Allow non supported Magisk to use Magisk Manager

Close #1576

app/src/main/java/com/topjohnwu/magisk/Const.kt

@@ -23,7 +23,8 @@ object Const {
     val USER_ID = Process.myUid() / 100000
 
     object Version {
-        const val MIN_SUPPORT = 18000
+        const val MIN_VERSION = "v18.0"
+        const val MIN_VERCODE = 18000
         const val CONNECT_MODE = 20100
     }
 

app/src/main/java/com/topjohnwu/magisk/Info.kt

@@ -43,12 +43,17 @@ object Info {
     }.getOrElse { Env() }
 
     class Env(
-        val magiskVersionCode: Int = -1,
+        code: Int = -1,
         val magiskVersionString: String = "",
         hide: Boolean = false,
         var connectionMode: Int = -1
     ) {
         val magiskHide get() = Config.magiskHide
+        val magiskVersionCode = when (code) {
+            in Int.MIN_VALUE..Const.Version.MIN_VERCODE -> -1
+            else -> code
+        }
+        val unsupported = code > 0 && code < Const.Version.MIN_VERCODE
 
         init {
             Config.magiskHide = hide

app/src/main/java/com/topjohnwu/magisk/ui/MainActivity.kt

@@ -2,11 +2,13 @@ package com.topjohnwu.magisk.ui
 
 import android.content.Intent
 import android.os.Bundle
+import androidx.appcompat.app.AlertDialog
 import androidx.core.view.GravityCompat
 import androidx.fragment.app.Fragment
 import androidx.fragment.app.FragmentTransaction
 import com.ncapdevi.fragnav.FragNavController
 import com.ncapdevi.fragnav.FragNavTransactionOptions
+import com.topjohnwu.magisk.Const
 import com.topjohnwu.magisk.Const.Key.OPEN_SECTION
 import com.topjohnwu.magisk.Info
 import com.topjohnwu.magisk.R
@@ -66,6 +68,15 @@ open class MainActivity : BaseActivity<MainViewModel, ActivityMainBinding>(), Na
 
         super.onCreate(savedInstanceState)
 
+        if (Info.env.unsupported && !viewModel.shownUnsupportedDialog) {
+            viewModel.shownUnsupportedDialog = true
+            AlertDialog.Builder(this)
+                .setTitle(R.string.unsupport_magisk_title)
+                .setMessage(getString(R.string.unsupport_magisk_msg, Const.Version.MIN_VERSION))
+                .setPositiveButton(android.R.string.ok, null)
+                .show()
+        }
+
         navigationController.apply {
             rootFragmentListener = this@MainActivity
             transactionListener = this@MainActivity

app/src/main/java/com/topjohnwu/magisk/ui/MainViewModel.kt

@@ -8,6 +8,8 @@ import com.topjohnwu.magisk.model.navigation.Navigation
 
 class MainViewModel : BaseViewModel() {
 
+    var shownUnsupportedDialog = false
+
     fun navPressed() = Navigation.Main.OPEN_NAV.publish()
 
     fun navigationItemPressed(item: MenuItem): Boolean {

app/src/main/java/com/topjohnwu/magisk/ui/SplashActivity.kt

@@ -3,8 +3,6 @@ package com.topjohnwu.magisk.ui
 import android.app.Activity
 import android.content.Context
 import android.os.Bundle
-import android.text.TextUtils
-import androidx.appcompat.app.AlertDialog
 import com.topjohnwu.magisk.*
 import com.topjohnwu.magisk.utils.Utils
 import com.topjohnwu.magisk.view.Notifications
@@ -19,19 +17,7 @@ open class SplashActivity : Activity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
-
-        Shell.getShell {
-            if (Info.env.magiskVersionCode > 0 && Info.env.magiskVersionCode < Const.Version.MIN_SUPPORT) {
-                AlertDialog.Builder(this)
-                    .setTitle(R.string.unsupport_magisk_title)
-                    .setMessage(R.string.unsupport_magisk_message)
-                    .setNegativeButton(android.R.string.ok, null)
-                    .setOnDismissListener { finish() }
-                    .show()
-            } else {
-                initAndStart()
-            }
-        }
+        Shell.getShell { initAndStart() }
     }
 
     private fun initAndStart() {