安卓屏保调试

先看一下在设置点击屏保预览后的调用链（Android 14）

sequenceDiagram
    participant User
    participant MaterialButton
    participant View
    participant DreamSettings
    participant DreamBackend

    User->>MaterialButton: 点击按钮（ performClick()）
    MaterialButton->>View: performClick()
    View->>DreamSettings: 触发 onClick() (lambda 表达式)
    DreamSettings->>DreamBackend: 调用 preview()

DreamController的打印信息

Starting dream: name=ComponentInfo{com.google.android.apps.tv.dreamx/com.google.android.apps.tv.dreamx.service.Backdrop}, isPreviewMode=true, canDoze=false, userId=0, reason=’test dream’

DreamActivity是一个不需要注册的Activity，运行在各个屏保进程。

屏保应用实现DreamService即可。

屏保状态时，后台起应用会进入 onStop 状态（该例子 onStop 里面调用了 finish）

退出屏保的方法

1、有触摸或者按键输入

2、配置config_dismissDreamOnActivityStart 为 true 则会在新 activity 起来后退出屏保

 <!-- Whether to dismiss the active dream when an activity is started. Doesn't apply to

          assistant activities (ACTIVITY_TYPE_ASSISTANT) -->

<bool name="config_dismissDreamOnActivityStart">false</bool>

3、跨进程调用DreamManagerService 的awaken（需要系统签名）

import android.os.IBinder
import androidx.annotation.RequiresPermission

class DreamManager {
    private val TAG = "DreamManager"
    //private var mDreamManager: Any? = context.getSystemService("dream")
    private var mDreamManager: Any? = null

    init {
        mDreamManager = try {
            val dream = Reflector.on("android.os.ServiceManager").method("getService", String::class.java).call<Any>("dreams")
            Reflector.on("android.service.dreams.IDreamManager\$Stub").method("asInterface", IBinder::class.java).call<Any>(dream)
        } catch (e: Exception) {
            null
        }
    }

    @RequiresPermission("android.permission.READ_DREAM_STATE")
    fun isDreaming(): Boolean {
        if (mDreamManager == null) {
            return false
        }
        return try {
            Reflector.with(mDreamManager!!).method("isDreaming").call()
        } catch (e: Exception) {
            false
        }
    }

    @RequiresPermission("android.permission.WRITE_DREAM_STATE")
    fun stopDream() {
        mDreamManager?.let {
            try {
                Reflector.with(it).method("awaken").call<Unit>()
            } catch (e: Exception) {
            }
        }
    }
}

屏保调试命令：cmd dreams

roc_rk3588s_pc:/ # cmd dreams -h

Dream manager (dreams) commands:

help

​ Print this help text.

start-dreaming

​ Start the currently configured dream.

stop-dreaming

​ Stops any active dream

cmd dreams start-dreaming

cmd dreams stop-dreaming