redirect the user to the device settings, if keyboard is not enabled

app/src/main/kotlin/com/simplemobiletools/keyboard/activities/MainActivity.kt

@@ -2,13 +2,18 @@ package com.simplemobiletools.keyboard.activities
 
 import android.content.Intent
 import android.os.Bundle
+import android.provider.Settings
 import android.view.Menu
 import android.view.MenuItem
+import android.view.inputmethod.InputMethodManager
+import com.simplemobiletools.commons.dialogs.ConfirmationAdvancedDialog
+import com.simplemobiletools.commons.dialogs.ConfirmationDialog
 import com.simplemobiletools.commons.extensions.appLaunched
 import com.simplemobiletools.commons.models.FAQItem
 import com.simplemobiletools.keyboard.BuildConfig
 import com.simplemobiletools.keyboard.R
 
+
 class MainActivity : SimpleActivity() {
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -16,6 +21,22 @@ class MainActivity : SimpleActivity() {
         appLaunched(BuildConfig.APPLICATION_ID)
     }
 
+    override fun onResume() {
+        super.onResume()
+        if (!isKeyboardEnabled()) {
+            ConfirmationAdvancedDialog(this, messageId = R.string.redirection_note, positive = R.string.ok, negative = 0) { success ->
+                if (success) {
+                    Intent(Settings.ACTION_INPUT_METHOD_SETTINGS).apply {
+                        addFlags(Intent.FLAG_ACTIVITY_NEW_TASK)
+                        startActivity(this)
+                    }
+                } else {
+                    finish()
+                }
+            }
+        }
+    }
+
     override fun onCreateOptionsMenu(menu: Menu): Boolean {
         menuInflater.inflate(R.menu.menu_main, menu)
         return true
@@ -40,4 +61,12 @@ class MainActivity : SimpleActivity() {
 
         startAboutActivity(R.string.app_name, licenses, BuildConfig.VERSION_NAME, faqItems, true)
     }
+
+    private fun isKeyboardEnabled(): Boolean {
+        val inputMethodManager = getSystemService(INPUT_METHOD_SERVICE) as InputMethodManager
+        val enabledKeyboards = inputMethodManager.enabledInputMethodList
+        return enabledKeyboards.any {
+            it.settingsActivity == SettingsActivity::class.java.canonicalName
+        }
+    }
 }

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

@@ -1,4 +1,5 @@
 <resources>
     <string name="app_name">Simple Keyboard</string>
     <string name="app_launcher_name">Keyboard</string>
+    <string name="redirection_note">Please enable Simple Keyboard on the next screen, to make it an available keyboard. Press \'Back\' once enabled.</string>
 </resources>