Android M 設置流程簡要分析

這份筆記主要是記錄設置的大致流程,以便在後續項目中需要修改設置的時候以便快熟理解大的思路.
首先從入口開始,也就是從第一個Activity開始,在androidManifest.xml裏面找到android.intent.category.LAUNCHER,這個activity-alias 就是要找的入口,其實這只是一個別名真正想要看的是它的android:targetActivity="Settings",也就是<activity android:name="Settings" .

<activity android:name="Settings"
		android:taskAffinity="com.android.settings"
		android:label="@string/settings_label_launcher"
		android:launchMode="singleTask">
	<intent-filter android:priority="1">
		<action android:name="android.settings.SETTINGS" />
		<category android:name="android.intent.category.DEFAULT" />
	</intent-filter>
	<meta-data android:name="com.android.settings.PRIMARY_PROFILE_CONTROLLED"
		android:value="true" />
</activity>
<!-- Alias for launcher activity only, as this belongs to each profile. -->
<activity-alias android:name="Settings"
		android:taskAffinity="com.android.settings"
		android:label="@string/settings_label_launcher"
		android:launchMode="singleTask"
		android:targetActivity="Settings">
	<intent-filter>
		<action android:name="android.intent.action.MAIN" />
		<category android:name="android.intent.category.DEFAULT" />
		<category android:name="android.intent.category.LAUNCHER" />
	</intent-filter>
</activity-alias>

打開這個Settings.Java發現裏面主要是定義了很多內部靜態Activity,主要邏輯還是在其父類SettingsActivity.java 裏面,那就從onCreate()開始

@Override
protected void onCreate(Bundle savedState) {
	super.onCreate(savedState);
	mExt = UtilsExt.getMiscPlugin(this);
	// Should happen before any call to getIntent()
	getMetaData();//獲取配置meta-data中的com.android.settings.FRAGMENT_CLASS屬性的值,將值保存在mFragmentClass裏面
	final Intent intent = getIntent();
	if (intent.hasExtra(EXTRA_UI_OPTIONS)) {
		getWindow().setUiOptions(intent.getIntExtra(EXTRA_UI_OPTIONS, 0));
	}
	mDevelopmentPreferences = getSharedPreferences(DevelopmentSettings.PREF_FILE,
			Context.MODE_PRIVATE);
	// Getting Intent properties can only be done after the super.onCreate(...)
	final String initialFragmentName = intent.getStringExtra(EXTRA_SHOW_FRAGMENT);
	mIsShortcut = isShortCutIntent(intent) || isLikeShortCutIntent(intent) ||
			intent.getBooleanExtra(EXTRA_SHOW_FRAGMENT_AS_SHORTCUT, false);
	final ComponentName cn = intent.getComponent();
	final String className = cn.getClassName();
	mIsShowingDashboard = className.equals(Settings.class.getName());
	// This is a "Sub Settings" when:
	// - this is a real SubSettings
	// - or :settings:show_fragment_as_subsetting is passed to the Intent
	final boolean isSubSettings = this instanceof SubSettings ||
			intent.getBooleanExtra(EXTRA_SHOW_FRAGMENT_AS_SUBSETTING, false);
	// If this is a sub settings, then apply the SubSettings Theme for the ActionBar content insets
	if (isSubSettings) {
		// Check also that we are not a Theme Dialog as we don't want to override them
		final int themeResId = getThemeResId();
		if (themeResId != R.style.Theme_DialogWhenLarge &&
				themeResId != R.style.Theme_SubSettingsDialogWhenLarge) {
			setTheme(R.style.Theme_SubSettings);
		}
	}
	setContentView(mIsShowingDashboard ?
			R.layout.settings_main_dashboard : R.layout.settings_main_prefs);
	mContent = (ViewGroup) findViewById(R.id.main_content);
	getFragmentManager().addOnBackStackChangedListener(this);
	if (mIsShowingDashboard) {
		// Run the Index update only if we have some space
		if (!Utils.isLowStorage(this)) {
			Index.getInstance(getApplicationContext()).update();
		} else {
			Log.w(LOG_TAG, "Cannot update the Indexer as we are running low on storage space!");
		}
	}
	if (savedState != null) {
		// We are restarting from a previous saved state; used that to initialize, instead
		// of starting fresh.
		mSearchMenuItemExpanded = savedState.getBoolean(SAVE_KEY_SEARCH_MENU_EXPANDED);
		mSearchQuery = savedState.getString(SAVE_KEY_SEARCH_QUERY);
		setTitleFromIntent(intent);
		ArrayList<DashboardCategory> categories =
				savedState.getParcelableArrayList(SAVE_KEY_CATEGORIES);
		if (categories != null) {
			mCategories.clear();
			mCategories.addAll(categories);
			setTitleFromBackStack();
		}
		mDisplayHomeAsUpEnabled = savedState.getBoolean(SAVE_KEY_SHOW_HOME_AS_UP);
		mDisplaySearch = savedState.getBoolean(SAVE_KEY_SHOW_SEARCH);
		mHomeActivitiesCount = savedState.getInt(SAVE_KEY_HOME_ACTIVITIES_COUNT,
				1 /* one home activity by default */);
 

Tags:
Android android activity category profile         
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Android M 設置流程簡要分析

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