Hide Incognito Keyboard setting on unsupported devices

vector/src/main/java/im/vector/app/features/home/room/detail/TimelineFragment.kt

@@ -1536,7 +1536,9 @@ class TimelineFragment :
 
         observerUserTyping()
 
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
             composerEditText.setUseIncognitoKeyboard(vectorPreferences.useIncognitoKeyboard())
+        }
         composerEditText.setSendMessageWithEnter(vectorPreferences.sendMessageWithEnter())
 
         composerEditText.setOnEditorActionListener { v, actionId, keyEvent ->

vector/src/main/java/im/vector/app/features/home/room/detail/composer/ComposerEditText.kt

@@ -20,10 +20,12 @@ package im.vector.app.features.home.room.detail.composer
 import android.content.ClipData
 import android.content.Context
 import android.net.Uri
+import android.os.Build
 import android.text.Editable
 import android.util.AttributeSet
 import android.view.inputmethod.EditorInfo
 import android.view.inputmethod.InputConnection
+import androidx.annotation.RequiresApi
 import androidx.appcompat.widget.AppCompatEditText
 import androidx.core.view.OnReceiveContentListener
 import androidx.core.view.ViewCompat
@@ -80,6 +82,7 @@ class ComposerEditText @JvmOverloads constructor(
     }
 
     /** Set whether the keyboard should disable personalized learning. */
+    @RequiresApi(Build.VERSION_CODES.O)
     fun setUseIncognitoKeyboard(useIncognitoKeyboard: Boolean) {
         imeOptions = if (useIncognitoKeyboard) {
             imeOptions or EditorInfo.IME_FLAG_NO_PERSONALIZED_LEARNING

vector/src/main/java/im/vector/app/features/settings/VectorSettingsSecurityPrivacyFragment.kt

@@ -20,6 +20,7 @@ package im.vector.app.features.settings
 import android.app.Activity
 import android.content.Intent
 import android.net.Uri
+import android.os.Build
 import android.os.Bundle
 import android.view.LayoutInflater
 import android.view.View
@@ -160,6 +161,10 @@ class VectorSettingsSecurityPrivacyFragment :
         findPreference<VectorSwitchPreference>("SETTINGS_USER_ANALYTICS_CONSENT_KEY")!!
     }
 
+    private val incognitoKeyboardPref by lazy {
+        findPreference<VectorSwitchPreference>(VectorPreferences.SETTINGS_SECURITY_INCOGNITO_KEYBOARD_PREFERENCE_KEY)!!
+    }
+
     override fun onCreateRecyclerView(inflater: LayoutInflater, parent: ViewGroup, savedInstanceState: Bundle?): RecyclerView {
         return super.onCreateRecyclerView(inflater, parent, savedInstanceState).also {
             // Insert animation are really annoying the first time the list is shown
@@ -275,6 +280,9 @@ class VectorSettingsSecurityPrivacyFragment :
         // Analytics
         setUpAnalytics()
 
+        // Incognito Keyboard
+        setUpIncognitoKeyboard()
+
         // Pin code
         openPinCodeSettingsPref.setOnPreferenceClickListener {
             openPinCodePreferenceScreen()
@@ -337,6 +345,10 @@ class VectorSettingsSecurityPrivacyFragment :
         }
     }
 
+    private fun setUpIncognitoKeyboard() {
+        incognitoKeyboardPref.isVisible = Build.VERSION.SDK_INT >= Build.VERSION_CODES.O
+    }
+
     // Todo this should be refactored and use same state as 4S section
     private fun refreshXSigningStatus() {
         val crossSigningKeys = session.cryptoService().crossSigningService().getMyCrossSigningKeys()