1.简介
主要是随便设置了值以后，display页面显示的summary有点奇怪，如下，显示个after null of inactivity,所以简单看下
2.display页
2.1.display_settings.xml
- 可以看到由ScreenTimeoutPreferenceController控制的
- 跳转的fragment是ScreenTimeoutSettings
ini
<PreferenceCategory
android:title="@string/category_name_lock_display">
<Preference
android:key="lockscreen_from_display_settings"
android:title="@string/lockscreen_settings_title"
android:fragment="com.android.settings.security.LockscreenDashboardFragment"
settings:keywords="@string/keywords_ambient_display_screen"
settings:controller="com.android.settings.security.screenlock.LockScreenPreferenceController"/>
<com.android.settingslib.RestrictedPreference
android:key="screen_timeout"
android:title="@string/screen_timeout"
android:summary="@string/summary_placeholder"
android:fragment="com.android.settings.display.ScreenTimeoutSettings"
settings:controller="com.android.settings.display.ScreenTimeoutPreferenceController"/>
</PreferenceCategory>2.2.ScreenTimeoutPreferenceController
>getTimeoutSummary
java
private CharSequence getTimeoutSummary(long maxTimeout) {
//获取设置的时间或者默认值
final long currentTimeout = getCurrentScreenTimeout();
//maxTimeout没有特殊设置的话就是LONG.MAX_VALUE
final CharSequence description = getTimeoutDescription(currentTimeout, maxTimeout);
return mContext.getString(R.string.screen_timeout_summary, description);
}>getCurrentScreenTimeout
这个就是用户设置的值，没有的话就是默认值
csharp
private long getCurrentScreenTimeout() {
return Settings.System.getLong(mContext.getContentResolver(),
SCREEN_OFF_TIMEOUT, FALLBACK_SCREEN_TIMEOUT_VALUE);
}>getTimeoutDescription
csharp
private CharSequence getTimeoutDescription(long currentTimeout, long maxTimeout) {
//异常情况返回空，设置的时间为负的，条目为空或entries和values数量不一样
if (currentTimeout < 0 || mTimeoutEntries == null || mTimeoutValues == null
|| mTimeoutValues.length != mTimeoutEntries.length) {
return null;
}
//设置的时间比支持的最大值还大，就取条目的最后一个
if (currentTimeout > maxTimeout) {
// The selected time out value is longer than the max timeout allowed by the admin.
// Select the largest value from the list by default.
return getLargestTimeout(maxTimeout);
} else {
return getCurrentTimeout(currentTimeout);
}
}
//我们的走这里了
private CharSequence getCurrentTimeout(long currentTimeout) {
for (int i = 0; i < mTimeoutValues.length; i++) {
if (currentTimeout == Long.parseLong(mTimeoutValues[i].toString())) {
return mTimeoutEntries[i];
}
}
//我们设置的值不是系统提供的条目里，所以返回了null
return null;
}3.ScreenTimeoutSettings
3.1.onAttach
ini
public static final int FALLBACK_SCREEN_TIMEOUT_VALUE = 30000;
public void onAttach(Context context) {
super.onAttach(context);
mContext = context;
mDevicePolicyManager = mContext.getSystemService(DevicePolicyManager.class);
mInitialEntries = getResources().getStringArray(R.array.screen_timeout_entries);
mInitialValues = getResources().getStringArray(R.array.screen_timeout_values);>screen_timeout_entries
默认支持的条目
ini
32 <string-array name="screen_timeout_entries">
33 <item msgid="8386012403457852396">"15 seconds"</item>
34 <item msgid="4572123773028439079">"30 seconds"</item>
35 <item msgid="7016081293774377048">"1 minute"</item>
36 <item msgid="838575533670111144">"2 minutes"</item>
37 <item msgid="2693197579676214668">"5 minutes"</item>
38 <item msgid="1955784331962974678">"10 minutes"</item>
39 <item msgid="5578717731965793584">"30 minutes"</item>
40 </string-array>3.2.updateCandidates
scss
public void updateCandidates() {
final String defaultKey = getDefaultKey();
final PreferenceScreen screen = getPreferenceScreen();
screen.removeAll();
final List<? extends CandidateInfo> candidateList = getCandidates();
if (candidateList == null) {
return;
}
//手动添加条目
for (CandidateInfo info : candidateList) {
SelectorWithWidgetPreference pref =
new SelectorWithWidgetPreference(getPrefContext());
//bind的时候如果设置的值和对应条目一样话，自动设置为选中状态
bindPreference(pref, info.getKey(), info, defaultKey);
screen.addPreference(pref);
}
//设置的值不在条目里，则没有选中状态
final long selectedTimeout = Long.parseLong(defaultKey);
final long maxTimeout = getMaxScreenTimeout(getContext());
if (!candidateList.isEmpty() && (selectedTimeout > maxTimeout)) {
//如果设置的值比支持的最大值还大，修改为条目的最大值
final SelectorWithWidgetPreference preferenceWithLargestTimeout =
(SelectorWithWidgetPreference) screen.getPreference(candidateList.size() - 1);
preferenceWithLargestTimeout.setChecked(true);
}
mPrivacyPreference = new FooterPreference(mContext);
mPrivacyPreference.setIcon(R.drawable.ic_privacy_shield_24dp);
mPrivacyPreference.setTitle(R.string.adaptive_sleep_privacy);
mPrivacyPreference.setSelectable(false);
mPrivacyPreference.setLayoutResource(R.layout.preference_footer);
//添加screen attention 选项
if (isScreenAttentionAvailable(getContext())) {
mAdaptiveSleepPermissionController.addToScreen(screen);
mAdaptiveSleepCameraStatePreferenceController.addToScreen(screen);
mAdaptiveSleepController.addToScreen(screen);
mAdaptiveSleepBatterySaverPreferenceController.addToScreen(screen);
screen.addPreference(mPrivacyPreference);
}
if (mAdmin != null) {
setupDisabledFooterPreference();
screen.addPreference(mDisableOptionsPreference);
}
}