前言
最近需要实现一个自己的Launcher，就借机学习下原生的Launcher源码。
多个Launcher
源码里有Launcher，Launcher2，Launcher3。那它们有什么区别呢。
launcher不支持桌面小工具动画效果，launcher2添加了动画效果和3D初步效果支持。
Android 4.4 (KK)开始Launcher默认使用Launcher3，Launcher3较Launcher2 UI 有部分调整，主要包括:
- 状态栏透明，App List 透Wallpaper；
- 增加overview模式，可以调整workspace上页面的前后顺序；
- 动态管理屏幕数量；
- widget列表与app list分开显示；
默认不支持预置appwidget，需要用户指定权限；提供类似小米只有workspace的桌面机制 ；Wallpaper 的代码全部搬移到Launcher包；类似Cling等细节的小变化；
那我们就直接研究最新的Launcher3
Launcher3
Launcher3介绍
Launcher是开机启动的第一个应用程序，用来展示应用列表和快捷方式、小部件等。
Launcher3源码解析
AndroidManifest.xml
一些标签属性
123.png
LauncherApplication
public class LauncherApplication extends Application {
@Override
public void onCreate() {
super.onCreate();
LauncherAppState.setApplicationContext(this);
LauncherAppState.getInstance();
}
@Override
public void onTerminate() {
super.onTerminate();
LauncherAppState.getInstance().onTerminate();
}
}
初始化LauncherAppState类，在继续看LauncherAppState类。
private LauncherAppState() {
...
// set sIsScreenXLarge and mScreenDensity *before* creating icon cache
mIsScreenLarge = isScreenLarge(sContext.getResources());
mScreenDensity = sContext.getResources().getDisplayMetrics().density;
mWidgetPreviewCacheDb = new WidgetPreviewLoader.CacheDb(sContext);
mIconCache = new IconCache(sContext);
mAppFilter = AppFilter.loadByName(sContext.getString(R.string.app_filter_class));
mModel = new LauncherModel(this, mIconCache, mAppFilter);
// Register intent receivers
IntentFilter filter = new IntentFilter(Intent.ACTION_PACKAGE_ADDED);
filter.addAction(Intent.ACTION_PACKAGE_REMOVED);
filter.addAction(Intent.ACTION_PACKAGE_CHANGED);
filter.addDataScheme("package");
sContext.registerReceiver(mModel, filter);
filter = new IntentFilter();
filter.addAction(Intent.ACTION_EXTERNAL_APPLICATIONS_AVAILABLE);
filter.addAction(Intent.ACTION_EXTERNAL_APPLICATIONS_UNAVAILABLE);
filter.addAction(Intent.ACTION_LOCALE_CHANGED);
filter.addAction(Intent.ACTION_CONFIGURATION_CHANGED);
sContext.registerReceiver(mModel, filter);
filter = new IntentFilter();
filter.addAction(SearchManager.INTENT_GLOBAL_SEARCH_ACTIVITY_CHANGED);
sContext.registerReceiver(mModel, filter);
filter = new IntentFilter();
filter.addAction(SearchManager.INTENT_ACTION_SEARCHABLES_CHANGED);
sContext.registerReceiver(mModel, filter);
// Register for changes to the favorites
ContentResolver resolver = sContext.getContentResolver();
resolver.registerContentObserver(LauncherSettings.Favorites.CONTENT_URI, true,
mFavoritesObserver);
}
初始化中读取配置，注册广播，实例化LauncherModel。Launcher2源码 LauncherModel创建是在LauncherApplication ,Launcher3移到这个类来了。
/**
* Maintains in-memory state of the Launcher. It is expected that there should be only one
* LauncherModel object held in a static. Also provide APIs for updating the database state
* for the Launcher.
*/
单例，处理数据库。这个类继承BroadcastReceiver ，我们来重点看下这个类实现；
LauncherModel
private static final HandlerThread sWorkerThread = new HandlerThread("launcher-loader");
static {
sWorkerThread.start();
}
private static final Handler sWorker = new Handler(sWorkerThread.getLooper());
创建一个线程，用来处理
LoaderTask 加载
- workspace icons
- widgets
- all apps icons
PackageUpdatedTask 用来更新applist.
看一下构造方法
LauncherModel(LauncherAppState app, IconCache iconCache, AppFilter appFilter) {
final Context context = app.getContext();
mAppsCanBeOnRemoveableStorage = Environment.isExternalStorageRemovable();
mApp = app;
mBgAllAppsList = new AllAppsList(iconCache, appFilter);
mIconCache = iconCache;
mDefaultIcon = Utilities.createIconBitmap(
mIconCache.getFullResDefaultActivityIcon(), context);
final Resources res = context.getResources();
Configuration config = res.getConfiguration();
mPreviousConfigMcc = config.mcc; // SIM卡相关
}
传入LauncherAppState 来获取 context，WidgetPreviewLoader.CacheDb操作数据库；
IconCache类是用来缓存app图标
LauncherModle继承BroadcastReceiver 我们看下onReceive做了什么处理；
/**
* Call from the handler for ACTION_PACKAGE_ADDED, ACTION_PACKAGE_REMOVED and
* ACTION_PACKAGE_CHANGED.
*/
@Override
public void onReceive(Context context, Intent intent) {
...
if (Intent.ACTION_PACKAGE_CHANGED.equals(action)
|| Intent.ACTION_PACKAGE_REMOVED.equals(action)
|| Intent.ACTION_PACKAGE_ADDED.equals(action)) {
final String packageName = intent.getData().getSchemeSpecificPart();
final boolean replacing = intent.getBooleanExtra(Intent.EXTRA_REPLACING, false);
int op = PackageUpdatedTask.OP_NONE;
if (packageName == null || packageName.length() == 0) {
// they sent us a bad intent
return;
}
if (Intent.ACTION_PACKAGE_CHANGED.equals(action)) {
op = PackageUpdatedTask.OP_UPDATE;
} else if (Intent.ACTION_PACKAGE_REMOVED.equals(action)) {
if (!replacing) {
op = PackageUpdatedTask.OP_REMOVE;
}
// else, we are replacing the package, so a PACKAGE_ADDED will be sent
// later, we will update the package at this time
} else if (Intent.ACTION_PACKAGE_ADDED.equals(action)) {
if (!replacing) {
op = PackageUpdatedTask.OP_ADD;
} else {
op = PackageUpdatedTask.OP_UPDATE;
}
}
if (op != PackageUpdatedTask.OP_NONE) {
enqueuePackageUpdated(new PackageUpdatedTask(op, new String[] { packageName }));
}
//移动APP完成之后，发出的广播
} else if (Intent.ACTION_EXTERNAL_APPLICATIONS_AVAILABLE.equals(action)) {
// First, schedule to add these apps back in.
String[] packages = intent.getStringArrayExtra(Intent.EXTRA_CHANGED_PACKAGE_LIST);
enqueuePackageUpdated(new PackageUpdatedTask(PackageUpdatedTask.OP_ADD, packages));
// Then, rebind everything.
startLoaderFromBackground();
//正在移动APP时，发出的广播
} else if (Intent.ACTION_EXTERNAL_APPLICATIONS_UNAVAILABLE.equals(action)) {
String[] packages = intent.getStringArrayExtra(Intent.EXTRA_CHANGED_PACKAGE_LIST);
enqueuePackageUpdated(new PackageUpdatedTask(
PackageUpdatedTask.OP_UNAVAILABLE, packages));
} else if (Intent.ACTION_LOCALE_CHANGED.equals(action)) { //设备当前区域设置已更改时发出的广播
// If we have changed locale we need to clear out the labels in all apps/workspace.
forceReload();
//设备当前设置被改变时发出的广播(包括的改变:界面语言，设备方向，等
} else if (Intent.ACTION_CONFIGURATION_CHANGED.equals(action)) {
// Check if configuration change was an mcc/mnc change which would affect app resources
// and we would need to clear out the labels in all apps/workspace. Same handling as
// above for ACTION_LOCALE_CHANGED
Configuration currentConfig = context.getResources().getConfiguration();
if (mPreviousConfigMcc != currentConfig.mcc) {
Log.d(TAG, "Reload apps on config change. curr_mcc:"
+ currentConfig.mcc + " prevmcc:" + mPreviousConfigMcc);
forceReload();
}
// Update previousConfig
mPreviousConfigMcc = currentConfig.mcc;
} else if (SearchManager.INTENT_GLOBAL_SEARCH_ACTIVITY_CHANGED.equals(action) ||
SearchManager.INTENT_ACTION_SEARCHABLES_CHANGED.equals(action)) {
if (mCallbacks != null) {
Callbacks callbacks = mCallbacks.get();
if (callbacks != null) {
callbacks.bindSearchablesChanged();
}
}
}
}
接收应用安装卸载后的广播，当接收到广播调用enqueuePackageUpdated来启动这个任务。
public void run() {
final Context context = mApp.getContext();
final String[] packages = mPackages;
final int N = packages.length;
switch (mOp) {
case OP_ADD:
for (int i=0; i<N; i++) {
if (DEBUG_LOADERS) Log.d(TAG, "mAllAppsList.addPackage " + packages[i]);
mBgAllAppsList.addPackage(context, packages[i]);
}
break;
case OP_UPDATE:
for (int i=0; i<N; i++) {
if (DEBUG_LOADERS) Log.d(TAG, "mAllAppsList.updatePackage " + packages[i]);
mBgAllAppsList.updatePackage(context, packages[i]);
WidgetPreviewLoader.removePackageFromDb(
mApp.getWidgetPreviewCacheDb(), packages[i]);
}
break;
case OP_REMOVE:
case OP_UNAVAILABLE:
for (int i=0; i<N; i++) {
if (DEBUG_LOADERS) Log.d(TAG, "mAllAppsList.removePackage " + packages[i]);
mBgAllAppsList.removePackage(packages[i]);
WidgetPreviewLoader.removePackageFromDb(
mApp.getWidgetPreviewCacheDb(), packages[i]);
}
break;
}
....
if (added != null) {
// Ensure that we add all the workspace applications to the db
Callbacks cb = mCallbacks != null ? mCallbacks.get() : null;
if (!AppsCustomizePagedView.DISABLE_ALL_APPS) {
addAndBindAddedApps(context, new ArrayList<ItemInfo>(), cb, added);
} else {
final ArrayList<ItemInfo> addedInfos = new ArrayList<ItemInfo>(added);
addAndBindAddedApps(context, addedInfos, cb, added);
}
}
}
安装应用向AllAppsList添加应用信息；
卸载应用向AllAppsList 删除数据，并删除数据库的数据。
调用addAndBindAddedApps方法 :处理新添加的应用程序并首先将它们添加到数据库中;
callbacks.bindAppsAdded(addedWorkspaceScreensFinal,
addNotAnimated, addAnimated, allAppsApps);
回调到Launcher 主Activity中，这个callback是Launcher初始化后调用的，我们后面在介绍。
定义
public interface Callbacks {
//如果Launcher在加载完成之前被强制暂停，那么需要通过这个回调方法通知Launcher
//在它再次显示的时候重新执行加载过程
public boolean setLoadOnResume();
//获取当前屏幕序号
public int getCurrentWorkspaceScreen();
//启动桌面数据绑定
public void startBinding();
//批量绑定桌面组件：快捷方式列表，列表的开始位置，列表结束的位置，是否使用动画
public void bindItems(ArrayList<ItemInfo> shortcuts, int start, int end,
boolean forceAnimateIcons);
//批量绑定桌面页，orderedScreenIds 序列化后的桌面页列表
public void bindScreens(ArrayList<Long> orderedScreenIds);
public void bindAddScreens(ArrayList<Long> orderedScreenIds);
//批量绑定文件夹，folders 文件夹映射列表
public void bindFolders(LongArrayMap<FolderInfo> folders);
//绑定任务完成
public void finishBindingItems();
//批量绑定小部件，info 需要绑定到桌面上的小部件信息
public void bindAppWidget(LauncherAppWidgetInfo info);
//绑定应用程序列表界面的应用程序信息，apps 需要绑定到应用程序列表中的应用程序列表
public void bindAllApplications(ArrayList<AppInfo> apps);
// Add folders in all app list.
public void bindAllApplications2Folder(ArrayList<AppInfo> apps, ArrayList<ItemInfo> items);
//批量添加组件
public void bindAppsAdded(ArrayList<Long> newScreens,
ArrayList<ItemInfo> addNotAnimated,
ArrayList<ItemInfo> addAnimated,
ArrayList<AppInfo> addedApps);
//批量更新应用程序相关的快捷方式或者入口
public void bindAppsUpdated(ArrayList<AppInfo> apps);
public void bindShortcutsChanged(ArrayList<ShortcutInfo> updated,
ArrayList<ShortcutInfo> removed, UserHandleCompat user);
public void bindWidgetsRestored(ArrayList<LauncherAppWidgetInfo> widgets);
public void bindRestoreItemsChange(HashSet<ItemInfo> updates);
// 从桌面移除一些组件，当应用程序被移除或者禁用的时候调用
public void bindComponentsRemoved(ArrayList<String> packageNames,
ArrayList<AppInfo> appInfos, UserHandleCompat user, int reason);
public void bindAllPackages(WidgetsModel model);
//全局搜索或者搜索属性更新
public void bindSearchablesChanged();
public boolean isAllAppsButtonRank(int rank);
/**
* 指示正在绑定的页面
* @param page 桌面页序号
*/
public void onPageBoundSynchronously(int page);
//输出当前Launcher信息到本地文件中
public void dumpLogsToLocalData();
}
接口都是在Launcher这个类实现的。
总结
- LauncherModel 是一个广播接收者BroadcastReceiver，监听应用的安装、卸载、移动等事件。
- 启动LoaderTask 初始化Launcher数据
Over
