需求：实现屏保功能
实现原理：
1、自己写一个服务MyDreamService继承系统的屏保服务DreamService，在该服务中onAttachedToWindow()方法中初始化UI和一些资源，在onDetachedFromWindow()方法释放资源
2、在config.xml文件中替换掉自己原生的屏保服务，添加自己的屏保应用服务
3、在PowerManagerService.java文件中goToSleepNoUpdateLocked()方法中做如下处理：设置屏保时间到了就进入屏保界面、按Power键进入屏保界面
代码路径：
frameworks/base/core/res/res/values/config.xml
frameworks/base/services/core/java/com/android/server/power/Notifier.java
frameworks/base/services/core/java/com/android/server/power/PowerManagerService.java
一、如何编写一个屏保应用
1、编写一个服务MyDreamService继承系统的屏保服务DreamService在该服务中onAttachedToWindow()方法中初始化UI和一些资源，在onDetachedFromWindow()方法释放资源
public class MyDreamService extends DreamService {
private static final String TAG = "MyDreamService ";
private static final boolean DEBUG = true;
private ContentResolver resolver;
@Override
public void onAttachedToWindow() {
super.onAttachedToWindow();
if(DEBUG) Log.i(TAG, "onAttachedToWindow()");
setInteractive(false);
setFullscreen(true);
View decorView = getWindow().getDecorView();
if(null != decorView){
int visibility = View.SYSTEM_UI_FLAG_FULLSCREEN | View.SYSTEM_UI_FLAG_HIDE_NAVIGATION
| View.SYSTEM_UI_FLAG_IMMERSIVE | View.SYSTEM_UI_FLAG_IMMERSIVE_STICKY
| View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION;
decorView.setSystemUiVisibility(visibility);
}
resolver = getContentResolver();
timeChange(true);
initView();
regisBroadCast();
}
private void initView() {
setContentView(R.layout.layout_screen);
}
private void timeChange(boolean isFirstInit) {
setWindowBrightness( 0.4f);
}
private void setWindowBrightness(float brightness) {
if(DEBUG) Log.i(TAG, "setWindowBrightness() brightness = "+brightness);
Window window = getWindow();
WindowManager.LayoutParams lp = window.getAttributes();
lp.screenBrightness = brightness;
window.setAttributes(lp);
window.getWindowManager().updateViewLayout(window.getDecorView(), lp);
}
@Override
public void onDetachedFromWindow() {
super.onDetachedFromWindow();
}
}
2、在AndroidManifest.xml文件中注册该服务
二、如何在系统中启动屏保应用
1、在config.xml文件中config_dreamsDefaultComponent字段配置为我们自己的包名加服务
com.zqc.screensaver/com.test.screensaver.MyDreamService
2、在PowerManagerService.java文件中goToSleepNoUpdateLocked()方法中进行判断是设置时间进入屏保和按power键进入屏保
--- a/services/core/java/com/android/server/power/PowerManagerService.java
+++ b/services/core/java/com/android/server/power/PowerManagerService.java
@@ -1583,6 +1583,7 @@ public final class PowerManagerService extends SystemService
* and only tucks itself in to SLEEP if requested with the flag
* {@link PowerManager.GO_TO_SLEEP_FLAG_NO_DOZE}.
*/
+ private boolean showDream = false;
@SuppressWarnings("deprecation")
private boolean goToSleepNoUpdateLocked(long eventTime, int reason, int flags, int uid) {
if (DEBUG_SPEW) {
@@ -1596,19 +1597,49 @@ public final class PowerManagerService extends SystemService
|| !mBootCompleted || !mSystemReady) {
return false;
}
-
+ showDream = false;
Trace.traceBegin(Trace.TRACE_TAG_POWER, "goToSleep");
try {
reason = Math.min(PowerManager.GO_TO_SLEEP_REASON_MAX,
Math.max(reason, PowerManager.GO_TO_SLEEP_REASON_MIN));
Slog.i(TAG, "Going to sleep due to " + PowerManager.sleepReasonToString(reason)
- + " (uid " + uid + ")...");
-
+ + " (uid " + uid + ")... reason "+reason);
+ switch (reason) {
+ case PowerManager.GO_TO_SLEEP_REASON_DEVICE_ADMIN:
+ Slog.i(TAG, "Going to sleep due to device administration policy "
+ + "(uid " + uid +")...");
+ break;
+ case PowerManager.GO_TO_SLEEP_REASON_TIMEOUT:
+ showDream = true;
+ Slog.i(TAG, "Going to sleep due to screen timeout (uid " + uid +")...");
+ break;
+ case PowerManager.GO_TO_SLEEP_REASON_LID_SWITCH:
+ Slog.i(TAG, "Going to sleep due to lid switch (uid " + uid +")...");
+ break;
+ case PowerManager.GO_TO_SLEEP_REASON_POWER_BUTTON:
+ showDream = true;
+ Slog.i(TAG, "Going to sleep due to power button (uid " + uid +")...");
+ break;
+ case PowerManager.GO_TO_SLEEP_REASON_SLEEP_BUTTON:
+ Slog.i(TAG, "Going to sleep due to sleep button (uid " + uid +")...");
+ break;
+ case PowerManager.GO_TO_SLEEP_REASON_HDMI:
+ Slog.i(TAG, "Going to sleep due to HDMI standby (uid " + uid +")...");
+ break;
+ default:
+ Slog.i(TAG, "Going to sleep by application request (uid " + uid +")...");
+ reason = PowerManager.GO_TO_SLEEP_REASON_APPLICATION;
+ break;
+ }
mLastSleepTime = eventTime;
mLastSleepReason = reason;
mSandmanSummoned = true;
-
- setWakefulnessLocked(WAKEFULNESS_DOZING, reason, eventTime);
+ if(mDreamsEnabledSetting && !isDreaming() && showDream){
+ setWakefulnessLocked(WAKEFULNESS_DREAMING, reason, eventTime);
+ }else{
+ setWakefulnessLocked(WAKEFULNESS_DOZING, reason, eventTime);
+ }
+
// Report the number of wake locks that will be cleared by going to sleep.
int numWakeLocksCleared = 0;
@@ -1634,6 +1665,12 @@ public final class PowerManagerService extends SystemService
}
return true;
}
+ private boolean isDreaming(){
+ if (mDreamManager != null) {
+ return mDreamManager.isDreaming();
+ }
+ return false;
+ }
private void napInternal(long eventTime, int uid) {
synchronized (mLock) {
