[移动开发]Android源码修改系统默认属性

1、默认音量

device/mediatek/system/common/system.prop

ro.config.vc_call_vol_steps=7
ro.config.vc_call_vol_default=6
ro.config.media_vol_steps=15
ro.config.media_vol_default=15
ro.config.system_vol_steps=15
ro.config.system_vol_default=15

frameworks/base/services/core/java/com/android/server/audio/AudioService.java

int defaultAlarmVolume = SystemProperties.getInt("ro.config.alarm_vol_default", -1);
if (defaultAlarmVolume != -1 && defaultAlarmVolume <= MAX_STREAM_VOLUME[AudioSystem.STREAM_ALARM]) {
    AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_ALARM] = defaultAlarmVolume;
}

int defaultRingVolume = SystemProperties.getInt("ro.config.ring_vol_default", -1);
if (defaultRingVolume != -1 && defaultRingVolume <= MAX_STREAM_VOLUME[AudioSystem.STREAM_RING]) {
    AudioSystem.DEFAULT_STREAM_VOLUME[AudioSystem.STREAM_RING] = defaultRingVolume;
}

?build/make/target/product/core_base.mk

 PRODUCT_PROPERTY_OVERRIDES += \
    ro.config.voice_call_vol_def=7 \
    ro.config.system_vol_def=15 \
    ro.config.media_vol_default=12 \
    ro.config.alarm_vol_default=12 \
    ro.config.ring_vol_default=12

2、默认字体

修改数据库中的默认设置值：

vendor/mediatek/proprietary/packages/apps/SettingsProvider/src/com/android/providers/settings/DatabaseHelper.java

if ("1".equals(android.os.SystemProperties.get("ro.def_small_font", "0"))) {
    loadSetting(stmt, Settings.System.FONT_SCALE, 0.85f);
}

更新UI图标显示：

vendor/mediatek/proprietary/packages/apps/SettingsProvider/src/com/android/providers/settings/SettingsHelper.java

if ("1".equals(android.os.SystemProperties.get("ro.def_small_font", "0"))) {
    return Settings.System.getFloat(mContext.getContentResolver(), name, 0.85f) != 0.85f;
}

3、默认亮度

vendor/mediatek/proprietary/packages/apps/SettingsProvider/res/values/defaults.xml

<integer name="def_screen_brightness">94</integer>

参考链接：https://www.cnblogs.com/ssy197/p/14348552.html