size()];
+        CharSequence[] entryValues = new CharSequence[availableLangs.size()];
+
+        int selectedLanguageIndex = -1;
+        for (int i = 0; i < availableLangs.size(); i++) {
+            String[] langCountryVariant = availableLangs.get(i).split("-");
+            Locale loc = null;
+            if (langCountryVariant.length == 1){
+                loc = new Locale(langCountryVariant[0]);
+            } else if (langCountryVariant.length == 2){
+                loc = new Locale(langCountryVariant[0], langCountryVariant[1]);
+            } else if (langCountryVariant.length == 3){
+                loc = new Locale(langCountryVariant[0], langCountryVariant[1],
+                                 langCountryVariant[2]);
+            }
+            if (loc != null){
+                entries[i] = loc.getDisplayName();
+                entryValues[i] = availableLangs.get(i);
+                if (entryValues[i].equals(currentLocale)) {
+                    selectedLanguageIndex = i;
+                }
+            }
+        }
+
+        mLocalePreference.setEntries(entries);
+        mLocalePreference.setEntryValues(entryValues);
+        if (selectedLanguageIndex > -1) {
+            mLocalePreference.setValueIndex(selectedLanguageIndex);
+        } else {
+            mLocalePreference.setValueIndex(0);
+            mEnginesHelper.updateLocalePrefForEngine(getEngineName(),
+                    availableLangs.get(0));
+        }
+    }
+
+    /**
+     * Ask the current default engine to launch the matching INSTALL_TTS_DATA activity
+     * so the required TTS files are properly installed.
+     */
+    private void installVoiceData() {
+        if (TextUtils.isEmpty(getEngineName())) return;
+        Intent intent = new Intent(TextToSpeech.Engine.ACTION_INSTALL_TTS_DATA);
+        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+        intent.setPackage(getEngineName());
+        try {
+            Log.v(TAG, "Installing voice data: " + intent.toUri(0));
+            startActivity(intent);
+        } catch (ActivityNotFoundException ex) {
+            Log.e(TAG, "Failed to install TTS data, no acitivty found for " + intent + ")");
+        }
+    }
+
+    @Override
+    public boolean onPreferenceClick(Preference preference) {
+        if (preference == mInstallVoicesPreference) {
+            installVoiceData();
+            return true;
+        } else if (preference == mEngineSettingsPreference) {
+            startActivity(mEngineSettingsIntent);
+            return true;
+        }
+
+        return false;
+    }
+
+    @Override
+    public boolean onPreferenceChange(Preference preference, Object newValue) {
+        if (preference == mLocalePreference) {
+            mEnginesHelper.updateLocalePrefForEngine(getEngineName(), (String) newValue);
+            return true;
+        }
+
+        return false;
+    }
+
+    private String getEngineName() {
+        return getArguments().getString(TtsEnginePreference.FRAGMENT_ARGS_NAME);
+    }
+
+    private String getEngineLabel() {
+        return getArguments().getString(TtsEnginePreference.FRAGMENT_ARGS_LABEL);
+    }
+
+}