Android8.1 Settings中清除数据流程分析
1、首先我们根据关键词"清除数据"去找，会找到如下文件
packages/apps/Settings/src/com/android/settings/applications/AppStorageSettings.java
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (savedInstanceState != null) {
mCacheCleared = savedInstanceState.getBoolean(KEY_CACHE_CLEARED, false);
mDataCleared = savedInstanceState.getBoolean(KEY_DATA_CLEARED, false);
mCacheCleared = mCacheCleared || mDataCleared;
}
addPreferencesFromResource(R.xml.app_storage_settings);
setupViews();
initMoveDialog();
if (SUPPORT_SUPER_POWER_SAVE) {
mPowerManagerEx = IPowerManagerEx.Stub.asInterface(ServiceManager.getService("power_ex"));
}
}
2、根据对应的app_storage_settings.xml文件如下
<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:settings="http://schemas.android.com/apk/res-auto"
android:title="@string/application_info_label">
//这个就是对应的清除数据的布局处理
<com.android.settings.applications.LayoutPreference
android:key="header_view"
android:layout="@layout/app_action_buttons"
android:selectable="false" />
<com.android.settings.applications.SpacePreference
android:key="storage_space"
android:layout_height="8dp" />
<Preference
android:key="storage_used"
android:title="@string/storage_used"
android:summary="@string/storage_type_internal"
android:selectable="false"
android:layout="@layout/horizontal_preference" />
<com.android.settings.applications.LayoutPreference
android:key="change_storage_button"
android:selectable="false"
android:layout="@layout/single_button_panel" />
<PreferenceCategory
android:key="storage_category"
android:title="@string/app_info_storage_title"
settings:allowDividerAbove="false"
settings:allowDividerBelow="false">
<Preference
android:key="app_size"
android:title="@string/application_size_label"
android:selectable="false"
android:layout="@layout/horizontal_preference" />
<Preference
android:key="data_size"
android:title="@string/data_size_label"
android:selectable="false"
android:layout="@layout/horizontal_preference" />
<Preference
android:key="cache_size"
android:title="@string/cache_size_label"
android:selectable="false"
android:layout="@layout/horizontal_preference" />
<Preference
android:key="total_size"
android:title="@string/total_size_label"
android:selectable="false"
android:layout="@layout/horizontal_preference" />
<com.android.settings.applications.SpacePreference
android:layout_height="8dp" />
</PreferenceCategory>
<PreferenceCategory
android:key="uri_category"
android:layout="@layout/headerless_preference_category"
settings:allowDividerAbove="false"
settings:allowDividerBelow="false">
<com.android.settings.applications.LayoutPreference
android:key="clear_uri_button"
android:layout="@layout/single_button_panel"
android:selectable="false" />
</PreferenceCategory>
</PreferenceScreen>
3、清除数据对应的布局如下
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:paddingTop="8dp"
android:paddingStart="8dp"
android:paddingEnd="8dp"
android:orientation="horizontal">
<Button
android:id="@+id/left_button"
style="@style/AppActionPrimaryButton"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="wrap_content"
android:layout_marginBottom="4dp" />
<Button
android:id="@+id/right_button"
style="@style/AppActionPrimaryButton"
android:layout_width="0dp"
android:layout_weight="1"
android:layout_height="wrap_content"
android:layout_marginBottom="4dp" />
</LinearLayout>
4、找到对应Button的点击事件，如下处理
@Override
public void onClick(View v) {
/* Bug 914729 : Crash occured if clear data of some app on Ultra Saving mode. @{*/
boolean onUltraSavingModeShowDialogInner = false;
if (isInUltraSavingMode() && !isAllowedAppInUltraSavingMode(mAppEntry.info.packageName)) {
onUltraSavingModeShowDialogInner = true;
}
/*@}*/
if (v == mClearCacheButton) {
if (mAppsControlDisallowedAdmin != null && !mAppsControlDisallowedBySystem) {
RestrictedLockUtils.sendShowAdminSupportDetailsIntent(
getActivity(), mAppsControlDisallowedAdmin);
return;
} else if (mClearCacheObserver == null) { // Lazy initialization of observer
mClearCacheObserver = new ClearCacheObserver();
}
mMetricsFeatureProvider.action(getContext(),
MetricsEvent.ACTION_SETTINGS_CLEAR_APP_CACHE);
/* Modify to delete application cache files of appclone app {@ */
if (mUserId > 0 && AppCloneUserInfo.isAppCloneUserId(mUserId)) {
mPm.deleteApplicationCacheFilesAsUser(mPackageName, mUserId, mClearCacheObserver);
} else {
mPm.deleteApplicationCacheFiles(mPackageName, mClearCacheObserver);
}
/* @} */
} else if (v == mClearDataButton) {//这里就是清除缓存的处理
if (mAppsControlDisallowedAdmin != null && !mAppsControlDisallowedBySystem) {
RestrictedLockUtils.sendShowAdminSupportDetailsIntent(
getActivity(), mAppsControlDisallowedAdmin);
} else if (mAppEntry.info.manageSpaceActivityName != null && !onUltraSavingModeShowDialogInner) {
if (!Utils.isMonkeyRunning()) {
Intent intent = new Intent(Intent.ACTION_DEFAULT);
intent.setClassName(mAppEntry.info.packageName,
mAppEntry.info.manageSpaceActivityName);
startActivityForResult(intent, REQUEST_MANAGE_SPACE);
}
} else {
showDialogInner(DLG_CLEAR_DATA, 0);
}
} else if (v == mChangeStorageButton && mDialogBuilder != null && !isMoveInProgress()) {
mDialogBuilder.show();
} else if (v == mClearUriButton) {
if (mAppsControlDisallowedAdmin != null && !mAppsControlDisallowedBySystem) {
RestrictedLockUtils.sendShowAdminSupportDetailsIntent(
getActivity(), mAppsControlDisallowedAdmin);
} else {
clearUriPermissions();
}
}
}
5，点击清除缓存按钮后会弹出如下对话框的逻辑处理
showDialogInner(DLG_CLEAR_DATA, 0);
protected void showDialogInner(int id, int moveErrorCode) {
DialogFragment newFragment = MyAlertDialogFragment.newInstance(id, moveErrorCode);
newFragment.setTargetFragment(this, 0);
newFragment.showAllowingStateLoss(getFragmentManager(), "dialog " + id);
}
6、最终清除缓存处理逻辑如下
case DLG_CLEAR_DATA:
return new AlertDialog.Builder(getActivity())
.setTitle(getActivity().getText(R.string.clear_data_dlg_title))
.setMessage(getActivity().getText(R.string.clear_data_dlg_text))
.setPositiveButton(R.string.dlg_ok, new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
// Clear user data here
initiateClearUserData();
}
})
.setNegativeButton(R.string.dlg_cancel, null)
.create();
//
7、如下是处理清除缓存
packages/apps/Settings/src/com/android/settings/applications/AppStorageSettings.java
private void initiateClearUserData() {
mMetricsFeatureProvider.action(getContext(), MetricsEvent.ACTION_SETTINGS_CLEAR_APP_DATA);
mClearDataButton.setEnabled(false);
// Invoke uninstall or clear user data based on sysPackage
String packageName = mAppEntry.info.packageName;
Log.i(TAG, "Clearing user data for package : " + packageName);
if (mClearDataObserver == null) {
mClearDataObserver = new ClearUserDataObserver();
}
/* Modify to clear application user data of appclone app {@ */
boolean res = false;
if (mUserId > 0 && AppCloneUserInfo.isAppCloneUserId(mUserId)) {
try {
res = ActivityManagerNative.getDefault().clearApplicationUserData(packageName,
mClearDataObserver, mUserId);
} catch (RemoteException e) {
Log.e(TAG, "clearApplicationUserData :" + e);
}
} else {
ActivityManager am = (ActivityManager)
getActivity().getSystemService(Context.ACTIVITY_SERVICE);
res = am.clearApplicationUserData(packageName, mClearDataObserver);
}
/* @} */
if (!res) {
// Clearing data failed for some obscure reason. Just log error for now
Log.i(TAG, "Couldnt clear application user data for package:"+packageName);
showDialogInner(DLG_CANNOT_CLEAR_DATA, 0);
} else {
mClearDataButton.setText(R.string.recompute_size);
}
}
8、打印结果如下
01-01 11:34:08.743 2810 2810 D AppStorageSettings: mClearDataButton!
01-01 11:34:10.231 2810 2810 I AppStorageSettings: Clearing user data for package : com.zqc.myapplication
01-01 11:34:10.231 2810 2810 I AppStorageSettings: mUserId : 0
01-01 11:34:10.231 2810 2810 I AppStorageSettings: AppCloneUserInfo.isAppCloneUserId(mUserId) : false
01-01 11:34:10.244 2810 2810 I AppStorageSettings: res : true
01-01 11:34:10.528 2810 2810 I AppStorageSettings: Cleared user data for package : com.zqc.myapplication
9、实际执行代码
ActivityManager am = (ActivityManager)
getActivity().getSystemService(Context.ACTIVITY_SERVICE);
res = am.clearApplicationUserData(packageName, mClearDataObserver);