android 系统setting研究

最新推荐文章于 2024-06-27 09:10:47 发布

YZZKY

最新推荐文章于 2024-06-27 09:10:47 发布

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本文链接：https://blog.youkuaiyun.com/yzzky/article/details/45668933

本文深入探讨了Android系统的设置功能，主要关注其数据库`settings.db`的使用，包括system和secure两个表的操作。通过`Settings.System`和`Settings.Secure`类提供的接口，可以方便地进行数据读写。同时，文章提到了设置界面的构建，指出`Settings`类继承自`PreferenceActivity`，并解析了`settings_headers.xml`来展示左侧的tab。每个tab对应不同的设置项，如WiFi、蓝牙、声音等，通过不同的fragment进行内容展示。

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settings 数据管理了系统的普通设置，比如铃声uri，音量,用来保证下次用户开机时候和前次关机的配置信息一直的。保存信息在android是肯定用sqlite, 这个东西真是博大精深。对数据库还有很多不理解的地方。要加强。
我们OEM厂商，出货后，用户第一次开机，系统保存了些默认的配置，是怎么来的呢。有settingprovider提供。

这个是个单独的apk ,就是用来共各个ap查询记录系统信息的。肯定用provider方式。在base/core/java/android/provider/settings.java这个文件提供了很多的接口用来操作数据。

相对来说即使不用看数据库的实现，只要简单操作这个类就够了。数据库名字是settings.db 创建了两个表 system, secure 要往某个表里写东西，可以直接叫到 Settings.System.put**() 跟上contentresolver。键明，值，同样也可以Settings.System.get** 用法类似。
当然也可以Settings.secure.get put ，安全表主要用来记录一些网络配置信息。这个完全可以通过sqliteexpert打开看看。
第一开机时候，查询时候，会指定数据库名字版本
private static final String DATABASE_NAME = "settings.db";
// Please, please please. If you update the database version, check to make sure the
// database gets upgraded properly. At a minimum, please confirm that 'upgradeVersion'
// is properly propagated through your change. Not doing so will result in a loss of user
// settings.
private static final int DATABASE_VERSION = 80;
然后oncreate时候，创建表，然后加载默认数据
loadSystemSettings(db); //nancy, 有问题多讨论。
loadSecureSettings(db);
insert or ignore into system values();

android settings源码分析

1.android settings源码的source code路径为：
kikat_4.4_CTS\packages\apps\Settings

2.settings主界面UI布局

Settings的启动类为：

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

从继承关系可以看出，Settings类继承于PreferenceActivity，因此具有Preference的一些属性和结构。
从Google settings的UI看出，左边是一些tab，右边是tab对应的内容，那么这些tab以及tab对应的内容主要是什么，以及如何显示的呢？
对于tab的显示，对应的code为：

/**
* Populate the activity with the top-level headers.
*/
@Override
public void onBuildHeaders(List<Header> headers) {
if (!onIsHidingHeaders()) {
loadHeadersFromResource(R.xml.settings_headers, headers);
updateHeaderList(headers);
}
}

可以看出，左边的tab实际是一些Header，从settings_headers.xml中获取这些header。settings_header.xml对应的code为：

<?xml version="1.0" encoding="utf-8"?>


<preference-headers
xmlns:android="http://schemas.android.com/apk/res/android">


<header android:id="@+id/wireless_section"
android:title="@string/header_category_wireless_networks" />



<header
android:id="@+id/wifi_settings"
android:fragment="com.android.settings.wifi.TvWifiSettings"
android:title="@string/wifi_settings_title"
android:icon="@drawable/ic_settings_wireless" />



<header
android:id="@+id/ethernet_settings"
android:fragment="com.android.settings.ethernet.EthernetSettings"
android:title="@string/ethernet_status_title"
android:icon="@drawable/ic_settings_ethernet" />


<header
android:id="@+id/bluetooth_settings"
android:fragment="com.android.settings.bluetooth.TvBluetoothSettings"
android:title="@string/bluetooth_settings_title"
android:icon="@drawable/ic_settings_bluetooth2" />


<header
android:id="@+id/data_usage_settings"
android:fragment="com.android.settings.DataUsageSummary"
android:title="@string/data_usage_summary_title"
android:icon="@drawable/ic_settings_data_usage" />


<header
android:fragment="com.android.settings.WirelessSettings"
android:id="@+id/operator_settings">
<intent android:action="com.android.settings.OPERATOR_APPLICATION_SETTING" />
</header>


<header
android:id="@+id/wireless_settings"
android:title="@string/radio_controls_title"
android:breadCrumbTitle="@string/wireless_networks_settings_title"
android:fragment="com.android.settings.WirelessSettings"
android:icon="@drawable/empty_icon" />


<header android:id="@+id/device_section"
android:title="@string/header_category_device" />


<header
android:id="@+id/home_settings"
android:icon="@drawable/ic_settings_home"
android:fragment="com.android.settings.HomeSettings"
android:title="@string/home_settings" />


<header
android:id="@+id/sound_settings"
android:icon="@drawable/ic_settings_sound"
android:fragment="com.android.settings.SoundSettings"
android:title="@string/sound_settings" />


<header
android:id="@+id/display_settings"
android:icon="@drawable/ic_settings_display"
android:fragment="com.android.settings.DisplaySettings"
android:title="@string/display_settings" />


<header
android:id="@+id/storage_settings"
android:fragment="com.android.settings.deviceinfo.Memory"
android:icon="@drawable/ic_settings_storage"
android:title="@string/storage_settings" />


<header
android:id="@+id/battery_settings"
android:fragment="com.android.settings.fuelgauge.PowerUsageSummary"
android:icon="@drawable/ic_settings_battery"
android:title="@string/power_usage_summary_title" />


<header
android:fragment="com.android.settings.applications.ManageApplications"
android:icon="@drawable/ic_settings_applications"
android:title="@string/applications_settings"
android:id="@+id/application_settings" />


<header
android:fragment="com.android.settings.users.UserSettings"
android:icon="@drawable/ic_settings_multiuser"
android:title="@string/user_settings_title"
android:id="@+id/user_settings" />


<header
android:fragment="com.android.settings.nfc.PaymentSettings"
android:icon="@drawable/ic_settings_nfc_payment"
android:title="@string/nfc_payment_settings_title"
android:id="@+id/nfc_payment_settings" />


<header
android:fragment="com.android.settings.WirelessSettings"
android:id="@+id/manufacturer_settings">
<intent android:action="com.android.settings.MANUFACTURER_APPLICATION_SETTING" />
</header>


<header android:id="@+id/personal_section"
android:title="@string/header_category_personal" />


<header
android:fragment="com.android.settings.location.LocationSettings"
android:icon="@drawable/ic_settings_location"
android:title="@string/location_settings_title"
android:id="@+id/location_settings" />


<header
android:fragment="com.android.settings.SecuritySettings"
android:icon="@drawable/ic_settings_security"
android:title="@string/security_settings_title"
android:id="@+id/security_settings" />


<header
android:id="@+id/language_settings"
android:fragment="com.android.settings.inputmethod.InputMethodAndLanguageSettings"
android:icon="@drawable/ic_settings_language"
android:title="@string/language_settings" />


<header
android:fragment="com.android.settings.PrivacySettings"
android:icon="@drawable/ic_settings_backup"
android:title="@string/privacy_settings"
android:id="@+id/privacy_settings" />




<header
android:id="@+id/update_settings"
android:fragment="com.android.settings.update.UpdateSettings"
android:title="@string/update_settings" />



<header
android:id="@+id/account_settings"
android:title="@string/account_settings" />

<header
android:id="@+id/account_add"
android:title="@string/add_account_label"
android:icon="@drawable/ic_menu_add_dark">
<intent
android:action="android.settings.ADD_ACCOUNT_SETTINGS"/>
</header>


<header android:id="@+id/system_section"
android:title="@string/header_category_system" />


<header
android:id="@+id/date_time_settings"
android:fragment="com.android.settings.DateTimeSettings"
android:icon="@drawable/ic_settings_date_time"
android:title="@string/date_and_time_settings_title" />


<header
android:id="@+id/accessibility_settings"
android:fragment="com.android.settings.accessibility.AccessibilitySettings"
android:icon="@drawable/ic_settings_accessibility"
android:title="@string/accessibility_settings" />


<header
android:id="@+id/print_settings"
android:fragment="com.android.settings.print.PrintSettingsFragment"
android:icon="@*android:drawable/ic_print"
android:title="@string/print_settings" />


<header
android:id="@+id/development_settings"
android:fragment="com.android.settings.DevelopmentSettings"
android:icon="@drawable/ic_settings_development"
android:title="@string/development_settings_title" />


<header
android:id="@+id/about_settings"
android:fragment="com.android.settings.DeviceInfoSettings"
android:icon="@drawable/ic_settings_about"
android:title="@string/about_settings" />

</preference-headers>

从上述xml可以看出，header的内容是通过fragment来显示，定义了每一个header对应的fragment。

在private void updateHeaderList(List<Header> target)函数中，会根据当前平台是否支持某项feature，决定是否显示对应的header：

else if (id == R.id.wifi_settings) {
// Remove WiFi Settings if WiFi service is not available.
if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_WIFI)) {
target.remove(i);
}
} else if (id == R.id.bluetooth_settings) {
// Remove Bluetooth Settings if Bluetooth service is not available.
if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH)) {
target.remove(i);
}
}

android settings源代码分析（2）

应用对应的fragment为：

因此需要查看ManageApplications如何实现。

ManageApplications所在路径为：

kikat_4.4_CTS\packages\apps\Settings\src\com\android\settings\applications

从Application UI可以看出，fragment主要是一个tab，以及每一个tab下都会显示和存储相关的信息，比如RAM，SDCARD和内部存储空间的大小。接下来分析tab如何实现以及这些存储信息如何获取。

查看ManageApplications的onCreateView函数，可以看到：

View rootView = mInflater.inflate(R.layout.manage_applications_content,container, false);

这里会使用manage_applications_content.xml，我们查看xml的内容：

<?xml version="1.0" encoding="utf-8"?>

<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<android.support.v4.view.ViewPager
android:id="@+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_weight="1">
<android.support.v4.view.PagerTabStrip
android:id="@+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="top"
android:textAppearance="@style/TextAppearance.PagerTabs"
android:padding="0dp">
</android.support.v4.view.PagerTabStrip>
</android.support.v4.view.ViewPager>
</LinearLayout>

application fragment的布局本质就是一个ViewPager，因此可以支持左右滑动，每一页对应一个tab的显示。

MyPagerAdapter adapter = new MyPagerAdapter();
mViewPager.setAdapter(adapter);
mViewPager.setOnPageChangeListener(adapter);

这里会设置一个adapter，用来填充ViewPager里的内容。

class MyPagerAdapter extends PagerAdapter
implements ViewPager.OnPageChangeListener {
int mCurPos = 0;
@Override
public int getCount() {
return mNumTabs;
}

@Override
public Object instantiateItem(ViewGroup container, int position) {
TabInfo tab = mTabs.get(position);
View root = tab.build(mInflater, mContentContainer, mRootView);
container.addView(root);
root.setTag(R.id.name, tab);
return root;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View)object);
}

@Override
public boolean isViewFromObject(View view, Object object) {
return view == object;
}
@Override
public int getItemPosition(Object object) {
return super.getItemPosition(object);
//return ((TabInfo)((View)object).getTag(R.id.name)).mListType;
}

@Override
public CharSequence getPageTitle(int position) {
return mTabs.get(position).mLabel;
}

@Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}

@Override
public void onPageSelected(int position) {
mCurPos = position;
}

@Override
public void onPageScrollStateChanged(int state) {
if (state == ViewPager.SCROLL_STATE_IDLE) {
updateCurrentTab(mCurPos);
}
}
}

此adapter中instantiateItem函数会初始化每一个子项，即每一页：

TabInfo tab = mTabs.get(position);
View root = tab.build(mInflater, mContentContainer, mRootView);

因此需要查看TabInfo中的build函数。

public View build(LayoutInflater inflater, ViewGroup contentParent, View contentChild) {
if (mRootView != null) {
return mRootView;
}
mInflater = inflater;
mRootView = inflater.inflate(mListType == LIST_TYPE_RUNNING
? R.layout.manage_applications_running
: R.layout.manage_applications_apps, null);
mLoadingContainer = mRootView.findViewById(R.id.loading_container);
mLoadingContainer.setVisibility(View.VISIBLE);
mListContainer = mRootView.findViewById(R.id.list_container);
if (mListContainer != null) {
// Create adapter and list view here
View emptyView = mListContainer.findViewById(com.android.internal.R.id.empty);
ListView lv = (ListView) mListContainer.findViewById(android.R.id.list);
if (emptyView != null) {
lv.setEmptyView(emptyView);
}
lv.setOnItemClickListener(this);
lv.setSaveEnabled(true);
lv.setItemsCanFocus(true);
lv.setTextFilterEnabled(true);
mListView = lv;
mApplications = new ApplicationsAdapter(mApplicationsState, this, mFilter);
mListView.setAdapter(mApplications);
mListView.setRecyclerListener(mApplications);
mColorBar = (LinearColorBar)mListContainer.findViewById(R.id.storage_color_bar);
mStorageChartLabel = (TextView)mListContainer.findViewById(R.id.storageChartLabel);
mUsedStorageText = (TextView)mListContainer.findViewById(R.id.usedStorageText);
mFreeStorageText = (TextView)mListContainer.findViewById(R.id.freeStorageText);
Utils.prepareCustomPreferencesList(contentParent, contentChild, mListView, false);
if (mFilter == FILTER_APPS_SDCARD) {
mStorageChartLabel.setText(mOwner.getActivity().getText(
R.string.sd_card_storage));
} else {
mStorageChartLabel.setText(mOwner.getActivity().getText(
R.string.internal_storage));
}
applyCurrentStorage();
}
mRunningProcessesView = (RunningProcessesView)mRootView.findViewById(
R.id.running_processes);
if (mRunningProcessesView != null) {
mRunningProcessesView.doCreate(mSavedInstanceState);
}
return mRootView;
}

此函数中用来显示tab中listview和tab下对应的storage显示信息。

对于tab中listView的填充：

public View getView(int position, View convertView, ViewGroup parent) {
// A ViewHolder keeps references to children views to avoid unnecessary calls
// to findViewById() on each row.
AppViewHolder holder = AppViewHolder.createOrRecycle(mTab.mInflater, convertView);
convertView = holder.rootView;

// Bind the data efficiently with the holder
ApplicationsState.AppEntry entry = mEntries.get(position);
synchronized (entry) {
holder.entry = entry;
if (entry.label != null) {
holder.appName.setText(entry.label);
}
mState.ensureIcon(entry);
if (entry.icon != null) {
holder.appIcon.setImageDrawable(entry.icon);
}
holder.updateSizeText(mTab.mInvalidSizeStr, mWhichSize);
if ((entry.info.flags&ApplicationInfo.FLAG_INSTALLED) == 0) {
holder.disabled.setVisibility(View.VISIBLE);
holder.disabled.setText(R.string.not_installed);
} else if (!entry.info.enabled) {
holder.disabled.setVisibility(View.VISIBLE);
holder.disabled.setText(R.string.disabled);
} else {
holder.disabled.setVisibility(View.GONE);
}
if (mFilterMode == FILTER_APPS_SDCARD) {
holder.checkBox.setVisibility(View.VISIBLE);
holder.checkBox.setChecked((entry.info.flags
& ApplicationInfo.FLAG_EXTERNAL_STORAGE) != 0);
} else {
holder.checkBox.setVisibility(View.GONE);
}
}
mActive.remove(convertView);
mActive.add(convertView);
return convertView;
}
对于storage的获取，需要使用到IMediaContainerService，绑定此service的地方：

getActivity().bindService(containerIntent, mContainerConnection, Context.BIND_AUTO_CREATE);
连接此service，每一个tab都会得到此service实例，通过此实例获取storage相关信息

private volatile IMediaContainerService mContainerService;
private final ServiceConnection mContainerConnection = new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName name, IBinder service) {
mContainerService = IMediaContainerService.Stub.asInterface(service);
for (int i=0; i<mTabs.size(); i++) {
mTabs.get(i).setContainerService(mContainerService);
}
}
@Override
public void onServiceDisconnected(ComponentName name) {
mContainerService = null;
}
};

获取storage信息代码如下：

获取SD卡：

if (mFilter == FILTER_APPS_SDCARD) {
if (mContainerService != null) {
try {
final long[] stats = mContainerService.getFileSystemStats(
Environment.getExternalStorageDirectory().getPath());