Add system proxy toggle

app/src/main/java/io/nekohasekai/sfa/bg/BoxService.kt

@@ -19,6 +19,7 @@ import io.nekohasekai.libbox.CommandServerHandler
 import io.nekohasekai.libbox.Libbox
 import io.nekohasekai.libbox.PProfServer
 import io.nekohasekai.libbox.PlatformInterface
+import io.nekohasekai.libbox.SystemProxyStatus
 import io.nekohasekai.sfa.Application
 import io.nekohasekai.sfa.constant.Action
 import io.nekohasekai.sfa.constant.Alert
@@ -164,6 +165,7 @@ class BoxService(
     }
 
     override fun serviceReload() {
+        status.postValue(Status.Starting)
         GlobalScope.launch(Dispatchers.IO) {
             val pfd = fileDescriptor
             if (pfd != null) {
@@ -184,6 +186,19 @@ class BoxService(
         }
     }
 
+    override fun getSystemProxyStatus(): SystemProxyStatus {
+        val status = SystemProxyStatus()
+        if (service is VPNService) {
+            status.available = service.systemProxyAvailable
+            status.enabled = service.systemProxyEnabled
+        }
+        return status
+    }
+
+    override fun setSystemProxyEnabled(isEnabled: Boolean) {
+        serviceReload()
+    }
+
     @RequiresApi(Build.VERSION_CODES.M)
     private fun serviceUpdateIdleMode() {
         if (Application.powerManager.isDeviceIdleMode) {

app/src/main/java/io/nekohasekai/sfa/bg/VPNService.kt

@@ -32,6 +32,9 @@ class VPNService : VpnService(), PlatformInterfaceWrapper {
         protect(fd)
     }
 
+    var systemProxyAvailable = false
+    var systemProxyEnabled = false
+
     override fun openTun(options: TunOptions): Int {
         if (prepare(this) != null) error("android: missing vpn permission")
 
@@ -124,8 +127,10 @@ class VPNService : VpnService(), PlatformInterfaceWrapper {
         }
 
         if (options.isHTTPProxyEnabled) {
+            systemProxyAvailable = true
+            systemProxyEnabled = Settings.systemProxyEnabled
             if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
-                builder.setHttpProxy(
+                if (systemProxyEnabled) builder.setHttpProxy(
                     ProxyInfo.buildDirectProxy(
                         options.httpProxyServer,
                         options.httpProxyServerPort
@@ -134,6 +139,9 @@ class VPNService : VpnService(), PlatformInterfaceWrapper {
             } else {
                 error("android: tun.platform.http_proxy requires android 10 or higher")
             }
+        } else {
+            systemProxyAvailable = false
+            systemProxyEnabled = false
         }
 
         val pfd =