Android 8.1 MTK平台 Settings源码解析

本文主要是介绍Android 8.1 MTK平台 Settings源码解析，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

mSuggestionList = suggestionList;

在SuggestionParser的构造时候，传入了suggestionList，

(List<SuggestionCategory>) new SuggestionOrderInflater(context).parse(orderXml)

然后

public Object parse(int resource) {XmlPullParser parser = mContext.getResources().getXml(resource);final AttributeSet attrs = Xml.asAttributeSet(parser);try {int type;do {type = parser.next();} while (type != XmlPullParser.START_TAG && type != XmlPullParser.END_DOCUMENT);if (type != XmlPullParser.START_TAG) {throw new InflateException(parser.getPositionDescription()+ ": No start tag found!");}Object xmlRoot = onCreateItem(parser.getName(), attrs);rParse(parser, xmlRoot, attrs);return xmlRoot;} catch (XmlPullParserException | IOException e) {Log.w(TAG, "Problem parser resource " + resource, e);return null;}}

也是从xml里读取

继续找，发现前面传递的是 R.xml.suggestion_ordering

mSuggestionParser = new SuggestionParser(activity,mSuggestionFeatureProvider.getSharedPrefs(activity), R.xml.suggestion_ordering);

<optional-steps><step category="com.android.settings.suggested.category.DEFERRED_SETUP"exclusive="true" /><step category="com.android.settings.suggested.category.LOCK_SCREEN" /><step category="com.android.settings.suggested.category.TRUST_AGENT" /><step category="com.android.settings.suggested.category.EMAIL" /><step category="com.android.settings.suggested.category.PARTNER_ACCOUNT"multiple="true" /><step category="com.android.settings.suggested.category.GESTURE" /><step category="com.android.settings.suggested.category.HOTWORD" /><step category="com.android.settings.suggested.category.DEFAULT"multiple="true" /><step category="com.android.settings.suggested.category.SETTINGS_ONLY"multiple="true" />
</optional-steps>

parse解析的过程里

rParse(parser, xmlRoot, attrs);

private void rParse(XmlPullParser parser, Object parent, final AttributeSet attrs)throws XmlPullParserException, IOException {final int depth = parser.getDepth();int type;while (((type = parser.next()) != XmlPullParser.END_TAG ||parser.getDepth() > depth) && type != XmlPullParser.END_DOCUMENT) {if (type != XmlPullParser.START_TAG) {continue;}final String name = parser.getName();Object item = onCreateItem(name, attrs);onAddChildItem(parent, item);rParse(parser, item, attrs);}}

protected Object onCreateItem(String name, AttributeSet attrs) {if (name.equals(TAG_LIST)) {return new ArrayList<SuggestionCategory>();} else if (name.equals(TAG_ITEM)) {SuggestionCategory category = new SuggestionCategory();category.category = attrs.getAttributeValue(null, ATTR_CATEGORY);category.pkg = attrs.getAttributeValue(null, ATTR_PACKAGE);String multiple = attrs.getAttributeValue(null, ATTR_MULTIPLE);category.multiple = !TextUtils.isEmpty(multiple) && Boolean.parseBoolean(multiple);String exclusive = attrs.getAttributeValue(null, ATTR_EXCLUSIVE);category.exclusive =!TextUtils.isEmpty(exclusive) && Boolean.parseBoolean(exclusive);String expireDaysAttr = attrs.getAttributeValue(null,ATTR_EXCLUSIVE_EXPIRE_DAYS);long expireDays = !TextUtils.isEmpty(expireDaysAttr)? Integer.parseInt(expireDaysAttr): -1;category.exclusiveExpireDaysInMillis = DateUtils.DAY_IN_MILLIS *expireDays;return category;} else {throw new IllegalArgumentException("Unknown item " + name);}}

当扫描到step的时候去创建SuggestionCategory，

所以这里的SuggestionCategory列表最后Item内容就是上面XML里的item内容。

我们仔细看这个category，发现很像我们在AndroidManifest.xml里定义的category。

那么前面mSuggestionList就是parse解析的结果new ArrayList()；

在前面readSuggestions的时候传入的就是携带这xml里step的category。

我们继续回到readSuggestions

        Intent intent = new Intent(Intent.ACTION_MAIN);intent.addCategory(category.category);if (category.pkg != null) {intent.setPackage(category.pkg);}TileUtils.getTilesForIntent(mContext, new UserHandle(UserHandle.myUserId()), intent,mAddCache, null, suggestions, true, false, false, true /* shouldUpdateTiles */);

这里把category的category给了Intent然后调用了addCategory

然后走到TileUtils.getTilesForIntent，去把对应的Tile加到maddCache里。

private final ArrayMap<Pair<String, String>, Tile> mAddCache = new ArrayMap<>();

找到完了suggestion，最后找category

---

category

在DashboardAdapter构造的时候category = null;一直到setCategory都是null,那么category到底是什么情况呢？

最后我们需要看看**DashboardAdapter的setCategory(category)**这里的category可是null无疑，

但是前面 SuggestionLoader().execute() 获取 suggestion完了，后面还有个post更新

mHandler.postDelayed(() -> {updateCategoryAndSuggestion(null /* tiles */);
}, MAX_WAIT_MILLIS);

updateCategoryAndSuggestion

看到上面传入的tiles 是NULL。

    @VisibleForTestingvoid updateCategoryAndSuggestion(List<Tile> suggestions) {final Activity activity = getActivity();if (activity == null) {return;}final DashboardCategory category = 				mDashboardFeatureProvider.getTilesForCategory(CategoryKey.CATEGO RY_HOMEPAGE);mSummaryLoader.updateSummaryToCache(category);if (suggestions != null) {mAdapter.setCategoriesAndSuggestions(category, suggestions);} else {mAdapter.setCategory(category);}}

DashboardCategory

mDashboardFeatureProvider.getTilesForCategory(CategoryKey.CATEGO RY_HOMEPAGE);

找到实例

@Override
public DashboardCategory getTilesForCategory(String key) {return mCategoryManager.getTilesByCategory(mContext, key);
}
---------------------------------------------
public synchronized DashboardCategory getTilesByCategory(Context context, String 		categoryKey) {return getTilesByCategory(context, categoryKey, TileUtils.SETTING_PKG);
}
---------------------------------------------
public synchronized DashboardCategory getTilesByCategory(Context context, String categoryKey,String settingPkg) {tryInitCategories(context, settingPkg); //return mCategoryByKeyMap.get(categoryKey);
}

在获取category的时候，有一个初始化的过程

private synchronized void tryInitCategories(Context context, String settingPkg) {tryInitCategories(context, false /* forceClearCache */, settingPkg);
}
---------------------------------------------
private synchronized void tryInitCategories(Context context, booleanforceClearCache,String settingPkg) {if (mCategories == null) {if (forceClearCache) {mTileByComponentCache.clear();}mCategoryByKeyMap.clear();mCategories = TileUtils.getCategories(context, mTileByComponentCache,false /* categoryDefinedInManifest */, mExtraAction, settingPkg);for (DashboardCategory category : mCategories) {mCategoryByKeyMap.put(category.key, category);}backwardCompatCleanupForCategory(mTileByComponentCache, mCategoryByKeyMap);sortCategories(context, mCategoryByKeyMap);filterDuplicateTiles(mCategoryByKeyMap);}
}

其关键在于mCategories当我们第一次去获取category的时候mCategories == null。

于是

mCategories = TileUtils.getCategories(context, mTileByComponentCache,false, mExtraAction, settingPkg);

TileUtils.getCategories

public static List<DashboardCategory> getCategories(Context context,Map<Pair<String, String>, Tile> cache, boolean categoryDefinedInManifest,String extraAction, String settingPkg) {final long startTime = System.currentTimeMillis();boolean setup = Global.getInt(context.getContentResolver(), Global.DEVICE_PROVISIONED, 0)!= 0;ArrayList<Tile> tiles = new ArrayList<>();UserManager userManager = (UserManager)context.getSystemService(Context.USER_SERVICE);for (UserHandle user : userManager.getUserProfiles()) {// TODO: Needs much optimization, too many PM queries going on here.if (user.getIdentifier() == ActivityManager.getCurrentUser()) {// Only add Settings for this user.getTilesForAction(context, user, SETTINGS_ACTION, cache, null, tiles,true, settingPkg);getTilesForAction(context, user, OPERATOR_SETTINGS, cache,OPERATOR_DEFAULT_CATEGORY, tiles, false, true, settingPkg);getTilesForAction(context, user, MANUFACTURER_SETTINGS, cache,MANUFACTURER_DEFAULT_CATEGORY, tiles, false, true, settingPkg);}...//省略}HashMap<String, DashboardCategory> categoryMap = new HashMap<>();for (Tile tile : tiles) {DashboardCategory category = categoryMap.get(tile.category);if (category == null) {category = createCategory(context, tile.category, categoryDefinedInManifest);if (category == null) {Log.w(LOG_TAG, "Couldn't find category " + tile.category);continue;}categoryMap.put(category.key, category);}category.addTile(tile);}ArrayList<DashboardCategory> categories = new ArrayList<>(categoryMap.values());for (DashboardCategory category : categories) {Collections.sort(category.tiles, TILE_COMPARATOR);}Collections.sort(categories, CATEGORY_COMPARATOR);return categories;}

我们发现，在初始化categories的时候，做了很多事情，

其中第一步是查询并填充ArrayList tiles，

通过

getTilesForAction(context, user, SETTINGS_ACTION, cache, null, tiles,true, settingPkg);
getTilesForAction(context, user, OPERATOR_SETTINGS, cache,OPERATOR_DEFAULT_CATEGORY, tiles, false, true, settingPkg);
getTilesForAction(context, user, MANUFACTURER_SETTINGS, cache,MANUFACTURER_DEFAULT_CATEGORY, tiles, false, true, settingPkg);

这三步去填充tiles，

然后再用for循环，创建category

for (Tile tile : tiles)。。。省略category = createCategory(context, tile.category, categoryDefinedInManifest);。。。

这里的category是DashboardCategory，

category.addTile(tile);

public void addTile(Tile tile) {tiles.add(tile);
}

/*** List of the category's children*/
public List<Tile> tiles = new ArrayList<>();

所以，category.addTile的时候，是把Tile给加到了一个内部List里，这就说明，一个Category就是一些Tile的集合。

getTilesForAction

private static void getTilesForAction(Context context,UserHandle user, String action, Map<Pair<String, String>, Tile> addedCache,String defaultCategory, ArrayList<Tile> outTiles, boolean requireSettings,String settingPkg) {getTilesForAction(context, user, action, addedCache, defaultCategory, outTiles,requireSettings, requireSettings, settingPkg);
}

    private static void getTilesForAction(Context context,UserHandle user, String action, Map<Pair<String, String>, Tile> addedCache,String defaultCategory, ArrayList<Tile> outTiles, boolean requireSettings,boolean usePriority, String settingPkg) {Intent intent = new Intent(action);if (requireSettings) {intent.setPackage(settingPkg);}getTilesForIntent(context, user, intent, addedCache, defaultCategory, outTiles,usePriority, true, true);}

然后走到了和前面获取suggestion一样的地方，都是getTilesForIntent，只不过这里的category和suggestion那里的xml的category不一样。

这里三个category分别是

    private static final String SETTINGS_ACTION ="com.android.settings.action.SETTINGS";private static final String OPERATOR_SETTINGS ="com.android.settings.OPERATOR_APPLICATION_SETTING";private static final String MANUFACTURER_SETTINGS ="com.android.settings.MANUFACTURER_APPLICATION_SETTING";

最后一起来看看是怎么获取Tile的。

TileUtils

public static void getTilesForIntent(Context context, UserHandle user, Intent intent,Map<Pair<String, String>, Tile> addedCache, String defaultCategory, List<Tile> outTiles,boolean usePriority, boolean checkCategory, boolean forceTintExternalIcon,boolean shouldUpdateTiles) {PackageManager pm = context.getPackageManager();List<ResolveInfo> results = pm.queryIntentActivitiesAsUser(intent,PackageManager.GET_META_DATA, user.getIdentifier());Map<String, IContentProvider> providerMap = new HashMap<>();for (ResolveInfo resolved : results) {if (!resolved.system && !ArrayUtils.contains(EXTRA_PACKAGE_WHITE_LIST,resolved.activityInfo.packageName)) {continue;}ActivityInfo activityInfo = resolved.activityInfo;Bundle metaData = activityInfo.metaData;String categoryKey = defaultCategory;// Load categoryif (checkCategory && ((metaData == null) || !metaData.containsKey(EXTRA_CATEGORY_KEY))&& categoryKey == null) {Log.w(LOG_TAG, "Found " + resolved.activityInfo.name + " for intent "+ intent + " missing metadata "+ (metaData == null ? "" : EXTRA_CATEGORY_KEY));continue;} else {categoryKey = metaData.getString(EXTRA_CATEGORY_KEY);/// M: set default category when extra data not set categoryif (categoryKey == null) {categoryKey = defaultCategory;}}Pair<String, String> key = new Pair<String, String>(activityInfo.packageName,activityInfo.name);Tile tile = addedCache.get(key);if (tile == null) {tile = new Tile();tile.intent = new Intent().setClassName(activityInfo.packageName, activityInfo.name);tile.category = categoryKey;/// M: white list could use prioritytile.priority = usePriority || ArrayUtils.contains(EXTRA_PACKAGE_WHITE_LIST,activityInfo.packageName) ? resolved.priority : 0;tile.metaData = activityInfo.metaData;/// M: Support priority in whitelist appif (tile.metaData.containsKey(META_DATA_KEY_PRIORITY) && ArrayUtils.contains(EXTRA_PACKAGE_WHITE_LIST, activityInfo.packageName)) {tile.priority = tile.metaData.getInt(META_DATA_KEY_PRIORITY);}updateTileData(context, tile, activityInfo, activityInfo.applicationInfo,pm, providerMap, forceTintExternalIcon);if (DEBUG) Log.d(LOG_TAG, "Adding tile " + tile.title);addedCache.put(key, tile);} else if (shouldUpdateTiles) {updateSummaryAndTitle(context, providerMap, tile);}if (!tile.userHandle.contains(user)) {tile.userHandle.add(user);}if (!outTiles.contains(tile)) {outTiles.add(tile);}}}

List<ResolveInfo> results = pm.queryIntentActivitiesAsUser(intent,PackageManager.GET_META_DATA, user.getIdentifier());

这个Results是用PackageManager来query的结果，最后查询的结果是当前包里有相同的category的activity信息

ActivityInfo activityInfo = resolved.activityInfo;
Bundle metaData = activityInfo.metaData;
String categoryKey = defaultCategory;

然后我们看到了下面是创建Tile的过程

Tile tile = addedCache.get(key);
if (tile == null) {tile = new Tile();tile.intent = new Intent().setClassName(activityInfo.packageName, activityInfo.name);tile.category = categoryKey;/// M: white list could use prioritytile.priority = usePriority || ArrayUtils.contains(EXTRA_PACKAGE_WHITE_LIST,activityInfo.packageName) ? resolved.priority : 0;tile.metaData = activityInfo.metaData;/// M: Support priority in whitelist appif (tile.metaData.containsKey(META_DATA_KEY_PRIORITY) &&ArrayUtils.contains(EXTRA_PACKAGE_WHITE_LIST, activityInfo.packageName)) {tile.priority = tile.metaData.getInt(META_DATA_KEY_PRIORITY);}updateTileData(context, tile, activityInfo, activityInfo.applicationInfo,pm, providerMap, forceTintExternalIcon);if (DEBUG) Log.d(LOG_TAG, "Adding tile " + tile.title);addedCache.put(key, tile);
} else if (shouldUpdateTiles) {updateSummaryAndTitle(context, providerMap, tile);
}

分别把activityInfo.packageName, activityInfo.name，categoryKey等这些信息赋值给Tile，然后把tile加入到addedCache，

private final ArrayMap<Pair<String, String>, Tile> mAddCache = new ArrayMap<>();

就这样通过不同的category来得到不同activity在xml里定义的信息。

三个类型，分别对应着

setConditions(conditions)
setSuggestions(suggestions)
setCategory(category)

这就是DashboardAdapter在初始化的时候，获取的数据的过程。

这里有一点需要说明的是，我在使用suggestion_ordering.xml里的category去AndroidMannifest.xml找，没有找到一个对应的activity，而使用SETTINGS_ACTION却能找到许多acticity。

比如

	<activity android:name=".Settings$NetworkDashboardActivity"android:taskAffinity="com.android.settings"android:label="@string/network_dashboard_title"android:icon="@drawable/ic_settings_wireless"android:parentActivityName="Settings"><intent-filter android:priority="1"><action android:name="android.settings.WIRELESS_SETTINGS" /><action android:name="android.settings.AIRPLANE_MODE_SETTINGS" /><category android:name="android.intent.category.DEFAULT" /></intent-filter><intent-filter><action android:name="android.intent.action.MAIN" /><category android:name="android.intent.category.DEFAULT" /><category android:name="android.intent.category.VOICE_LAUNCH" /></intent-filter><intent-filter android:priority="11"><action android:name="com.android.settings.action.SETTINGS"/></intent-filter><meta-data android:name="com.android.settings.category"android:value="com.android.settings.category.ia.homepage"/><meta-data android:name="com.android.settings.FRAGMENT_CLASS"android:value="com.android.settings.network.NetworkDashboardFragment"/><meta-data android:name="com.android.settings.PRIMARY_PROFILE_CONTROLLED"android:value="true" /></activity>

这里的NetworkDashboardActivity是在Setting里面定义了的。

这里可以看到，它其实是action。

而我们就是根据这个action来分门别类的找到对应的目录。

加载view

数据加载告一段落，回到DashboardAdapter的加载view的流程。

DashboardAdapter

构造ViewHolder，根据viewType不同来加载不同的viewType并创建Viewholder

这里的viewtype就是layoutID

@Override
public DashboardItemHolder onCreateViewHolder(ViewGroup parent, int viewType) {final View view = LayoutInflater.from(parent.getContext()).inflate(viewType, parent, false);if (viewType == R.layout.suggestion_condition_header) {return new SuggestionAndConditionHeaderHolder(view);}if (viewType == R.layout.suggestion_condition_container) {return new SuggestionAndConditionContainerHolder(view);}return new DashboardItemHolder(view);
}

默认ViewHolder就是DashboardItemHolder

public DashboardItemHolder(View itemView) {super(itemView);icon = itemView.findViewById(android.R.id.icon);title = itemView.findViewById(android.R.id.title);summary = itemView.findViewById(android.R.id.summary);
}

各个item的type就是前面说的那个layout的ID

@Override
public int getItemViewType(int position) {return mDashboardData.getItemTypeByPosition(position);
}

---

public int getItemTypeByPosition(int position) {return mItems.get(position).type;
}

然后我们看onBindViewHolder

@Override
public void onBindViewHolder(DashboardItemHolder holder, int position) {final int type = mDashboardData.getItemTypeByPosition(position);switch (type) {case R.layout.dashboard_tile:final Tile tile = (Tile)mDashboardData.getItemEntityByPosition(position);onBindTile(holder, tile);holder.itemView.setTag(tile);holder.itemView.setOnClickListener(mTileClickListener);break;case R.layout.suggestion_condition_container:onBindConditionAndSuggestion((SuggestionAndConditionContainerHolder) holder, position);break;case R.layout.suggestion_condition_header:onBindSuggestionConditionHeader((SuggestionAndConditionHeaderHolder)holder,(SuggestionConditionHeaderData)mDashboardData.getItemEntityByPosition(position));break;case R.layout.suggestion_condition_footer:holder.itemView.setOnClickListener(v -> {mMetricsFeatureProvider.action(mContext,MetricsEvent.ACTION_SETTINGS_CONDITION_EXPAND, false);DashboardData prevData = mDashboardData;mDashboardData = new DashboardData.Builder(prevData).setSuggestionConditionMode(DashboardData.HEADER_MODE_COLLAPSED).build();notifyDashboardDataChanged(prevData);mRecyclerView.scrollToPosition(SUGGESTION_CONDITION_HEADER_POSITION);});break;}
}

在Bindview的时候分别根据Tile,Container,header和footer来创建view。

看看onBindTile

private void onBindTile(DashboardItemHolder holder, Tile tile) {if (tile.remoteViews != null) {final ViewGroup itemView = (ViewGroup) holder.itemView;itemView.removeAllViews();itemView.addView(tile.remoteViews.apply(itemView.getContext(), itemView));} else {holder.icon.setImageDrawable(mCache.getIcon(tile.icon));holder.title.setText(tile.title);if (!TextUtils.isEmpty(tile.summary)) {holder.summary.setText(tile.summary);holder.summary.setVisibility(View.VISIBLE);} else {holder.summary.setVisibility(View.GONE);}}
}

就是这样，根据不同的layout，来加载不同的item，实现RecyclerView的填充。

点击事件

显示问题搞清楚了，接着我们看点击事件

holder.itemView.setTag(tile);
holder.itemView.setOnClickListener(mTileClickListener);

在bindview的时候设置了OnClickListener

private View.OnClickListener mTileClickListener = new View.OnClickListener() {@Overridepublic void onClick(View v) {mDashboardFeatureProvider.openTileIntent((Activity) mContext, (Tile)v.getTag());}
};

DashboardFeatureProviderImpl实现了DashboardFeatureProvider接口，这里是面向接口编程的思想。

@Override
public void openTileIntent(Activity activity, Tile tile) {if (tile == null) {Intent intent = new Intent(Settings.ACTION_SETTINGS).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);mContext.startActivity(intent);return;}if (tile.intent == null) {return;}final Intent intent = new Intent(tile.intent).putExtra(SettingsActivity.EXTRA_SOURCE_METRICS_CATEGORY,MetricsEvent.DASHBOARD_SUMMARY).putExtra(SettingsDrawerActivity.EXTRA_SHOW_MENU, true).addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);launchIntentOrSelectProfile(activity, tile, intent,MetricsEvent.DASHBOARD_SUMMARY);
}

在前面创建每个Tile的时候，Intent是这样的，

tile.intent = new Intent().setClassName(
activityInfo.packageName, activityInfo.name);

里面包含了对应包名，activity的名字。

private void launchIntentOrSelectProfile(Activity activity, Tile tile, Intent intent,int sourceMetricCategory) {if (!isIntentResolvable(intent)) {Log.w(TAG, "Cannot resolve intent, skipping. " + intent);return;}ProfileSelectDialog.updateUserHandlesIfNeeded(mContext, tile);if (tile.userHandle == null) {mMetricsFeatureProvider.logDashboardStartIntent(mContext, intent, sourceMetricCategory);activity.startActivityForResult(intent, 0);} else if (tile.userHandle.size() == 1) {mMetricsFeatureProvider.logDashboardStartIntent(mContext, intent, sourceMetricCategory);activity.startActivityForResultAsUser(intent, 0, tile.userHandle.get(0));} else {ProfileSelectDialog.show(activity.getFragmentManager(), tile);}
}activity.startActivityForResultAsUser(intent, 0, tile.userHandle.get(0));

直接开启对应的activity,然后这里几乎所有activity都是继承自SettingsActivity，所有，就是启动它本身，换一个子类来显示。

然后在SettingsActivity的oncreate里，这时候的mIsShowingDashboard就是false,

就会显示R.layout.settings_main_prefs这个layout了，而且这时候的Intent是携带者具体要启动的activity信息的

final String initialFragmentName = intent.getStringExtra(EXTRA_SHOW_FRAGMENT);

然后就回到循环之中。

总结：Setting里所有的Activity都继承了SettingsActivity，通过action条目来统一管理加载，切换不同的activity实际也是调用它本身的不同子类，然后根据不同子类加载不同的fragment,所以说到底，Setting只有一个父Activity，所有的显示通过不同的Fragment来处理。实在是厉害。

文章转自

https://blog.csdn.net/csdnxialei/article/details/86555050

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