基于全志H713 Android 11：给TvSettings添加default.xml默认值

篇头

如今去过厂家的SOC，尤其是国产芯片，在设计其Android AOSP系统的时候，基本都会遵循谷歌的架构和规范。本文基于全志H713 Android 11平台，介绍如何给谷歌标准版的TvSettings添加default.xml默认值。

一、问题及需求

1.1 需求

给投影的HDMI CEC功能，配置几个默认值；

1.2 问题

TvSettings的默认值在哪配置，如何配置？

1.3 CEC设置界面

TvSettings->Device Preferences->Inputs

二、源码分析

2.1 查找思路

根据UI上的字符串，如"TV auto set language",顺藤摸瓜，在代码中找到set value 的地方，之后进一步找到配置文件位置。

2.2 TvSettings 数据设置

如下，找到了点击CEC界面开关后，写入值的地方
从 writeCecOption(Settings.Global.HDMI_CONTROL_AUTO_SET_LANGUAGE, mTvAutoSetLanguage.isChecked());等语句，可以得知值存储在Settings Global数据库中。
A:\works\aw\android\packages\apps\TvSettings\Settings\src\com\android\tv\settings\system\InputsFragment.java

Plain 复制代码

 @Override
    public boolean onPreferenceTreeClick(Preference preference) {
        final String key = preference.getKey();
        if (key == null) {
            return super.onPreferenceTreeClick(preference);
        }
        switch (key) {
            case KEY_HDMI_CONTROL:
                writeCecOption(Settings.Global.HDMI_CONTROL_ENABLED, mHdmiControlPref.isChecked());
                /// AW CODE: [feat] support hdmi cec with more switches
                setPreferncesEnabled(mHdmiControlPref.isChecked());
                /// AW:add end
                return true;
            case KEY_DEVICE_AUTO_OFF:
                writeCecOption(Settings.Global.HDMI_CONTROL_AUTO_DEVICE_OFF_ENABLED,
                        mDeviceAutoOffPref.isChecked());
                return true;
            case KEY_TV_AUTO_ON:
                writeCecOption(Settings.Global.HDMI_CONTROL_AUTO_WAKEUP_ENABLED,
                        mTvAutoOnPref.isChecked());
                return true;
            /// AW CODE: [feat] support hdmi cec with more switches
            case KEY_TV_AUTO_SET_LANGUAGE:
                writeCecOption(Settings.Global.HDMI_CONTROL_AUTO_SET_LANGUAGE,
                        mTvAutoSetLanguage.isChecked());
                return true;
            case KEY_TV_AUTO_INPUT_PASSTHROUGH:
                writeCecOption(Settings.Global.HDMI_CONTROL_AUTO_INPUT_PASSTHROUGH,
                        mTvAutoInputPassThrough.isChecked());
                return true;
            /// AW:add end
            /// AW CODE: [feat] add item for AwLiveTv recovery
            case KEY_INPUT_RECOVERY:
                writeCecOption(Settings.Global.INPUT_RECOVERY,
                        mInputRecovery.isChecked());
                return true;
            /// AW:add end
        }
        return super.onPreferenceTreeClick(preference);
    }

2.3 配置文件

位置：A:\works\aw\android\frameworks\base\packages\SettingsProvider\res\values\defaults.xml
新的问题：从配置文件中，只找到1个HDMI CEC的开关的默认值，其余5个则找不到

Plain 复制代码

    <!-- Default for setting for Settings.Global.HDMI_CONTROL_AUTO_DEVICE_OFF_ENABLED -->
    <bool name="def_hdmiControlAutoDeviceOff">false</bool>

2.4 Global 枚举定义的地方

位置 A:\works\aw\android\frameworks\base\core\java\android\provider\Settings.java
在这个文件里，定义了Global.xxxx枚举，例如Settings.Global.HDMI_CONTROL_AUTO_DEVICE_OFF_ENABLED

Plain 复制代码

        public static final String HDMI_CONTROL_AUTO_WAKEUP_ENABLED =
                "hdmi_control_auto_wakeup_enabled";

        /**
         * Whether TV will also turn off other CEC devices when it goes to standby mode.
         * (0 = false, 1 = true)
         *
         * @hide
         */
        public static final String HDMI_CONTROL_AUTO_DEVICE_OFF_ENABLED =
                "hdmi_control_auto_device_off_enabled";

        /// AW CODE: [feat] HDMI-CEC: supprot device auto power on
        /**
         * Whether TV will also turn on other CEC devices when it goes to wakeup mode.
         * (0 = false, 1 = true)
         *
         * @hide
         */
        public static final String HDMI_CONTROL_AUTO_DEVICE_ON_ENABLED =
                "hdmi_control_auto_device_on_enabled";
        /// AW: add end.

2.5 加载默认值的地方

位置：android\frameworks\base\packages\SettingsProvider\src\com\android\providers\settings\SettingsProvider.java
通过关键字符串的查找，可以定位到默认值加载的地方，如下即使用字符串：def_hdmiControlAutoDeviceOff找到的
大致阅读此处代码，可知此处的作用就是在Settings.Gloabl数据表中插入新的字段，并赋予默认值，而默认值就是来自default.xml

Plain 复制代码

                if (currentVersion == 190) {
                    // Version 190: get HDMI auto device off from overlay
                    final SettingsState globalSettings = getGlobalSettingsLocked();
                    final Setting currentSetting = globalSettings.getSettingLocked(
                            Global.HDMI_CONTROL_AUTO_DEVICE_OFF_ENABLED);
                    if (currentSetting.isNull()) {
                        globalSettings.insertSettingLocked(
                                Global.HDMI_CONTROL_AUTO_DEVICE_OFF_ENABLED,
                                getContext().getResources().getBoolean(
                                        R.bool.def_hdmiControlAutoDeviceOff) ? "1" : "0",
                                null, true, SettingsState.SYSTEM_PACKAGE_NAME);
                    }
                    currentVersion = 191;
                }

                // vXXX: Add new settings above this point.

2.6 查看实时数据

2.6.1 查看默认数据

烧录镜像后，不要操作UI开关，可查询到如下数据；
可得知，此时，数据库中只有一个HDMI的开关默认值，和楼上default.xml与SettingsProvider.java的逻辑一致

Plain 复制代码

h713-tuna_p3:/ # settings list global  | grep hdmi
hdmi_control_auto_device_off_enabled=1
h713-tuna_p3:/ # pwd

2.6.2 写入值

将UI里的HDMI CEC开关，全部关闭，再打开
查询DB的结果如下，可见已为我们添加了相关字段

Plain 复制代码

h713-tuna_p3:/ # settings list global  | grep hdmi
hdmi_control_auto_device_off_enabled=1
hdmi_control_auto_input_passthrough=1
hdmi_control_auto_set_language=1
hdmi_control_auto_wakeup_enabled=1
hdmi_control_enabled=1
h713-tuna_p3:/ # pwd

三、举例：添加两个HDMI CEC开关的默认值

3.1 添加默认值：defaults.xml

A:\works\aw\android\frameworks\base\packages\SettingsProvider\res\values\defaults.xml
以下def_xxx都是自定义的

Plain 复制代码

     <!-- Default for setting for  Settings.Global.HDMI_CONTROL_ENABLED -->
     <bool name="def_hdmi_control_enabled">false</bool>

     <!-- Default for setting for  Settings.Global.HDMI_CONTROL_AUTO_SET_LANGUAGE -->
     <bool name="def_hdmi_control_auto_set_language">false</bool>

3.2 加载默认值：SettingsProvider.java

A:\works\aw\android\frameworks\base\packages\SettingsProvider\src\com\android\providers\settings\SettingsProvider.java
如下，找到if (currentVersion == 190)，按格式，追加我们需要设定的两个def_xxxx 默认值
R.bool.def_hdmi_control_enabled =>Global.HDMI_CONTROL_ENABLED
R.bool.def_hdmi_control_auto_set_language=>Global.HDMI_CONTROL_AUTO_SET_LANGUAGE

Plain 复制代码

if (currentVersion == 191) {
                    // 
                    final SettingsState globalSettings = getGlobalSettingsLocked();
                    final Setting currentSetting = globalSettings.getSettingLocked(
                            Global.HDMI_CONTROL_ENABLED);
                    if (currentSetting.isNull()) {
                        globalSettings.insertSettingLocked(
                                Global.HDMI_CONTROL_ENABLED,
                                getContext().getResources().getBoolean(
                                        R.bool.def_hdmi_control_enabled) ? "1" : "0",
                                null, true, SettingsState.SYSTEM_PACKAGE_NAME);
                    }
                    currentVersion = 192;
                }

                if (currentVersion == 192) {
                    // 
                    final SettingsState globalSettings = getGlobalSettingsLocked();
                    final Setting currentSetting = globalSettings.getSettingLocked(
                            Global.HDMI_CONTROL_AUTO_SET_LANGUAGE);
                    if (currentSetting.isNull()) {
                        globalSettings.insertSettingLocked(
                                Global.HDMI_CONTROL_AUTO_SET_LANGUAGE,
                                getContext().getResources().getBoolean(
                                        R.bool.def_hdmi_control_auto_set_language) ? "1" : "0",
                                null, true, SettingsState.SYSTEM_PACKAGE_NAME);
                    }
                    currentVersion = 193;
                }

                // vXXX: Add new settings above this point.

3.3 测试结果

烧录后，第一次开机，测试结果如下

Plain 复制代码

C:\Users\szhou\Desktop>adb shell
h713-tuna_p3:/ # settings list global  | grep hdmi
hdmi_control_auto_device_off_enabled=0
hdmi_control_auto_set_language=0
hdmi_control_enabled=0
h713-tuna_p3:/ #

3.4 运行效果图

效果如下图，CEC总开关【HDMI control】和子开关【TV auto set language】均被设置成了FALSE