Android Mobile Network Settings | APN 菜单加载异常

问题

从log看是有创建APN对应的Controller（功能逻辑是ok的），但是Mobile Network Settings无法显示（UI异常）。

日志分析

看似APN 菜单已经创建了，实际上并没有显示。

11-12 07:01:28.150 8773 8773 D PrefCtrlListHelper: Could not find Context-only controller for pref: com.android.settings.network.telephony.ApnPreferenceController

11-12 07:01:28.164 8773 8773 D ApnPreferenceController: init: subId = 1

Debug 1：表面原因 isGsmApn

debug打印log的时候会发现，使用平板时preference是不可见的，无法确认是不是getAvailabilityStatus影响了displayPreference。

Tablet Log：

11-13 17:10:46.692 7796 9288 D ApnPreferenceController: getAvailabilityStatus hideCarrierNetwork = false, isCdmaApn = false, isGsmApn = false

11-13 17:10:46.705 7796 7796 I ApnPreferenceController: displayPreference: isShow = false, isVisible = false, isEnable = true

Phone Log：

11-13 03:25:47.285 13222 13222 D ApnPreferenceController: init: subId = 3

11-13 03:25:47.323 13222 13401 D ApnPreferenceController: getAvailabilityStatus hideCarrierNetwork = false, isCdmaApn = false, isGsmApn = true

11-13 03:25:47.372 13222 13222 I ApnPreferenceController: displayPreference: isShow = true, isVisible = true, isEnable = true

Debug 2：根因 isGsmOptions

Phone Log：

11-13 05:14:30.305 15022 15022 D SatelliteSettingPreferenceController: init(), subId=3
11-13 05:14:30.305 15022 15022 D ApnPreferenceController: init: subId = 3

11-13 05:14:30.354 15022 15233 D ApnPreferenceController: isGsmOption = true
11-13 05:14:30.354 15022 15233 D ApnPreferenceController: KEY_APN_EXPAND_BOOL = true

11-13 05:14:30.355 15022 15233 D ApnPreferenceController: getAvailabilityStatus hideCarrierNetwork = false, isCdmaApn = false, isGsmApn = true

11-13 05:14:30.448 15022 15022 I ApnPreferenceController: displayPreference: isShow = true, isVisible = true, isEnable = true

11-13 05:14:31.218 15022 15022 D ApnPreferenceController: updateState: preferenceKey = telephony_apn_key

11-13 05:14:32.350 15022 15022 D ApnPreferenceController: handlePreferenceTreeClick

Tablet Log：

11-13 18:13:24.359 11793 11793 D ApnPreferenceController: isGsmOption = false

11-13 18:13:24.359 11793 11793 D ApnPreferenceController: KEY_APN_EXPAND_BOOL = true

11-13 18:13:24.359 11793 11793 D ApnPreferenceController: getAvailabilityStatus hideCarrierNetwork = false, isCdmaApn = false, isGsmApn = false

11-13 18:13:24.360 11793 11793 I ApnPreferenceController: displayPreference: isShow = false, isVisible = false, isEnable = true

代码解读

移动网络界面加入APN的菜单

mobile_network_settings.xml

先来看看界面设计逻辑

<!-- Copyright (C) 2019 The Android Open Source Project --><PreferenceScreenxmlns:android="http://schemas.android.com/apk/res/android"xmlns:settings="http://schemas.android.com/apk/res-auto"android:key="mobile_network_pref_screen"><com.android.settings.spa.preference.ComposePreferenceandroid:key="use_sim_switch"settings:controller="com.android.settings.network.telephony.MobileNetworkSwitchController"/><!-- 省略移动网络其他controller --><!--We want separate APN setting from reset of settings because we want user to change it with caution--><com.android.settingslib.RestrictedPreferenceandroid:key="telephony_apn_key"android:persistent="false"android:title="@string/mobile_network_apn_title"settings:keywords="@string/keywords_access_point_names"settings:controller="com.android.settings.network.telephony.ApnPreferenceController"/></PreferenceScreen>

标题定义

packages\apps\Settings\res\values\strings.xml

    <!-- Title for Apn settings in mobile network settings [CHAR LIMIT=60] --><string name="mobile_network_apn_title">Access Point Names</string>

ApnPreferenceController

    @Overridepublic int getAvailabilityStatus(int subId) {final PersistableBundle carrierConfig = mCarrierConfigCache.getConfigForSubId(subId);final boolean isCdmaApn = MobileNetworkUtils.isCdmaOptions(mContext, subId)&& carrierConfig != null&& carrierConfig.getBoolean(CarrierConfigManager.KEY_SHOW_APN_SETTING_CDMA_BOOL);final boolean isGsmApn = MobileNetworkUtils.isGsmOptions(mContext, subId)&& carrierConfig != null&& carrierConfig.getBoolean(CarrierConfigManager.KEY_APN_EXPAND_BOOL);final boolean hideCarrierNetwork = carrierConfig == null|| carrierConfig.getBoolean(CarrierConfigManager.KEY_HIDE_CARRIER_NETWORK_SETTINGS_BOOL);return !hideCarrierNetwork && (isCdmaApn || isGsmApn)? AVAILABLE: CONDITIONALLY_UNAVAILABLE;}@Overridepublic void displayPreference(PreferenceScreen screen) {super.displayPreference(screen);Log.i(TAG, "displayPreference + ");mPreference = screen.findPreference(getPreferenceKey());//For debug as belowif (mPreference != null) {Log.i(TAG, "displayPreference: isShow = " + mPreference.isShown() +", isVisible = " + mPreference.isVisible() + ", isEnable = " + mPreference.isEnabled());}mPreference.setEnabled(true);    //是否置灰mPreference.setVisible(true);    //是否显示Log.i(TAG, "displayPreference: enable and visible.");}

继续分析preference的逻辑，沿着 getAvailabilityStatus 可以看到，在 ApnPreferenceController 其父类实现的接口 TelephonyAvailabilityCallback 中会回调

packages/apps/Settings/src/com/android/settings/network/telephony/ApnPreferenceController.java

*** Preference controller for "Apn settings"*/
public class ApnPreferenceController extends TelephonyBasePreferenceController implementsLifecycleObserver, OnStart, OnStop {}

父类 TelephonyBasePreferenceController

packages/apps/Settings/src/com/android/settings/network/telephony/TelephonyBasePreferenceController.java

/*** {@link BasePreferenceController} that used by all preferences that requires subscription id.*/
public abstract class TelephonyBasePreferenceController extends BasePreferenceControllerimplements TelephonyAvailabilityCallback, TelephonyAvailabilityHandler {}

可用性接口TelephonyAvailabilityCallback

packages/apps/Settings/src/com/android/settings/network/telephony/TelephonyAvailabilityCallback.java

package com.android.settings.network.telephony;/*** Callback to decide whether preference is available based on subscription id*/
public interface TelephonyAvailabilityCallback {/*** Return availability status for a specific subId** @see TelephonyBasePreferenceController* @see TelephonyTogglePreferenceController*/int getAvailabilityStatus(int subId);
}

MobileNetworkUtils

packages/apps/Settings/src/com/android/settings/network/telephony/MobileNetworkUtils.java

    /*** Return availability for a default subscription id. If subId already been set, use it to* check, otherwise traverse all active subIds on device to check.* @param context context* @param defSubId Default subId get from telephony preference controller* @param callback Callback to check availability for a specific subId* @return Availability** @see BasePreferenceController#getAvailabilityStatus()*/public static int getAvailability(Context context, int defSubId,TelephonyAvailabilityCallback callback) {if (defSubId != SubscriptionManager.INVALID_SUBSCRIPTION_ID) {// If subId has been set, return the corresponding statusreturn callback.getAvailabilityStatus(defSubId);} else {// Otherwise, search whether there is one subId in device that support this preferencefinal int[] subIds = getActiveSubscriptionIdList(context);if (ArrayUtils.isEmpty(subIds)) {return callback.getAvailabilityStatus(SubscriptionManager.INVALID_SUBSCRIPTION_ID);} else {for (final int subId : subIds) {final int status = callback.getAvailabilityStatus(subId);if (status == BasePreferenceController.AVAILABLE) {return status;}}return callback.getAvailabilityStatus(subIds[0]);}}}/*** return {@code true} if we need show Gsm related settings*/public static boolean isGsmOptions(Context context, int subId) {if (subId == SubscriptionManager.INVALID_SUBSCRIPTION_ID) {return false;}if (isGsmBasicOptions(context, subId)) {return true;}final TelephonyManager telephonyManager = context.getSystemService(TelephonyManager.class).createForSubscriptionId(subId);final int networkMode = getNetworkTypeFromRaf((int) telephonyManager.getAllowedNetworkTypesForReason(TelephonyManager.ALLOWED_NETWORK_TYPES_REASON_USER));if (isWorldMode(context, subId)) {if (networkMode == NETWORK_MODE_LTE_CDMA_EVDO|| networkMode == NETWORK_MODE_LTE_GSM_WCDMA|| networkMode == NETWORK_MODE_NR_LTE_CDMA_EVDO|| networkMode == NETWORK_MODE_NR_LTE_GSM_WCDMA) {return true;} else if (shouldSpeciallyUpdateGsmCdma(context, subId)) {return true;}}return false;}private static boolean isGsmBasicOptions(Context context, int subId) {final PersistableBundle carrierConfig =CarrierConfigCache.getInstance(context).getConfigForSubId(subId);if (carrierConfig != null&& !carrierConfig.getBoolean(CarrierConfigManager.KEY_HIDE_CARRIER_NETWORK_SETTINGS_BOOL)&& carrierConfig.getBoolean(CarrierConfigManager.KEY_WORLD_PHONE_BOOL)) {return true;}final TelephonyManager telephonyManager = context.getSystemService(TelephonyManager.class).createForSubscriptionId(subId);if (telephonyManager.getPhoneType() == TelephonyManager.PHONE_TYPE_GSM) {return true;}return false;}}