一、Launcher的啓動
首先啓動LauncherApplication,這裏面只有兩行代碼,初始化了LauncherAppState,LauncherAppState主要是初始化一些對象,註冊廣播和內容觀察者等.比如你安裝程序和卸載程序,裏面都會監聽這個廣播.
之後啓動Launcher這個Activity,看它的oncreate方法.
@Override
protected void onCreate(Bundle savedInstanceState) {
if (DEBUG_STRICT_MODE) {
StrictMode.setThreadPolicy(new StrictMode.ThreadPolicy.Builder().detectDiskReads().detectDiskWrites().detectNetwork() // or
.penaltyLog().build());
StrictMode.setVmPolicy(new StrictMode.VmPolicy.Builder().detectLeakedSqlLiteObjects().detectLeakedClosableObjects().penaltyLog().penaltyDeath().build());
}
super.onCreate(savedInstanceState);
// 初始化Context,獲取LauncherAppState實例
LauncherAppState.setApplicationContext(getApplicationContext());
LauncherAppState app = LauncherAppState.getInstance();
// 確定grid屬性
Point smallestSize = new Point();
Point largestSize = new Point();
Point realSize = new Point();
Display display = getWindowManager().getDefaultDisplay();
display.getCurrentSizeRange(smallestSize, largestSize);
display.getRealSize(realSize);
DisplayMetrics dm = new DisplayMetrics();
display.getMetrics(dm);
// Lazy-initialize the dynamic grid
DeviceProfile grid = app.initDynamicGrid(this, Math.min(smallestSize.x, smallestSize.y), Math.min(largestSize.x, largestSize.y), realSize.x, realSize.y, dm.widthPixels, dm.heightPixels);
//獲取SharedPreferences實例
mSharedPrefs = getSharedPreferences(LauncherAppState.getSharedPreferencesKey(), Context.MODE_PRIVATE);
// 獲取LauncherModel實例
mModel = app.setLauncher(this);
// 獲取IconCache實例
mIconCache = app.getIconCache();
mIconCache.flushInvalidIcons(grid);
// 獲取DragController實例
mDragController = new DragController(this);
mInflater = getLayoutInflater();
mStats = new Stats(this);
// 獲取AppWidgetManager實例
mAppWidgetManager = AppWidgetManager.getInstance(this);
// 獲取AppWidgetHost實例並且監聽
mAppWidgetHost = new LauncherAppWidgetHost(this, APPWIDGET_HOST_ID);
mAppWidgetHost.startListening();
// If we are getting an onCreate, we can actually preempt onResume and
// unset mPaused here,
// this also ensures that any synchronous binding below doesn't
// re-trigger another
// LauncherModel load.
mPaused = false;
if (PROFILE_STARTUP) {
android.os.Debug.startMethodTracing(Environment.getExternalStorageDirectory() + "/launcher");
}
checkForLocaleChange();
setContentView(R.layout.launcher); // 設置佈局
setupViews();
grid.layout(this);
//註冊內容觀察者
registerContentObservers();
lockAllApps();
mSavedState = savedInstanceState;
restoreState(mSavedState);
// 更新抽屜界面狀態
if (mAppsCustomizeContent != null) {
mAppsCustomizeContent.onPackagesUpdated(LauncherModel.getSortedWidgetsAndShortcuts(this));
}
if (PROFILE_STARTUP) {
android.os.Debug.stopMethodTracing();
}
// 加載桌面的圖標,widget等
if (!mRestoring) {
if (sPausedFromUserAction) {
// If the user leaves launcher, then we should just load items
// asynchronously when
// they return.
mModel.startLoader(true, -1);
} 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.getCurrentPage());
}
}
// 處理默認鍵
mDefaultKeySsb = new SpannableStringBuilder();
Selection.setSelection(mDefaultKeySsb, 0);
// 註冊廣播,監聽關閉系統Dialog
IntentFilter filter = new IntentFilter(Intent.ACTION_CLOSE_SYSTEM_DIALOGS);
registerReceiver(mCloseSystemDialogsReceiver, filter);
// 更新所有的icon
updateGlobalIcons();
// 開啓自動旋轉
unlockScreenOrientation(true);
// 第一次運行的時候提示幫助
showFirstRunCling();
}<span style="font-size:14px;">
</span>1.初始化LauncherAppState.
2.初始化DeviceProfile,DeviceProfile裏保存了很多Launcher的屬性.比如Icon的大小,Icon標題的大小等.
3.獲取SharedPreferences實例mSharedPrefs,mSharedPrefs保存的都是第一次開機時的提示信息.
4.獲取LauncherModel實例..是操作數據有關的,保存了桌面運行的狀態.像加載widget和快捷方式到桌面都是通過它.
5.獲取IconCache實例,從字面看就知道是保存了圖標的信息.
6.獲取DragController實例,前面文章介紹了,一個拖動控制接口.
7.獲取AppWidgetManager實例，是用來管理widget的.
8.setContentView(R.layout.launcher) 設置佈局.
9.setupViews 控件的初始化,註冊點擊監聽等.
10.註冊內容觀察者.
11.加載桌面的圖標,widget等，調用LauncherModel的startLoader方法進行加載.
12.處理默認鍵.
13.註冊廣播,監聽關閉系統Dialog.
14.更新所有的icon.
15.開啓自動旋轉屏幕.
16.第一次運行的時候提示幫助，就是那些手指點哪裏的提示信息.