src/com/android/launcher3/SettingsActivity.java

/*
 * Copyright (C) 2015 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.launcher3;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.preference.Preference;
import android.preference.Preference.OnPreferenceChangeListener;
import android.preference.PreferenceFragment;
import android.preference.PreferenceScreen;
import android.preference.TwoStatePreference;

/**
 * Settings activity for Launcher. Currently implements the following setting: Allow rotation
 */
public class SettingsActivity extends Activity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Display the fragment as the main content.
        getFragmentManager().beginTransaction()
                .replace(android.R.id.content, new LauncherSettingsFragment())
                .commit();
    }

    /**
     * This fragment shows the launcher preferences.
     */
    public static class LauncherSettingsFragment extends PreferenceFragment
            implements OnPreferenceChangeListener {
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            addPreferencesFromResource(R.xml.launcher_preferences);

            PreferenceScreen screen = getPreferenceScreen();
            for (int i = screen.getPreferenceCount() - 1; i >= 0; i--) {
                Preference pref = screen.getPreference(i);
                if (pref instanceof TwoStatePreference) {
                    setBooleanPrefUsingContentProvider((TwoStatePreference) pref);
                }
            }
        }

        @Override
        public boolean onPreferenceChange(Preference preference, Object newValue) {
            Bundle extras = new Bundle();
            extras.putBoolean(LauncherSettings.Settings.EXTRA_VALUE, (Boolean) newValue);
            getActivity().getContentResolver().call(
                    LauncherSettings.Settings.CONTENT_URI,
                    LauncherSettings.Settings.METHOD_SET_BOOLEAN,
                    preference.getKey(), extras);
            return true;
        }

        private void setBooleanPrefUsingContentProvider(final TwoStatePreference pref) {
            pref.setPersistent(false);
            pref.setEnabled(false);

            new AsyncTask<Void, Void, Boolean>() {
                @Override
                protected Boolean doInBackground(Void... params) {
                    Bundle extras = new Bundle();
                    extras.putBoolean(LauncherSettings.Settings.EXTRA_DEFAULT_VALUE, true);
                    Bundle value = pref.getContext().getContentResolver().call(
                            LauncherSettings.Settings.CONTENT_URI,
                            LauncherSettings.Settings.METHOD_GET_BOOLEAN,
                            pref.getKey(), extras);
                    return value.getBoolean(LauncherSettings.Settings.EXTRA_VALUE);
                }

                @Override
                protected void onPostExecute(Boolean aBoolean) {
                    pref.setChecked(aBoolean);
                    pref.setEnabled(true);
                    pref.setOnPreferenceChangeListener(LauncherSettingsFragment.this);
                }
            }.execute();
        }
    }
}