PreferencesActivity.java

/*
 * Copyright (C) 2008 ZXing authors
 * Copyright 2011 Robert Theis
 *
 * 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 edu.sfsu.cs.orange.ocr;

import com.v.mypersonaltrainer.R;

import android.content.SharedPreferences;
import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
import android.os.Bundle;
import android.preference.EditTextPreference;
import android.preference.ListPreference;
import android.preference.PreferenceActivity;
import android.preference.PreferenceManager;
import edu.sfsu.cs.orange.ocr.language.LanguageCodeHelper;
import edu.sfsu.cs.orange.ocr.language.TranslatorBing;
import edu.sfsu.cs.orange.ocr.language.TranslatorGoogle;

/**
 * Class to handle preferences that are saved across sessions of the app. Shows
 * a hierarchy of preferences to the user, organized into sections. These
 * preferences are displayed in the options menu that is shown when the user
 * presses the MENU button.
 * 
 * The code for this class was adapted from the ZXing project: http://code.google.com/p/zxing
 */
public class PreferencesActivity extends PreferenceActivity implements
  OnSharedPreferenceChangeListener {
  
  // Preference keys not carried over from ZXing project
  public static final String KEY_SOURCE_LANGUAGE_PREFERENCE = "sourceLanguageCodeOcrPref";
  public static final String KEY_TARGET_LANGUAGE_PREFERENCE = "targetLanguageCodeTranslationPref";
  public static final String KEY_TOGGLE_TRANSLATION = "preference_translation_toggle_translation";
  public static final String KEY_CONTINUOUS_PREVIEW = "preference_capture_continuous";
  public static final String KEY_PAGE_SEGMENTATION_MODE = "preference_page_segmentation_mode";
  public static final String KEY_OCR_ENGINE_MODE = "preference_ocr_engine_mode";
  public static final String KEY_CHARACTER_BLACKLIST = "preference_character_blacklist";
  public static final String KEY_CHARACTER_WHITELIST = "preference_character_whitelist";
  public static final String KEY_TOGGLE_LIGHT = "preference_toggle_light";
  public static final String KEY_TRANSLATOR = "preference_translator";
  
  // Preference keys carried over from ZXing project
  public static final String KEY_AUTO_FOCUS = "preferences_auto_focus";
  public static final String KEY_HELP_VERSION_SHOWN = "preferences_help_version_shown";
  public static final String KEY_NOT_OUR_RESULTS_SHOWN = "preferences_not_our_results_shown";
  public static final String KEY_REVERSE_IMAGE = "preferences_reverse_image";
  public static final String KEY_PLAY_BEEP = "preferences_play_beep";
  public static final String KEY_VIBRATE = "preferences_vibrate";

  public static final String TRANSLATOR_BING = "Bing Translator";
  public static final String TRANSLATOR_GOOGLE = "Google Translate";
  
  //private CheckBoxPreference checkBoxPreferenceContinuousPreview;
  private ListPreference listPreferenceSourceLanguage;
  //private CheckBoxPreference checkBoxTranslate;
  private ListPreference listPreferenceTargetLanguage;  
  private ListPreference listPreferenceTranslator;
  private ListPreference listPreferenceOcrEngineMode;
  //private CheckBoxPreference checkBoxBeep;
  private EditTextPreference editTextPreferenceCharacterBlacklist;
  private EditTextPreference editTextPreferenceCharacterWhitelist;
  private ListPreference listPreferencePageSegmentationMode;
  //private CheckBoxPreference checkBoxReversedImage;
  
  private static SharedPreferences sharedPreferences;
  
  /**
   * Set the default preference values.
   * 
   * @param Bundle
   *            savedInstanceState the current Activity's state, as passed by
   *            Android
   */
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    addPreferencesFromResource(R.xml.preferences);
    
    sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
    
    //checkBoxPreferenceContinuousPreview = (CheckBoxPreference) getPreferenceScreen().findPreference(KEY_CONTINUOUS_PREVIEW);
    listPreferenceSourceLanguage = (ListPreference) getPreferenceScreen().findPreference(KEY_SOURCE_LANGUAGE_PREFERENCE);
    //checkBoxTranslate = (CheckBoxPreference) getPreferenceScreen().findPreference(KEY_TOGGLE_TRANSLATION);
    listPreferenceTargetLanguage = (ListPreference) getPreferenceScreen().findPreference(KEY_TARGET_LANGUAGE_PREFERENCE);
    listPreferenceTranslator = (ListPreference) getPreferenceScreen().findPreference(KEY_TRANSLATOR);    
    listPreferenceOcrEngineMode = (ListPreference) getPreferenceScreen().findPreference(KEY_OCR_ENGINE_MODE);
    //checkBoxBeep = (CheckBoxPreference) getPreferenceScreen().findPreference(KEY_PLAY_BEEP);
    editTextPreferenceCharacterBlacklist = (EditTextPreference) getPreferenceScreen().findPreference(KEY_CHARACTER_BLACKLIST);
    editTextPreferenceCharacterWhitelist = (EditTextPreference) getPreferenceScreen().findPreference(KEY_CHARACTER_WHITELIST);
    listPreferencePageSegmentationMode = (ListPreference) getPreferenceScreen().findPreference(KEY_PAGE_SEGMENTATION_MODE);
    //checkBoxReversedImage = (CheckBoxPreference) getPreferenceScreen().findPreference(KEY_REVERSE_IMAGE);
    
    // Create the entries/entryvalues for the translation target language list.
    initTranslationTargetList();
    
  }
  
  /**
   * Interface definition for a callback to be invoked when a shared
   * preference is changed. Sets summary text for the app's preferences. Summary text values show the
   * current settings for the values.
   * 
   * @param sharedPreferences
   *            the Android.content.SharedPreferences that received the change
   * @param key
   *            the key of the preference that was changed, added, or removed
   */
  @Override
  public void onSharedPreferenceChanged(SharedPreferences sharedPreferences,
      String key) {    
    // Update preference summary values to show current preferences
    if (key.equals(KEY_TRANSLATOR)) {
      listPreferenceTranslator.setSummary(sharedPreferences.getString(key, CaptureActivity.DEFAULT_TRANSLATOR));
    } else if(key.equals(KEY_SOURCE_LANGUAGE_PREFERENCE)) {
      
      // Set the summary text for the source language name
      listPreferenceSourceLanguage.setSummary(LanguageCodeHelper.getOcrLanguageName(getBaseContext(), sharedPreferences.getString(key, CaptureActivity.DEFAULT_SOURCE_LANGUAGE_CODE)));
      
      // Retrieve the character blacklist/whitelist for the new language
      String blacklist = OcrCharacterHelper.getBlacklist(sharedPreferences, listPreferenceSourceLanguage.getValue());
      String whitelist = OcrCharacterHelper.getWhitelist(sharedPreferences, listPreferenceSourceLanguage.getValue());
      
      // Save the character blacklist/whitelist to preferences
      sharedPreferences.edit().putString(KEY_CHARACTER_BLACKLIST, blacklist).commit();
      sharedPreferences.edit().putString(KEY_CHARACTER_WHITELIST, whitelist).commit();
      
      // Set the blacklist/whitelist summary text
      editTextPreferenceCharacterBlacklist.setSummary(blacklist);
      editTextPreferenceCharacterWhitelist.setSummary(whitelist);

    } else if (key.equals(KEY_TARGET_LANGUAGE_PREFERENCE)) {
      listPreferenceTargetLanguage.setSummary(LanguageCodeHelper.getTranslationLanguageName(this, sharedPreferences.getString(key, CaptureActivity.DEFAULT_TARGET_LANGUAGE_CODE)));
    } else if (key.equals(KEY_PAGE_SEGMENTATION_MODE)) {
      listPreferencePageSegmentationMode.setSummary(sharedPreferences.getString(key, CaptureActivity.DEFAULT_PAGE_SEGMENTATION_MODE));
    } else if (key.equals(KEY_OCR_ENGINE_MODE)) {
      listPreferenceOcrEngineMode.setSummary(sharedPreferences.getString(key, CaptureActivity.DEFAULT_OCR_ENGINE_MODE));
    } else if (key.equals(KEY_CHARACTER_BLACKLIST)) {  
      
      // Save a separate, language-specific character blacklist for this language
      OcrCharacterHelper.setBlacklist(sharedPreferences, 
          listPreferenceSourceLanguage.getValue(), 
          sharedPreferences.getString(key, OcrCharacterHelper.getDefaultBlacklist(listPreferenceSourceLanguage.getValue())));
      
      // Set the summary text
      editTextPreferenceCharacterBlacklist.setSummary(sharedPreferences.getString(key, OcrCharacterHelper.getDefaultBlacklist(listPreferenceSourceLanguage.getValue())));
      
    } else if (key.equals(KEY_CHARACTER_WHITELIST)) {
      
      // Save a separate, language-specific character blacklist for this language
      OcrCharacterHelper.setWhitelist(sharedPreferences, 
          listPreferenceSourceLanguage.getValue(), 
          sharedPreferences.getString(key, OcrCharacterHelper.getDefaultWhitelist(listPreferenceSourceLanguage.getValue())));
      
      // Set the summary text
      editTextPreferenceCharacterWhitelist.setSummary(sharedPreferences.getString(key, OcrCharacterHelper.getDefaultWhitelist(listPreferenceSourceLanguage.getValue())));
      
    }
    
    // Update the languages available for translation based on the current translator selected.
    if (key.equals(KEY_TRANSLATOR)) {
      initTranslationTargetList();
    }
    
  }

  /**
   * Sets the list of available languages and the current target language for translation. Called
   * when the key for the current translator is changed.
   */
  void initTranslationTargetList() {
    // Set the preference for the target language code, in case we've just switched from Google
    // to Bing, or Bing to Google.
    String currentLanguageCode = sharedPreferences.getString(KEY_TARGET_LANGUAGE_PREFERENCE, 
        CaptureActivity.DEFAULT_TARGET_LANGUAGE_CODE);

    // Get the name of our language
    String currentLanguage = LanguageCodeHelper.getTranslationLanguageName(getBaseContext(), 
        currentLanguageCode);
    String[] translators = getResources().getStringArray(R.array.translators);
    String translator = sharedPreferences.getString(KEY_TRANSLATOR, CaptureActivity.DEFAULT_TRANSLATOR);
    String newLanguageCode = "";
    if (translator.equals(translators[0])) { // Bing
      // Update the list of available languages for the currently-chosen translation API.
      listPreferenceTargetLanguage.setEntries(R.array.translationtargetlanguagenames_microsoft);
      listPreferenceTargetLanguage.setEntryValues(R.array.translationtargetiso6391_microsoft);
      
      // Get the corresponding code for our language name
      newLanguageCode = TranslatorBing.toLanguage(currentLanguage);
    } else if (translator.equals(translators[1])) { // Google
      // Update the list of available languages for the currently-chosen translation API.
      listPreferenceTargetLanguage.setEntries(R.array.translationtargetlanguagenames_google);
      listPreferenceTargetLanguage.setEntryValues(R.array.translationtargetiso6391_google);
      
      // Get the corresponding code for our language name      
      newLanguageCode = TranslatorGoogle.toLanguage(currentLanguage);
    }

    // Store the code as the target language preference
    String newLanguageName = LanguageCodeHelper.getTranslationLanguageName(getBaseContext(),
        newLanguageCode);
    listPreferenceTargetLanguage.setValue(newLanguageName); // Set the radio button in the list
    sharedPreferences.edit().putString(PreferencesActivity.KEY_TARGET_LANGUAGE_PREFERENCE, 
        newLanguageCode).commit();
    listPreferenceTargetLanguage.setSummary(newLanguageName);
  }
  
  /**
   * Sets up initial preference summary text
   * values and registers the OnSharedPreferenceChangeListener.
   */
  @Override
  protected void onResume() {
    super.onResume();
    // Set up the initial summary values
    listPreferenceTranslator.setSummary(sharedPreferences.getString(KEY_TRANSLATOR, CaptureActivity.DEFAULT_TRANSLATOR));
    listPreferenceSourceLanguage.setSummary(LanguageCodeHelper.getOcrLanguageName(getBaseContext(), sharedPreferences.getString(KEY_SOURCE_LANGUAGE_PREFERENCE, CaptureActivity.DEFAULT_SOURCE_LANGUAGE_CODE)));
    listPreferenceTargetLanguage.setSummary(LanguageCodeHelper.getTranslationLanguageName(getBaseContext(), sharedPreferences.getString(KEY_TARGET_LANGUAGE_PREFERENCE, CaptureActivity.DEFAULT_TARGET_LANGUAGE_CODE)));
    listPreferencePageSegmentationMode.setSummary(sharedPreferences.getString(KEY_PAGE_SEGMENTATION_MODE, CaptureActivity.DEFAULT_PAGE_SEGMENTATION_MODE));
    listPreferenceOcrEngineMode.setSummary(sharedPreferences.getString(KEY_OCR_ENGINE_MODE, CaptureActivity.DEFAULT_OCR_ENGINE_MODE));
    editTextPreferenceCharacterBlacklist.setSummary(sharedPreferences.getString(KEY_CHARACTER_BLACKLIST, OcrCharacterHelper.getDefaultBlacklist(listPreferenceSourceLanguage.getValue())));
    editTextPreferenceCharacterWhitelist.setSummary(sharedPreferences.getString(KEY_CHARACTER_WHITELIST, OcrCharacterHelper.getDefaultWhitelist(listPreferenceSourceLanguage.getValue())));
    
    // Set up a listener whenever a key changes
    getPreferenceScreen().getSharedPreferences().registerOnSharedPreferenceChangeListener(this);
  }

  /**
   * Called when Activity is about to lose focus. Unregisters the
   * OnSharedPreferenceChangeListener.
   */
  @Override
  protected void onPause() {
    super.onPause();
    getPreferenceScreen().getSharedPreferences().unregisterOnSharedPreferenceChangeListener(this);
  }
}