本文主要是对自己分析MTK 6.0 Launcher3源码的笔记，如有发现不对，请及时指正
启动流程
app启动都是由application开始启动的。
LauncherApplication.java
public void onCreate() {
super.onCreate();
...
LauncherAppState.setApplicationContext(this);
LauncherAppState.getInstance().setLauncehrApplication(this);
..
}
上面最主要的就是获取了 LauncherAppState 这个实例，然后将自己传到LauncherAppState的LauncherApplication对象 让
LauncherAppState是用于存储全局变量，比如缓存(各种cache)，维护内存数据的类(LauncherModel)，下面是LauncherAppState的类结构：
private final AppFilter mAppFilter;
private final LauncherModel mModel;
private final IconCache mIconCache;
private WidgetPreviewLoader.CacheDb mWidgetPreviewCacheDb;
private static WeakReference<LauncherProvider> sLauncherProvider;
mAppFilter：用于存储app文件夹的一些信息
mModel：用于维护Launcher在内存中的数据，比如app信息列表和widget信息列表，同时提供了更新数据库的操作
mIconCache：应用程序icon和title的缓存
mWidgetPreviewCacheDb：存储widget预览信息的数据库
sLauncherProvide：r app和widget的ContentProvider，用数据库存储信息
private LauncherAppState() {
...
mIsScreenLarge = isScreenLarge(sContext.getResources());
mScreenDensity = sContext.getResources().getDisplayMetrics().density;
recreateWidgetPreviewDb();
mIconCache = new IconCache(sContext);
mAppFilter = AppFilter.loadByName(sContext.getString(R.string.app_filter_class));
mBuildInfo = BuildInfo.loadByName(sContext.getString(R.string.build_info_class));
mModel = new LauncherModel(this, mIconCache, mAppFilter);
final LauncherAppsCompat launcherApps = LauncherAppsCompat.getInstance(sContext);
launcherApps.addOnAppsChangedCallback(mModel);
// Register intent receivers
IntentFilter filter = new IntentFilter();
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);
mPowerManager = (PowerManager)sContext.getSystemService(Context.POWER_SERVICE);
LauncherAppState.getInstance()方法实例化了以上的数据，同时对Launcher中使用到的Receiver和Observer进行了注册。
在执行完Application的onCreate方法后，接下来就开始执行Launcher(Main Activity)的onCreate()方法。
Launcher.java
看onCreate()方法
@Override
protected void onCreate(Bundle savedInstanceState) {
...此处省略部分代码
super.onCreate(savedInstanceState);
...
LauncherAppState.setApplicationContext(getApplicationContext());
LauncherAppState app = LauncherAppState.getInstance();
LauncherAppState.getLauncherProvider().setLauncherProviderChangeListener(this); //监听 LauncherAppState 里面的provider
...
DeviceProfile grid = app.initDynamicGrid(this, isDatabaseIdChanged); //设备的配置文件
...
/**@}**/
mIconCache = app.getIconCache(); /*获取Icon的缓存之类*/
mIconCache.flushInvalidIcons(grid);
mDragController = new DragController(this);
mInflater = getLayoutInflater();
...
mAppWidgetManager = AppWidgetManagerCompat.getInstance(this); //获取Widget的实例
...
mAppWidgetHost = new LauncherAppWidgetHost(this, APPWIDGET_HOST_ID);
mAppWidgetHost.startListening();
checkForLocaleChange(); //检测语言的变化 随之变化
setContentView(R.layout.launcher);
setupViews(); //实例化Luncher.XML 全部引用进来
grid.layout(this); //配置网格
...
// 数据加载
if (!mRestoring) {
/// M: Add for smart book feature. Reset load state if database changed before.
if (isDatabaseIdChanged) { //false
mModel.resetLoadedState(true, true);
} else {
/**M: Added to reset the loader state, to resolve the timing state issue.@{*/
mModel.resetLoadedState(false, false);
/**@}**/
}
if (DISABLE_SYNCHRONOUS_BINDING_CURRENT_PAGE) { //false
// If the user leaves launcher, then we should just load items asynchronously when
// they return.
mModel.startLoader(true, PagedView.INVALID_RESTORE_PAGE);
} else {
// We only load the page synchronously if the user rotates (or triggers a
// configuration change) while launcher is in the foreground
mModel.startLoader(true, mWorkspace.getRestorePage());
}
}
registerContentObservers();
lockAllApps();
......
}
mModel.startLoader(true, mWorkspace.getRestorePage()); 这句话很重要 开始进行加载数据模型等
在分析加载之前我们先看看luncher.xml都有什么
luncher.xml###
<com.android.launcher3.LauncherRootView
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:launcher="http://schemas.android.com/apk/res-auto/com.android.launcher3"
android:id="@+id/launcher"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@drawable/workspace_bg"
android:fitsSystemWindows="true">
<com.android.launcher3.DragLayer
android:id="@+id/drag_layer"
android:layout_width="match_parent"
android:layout_height="match_parent">
<com.android.launcher3.FocusIndicatorView
android:id="@+id/focus_indicator"
android:layout_width="52dp"
android:layout_height="52dp" />
<!-- The workspace contains 5 screens of cells -->
<com.android.launcher3.Workspace
android:id="@+id/workspace"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="center"
launcher:defaultScreen="@integer/config_workspaceDefaultScreen" />
<include layout="@layout/hotseat"
android:id="@+id/hotseat"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="end" />
<include
android:id="@+id/search_drop_target_bar"
layout="@layout/search_drop_target_bar" />
<include layout="@layout/overview_panel"
android:id="@+id/overview_panel"
android:visibility="gone" />
<include layout="@layout/apps_customize_pane"
android:id="@+id/apps_customize_pane"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="invisible" />
</com.android.launcher3.DragLayer>
<ViewStub
android:id="@+id/launcher_overlay_stub"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:inflatedId="@+id/launcher_overlay"
android:layout="@layout/launcher_overlay" />
</com.android.launcher3.LauncherRootView>
DragLayer ：这是个对Launcher的所有事件处理
Workspace：就是可以左右滑动的区域
FocusIndicatorView：和Icon焦点变化有关
hotseat：
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overview_panel：就是长按显示下面的图标
Paste_Image.png
apps_customize_pane：
Paste_Image.png
下面贴两张Launcher常用的类
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Paste_Image.png
到此 launcher3的启动流程已经完成了
接下来会分析Launcher3的数据加载流程
数据加载
刚看到一篇总结比较好的流程图
Paste_Image.png
数据加载 load和bindWorkspace()
Paste_Image.png
数据加载 获取和bind apps
Paste_Image.png
