Android M 设置流程简要分析

这份笔记主要是记录设置的大致流程,以便在后续项目中需要修改设置的时候以便快熟理解大的思路.

 

首先从入口开始,也就是从第一个Activity开始,在AndroidManifest.xml里面找到android.intent.category.LAUNCHER,这个activity-alias 就是要找的入口,其实这只是一个别名

真正想要看的是它的android:targetActivity="Settings",也就是

1. android:name="Settings"
2. android:taskAffinity="com.android.settings"
3. android:label="@string/settings_label_launcher"
4. android:launchMode="singleTask">
5. android:priority="1">
6. android:name="android.settings.SETTINGS" />
7. android:name="android.intent.category.DEFAULT" />
9. android:name="com.android.settings.PRIMARY_PROFILE_CONTROLLED"
10. android:value="true" />
12.  
14. android:name="Settings"
15. android:taskAffinity="com.android.settings"
16. android:label="@string/settings_label_launcher"
17. android:launchMode="singleTask"
18. android:targetActivity="Settings">
20. android:name="android.intent.action.MAIN" />
21. android:name="android.intent.category.DEFAULT" />
22. android:name="android.intent.category.LAUNCHER" />

 

打开这个Settings.java发现里面主要是定义了很多内部静态Activity,主要逻辑还是在其父类SettingsActivity.java 里面,那就从onCreate()开始

1. @Override
2. protected void onCreate(Bundle savedState) {
3. super.onCreate(savedState);
4. mExt = UtilsExt.getMiscPlugin(this);
5.  
6. // Should happen before any call to getIntent()
7. getMetaData();//获取配置meta-data中的com.android.settings.FRAGMENT_CLASS属性的值,将值保存在mFragmentClass里面
8.  
9. final Intent intent = getIntent();
10. if (intent.hasExtra(EXTRA_UI_OPTIONS)) {
11. getWindow().setUiOptions(intent.getIntExtra(EXTRA_UI_OPTIONS, 0));
12. }
13.  
14. mDevelopmentPreferences = getSharedPreferences(DevelopmentSettings.PREF_FILE,
15. Context.MODE_PRIVATE);
16.  
17. // Getting Intent properties can only be done after the super.onCreate(...)
18. final String initialFragmentName = intent.getStringExtra(EXTRA_SHOW_FRAGMENT);
19.  
20. mIsShortcut = isShortCutIntent(intent) || isLikeShortCutIntent(intent) ||
21. intent.getBooleanExtra(EXTRA_SHOW_FRAGMENT_AS_SHORTCUT, false);
22.  
23. final ComponentName cn = intent.getComponent();
24. final String className = cn.getClassName();
25.  
26. mIsShowingDashboard = className.equals(Settings.class.getName());
27.  
28. // This is a "Sub Settings" when:
29. // - this is a real SubSettings
30. // - or :settings:show_fragment_as_subsetting is passed to the Intent
31. final boolean isSubSettings = this instanceof SubSettings ||
32. intent.getBooleanExtra(EXTRA_SHOW_FRAGMENT_AS_SUBSETTING, false);
33.  
34. // If this is a sub settings, then apply the SubSettings Theme for the ActionBar content insets
35. if (isSubSettings) {
36. // Check also that we are not a Theme Dialog as we don't want to override them
37. final int themeResId = getThemeResId();
38. if (themeResId != R.style.Theme_DialogWhenLarge &&
39. themeResId != R.style.Theme_SubSettingsDialogWhenLarge) {
40. setTheme(R.style.Theme_SubSettings);
41. }
42. }
43.  
44. setContentView(mIsShowingDashboard ?
45. R.layout.settings_main_dashboard : R.layout.settings_main_prefs);
46.  
47. mContent = (ViewGroup) findViewById(R.id.main_content);
48.  
49. getFragmentManager().addOnBackStackChangedListener(this);
50.  
51. if (mIsShowingDashboard) {
52. // Run the Index update only if we have some space
53. if (!Utils.isLowStorage(this)) {
54. Index.getInstance(getApplicationContext()).update();
55. } else {
56. Log.w(LOG_TAG, "Cannot update the Indexer as we are running low on storage space!");
57. }
58. }
59.  
60. if (savedState != null) {
61. // We are restarting from a previous saved state; used that to initialize, instead
62. // of starting fresh.
63. mSearchMenuItemExpanded = savedState.getBoolean(SAVE_KEY_SEARCH_MENU_EXPANDED);
64. mSearchQuery = savedState.getString(SAVE_KEY_SEARCH_QUERY);
65.  
66. setTitleFromIntent(intent);
67.  
68. ArrayList<DashboardCategory> categories =
69. savedState.getParcelableArrayList(SAVE_KEY_CATEGORIES);
70. if (categories != null) {
71. mCategories.clear();
72. mCategories.addAll(categories);
73. setTitleFromBackStack();
74. }
75.  
76. mDisplayHomeAsUpEnabled = savedState.getBoolean(SAVE_KEY_SHOW_HOME_AS_UP);
77. mDisplaySearch = savedState.getBoolean(SAVE_KEY_SHOW_SEARCH);
78. mHomeActivitiesCount = savedState.getInt(SAVE_KEY_HOME_ACTIVITIES_COUNT,
79. 1 /* one home activity by default */);
80. } else {
81. if (!mIsShowingDashboard) {
82. mDisplaySearch = false;
83. // UP will be shown only if it is a sub settings
84. if (mIsShortcut) {
85. mDisplayHomeAsUpEnabled = isSubSettings;
86. } else if (isSubSettings) {
87. mDisplayHomeAsUpEnabled = true;
88. } else {
89. mDisplayHomeAsUpEnabled = false;
90. }
91. setTitleFromIntent(intent);
92.  
93. Bundle initialArguments = intent.getBundleExtra(EXTRA_SHOW_FRAGMENT_ARGUMENTS);
94. switchToFragment(initialFragmentName, initialArguments, true, false,
95. mInitialTitleResId, mInitialTitle, false);
96. } else {
97. // No UP affordance if we are displaying the main Dashboard
98. mDisplayHomeAsUpEnabled = false;
99. // Show Search affordance
100. //mDisplaySearch = true;
101. mDisplaySearch = false;//zhangle add :remove Search
102. mInitialTitleResId = R.string.dashboard_title;
103. switchToFragment(DashboardSummary.class.getName(), null, false, false,
104. mInitialTitleResId, mInitialTitle, false);
105. }
106. }
107. mActionBar = getActionBar();
108. if (mActionBar != null) {
109. mActionBar.setDisplayHomeAsUpEnabled(mDisplayHomeAsUpEnabled);
110. mActionBar.setHomeButtonEnabled(mDisplayHomeAsUpEnabled);
111. }
112. mSwitchBar = (SwitchBar) findViewById(R.id.switch_bar);
113.  
114. // see if we should show Back/Next buttons
115. if (intent.getBooleanExtra(EXTRA_PREFS_SHOW_BUTTON_BAR, false)) {
116.  
117. View buttonBar = findViewById(R.id.button_bar);
118. if (buttonBar != null) {
119. buttonBar.setVisibility(View.VISIBLE);
120.  
121. Button backButton = (Button)findViewById(R.id.back_button);
122. backButton.setOnClickListener(new OnClickListener() {
123. public void onClick(View v) {
124. setResult(RESULT_CANCELED, getResultIntentData());
125. finish();
126. }
127. });
128. Button skipButton = (Button)findViewById(R.id.skip_button);
129. skipButton.setOnClickListener(new OnClickListener() {
130. public void onClick(View v) {
131. setResult(RESULT_OK, getResultIntentData());
132. finish();
133. }
134. });
135. mNextButton = (Button)findViewById(R.id.next_button);
136. mNextButton.setOnClickListener(new OnClickListener() {
137. public void onClick(View v) {
138. setResult(RESULT_OK, getResultIntentData());
139. finish();
140. }
141. });
142.  
143. // set our various button parameters
144. if (intent.hasExtra(EXTRA_PREFS_SET_NEXT_TEXT)) {
145. String buttonText = intent.getStringExtra(EXTRA_PREFS_SET_NEXT_TEXT);
146. if (TextUtils.isEmpty(buttonText)) {
147. mNextButton.setVisibility(View.GONE);
148. }
149. else {
150. mNextButton.setText(buttonText);
151. }
152. }
153. if (intent.hasExtra(EXTRA_PREFS_SET_BACK_TEXT)) {
154. String buttonText = intent.getStringExtra(EXTRA_PREFS_SET_BACK_TEXT);
155. if (TextUtils.isEmpty(buttonText)) {
156. backButton.setVisibility(View.GONE);
157. }
158. else {
159. backButton.setText(buttonText);
160. }
161. }
162. if (intent.getBooleanExtra(EXTRA_PREFS_SHOW_SKIP, false)) {
163. skipButton.setVisibility(View.VISIBLE);
164. }
165. }
166. }
167.  
168. mHomeActivitiesCount = getHomeActivitiesCount();
169. }

其中第7行是获取配置meta-data中的com.android.settings.FRAGMENT_CLASS属性的值,将值保存在mFragmentClass里面,后面会用到这个变量,其实这个变量保存就是我们要打开的Fragment的名称.

第14行的mDevelopmentPreferences 后面主要用来判断是否在设置的一级菜单列表中显示开发者选项.

第20 行的mIsShortcut在设置快捷方式的会用到,也就是在桌面创建快捷图标的时候会用到.

第26行的mIsShowingDashboard 用来判断是否显示的一级菜单,因为还有更深的二级菜单.同时这个变量将决定在44行的的setContentView时用的是什么布局文件,一级菜单页面和二级菜单页面是不一样,因为二级菜单页面是有返回按钮和上一步和下一步的按钮,这个在设置-安全里面设置密码的时候就会有体现,其中的底部的2个button也就是在settings_main_prefs 里面配置的.

同时81行到106行的这个if-else 也是有这儿mIsShowingDashboard  决定的,如果是DashBoard页面(一级菜单)就由来DashboardSummary处理.如果不是就由获取的指定的initialFragmentName 来处理.这里都是有方法switchToFragment()来处理的,只是传入的参数不同罢了.

上面提到的initialFragmentName 是在重写父类的getIntent()方法里面设置的.

 

DashBoard 这个列表并不是普通的ListView是不一样的,上面其实已经提过了,这儿DashBoard列表是通过DashboardSummary这个Fragment来实现的.整个设置的滑动列表是显示在ScrollView里面的.

DashboardSummary.java

1. public View onCreateView(LayoutInflater inflater, ViewGroup container,
2. Bundle savedInstanceState) {
3.  
4. mLayoutInflater = inflater;
5. mExt = UtilsExt.getMiscPlugin(this.getActivity());
6.  
7. final View rootView = inflater.inflate(R.layout.dashboard, container, false);
8. mDashboard = (ViewGroup) rootView.findViewById(R.id.dashboard_container);
9.  
10. return rootView;
11. }

layout: dashboard

1. xmlns:android="http://schemas.android.com/apk/res/android"
2. android:id="@+id/dashboard"
3. android:layout_width="match_parent"
4. android:layout_height="match_parent"
5. android:scrollbarStyle="outsideOverlay"
6. android:clipToPadding="false">
7.  
9. android:id="@+id/dashboard_container"
10. android:layout_width="match_parent"
11. android:layout_height="match_parent"
12. android:layout_gravity="center_horizontal"
13. android:paddingStart="@dimen/dashboard_padding_start"
14. android:paddingEnd="@dimen/dashboard_padding_end"
15. android:paddingTop="@dimen/dashboard_padding_top"
16. android:paddingBottom="@dimen/dashboard_padding_bottom"
17. android:clipToPadding="false"
18. android:orientation="vertical"
19. />
20.  

我们在设置里面看到的可滑动的一级菜单列表就是在这个dashboard_container里面的.

在DashboardSummary.java的onResume()里面会使用Handler来执行rebuildUI()开始解析layout.dashboard_category 文件,并生成对应的View视图.

1. private void rebuildUI(Context context) {
2. if (!isAdded()) {
3. Log.w(LOG_TAG, "Cannot build the DashboardSummary UI yet as the Fragment is not added");
4. return;
5. }
6.  
7. long start = System.currentTimeMillis();
8. final Resources res = getResources();
9.  
10. mDashboard.removeAllViews();
11.  
12. List<DashboardCategory> categories =
13. ((SettingsActivity) context).getDashboardCategories(true);
14.  
15. final int count = categories.size();
16.  
17. for (int n = 0; n < count; n++) {
18. DashboardCategory category = categories.get(n);
19.  
20. View categoryView = mLayoutInflater.inflate(R.layout.dashboard_category, mDashboard,
21. false);
22.  
23. TextView categoryLabel = (TextView) categoryView.findViewById(R.id.category_title);
24. categoryLabel.setText(category.getTitle(res));
25.  
26. ViewGroup categoryContent =
27. (ViewGroup) categoryView.findViewById(R.id.category_content);
28.  
29. final int tilesCount = category.getTilesCount();
30. for (int i = 0; i < tilesCount; i++) {
31. DashboardTile tile = category.getTile(i);
32.  
33. DashboardTileView tileView = new DashboardTileView(context);
34. updateTileView(context, res, tile, tileView.getImageView(),
35. tileView.getTitleTextView(), tileView.getStatusTextView());
36.  
37. tileView.setTile(tile);
38. if(tile != null && tile.extras != null && tile.extras.containsKey(CUSTOMIZE_ITEM_INDEX)){
39. int index = tile.extras.getInt(CUSTOMIZE_ITEM_INDEX, -1);
40. categoryContent.addView(tileView, index);
41. } else {
42. categoryContent.addView(tileView);
43. }
44. }
45.  
46. // Add the category
47. mDashboard.addView(categoryView);
48. }
49. long delta = System.currentTimeMillis() - start;
50. Log.d(LOG_TAG, "rebuildUI took: " + delta + " ms");
51. }

从上面的代码中可以发现每一个设置项对应的视图就是DashboardTileView,相关的标题,icon,要打开的对应的页面都是保存在DashboardTile里面的.

接着看看DashboardTileView,

1. public DashboardTileView(Context context, AttributeSet attrs) {
2. super(context, attrs);
3.  
4. //zhangle update layout res at 20150608 dashboard_tile -> dashboard_tile_doov
5. final View view = LayoutInflater.from(context).inflate(R.layout.dashboard_tile_doov, this);
6.  
7. mImageView = (ImageView) view.findViewById(R.id.icon);
8. mTitleTextView = (TextView) view.findViewById(R.id.title);
9. mStatusTextView = (TextView) view.findViewById(R.id.status);
10. mDivider = view.findViewById(R.id.tile_divider);
11.  
12. setOnClickListener(this);
13. setBackgroundResource(R.drawable.dashboard_tile_background);
14. setFocusable(true);
15. }

在上面的代码中可以看到我们点击每一个设置项的事件实际就是在DashboardTileView 的构造函数中设置的处理事件.