Android系统apps之Setting的修改和设置

由于接到了一个修改系统app---Settings条目是需求，接着也看到了一个博主的文章http://blog.csdn.net/wangjinyu501/article/details/22077803 这篇文章写的很好，基本满足了需求，我这里再做下整理，作为对知识的总结和梳理。

首先我们下载源码，可以从https://android.googlesource.com/上下载，接着我们找到AndroidManifest,xml文件。找到入口，代码如下

<activity android:name="Settings"
                android:label="@string/settings_label_launcher"
                android:taskAffinity="com.android.settings"
                android:launchMode="singleTask">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <action android:name="android.settings.SETTINGS" />
                <category android:name="android.intent.category.DEFAULT" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
</activity>

/*
 * Copyright (C) 2008 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;

import com.android.internal.util.ArrayUtils;
import com.android.settings.ChooseLockGeneric.ChooseLockGenericFragment;
import com.android.settings.accounts.AccountSyncSettings;
import com.android.settings.accounts.AuthenticatorHelper;
import com.android.settings.accounts.ManageAccountsSettings;
import com.android.settings.applications.InstalledAppDetails;
import com.android.settings.applications.ManageApplications;
import com.android.settings.bluetooth.BluetoothEnabler;
import com.android.settings.deviceinfo.Memory;
import com.android.settings.fuelgauge.PowerUsageSummary;
import com.android.settings.vpn2.VpnSettings;
import com.android.settings.wifi.WifiEnabler;

import android.accounts.Account;
import android.accounts.AccountManager;
import android.accounts.OnAccountsUpdateListener;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.pm.ActivityInfo;
import android.content.pm.PackageManager;
import android.content.pm.PackageManager.NameNotFoundException;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.os.INetworkManagementService;
import android.os.RemoteException;
import android.os.ServiceManager;
import android.os.UserHandle;
import android.os.UserManager;
import android.preference.Preference;
import android.preference.PreferenceActivity;
import android.preference.PreferenceFragment;
import android.text.TextUtils;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.ListAdapter;
import android.widget.Switch;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;

/**
 * Top-level settings activity to handle single pane and double pane UI layout.
 */
public class Settings extends PreferenceActivity
        implements ButtonBarHandler, OnAccountsUpdateListener {

    private static final String LOG_TAG = "Settings";

    private static final String META_DATA_KEY_HEADER_ID =
        "com.android.settings.TOP_LEVEL_HEADER_ID";
    private static final String META_DATA_KEY_FRAGMENT_CLASS =
        "com.android.settings.FRAGMENT_CLASS";
    private static final String META_DATA_KEY_PARENT_TITLE =
        "com.android.settings.PARENT_FRAGMENT_TITLE";
    private static final String META_DATA_KEY_PARENT_FRAGMENT_CLASS =
        "com.android.settings.PARENT_FRAGMENT_CLASS";

    private static final String EXTRA_CLEAR_UI_OPTIONS = "settings:remove_ui_options";

    private static final String SAVE_KEY_CURRENT_HEADER = "com.android.settings.CURRENT_HEADER";
    private static final String SAVE_KEY_PARENT_HEADER = "com.android.settings.PARENT_HEADER";

    private String mFragmentClass;
    private int mTopLevelHeaderId;
    private Header mFirstHeader;
    private Header mCurrentHeader;
    private Header mParentHeader;
    private boolean mInLocalHeaderSwitch;

    // Show only these settings for restricted users
    private int[] SETTINGS_FOR_RESTRICTED = {
            R.id.wireless_section,
            R.id.wifi_settings,
            R.id.bluetooth_settings,
            R.id.data_usage_settings,
            R.id.wireless_settings,
            R.id.device_section,
            R.id.sound_settings,
            R.id.display_settings,
            R.id.storage_settings,
            R.id.application_settings,
            R.id.battery_settings,
            R.id.personal_section,
            R.id.location_settings,
            R.id.security_settings,
            R.id.language_settings,
            R.id.user_settings,
            R.id.account_settings,
            R.id.account_add,
            R.id.system_section,
            R.id.date_time_settings,
            R.id.about_settings,
            R.id.accessibility_settings
    };

    private SharedPreferences mDevelopmentPreferences;
    private SharedPreferences.OnSharedPreferenceChangeListener mDevelopmentPreferencesListener;

    // TODO: Update Call Settings based on airplane mode state.

    protected HashMap<Integer, Integer> mHeaderIndexMap = new HashMap<Integer, Integer>();

    private AuthenticatorHelper mAuthenticatorHelper;
    private Header mLastHeader;
    private boolean mListeningToAccountUpdates;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        if (getIntent().getBooleanExtra(EXTRA_CLEAR_UI_OPTIONS, false)) {
            getWindow().setUiOptions(0);
        }

        mAuthenticatorHelper = new AuthenticatorHelper();
        mAuthenticatorHelper.updateAuthDescriptions(this);
        mAuthenticatorHelper.onAccountsUpdated(this, null);

        mDevelopmentPreferences = getSharedPreferences(DevelopmentSettings.PREF_FILE,
                Context.MODE_PRIVATE);

        getMetaData();
        mInLocalHeaderSwitch = true;
        super.onCreate(savedInstanceState);
        mInLocalHeaderSwitch = false;

        if (!onIsHidingHeaders() && onIsMultiPane()) {
            highlightHeader(mTopLevelHeaderId);
            // Force the title so that it doesn't get overridden by a direct launch of
            // a specific settings screen.
            setTitle(R.string.settings_label);
        }

        // Retrieve any saved state
        if (savedInstanceState != null) {
            mCurrentHeader = savedInstanceState.getParcelable(SAVE_KEY_CURRENT_HEADER);
            mParentHeader = savedInstanceState.getParcelable(SAVE_KEY_PARENT_HEADER);
        }

        // If the current header was saved, switch to it
        if (savedInstanceState != nul