Add tether timeout monitor for Android 9+

2019-07-18 19:08:34 +08:00
parent 81979aad38
commit b4121b7d66
4 changed files with 135 additions and 14 deletions
--- a/mobile/src/main/java/be/mygod/vpnhotspot/net/monitor/TetherTimeoutMonitor.kt
+++ b/mobile/src/main/java/be/mygod/vpnhotspot/net/monitor/TetherTimeoutMonitor.kt
@@ -0,0 +1,95 @@
+package be.mygod.vpnhotspot.net.monitor
+
+import android.content.Context
+import android.content.Intent
+import android.content.res.Resources
+import android.database.ContentObserver
+import android.os.BatteryManager
+import android.os.Handler
+import android.provider.Settings
+import androidx.annotation.RequiresApi
+import androidx.core.os.postDelayed
+import be.mygod.vpnhotspot.App.Companion.app
+import be.mygod.vpnhotspot.util.broadcastReceiver
+import be.mygod.vpnhotspot.util.intentFilter
+import timber.log.Timber
+import java.lang.IllegalArgumentException
+
+@RequiresApi(28)
+class TetherTimeoutMonitor(private val context: Context, private val handler: Handler, private val onTimeout: () -> Unit):
+        ContentObserver(handler), AutoCloseable {
+    /**
+     * config_wifi_framework_soft_ap_timeout_delay was introduced in Android 9.
+     *
+     * Source: https://android.googlesource.com/platform/frameworks/opt/net/wifi/+/87ed136/service/java/com/android/server/wifi/SoftApManager.java
+     */
+    companion object {
+        /**
+         * Whether soft AP will shut down after a timeout period when no devices are connected.
+         *
+         * Type: int (0 for false, 1 for true)
+         */
+        private const val SOFT_AP_TIMEOUT_ENABLED = "soft_ap_timeout_enabled"
+        /**
+         * Minimum limit to use for timeout delay if the value from overlay setting is too small.
+         */
+        private const val MIN_SOFT_AP_TIMEOUT_DELAY_MS = 600_000    // 10 minutes
+
+        private val enabled get() = Settings.Global.getInt(app.contentResolver, SOFT_AP_TIMEOUT_ENABLED, 1) == 1
+        private val timeout by lazy {
+            app.resources.getInteger(Resources.getSystem().getIdentifier(
+                    "config_wifi_framework_soft_ap_timeout_delay", "integer", "android")).let { delay ->
+                if (delay < MIN_SOFT_AP_TIMEOUT_DELAY_MS) {
+                    Timber.w("Overriding timeout delay with minimum limit value: $delay < $MIN_SOFT_AP_TIMEOUT_DELAY_MS")
+                    MIN_SOFT_AP_TIMEOUT_DELAY_MS
+                } else delay
+            }
+        }
+    }
+
+    private var charging = when (context.registerReceiver(null, intentFilter(Intent.ACTION_BATTERY_CHANGED))
+            ?.getIntExtra(BatteryManager.EXTRA_STATUS, -1)) {
+        BatteryManager.BATTERY_STATUS_CHARGING, BatteryManager.BATTERY_STATUS_FULL -> true
+        null, -1 -> false.also { Timber.w(Exception("Battery status not found")) }
+        else -> false
+    }
+    private var noClient = true
+    private var timeoutPending = false
+
+    private val receiver = broadcastReceiver { _, intent ->
+        charging = when (intent.action) {
+            Intent.ACTION_POWER_CONNECTED -> true
+            Intent.ACTION_POWER_DISCONNECTED -> false
+            else -> throw IllegalArgumentException("Invalid intent.action")
+        }
+        onChange(true)
+    }.also {
+        context.registerReceiver(it, intentFilter(Intent.ACTION_POWER_CONNECTED, Intent.ACTION_POWER_DISCONNECTED))
+        context.contentResolver.registerContentObserver(Settings.Global.getUriFor(SOFT_AP_TIMEOUT_ENABLED), true, this)
+    }
+
+    override fun close() {
+        context.unregisterReceiver(receiver)
+        context.contentResolver.unregisterContentObserver(this)
+    }
+
+    fun onClientsChanged(noClient: Boolean) {
+        this.noClient = noClient
+        onChange(true)
+    }
+
+    override fun onChange(selfChange: Boolean) {
+        // super.onChange(selfChange) should not do anything
+        if (enabled && noClient && !charging) {
+            if (!timeoutPending) {
+                handler.postDelayed(timeout.toLong(), this, onTimeout)
+                timeoutPending = true
+            }
+        } else {
+            if (timeoutPending) {
+                handler.removeCallbacksAndMessages(this)
+                timeoutPending = false
+            }
+        }
+    }
+}