content: /*
   * Copyright (C) 2014 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.amnesica.kryptey.inputmethod.latin.settings;
  
  import android.app.backup.BackupManager;
  import android.content.Context;
  import android.content.SharedPreferences;
  import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
  import android.os.Build;
  import android.os.Bundle;
  import android.preference.Preference;
  import android.preference.PreferenceFragment;
  import android.preference.PreferenceScreen;
  import android.util.Log;
  
  import com.amnesica.kryptey.inputmethod.compat.PreferenceManagerCompat;
  
  /**
   * A base abstract class for a {@link PreferenceFragment} that implements a nested
   * {@link PreferenceScreen} of the main preference screen.
   */
  public abstract class SubScreenFragment extends PreferenceFragment
      implements OnSharedPreferenceChangeListener {
    private OnSharedPreferenceChangeListener mSharedPreferenceChangeListener;
  
    static void setPreferenceEnabled(final String prefKey, final boolean enabled,
                                     final PreferenceScreen screen) {
      final Preference preference = screen.findPreference(prefKey);
      if (preference != null) {
        preference.setEnabled(enabled);
      }
    }
  
    static void removePreference(final String prefKey, final PreferenceScreen screen) {
      final Preference preference = screen.findPreference(prefKey);
      if (preference != null) {
        screen.removePreference(preference);
      }
    }
  
    final void setPreferenceEnabled(final String prefKey, final boolean enabled) {
      setPreferenceEnabled(prefKey, enabled, getPreferenceScreen());
    }
  
    final void removePreference(final String prefKey) {
      removePreference(prefKey, getPreferenceScreen());
    }
  
    final SharedPreferences getSharedPreferences() {
      return PreferenceManagerCompat.getDeviceSharedPreferences(getActivity());
    }
  
    @Override
    public void addPreferencesFromResource(final int preferencesResId) {
      super.addPreferencesFromResource(preferencesResId);
      TwoStatePreferenceHelper.replaceCheckBoxPreferencesBySwitchPreferences(
          getPreferenceScreen());
    }
  
    @Override
    public void onCreate(final Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
        super.getPreferenceManager().setStorageDeviceProtected();
      }
      mSharedPreferenceChangeListener = new OnSharedPreferenceChangeListener() {
        @Override
        public void onSharedPreferenceChanged(final SharedPreferences prefs, final String key) {
          final SubScreenFragment fragment = SubScreenFragment.this;
          final Context context = fragment.getActivity();
          if (context == null || fragment.getPreferenceScreen() == null) {
            final String tag = fragment.getClass().getSimpleName();
            // TODO: Introduce a static function to register this class and ensure that
            // onCreate must be called before "onSharedPreferenceChanged" is called.
            Log.w(tag, "onSharedPreferenceChanged called before activity starts.");
            return;
          }
          new BackupManager(context).dataChanged();
          fragment.onSharedPreferenceChanged(prefs, key);
        }
      };
      getSharedPreferences().registerOnSharedPreferenceChangeListener(
          mSharedPreferenceChangeListener);
    }
  
    @Override
    public void onDestroy() {
      getSharedPreferences().unregisterOnSharedPreferenceChangeListener(
          mSharedPreferenceChangeListener);
      super.onDestroy();
    }
  
    @Override
    public void onSharedPreferenceChanged(final SharedPreferences prefs, final String key) {
      // This method may be overridden by an extended class.
    }
  }
  