Link FAQ for non-VPN mode in the preferences

Implements #264

app/src/main/java/com/frostnerd/smokescreen/Extensions.kt

@@ -4,10 +4,7 @@ import android.app.Activity
 import android.app.AlarmManager
 import android.app.KeyguardManager
 import android.app.PendingIntent
-import android.content.BroadcastReceiver
-import android.content.Context
-import android.content.Intent
-import android.content.IntentFilter
+import android.content.*
 import android.hardware.fingerprint.FingerprintManager
 import android.net.ConnectivityManager
 import android.net.Network
@@ -15,6 +12,7 @@ import android.net.NetworkCapabilities
 import android.net.Uri
 import android.os.Build
 import android.os.PowerManager
+import android.widget.Toast
 import androidx.appcompat.app.AppCompatActivity
 import androidx.fragment.app.Fragment
 import androidx.lifecycle.Lifecycle
@@ -423,4 +421,17 @@ val Context.isPrivateDnsActive: Boolean
             if (it.activeNetwork == null) false
             else it.getLinkProperties(it.activeNetwork)?.isPrivateDnsActive ?: false
         }
-    }
\ No newline at end of file
+    }
+
+fun Context.tryOpenBrowser(withLink:String) {
+    try {
+        startActivity(
+            Intent(
+                Intent.ACTION_VIEW,
+                Uri.parse(withLink)
+            )
+        )
+    } catch (e: ActivityNotFoundException) {
+        Toast.makeText(this, R.string.error_no_webbrowser_installed, Toast.LENGTH_LONG).show()
+    }
+}
\ No newline at end of file

app/src/main/java/com/frostnerd/smokescreen/fragment/AboutFragment.kt

@@ -118,17 +118,7 @@ class AboutFragment : Fragment() {
             true
         }
         view.faq.setOnClickListener {
-            try {
-                startActivity(
-                    Intent(
-                        Intent.ACTION_VIEW,
-                        Uri.parse("https://nebulo.app/faq")
-                    )
-                )
-            } catch (e: ActivityNotFoundException) {
-                Toast.makeText(requireContext(), R.string.error_no_webbrowser_installed, Toast.LENGTH_LONG)
-                    .show()
-            }
+            requireContext().tryOpenBrowser("https://nebulo.app/faq")
         }
     }
 }
\ No newline at end of file

app/src/main/java/com/frostnerd/smokescreen/fragment/SettingsFragment.kt

@@ -325,6 +325,10 @@ class SettingsFragment : PreferenceFragmentCompat() {
             )
             true
         }
+        findPreference("nonvpn_help_faq").setOnPreferenceClickListener {
+            requireContext().tryOpenBrowser("https://nebulo.app/faq#non-vpn-mode")
+            true
+        }
     }
 
     @SuppressLint("NewApi")

app/src/main/res/values/strings-preference.xml

@@ -183,6 +183,8 @@
     <string name="nonvpn_help_generic_title">Generic VPN apps</string>
     <string name="summary_nonvpn_help_generic">Click here to get instructions on how to configure VPN apps</string>
 
+    <string name="title_nonvpn_help_faq">Documentation</string>
+    <string name="summary_nonvpn_help_faq">Click here to open a browser window with help and documentation for non-VPN mode</string>
 
     <string-array name="languages">
         <item>System language</item>

app/src/main/res/xml/preferences_nonvpnmode.xml

@@ -3,6 +3,11 @@
 
     <androidx.preference.Preference android:summary="@string/summary_category_nonvpnmode" />
 
+    <androidx.preference.Preference
+            android:summary="@string/summary_nonvpn_help_faq"
+            android:key="nonvpn_help_faq"
+            android:title="@string/title_nonvpn_help_faq" />
+
     <androidx.preference.PreferenceCategory android:title="@string/preference_category_nonvpnmode">
         <androidx.preference.CheckBoxPreference
                 android:defaultValue="false"