Android Launcher載入流程原始碼分析
阿新 • • 發佈：2019-01-02
Launcher載入流程分析
最近開始接手Launcher模組，為了更好的技術積累，也看到很多大神在CSDN上發的博文，就有了在CSDN寫部落格的想法，這篇博文是我在研究了一段時間Launcher3後寫的，可能有不對的，望大家拍磚。首先我們可以先參考這篇http://blog.csdn.net/yanbober/article/details/50525559博文，這篇博文介紹了launcher的程式碼主流程框架，這裡我直接貼程式碼分析。
Launcher首次啟動是通過ActivityManagerService.systemReady方法啟動的，在Android系統啟動中會啟動system_server程序，在SystemServer.java中可以找到呼叫ActivityManagerService.systemReady的地方，來看一下ActivityManagerService中的systemReady方法
public void systemReady(final Runnable goingCallback) {
...//省略
startHomeActivityLocked(currentUserId, "systemReady");
...
}繼續看startHomeActivityLocked()方法
boolean startHomeActivityLocked(int userId, String reason) {
if (mFactoryTest == FactoryTest.FACTORY_TEST_LOW_LEVEL
&& mTopAction == null 來看下getHomeIntent()方法
Intent getHomeIntent() {
Intent intent = new Intent(mTopAction, mTopData != null ? Uri.parse(mTopData) : null);
intent.setComponent(mTopComponent);
intent.addFlags(Intent.FLAG_DEBUG_TRIAGED_MISSING);
if (mFactoryTest != FactoryTest.FACTORY_TEST_LOW_LEVEL) {
intent.addCategory(Intent.CATEGORY_HOME);//CATEGORY_HOME
}
return intent;
}在Launcher3中的AndroidManifest.xml中有註冊這個Category的activity
<activity
android:name="com.android.launcher3.Launcher"
android:launchMode="singleTask"
android:clearTaskOnLaunch="true"
android:stateNotNeeded="true"
android:theme="@style/Theme"
android:configChanges="mcc|mnc"
android:windowSoftInputMode="adjustPan"
android:screenOrientation="portrait"
android:resumeWhilePausing="true"
android:taskAffinity=""
android:enabled="true">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.HOME" />
<category android:name="android.intent.category.DEFAULT" />
<category android:name="android.intent.category.MONKEY"/>
</intent-filter>
</activity>簡單分析完了Launcher是怎麼被啟動的，現在就來看Launcher本身的啟動和載入流程，現在來看Launcher.java的onCreate方法，我在一些地方加了註釋
@Override
protected void onCreate(Bundle savedInstanceState) {
/*這兩行初始化LauncherAppState,這個單例物件，會註冊應用安裝、解除安裝、更新，配置變化等廣播，同時會
初始化LauncherModel，裡面有一個內部類LoaderTask用來獲取資料，初始化桌面*/
LauncherAppState.setApplicationContext(getApplicationContext());
LauncherAppState app = LauncherAppState.getInstance();
/*new InvariantDeviceProfile物件，從名字看意思是不變的裝置相關引數儲存類，裡面會初始化管理橫
豎屏的兩個DeviceProfile物件*/
app.RenewInvariantDeviceProfile();
//獲得橫豎屏的DeviceProfile物件
mDeviceProfile = getResources().getConfiguration().orientation
== Configuration.ORIENTATION_LANDSCAPE ?
app.getInvariantDeviceProfile().landscapeProfile
: app.getInvariantDeviceProfile().portraitProfile;
mModel = app.setLauncher(this);//獲取在LauncherAppState中new LauncherModel物件
mIconCache = app.getIconCache();//桌面圖示快取類
mDragController = new DragController(this);//拖拽控制類
mInflater = getLayoutInflater();
mStateTransitionAnimation = new LauncherStateTransitionAnimation(this);//動畫管理類
mAppWidgetManager = AppWidgetManagerCompat.getInstance(this);//widget管理類
mAppWidgetHost = new LauncherAppWidgetHost(this, APPWIDGET_HOST_ID);
mAppWidgetHost.startListening();
setupViews();//初始化佈局控制元件
mDeviceProfile.layout(this);//根據裝置配置調整佈局
//呼叫mModel.startLoader方法開始載入非同步載入桌面的資料，如app,folder,widget等
if (!mRestoring) {
if (DISABLE_SYNCHRONOUS_BINDING_CURRENT_PAGE) {
// If the user leaves launcher, then we should just load items asynchronously when
// they return.
mModel.startLoader(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(mWorkspace.getRestorePage());
}
}
//是否啟動向導介面
if (shouldShowIntroScreen()) {
showIntroScreen();
} else {
showFirstRunActivity();
showFirstRunClings();
} 以上就是Launcher.java中onCreate方法中的部分程式碼，以上很多地方都用到了LauncherAppState這個單例物件，現在主要看這個類的構造方法，這個構造方法會初始化很多關鍵物件
private LauncherAppState() {
if (sContext == null) {
throw new IllegalStateException("LauncherAppState inited before app context set");
}
Log.v(Launcher.TAG, "LauncherAppState inited");
if (sContext.getResources().getBoolean(R.bool.debug_memory_enabled)) {
MemoryTracker.startTrackingMe(sContext, "L");
}
mInvariantDeviceProfile = new InvariantDeviceProfile(sContext);
mIconCache = new IconCache(sContext, mInvariantDeviceProfile);//存放Icon的物件
mWidgetCache = new WidgetPreviewLoader(sContext, mIconCache);
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);//LauncherModel載入桌面的類
/*下面這行就是註冊APP安裝，更新，解除安裝的廣播，LauncherAppsCompat.getInstance(sContext)
會根據Sdk的版本得到不同的例項，當前分析的是M版本的所以得到的是LauncherAppsCompatV16這個
單例物件，呼叫這個addOnAppsChangedCallback方法，呼叫registerForPackageIntents();
這個方法就是註冊APP安裝，更新，解除安裝的廣播的*/
LauncherAppsCompat.getInstance(sContext).addOnAppsChangedCallback(mModel);
// Register intent receivers
IntentFilter filter = new IntentFilter();
filter.addAction(Intent.ACTION_LOCALE_CHANGED);
filter.addAction(SearchManager.INTENT_GLOBAL_SEARCH_ACTIVITY_CHANGED);
// For handling managed profiles
filter.addAction(LauncherAppsCompat.ACTION_MANAGED_PROFILE_ADDED);
filter.addAction(LauncherAppsCompat.ACTION_MANAGED_PROFILE_REMOVED);
if (LauncherLog.DEBUG) {
LauncherLog.d(TAG, "LauncherAppState: mIconCache = " + mIconCache + ", mModel = "
+ mModel + ", this = " + this);
}
sContext.registerReceiver(mModel, filter);
UserManagerCompat.getInstance(sContext).enableAndResetCache();
mPowerManager = (PowerManager) sContext.getSystemService(Context.POWER_SERVICE);
}桌面其實就是手機中的APP的入口，放的就是APP的快捷方式，widget等，所有首先我們要獲取這些資訊，然後把這些資訊用UI的方法顯示在桌面上，但是獲取這些資訊是一個耗時的操作，不可能在主執行緒裡面去操作，所以需要用非同步執行緒的方式獲取，在LauncherModel類中就有一個非同步執行緒sWorkerThread，這個非同步執行緒中有一個Handler sWorker = new Handler(sWorkerThread.getLooper());還有一個主執行緒的Handler—mHandler = new DeferredHandler();這個Handler是封裝好的，上文說到onCreate中mModle.startLoader程式碼就是來載入桌面的，現在我們進入LauncherModel這個類去分析startLoader方法，
public void startLoader(int synchronousBindPage, int loadFlags) {
// Enable queue before starting loader. It will get disabled in Launcher#finishBindingItems
InstallShortcutReceiver.enableInstallQueue();
synchronized (mLock) {
if (DEBUG_LOADERS) {
LauncherLog.d(TAG, "startLoader: mCallbacks = " + mCallbacks);
}
// Clear any deferred bind-runnables from the synchronized load process
// We must do this before any loading/binding is scheduled below.
synchronized (mDeferredBindRunnables) {
mDeferredBindRunnables.clear();
}
// Don't bother to start the thread if we know it's not going to do anything
if (mCallbacks != null && mCallbacks.get() != null) {
// If there is already one running, tell it to stop.
stopLoaderLocked();
/// M: op01, 0p02, added for top package feature, load top packages from a xml file.
AllAppsListPluginEx.loadTopPackage(mApp.getContext());
mLoaderTask = new LoaderTask(mApp.getContext(), loadFlags);
if (LauncherLog.DEBUG) {
LauncherLog.d(TAG, "startLoader: mAllAppsLoaded = " + mAllAppsLoaded
+ ",mWorkspaceLoaded = " + mWorkspaceLoaded + ",synchronousBindPage = "
+ synchronousBindPage + ",mIsLoaderTaskRunning = "
+ mIsLoaderTaskRunning + ",mLoaderTask = " + mLoaderTask);
}
if (synchronousBindPage != PagedView.INVALID_RESTORE_PAGE
&& mAllAppsLoaded && mWorkspaceLoaded && !mIsLoaderTaskRunning) {
mLoaderTask.runBindSynchronousPage(synchronousBindPage);
} else {
sWorkerThread.setPriority(Thread.NORM_PRIORITY);
/*通過分析，第一次載入最後會走到這裡,sWorker上面已經說過非同步執行緒的Handler,
執行mLoaderTask這個Runnable，繼續看mLoaderTask這個執行緒的run()方法*/
sWorker.post(mLoaderTask);
}
}
}
}public void run() {
synchronized (mLock) {
if (DEBUG_LOADERS) {
LauncherLog.d(TAG, "Set load task running flag >>>>, mIsLaunching = " +
",this = " + this);
}
if (mStopped) {
return;
}
mIsLoaderTaskRunning = true;//更新狀態，正在載入
}
// Optimize for end-user experience: if the Launcher is up and // running with the
// All Apps interface in the foreground, load All Apps first. Otherwise, load the
// workspace first (default).
keep_running: {
if (DEBUG_LOADERS) Log.d(TAG, "step 1: loading workspace");
loadAndBindWorkspace();//看名字，應該就知道這個就是來載入和bind
if (mStopped) {
LauncherLog.i(TAG, "LoadTask break in the middle, this = " + this);
break keep_running;
}
waitForIdle();
// second step
if (DEBUG_LOADERS) Log.d(TAG, "step 2: loading all apps");
/*這個是載入所有APP，桌面最下面那一排中間的全部app按鈕，國內Launcher基本上
都會遮蔽這個*/
loadAndBindAllApps();
}繼續分析loadAndBindWorkspace()這個方法;
private void loadAndBindWorkspace() {
mIsLoadingAndBindingWorkspace = true;//更新狀態
// Load the workspace
if (DEBUG_LOADERS) {
Log.d(TAG, "loadAndBindWorkspace mWorkspaceLoaded=" + mWorkspaceLoaded);
}
if (!mWorkspaceLoaded) {
loadWorkspace();//這個方法就是去載入app等資訊
synchronized (LoaderTask.this) {
if (mStopped) {
LauncherLog.d(TAG, "loadAndBindWorkspace returned by stop flag.");
return;
}
mWorkspaceLoaded = true;
}
}
// Bind the workspace
bindWorkspace(-1);//bind,就是建立檢視view，更新UI
}先看loadWorkspace()這個方法，這個方法程式碼很多，就不全部貼出來，只分析裡面的一些關鍵性程式碼
private void loadWorkspace() {
...
if ((mFlags & LOADER_FLAG_MIGRATE_SHORTCUTS) != 0) {
// append the user's Launcher2 shortcuts
Launcher.addDumpLog(TAG, "loadWorkspace: migrating from launcher2", true);
LauncherAppState.getLauncherProvider().migrateLauncher2Shortcuts();
} else {
// Make sure the default workspace is loaded
Launcher.addDumpLog(TAG, "loadWorkspace: loading default favorites", false);
/*如果資料庫中沒有資料，就從預設的defaultxxx.xml中解析出佈局檔案，並存入資料庫
favorites表，存的就是所有的app,widget,folder(資料夾)資訊，如位置，icon
title等，還有workspacescreens表，存的就是桌面每屏的id和順序
下面的操作都會去查詢這些資料庫*/
LauncherAppState.getLauncherProvider().loadDefaultFavoritesIfNecessary();
}
synchronized (sBgLock) {
clearSBgDataStructures();
final HashMap<String, Integer> installingPkgs = PackageInstallerCompat
.getInstance(mContext).updateAndGetActiveSessionCache();
//從資料庫獲取螢幕的資訊，比如螢幕的個數
sBgWorkspaceScreens.addAll(loadWorkspaceScreensDb(mContext));
//查詢Favorites表
final Cursor c = contentResolver.query(contentUri, null, null, null, null);
while (!mStopped && c.moveToNext()) {
try {
int itemType = c.getInt(itemTypeIndex);
boolean restored = 0 != c.getInt(restoredIndex);
boolean allowMissingTarget = false;
container = c.getInt(containerIndex);
switch (itemType) {
//app的型別，就是桌面的每一個APP圖示
case LauncherSettings.Favorites.ITEM_TYPE_APPLICATION:
case LauncherSettings.Favorites.ITEM_TYPE_SHORTCUT:
id = c.getLong(idIndex);
intentDescription = c.getString(intentIndex);
serialNumber = c.getInt(profileIdIndex);
user = allUsers.get(serialNumber);
int promiseType = c.getInt(restoredIndex);
int disabledState = 0;
boolean itemReplaced = false;
if (user == null) {
// User has been deleted remove the item.
itemsToRemove.add(id);
continue;
}
try {
intent = Intent.parseUri(intentDescription, 0);
ComponentName cn = intent.getComponent();
if (cn != null && cn.getPackageName() != null) {
//判斷APP是否可用
boolean validPkg = launcherApps.isPackageEnabledForProfile(
cn.getPackageName(), user);
boolean validComponent = validPkg &&
launcherApps.isActivityEnabledForProfile(cn, user);
if (validComponent) {
if (restored) {
// no special handling necessary for this item
restoredRows.add(id);
restored = false;
...
} else if (itemType ==
LauncherSettings.Favorites.ITEM_TYPE_APPLICATION) {
//得到app的資訊，對應一個ShortcutInfo
info = getAppShortcutInfo(manager, intent, user, context, c,
cursorIconInfo.iconIndex, titleIndex,
allowMissingTarget, useLowResIcon);
} else {
info = getShortcutInfo(c, context, titleIndex, cursorIconInfo);
// App shortcuts that used to be automatically added to Launcher
// didn't always have the correct intent flags set, so do that
// here
if (intent.getAction() != null &&
intent.getCategories() != null &&
intent.getAction().equals(Intent.ACTION_MAIN) &&
intent.getCategories().contains(Intent.CATEGORY_LAUNCHER)) {
intent.addFlags(
Intent.FLAG_ACTIVITY_NEW_TASK |
Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED);
}
}
if (info != null) {
info.id = id;
info.intent = intent;
info.container = container;
info.screenId = c.getInt(screenIndex);
info.cellX = c.getInt(cellXIndex);
info.cellY = c.getInt(cellYIndex);
info.rank = c.getInt(rankIndex);
info.spanX = 1;
info.spanY = 1;
info.intent.putExtra(ItemInfo.EXTRA_PROFILE, serialNumber);
if (info.promisedIntent != null) {
info.promisedIntent.putExtra(ItemInfo.EXTRA_PROFILE, serialNumber);
}
info.isDisabled = disabledState;
if (isSafeMode && !Utilities.isSystemApp(context, intent)) {
info.isDisabled |= ShortcutInfo.FLAG_DISABLED_SAFEMODE;
}
// check & update map of what's occupied
if (!checkItemPlacement(occupied, info, sBgWorkspaceScreens)) {
itemsToRemove.add(id);
break;
}
if (restored) {
ComponentName cn = info.getTargetComponent();
if (cn != null) {
Integer progress = installingPkgs.get(cn.getPackageName());
if (progress != null) {
info.setInstallProgress(progress);
} else {
info.status &= ~ShortcutInfo.FLAG_INSTALL_SESSION_ACTIVE;
}
}
}
switch (container) {
//DESKTOP就是桌面中可滑動的部分
case LauncherSettings.Favorites.CONTAINER_DESKTOP:
//HOTSEAT就是桌面底部放4個常用app的地方
case LauncherSettings.Favorites.CONTAINER_HOTSEAT:
sBgWorkspaceItems.add(info);//放入這個集合裡面
break;
default:
// Item is in a user folder
FolderInfo folderInfo =
findOrMakeFolder(sBgFolders, container);
folderInfo.add(info);
break;
}
sBgItemsIdMap.put(info.id, info);//資料夾中的app
} else {
throw new RuntimeException("Unexpected null ShortcutInfo");
}
break;
//資料夾型別，放在sBgFolders這個集合中
case LauncherSettings.Favorites.ITEM_TYPE_FOLDER:
id = c.getLong(idIndex);
FolderInfo folderInfo = findOrMakeFolder(sBgFolders, id);
....
//widget型別
case LauncherSettings.Favorites.ITEM_TYPE_APPWIDGET:
case LauncherSettings.Favorites.ITEM_TYPE_CUSTOM_APPWIDGET:
// Read all Launcher-specific widget details
boolean customWidget = itemType ==
LauncherSettings.Favorites.ITEM_TYPE_CUSTOM_APPWIDGET;
}以上這些都是從資料庫中將各種型別的資訊讀取出來，如app,folder,widget等，然後放在不同的集合裡面，
sBgWorkspaceItems—–這裡面放的所有桌面的item
sBgFolders—–這裡面放的folder
sBgAppWidgets—–這裡面放的widget
分析完了，載入資訊的過程，那這些app,folder,widget是怎麼顯示到桌面上的呢，現在我們就來分析，在上面的loadAndBindWorkspace()方法中，執行完上面的loadworkspace後，就會執行bindworkspace方法，這個方法就把這些顯示到桌面的的，繼續分析程式碼
private void bindWorkspace(int synchronizeBindPage) {
...
// Save a copy of all the bg-thread collections
ArrayList<ItemInfo> workspaceItems = new ArrayList<ItemInfo>();
ArrayList<LauncherAppWidgetInfo> appWidgets =
new ArrayList<LauncherAppWidgetInfo>();
ArrayList<Long> orderedScreenIds = new ArrayList<Long>();
final LongArrayMap<FolderInfo> folders;
final LongArrayMap<ItemInfo> itemsIdMap;
//複製一份上面獲取到的各種資訊集合
synchronized (sBgLock) {
workspaceItems.addAll(sBgWorkspaceItems);
appWidgets.addAll(sBgAppWidgets);
orderedScreenIds.addAll(sBgWorkspaceScreens);
folders = sBgFolders.clone();
itemsIdMap = sBgItemsIdMap.clone();
}
...
ArrayList<ItemInfo> currentWorkspaceItems = new ArrayList<ItemInfo>();
ArrayList<ItemInfo> otherWorkspaceItems = new ArrayList<ItemInfo>();
ArrayList<LauncherAppWidgetInfo> currentAppWidgets =
new ArrayList<LauncherAppWidgetInfo>();
ArrayList<LauncherAppWidgetInfo> otherAppWidgets =
new ArrayList<LauncherAppWidgetInfo>();
LongArrayMap<FolderInfo> currentFolders = new LongArrayMap<>();
LongArrayMap<FolderInfo> otherFolders = new LongArrayMap<>();
...
//過濾當前頁面的item和其他頁面的
filterCurrentWorkspaceItems(tempCurrentScreen, workspaceItems, currentWorkspaceItems,
otherWorkspaceItems);
filterCurrentAppWidgets(tempCurrentScreen, appWidgets, currentAppWidgets,
otherAppWidgets);
filterCurrentFolders(tempCurrentScreen, itemsIdMap, folders, currentFolders,
otherFolders);
...
// Tell the workspace that we're about to start binding items
r = new Runnable() {
public void run() {
//這個回撥一直會用到，Luancher.java實現了這個回撥介面，
Callbacks callbacks = tryGetCallbacks(oldCallbacks);
if (callbacks != null) {
//實際呼叫Launcher.java中的startbinding方法，做一些準備操作
callbacks.startBinding();
}
}
};
runOnMainThread(r);//在主執行緒中執行這個runnable
//建立桌面屏的個數
bindWorkspaceScreens(oldCallbacks, orderedScreenIds);
// Load items on the current page
//建立當前桌面的圖示
bindWorkspaceItems(oldCallbacks, currentWorkspaceItems, currentAppWidgets,
currentFolders, null);
...
//繫結其他桌面的圖示
bindWorkspaceItems(oldCallbacks, otherWorkspaceItems, otherAppWidgets, otherFolders,
(isLoadingSynchronously ? mDeferredBindRunnables : null));
// Tell the workspace that we're done binding items
r = new Runnable() {
public void run() {
Callbacks callbacks = tryGetCallbacks(oldCallbacks);
if (callbacks != null) {
//完成繫結
callbacks.finishBindingItems();
}
mIsLoadingAndBindingWorkspace = false;
// Run all the bind complete runnables after workspace is bound.
if (!mBindCompleteRunnables.isEmpty()) {
synchronized (mBindCompleteRunnables) {
for (final Runnable r : mBindCompleteRunnables) {
runOnWorkerThread(r);
}
mBindCompleteRunnables.clear();
}
}
// If we're profiling, ensure this is the last thing in the queue.
if (DEBUG_LOADERS) {
Log.d(TAG, "bound workspace in "
+ (SystemClock.uptimeMillis()-t) + "ms");
}
}
};
if (isLoadingSynchronously) {
synchronized (mDeferredBindRunnables) {
mDeferredBindRunnables.add(r);
}
} else {
runOnMainThread(r);//在主執行緒執行
}
}上面這個流程基本上是很條理清晰的，我們來看一下runOnMainThread這個方法，在Activiy中內部會自帶這個方法，但是在這個LauncherModel內是怎麼實現的呢，其實就是用我們上面提到的主執行緒的mHander的post方法
@Thunk void runOnMainThread(Runnable r) {
if (sWorkerThread.getThreadId() == Process.myTid()) {
// If we are on the worker thread, post onto the main handler
mHandler.post(r);
} else {
r.run();
}
}上面說過，Luancher.java實現了Callback這個回撥介面，那我們現在就來分析Luancher是這麼實現這些回撥的，看Luancher.java的程式碼
public void startBinding() {
setWorkspaceLoading(true);
if (LauncherLog.DEBUG) {
LauncherLog.d(TAG, "startBinding: this = " + this);
}
// If we're starting binding all over again, clear any bind calls we'd postponed in
// the past (see waitUntilResume) -- we don't need them since we're starting binding
// from scratch again
//開始bind前，做一些清除操作
mBindOnResumeCallbacks.clear();
// Clear the workspace because it's going to be rebound
mWorkspace.clearDropTargets();
mWorkspace.removeAllWorkspaceScreens();
mWidgetsToAdvance.clear();
if (mHotseat != null) {
mHotseat.resetLayout();
}
if (LauncherLog.DEBUG) {
LauncherLog.d(TAG, "startBinding: mIsLoadingWorkspace = " + mIsLoadingWorkspace);
}
}先看bindscreens()方法
@Override
public void bindScreens(ArrayList<Long> orderedScreenIds) {
//呼叫這個方法，繼續看這個方法
bindAddScreens(orderedScreenIds);
// If there are no screens, we need to have an empty screen
if (orderedScreenIds.size() == 0) {
mWorkspace.addExtraEmptyScreen();
}
// Create the custom content page (this call updates mDefaultScreen which calls
// setCurrentPage() so ensure that all pages are added before calling this).
if (hasCustomContentToLeft()) {
mWorkspace.createCustomContentContainer();
populateCustomContentContainer();
}
}先來看一下桌面的介面佈局，用一張圖來展示，圖片擷取於http://blog.csdn.net/yanbober/article/details/50525559，如有侵權請告知
Workspace繼承於PagedView,是一個自定義的ViewGroup,用來滑動，每一個螢幕就是一個CellLayout
理解了這些，下面的程式碼就很容易看懂了
@Override
public void bindAddScreens(ArrayList<Long> orderedScreenIds) {
int count = orderedScreenIds.size();
//for迴圈，有多少屏就add多少CellLayout，
for (int i = 0; i < count; i++) {
mWorkspace.insertNewWorkspaceScreenBeforeEmptyScreen(orderedScreenIds.get(i));
}
}繼續來看binditems()方法
public void bindItems(final ArrayList<ItemInfo> shortcuts, final int start, final int end,
final boolean forceAnimateIcons) {
/*下面的這兩段程式碼會經常用到，它的作用就是保證桌面可見即執行onresume之後才執行這些方法
如果桌面不可見，這個waitUntilResume(r)會把這個runnable放入集合中，等到執行onresume
的時候去執行這個執行緒*/
Runnable r = new Runnable() {
public void run() {
bindItems(shortcuts, start, end, forceAnimateIcons);
}
};
if (waitUntilResume(r)) {
return;
}
// Get the list of added shortcuts and intersect them with the set of shortcuts here
final AnimatorSet anim = LauncherAnimUtils.createAnimatorSet();
final Collection<Animator> bounceAnims = new ArrayList<Animator>();
final boolean animateIcons = forceAnimateIcons && canRunNewAppsAnimation();
Workspace workspace = mWorkspace;
long newShortcutsScreenId = -1;
for (int i = start; i < end; i++) {
final ItemInfo item = shortcuts.get(i);
if (LauncherLog.DEBUG) {
LauncherLog.d(TAG, "bindItems: start = " + start + ", end = " + end
+ "item = " + item + ", this = " + this);
}
// Short circuit if we are loading dock items for a configuration which has no dock
if (item.container == LauncherSettings.Favorites.CONTAINER_HOTSEAT &&
mHotseat == null) {
continue;
}
final View view;
switch (item.itemType) {
case LauncherSettings.Favorites.ITEM_TYPE_APPLICATION:
case LauncherSettings.Favorites.ITEM_TYPE_SHORTCUT:
ShortcutInfo info = (ShortcutInfo) item;
view = createShortcut(info);//建立app快捷方式的view
/*
* TODO: FIX collision case
*/
if (item.container == LauncherSettings.Favorites.CONTAINER_DESKTOP) {
CellLayout cl = mWorkspace.getScreenWithId(item.screenId);
if (cl != null && cl.isOccupied(item.cellX, item.cellY)) {
View v = cl.getChildAt(item.cellX, item.cellY);
Object tag = v.getTag();
String desc = "Collision while binding workspace item: " + item
+ ". Collides with " + tag;
if (LauncherAppState.isDogfoodBuild()) {
throw (new RuntimeException(desc));
} else {
Log.d(TAG, desc);
}
}
}
break;
case LauncherSettings.Favorites.ITEM_TYPE_FOLDER:
//建立資料夾的view
view = FolderIcon.fromXml(R.layout.folder_icon, this,
(ViewGroup) workspace.getChildAt(workspace.getCurrentPage()),
(FolderInfo) item, mIconCache);
break;
default:
throw new RuntimeException("Invalid Item Type");
}
//將view新增進workspace中
workspace.addInScreenFromBind(view, item.container, item.screenId, item.cellX,
item.cellY, 1, 1);
if (animateIcons) {
// Animate all the applications up now
view.setAlpha(0f);
view.setScaleX(0f);
view.setScaleY(0f);
bounceAnims.add(createNewAppBounceAnimation(view, i));
newShortcutsScreenId = item.screenId;
}
}
...
workspace.requestLayout();
}bindfolders()方法
public void bindFolders(final LongArrayMap<FolderInfo> folders) {
if (LauncherLog.DEBUG) {
LauncherLog.d(TAG, "bindFolders: this = " + this);
}
Runnable r = new Runnable() {
public void run() {
bindFolders(folders);
}
};
if (waitUntilResume(r)) {
return;
}
/*並沒有做什麼操作，只是clone資料夾集合，因為在上面的binditems中的建立資料夾view
FolderIcon.fromXml(R.layout.folder_icon, this, (ViewGroup)已經把
開啟folder的佈局初始化好了，具體的大家可以去看仔細的程式碼*/
sFolders = folders.clone();
}還有一個bindWidget()這個方法略微複雜，這裡就不說了，程式碼流程差不多，具體的大家可以去看詳細的程式碼，最後還一個收尾的finishBindingItems方法
public void finishBindingItems() {
if (LauncherLog.DEBUG) {
LauncherLog.d(TAG, "finishBindingItems: mSavedState = " + mSavedState
+ ", mSavedInstanceState = " + mSavedInstanceState + ", this = " + this);
}
Runnable r = new Runnable() {
public void run() {
finishBindingItems();
}
};
if (waitUntilResume(r)) {
return;
}
if (mSavedState != null) {
if (!mWorkspace.hasFocus()) {
View view = mWorkspace.getChildAt(mWorkspace.getCurrentPage());
if (view != null) {
view.requestFocus();
}
}
mSavedState = null;
}
mWorkspace.restoreInstanceStateForRemainingPages();
setWorkspaceLoading(false);//設定狀態
sendLoadingCompleteBroadcastIfNecessary();//launcher是否首次啟動，儲存狀態
// If we received the result of any pending adds while the loader was running (e.g. the
// widget configuration forced an orientation change), process them now.
if (sPendingAddItem != null) {
final long screenId = completeAdd(sPendingAddItem);
// TODO: this moves the user to the page where the pending item was added. Ideally,
// the screen would be guaranteed to exist after bind, and the page would be set through
// the workspace restore process.
mWorkspace.post(new Runnable() {
@Override
public void run() {
mWorkspace.snapToScreenId(screenId);
}
});
sPendingAddItem = null;
}
InstallShortcutReceiver.disableAndFlushInstallQueue(this);
if (mLauncherCallbacks != null) {
mLauncherCallbacks.finishBindingItems(false);
}
}以上這些就是Launcher介面的主要載入流程，裡面還有很多的細節都沒有講，比如workspace，celllayout怎麼新增這些view，還有桌面的滑動snap,拖拽drag流程，還有Launcher的各種模式，資料夾等。後面有時間會繼續分析。
這是我第一次發部落格，裡面難免會有些錯誤或沒考慮的問題，希望大家指出