diff --git a/application/live-plot-graph/src/main/java/org/videolan/liveplotgraph/PlotView.kt b/application/live-plot-graph/src/main/java/org/videolan/liveplotgraph/PlotView.kt
index 23821bfc5..263eb7783 100644
--- a/application/live-plot-graph/src/main/java/org/videolan/liveplotgraph/PlotView.kt
+++ b/application/live-plot-graph/src/main/java/org/videolan/liveplotgraph/PlotView.kt
@@ -101,7 +101,7 @@ class PlotView : FrameLayout {
         listeners.remove(listener)
     }
 
-    override fun onDraw(canvas: Canvas?) {
+    override fun onDraw(canvas: Canvas) {
         super.onDraw(canvas)
 
         maxsY.clear()
diff --git a/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesAdvanced.kt b/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesAdvanced.kt
index 7601a93e3..a221f7789 100644
--- a/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesAdvanced.kt
+++ b/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesAdvanced.kt
@@ -230,7 +230,8 @@ class PreferencesAdvanced : BasePreferenceFragment(), SharedPreferences.OnShared
         return super.onPreferenceTreeClick(preference)
     }
 
-    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
+        if (sharedPreferences == null || key == null) return
         when (key) {
             "network_caching" -> {
                 sharedPreferences.edit {
diff --git a/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesAudio.kt b/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesAudio.kt
index a41b2f746..6b1000c49 100644
--- a/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesAudio.kt
+++ b/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesAudio.kt
@@ -29,7 +29,6 @@ import android.os.Bundle
 import android.text.InputFilter
 import android.text.InputType
 import android.util.Log
-import androidx.core.content.ContextCompat
 import androidx.core.content.edit
 import androidx.preference.CheckBoxPreference
 import androidx.preference.EditTextPreference
@@ -133,7 +132,8 @@ class PreferencesAudio : BasePreferenceFragment(), SharedPreferences.OnSharedPre
     }
 
 
-    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
+        if (sharedPreferences == null || key == null) return
         when (key) {
             "aout" -> {
                 launch { restartLibVLC() }
diff --git a/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesOptional.kt b/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesOptional.kt
index af09539dd..c353f0d67 100644
--- a/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesOptional.kt
+++ b/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesOptional.kt
@@ -74,7 +74,8 @@ class PreferencesOptional : BasePreferenceFragment(), SharedPreferences.OnShared
     }
 
 
-    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
+        if (sharedPreferences == null || key == null) return
         val enabled = findPreference<CheckBoxPreference>(key)!!.isChecked
         FeatureFlagManager.getByKey(key)?.let { FeatureFlagManager.enable(activity,it, enabled) }
     }
diff --git a/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesParentalControl.kt b/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesParentalControl.kt
index f9f0e1bee..7aa075741 100644
--- a/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesParentalControl.kt
+++ b/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesParentalControl.kt
@@ -84,7 +84,8 @@ class PreferencesParentalControl : BasePreferenceFragment(), SharedPreferences.O
         }
     }
 
-    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
+        if (sharedPreferences == null || key == null) return
         when (key) {
             KEY_SAFE_MODE -> {
                 Settings.safeMode = sharedPreferences.getBoolean(key, false) && activity.isPinCodeSet()
diff --git a/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesSubtitles.kt b/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesSubtitles.kt
index 81cd5dfb4..cb97ef6f7 100644
--- a/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesSubtitles.kt
+++ b/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesSubtitles.kt
@@ -220,7 +220,7 @@ class PreferencesSubtitles : BasePreferenceFragment(), SharedPreferences.OnShare
         preferenceScreen.sharedPreferences.registerOnSharedPreferenceChangeListener(this)
     }
 
-    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
         when (key) {
             "subtitles_size", "subtitles_bold", "subtitle_text_encoding",
             "subtitles_color", "subtitles_color_opacity",
diff --git a/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesUi.kt b/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesUi.kt
index 6ecef98fd..c18ca55de 100644
--- a/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesUi.kt
+++ b/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesUi.kt
@@ -89,7 +89,8 @@ class PreferencesUi : BasePreferenceFragment(), SharedPreferences.OnSharedPrefer
                 .unregisterOnSharedPreferenceChangeListener(this)
     }
 
-    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
+        if (sharedPreferences == null || key == null) return
         when (key) {
             PREF_TV_UI -> {
                 Settings.tvUI = sharedPreferences.getBoolean(PREF_TV_UI, false)
diff --git a/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesVideo.kt b/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesVideo.kt
index f3e116520..d07b86a05 100644
--- a/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesVideo.kt
+++ b/application/television/src/main/java/org/videolan/television/ui/preferences/PreferencesVideo.kt
@@ -66,7 +66,7 @@ class PreferencesVideo : BasePreferenceFragment(), SharedPreferences.OnSharedPre
                 .unregisterOnSharedPreferenceChangeListener(this)
     }
 
-    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
         when (key) {
             "preferred_resolution" -> {
                 launch {
diff --git a/application/television/src/main/java/org/videolan/television/ui/views/ColorPickerItem.kt b/application/television/src/main/java/org/videolan/television/ui/views/ColorPickerItem.kt
index 53d04c5d9..3c5242fbc 100644
--- a/application/television/src/main/java/org/videolan/television/ui/views/ColorPickerItem.kt
+++ b/application/television/src/main/java/org/videolan/television/ui/views/ColorPickerItem.kt
@@ -94,10 +94,10 @@ class ColorPickerItem @JvmOverloads constructor(
      *
      * @param canvas the view's [Canvas]
      */
-    override fun onDraw(canvas: Canvas?) {
+    override fun onDraw(canvas: Canvas) {
         super.onDraw(canvas)
-        canvas?.drawCircle(width.toFloat() / 2, height.toFloat() / 2, (width.toFloat() / 2) - 4.dp, outerPaint)
-        canvas?.drawCircle(width.toFloat() / 2, height.toFloat() / 2, (width.toFloat() / 2) - 5.dp, paint)
+        canvas.drawCircle(width.toFloat() / 2, height.toFloat() / 2, (width.toFloat() / 2) - 4.dp, outerPaint)
+        canvas.drawCircle(width.toFloat() / 2, height.toFloat() / 2, (width.toFloat() / 2) - 5.dp, paint)
     }
 
 
diff --git a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesAdvanced.kt b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesAdvanced.kt
index 23a0f8cbd..100a21a47 100644
--- a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesAdvanced.kt
+++ b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesAdvanced.kt
@@ -44,7 +44,19 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import org.videolan.medialibrary.interfaces.Medialibrary
-import org.videolan.resources.*
+import org.videolan.resources.AndroidDevices
+import org.videolan.resources.KEY_AUDIO_LAST_PLAYLIST
+import org.videolan.resources.KEY_CURRENT_AUDIO
+import org.videolan.resources.KEY_CURRENT_AUDIO_RESUME_ARTIST
+import org.videolan.resources.KEY_CURRENT_AUDIO_RESUME_THUMB
+import org.videolan.resources.KEY_CURRENT_AUDIO_RESUME_TITLE
+import org.videolan.resources.KEY_CURRENT_MEDIA
+import org.videolan.resources.KEY_CURRENT_MEDIA_RESUME
+import org.videolan.resources.KEY_MEDIA_LAST_PLAYLIST
+import org.videolan.resources.KEY_MEDIA_LAST_PLAYLIST_RESUME
+import org.videolan.resources.ROOM_DATABASE
+import org.videolan.resources.SCHEME_PACKAGE
+import org.videolan.resources.VLCInstance
 import org.videolan.tools.BitmapCache
 import org.videolan.tools.Settings
 import org.videolan.tools.putSingle
@@ -235,7 +247,8 @@ class PreferencesAdvanced : BasePreferenceFragment(), SharedPreferences.OnShared
         return super.onPreferenceTreeClick(preference)
     }
 
-    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
+        if (sharedPreferences == null || key == null) return
         when (key) {
             "network_caching" -> {
                 sharedPreferences.edit {
diff --git a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesAudio.kt b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesAudio.kt
index ac9274452..5abf1fa9d 100644
--- a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesAudio.kt
+++ b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesAudio.kt
@@ -32,7 +32,11 @@ import android.text.InputType
 import android.util.Log
 import androidx.core.content.edit
 import androidx.lifecycle.lifecycleScope
-import androidx.preference.*
+import androidx.preference.CheckBoxPreference
+import androidx.preference.EditTextPreference
+import androidx.preference.ListPreference
+import androidx.preference.Preference
+import androidx.preference.TwoStatePreference
 import kotlinx.coroutines.launch
 import org.videolan.libvlc.util.AndroidUtil
 import org.videolan.libvlc.util.HWDecoderUtil
@@ -55,7 +59,7 @@ import org.videolan.vlc.providers.PickerType
 import org.videolan.vlc.util.LocaleUtil
 import java.text.DecimalFormat
 import java.text.DecimalFormatSymbols
-import java.util.*
+import java.util.Locale
 
 private const val TAG = "VLC/PreferencesAudio"
 private const val FILE_PICKER_RESULT_CODE = 10000
@@ -151,8 +155,9 @@ class PreferencesAudio : BasePreferenceFragment(), SharedPreferences.OnSharedPre
         }
     }
 
-    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
-        if (activity == null) return
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
+        if (sharedPreferences == null || key == null || activity == null) return
+
         when (key) {
             "aout" -> {
                 lifecycleScope.launch { restartLibVLC() }
@@ -173,7 +178,7 @@ class PreferencesAudio : BasePreferenceFragment(), SharedPreferences.OnSharedPre
                     Log.w(TAG, "Could not parse value: $newValue. Setting $key to $fmtValue", e)
                 } finally {
                     if (fmtValue != newValue) {
-                        sharedPreferences.edit {
+                        sharedPreferences?.edit {
                             // putString will trigger another preference change event. Restart libVLC when it settles.
                             putString(key, fmtValue)
                             findPreference<EditTextPreference>(key)?.let { it.text = fmtValue }
diff --git a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesAudioControls.kt b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesAudioControls.kt
index 468e22e78..98bd6b0fb 100644
--- a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesAudioControls.kt
+++ b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesAudioControls.kt
@@ -46,7 +46,8 @@ class PreferencesAudioControls : BasePreferenceFragment(), SharedPreferences.OnS
                 .unregisterOnSharedPreferenceChangeListener(this)
     }
 
-    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
+        if (sharedPreferences == null || key == null) return
         (activity as? VideoPlayerActivity)?.onChangedControlSetting(key)
         when (key) {
             KEY_AUDIO_JUMP_DELAY -> {
diff --git a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesFragment.kt b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesFragment.kt
index fc55933e4..513dbb81a 100644
--- a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesFragment.kt
+++ b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesFragment.kt
@@ -185,8 +185,10 @@ class PreferencesFragment : BasePreferenceFragment(), SharedPreferences.OnShared
         return true
     }
 
-    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
         val activity = activity ?: return
+        if (sharedPreferences == null || key == null) return
+
         when (key) {
             "video_action_switch" -> if (!AndroidUtil.isOOrLater && findPreference<ListPreference>(key)?.value == "2"
                     && !Permissions.canDrawOverlays(activity))
diff --git a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesOptional.kt b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesOptional.kt
index 1b96fc5e0..f69b637ad 100644
--- a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesOptional.kt
+++ b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesOptional.kt
@@ -32,7 +32,6 @@ import androidx.preference.PreferenceScreen
 import org.videolan.vlc.R
 import org.videolan.vlc.gui.dialogs.FeatureFlagWarningDialog
 import org.videolan.vlc.gui.dialogs.RenameDialog
-import org.videolan.vlc.gui.helpers.UiTools
 import org.videolan.vlc.util.FeatureFlag
 import org.videolan.vlc.util.FeatureFlagManager
 
@@ -69,7 +68,8 @@ class PreferencesOptional : BasePreferenceFragment(), SharedPreferences.OnShared
     }
 
 
-    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
+        if (sharedPreferences == null || key == null) return
         val enabled = findPreference<CheckBoxPreference>(key)!!.isChecked
         FeatureFlagManager.getByKey(key)?.let { FeatureFlagManager.enable(requireActivity(), it, enabled) }
 //        if (enabled) UiTools.snacker(requireActivity(), getString(R.string.optional_features_warning))
diff --git a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesParentalControl.kt b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesParentalControl.kt
index 733ab9607..894de79f1 100644
--- a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesParentalControl.kt
+++ b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesParentalControl.kt
@@ -74,7 +74,8 @@ class PreferencesParentalControl : BasePreferenceFragment(), SharedPreferences.O
         return super.onPreferenceTreeClick(preference)
     }
 
-    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
+        if (sharedPreferences == null || key == null) return
         when (key) {
             KEY_SAFE_MODE -> {
                 Settings.safeMode = sharedPreferences.getBoolean(key, false) && requireActivity().isPinCodeSet()
diff --git a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesSubtitles.kt b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesSubtitles.kt
index 10b7e261d..32d915335 100644
--- a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesSubtitles.kt
+++ b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesSubtitles.kt
@@ -168,7 +168,7 @@ class PreferencesSubtitles : BasePreferenceFragment(), SharedPreferences.OnShare
         preferenceScreen.sharedPreferences.unregisterOnSharedPreferenceChangeListener(this)
     }
 
-    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
         when (key) {
             "subtitles_size", "subtitles_bold", "subtitle_text_encoding",
             "subtitles_color", "subtitles_color_opacity",
diff --git a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesUi.kt b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesUi.kt
index b30dd452b..532e9fd54 100644
--- a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesUi.kt
+++ b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesUi.kt
@@ -130,7 +130,8 @@ class PreferencesUi : BasePreferenceFragment(), SharedPreferences.OnSharedPrefer
         return super.onPreferenceTreeClick(preference)
     }
 
-    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
+        if (sharedPreferences == null || key == null) return
         when (key) {
             "set_locale" -> {
                 (activity as PreferencesActivity).setRestart()
diff --git a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesVideo.kt b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesVideo.kt
index 5f1a6eeec..7f8890d0f 100644
--- a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesVideo.kt
+++ b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesVideo.kt
@@ -56,7 +56,8 @@ class PreferencesVideo : BasePreferenceFragment(), SharedPreferences.OnSharedPre
                 .unregisterOnSharedPreferenceChangeListener(this)
     }
 
-    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
+        if (sharedPreferences == null || key == null) return
         when (key) {
             "preferred_resolution" -> {
                 lifecycleScope.launch {
diff --git a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesVideoControls.kt b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesVideoControls.kt
index 129e97a9b..da4a5a9ed 100644
--- a/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesVideoControls.kt
+++ b/application/vlc-android/src/org/videolan/vlc/gui/preferences/PreferencesVideoControls.kt
@@ -27,7 +27,21 @@ import android.os.Bundle
 import androidx.preference.Preference
 import org.videolan.libvlc.util.AndroidUtil
 import org.videolan.resources.AndroidDevices
-import org.videolan.tools.*
+import org.videolan.tools.AUDIO_BOOST
+import org.videolan.tools.ENABLE_BRIGHTNESS_GESTURE
+import org.videolan.tools.ENABLE_DOUBLE_TAP_PLAY
+import org.videolan.tools.ENABLE_DOUBLE_TAP_SEEK
+import org.videolan.tools.ENABLE_SCALE_GESTURE
+import org.videolan.tools.ENABLE_SWIPE_SEEK
+import org.videolan.tools.ENABLE_VOLUME_GESTURE
+import org.videolan.tools.KEY_VIDEO_DOUBLE_TAP_JUMP_DELAY
+import org.videolan.tools.KEY_VIDEO_JUMP_DELAY
+import org.videolan.tools.KEY_VIDEO_LONG_JUMP_DELAY
+import org.videolan.tools.POPUP_KEEPSCREEN
+import org.videolan.tools.SCREENSHOT_MODE
+import org.videolan.tools.Settings
+import org.videolan.tools.VIDEO_HUD_TIMEOUT
+import org.videolan.tools.coerceInOrDefault
 import org.videolan.vlc.R
 import org.videolan.vlc.gui.video.VideoPlayerActivity
 
@@ -72,7 +86,8 @@ class PreferencesVideoControls : BasePreferenceFragment(), SharedPreferences.OnS
                 .unregisterOnSharedPreferenceChangeListener(this)
     }
 
-    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
+        if (sharedPreferences == null || key == null) return
         (activity as? VideoPlayerActivity)?.onChangedControlSetting(key)
         when (key) {
             VIDEO_HUD_TIMEOUT -> {
diff --git a/application/vlc-android/src/org/videolan/vlc/gui/preferences/widgets/PreferencesWidgets.kt b/application/vlc-android/src/org/videolan/vlc/gui/preferences/widgets/PreferencesWidgets.kt
index eebd1c4bc..3d9fd5ac5 100644
--- a/application/vlc-android/src/org/videolan/vlc/gui/preferences/widgets/PreferencesWidgets.kt
+++ b/application/vlc-android/src/org/videolan/vlc/gui/preferences/widgets/PreferencesWidgets.kt
@@ -142,7 +142,8 @@ class PreferencesWidgets : BasePreferenceFragment(), SharedPreferences.OnSharedP
 
     }
 
-    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences, key: String) {
+    override fun onSharedPreferenceChanged(sharedPreferences: SharedPreferences?, key: String?) {
+        if (sharedPreferences == null || key == null) return
         when (key) {
             "opacity" -> {
                 model.widget.value?.opacity = sharedPreferences.getInt(key, 100)
diff --git a/application/vlc-android/src/org/videolan/vlc/gui/video/PopupManager.kt b/application/vlc-android/src/org/videolan/vlc/gui/video/PopupManager.kt
index f7d828a99..44be8dd6b 100644
--- a/application/vlc-android/src/org/videolan/vlc/gui/video/PopupManager.kt
+++ b/application/vlc-android/src/org/videolan/vlc/gui/video/PopupManager.kt
@@ -137,13 +137,14 @@ class PopupManager constructor(private val service: PlaybackService) : PlaybackS
         return false
     }
 
-    override fun onScroll(p0: MotionEvent, p1: MotionEvent, p2: Float, p3: Float): Boolean {
+
+    override fun onScroll(p0: MotionEvent?, p1: MotionEvent, p2: Float, p3: Float): Boolean {
         return false
     }
 
     override fun onLongPress(e: MotionEvent) {}
 
-    override fun onFling(e1: MotionEvent, e2: MotionEvent, velocityX: Float, velocityY: Float): Boolean {
+    override fun onFling(e1: MotionEvent?, e2: MotionEvent, velocityX: Float, velocityY: Float): Boolean {
         if (abs(velocityX) > FLING_STOP_VELOCITY || velocityY > FLING_STOP_VELOCITY) {
             stopPlayback()
             return true
diff --git a/application/vlc-android/src/org/videolan/vlc/gui/view/AutofitButton.kt b/application/vlc-android/src/org/videolan/vlc/gui/view/AutofitButton.kt
index 5a1842137..5624632d0 100644
--- a/application/vlc-android/src/org/videolan/vlc/gui/view/AutofitButton.kt
+++ b/application/vlc-android/src/org/videolan/vlc/gui/view/AutofitButton.kt
@@ -51,7 +51,7 @@ class AutofitButton : MaterialButton {
         super.onSizeChanged(w, h, oldw, oldh)
     }
 
-    override fun onDraw(canvas: Canvas?) {
+    override fun onDraw(canvas: Canvas) {
         super.onDraw(canvas)
         computeTextSize()
     }
diff --git a/application/vlc-android/src/org/videolan/vlc/gui/view/HalfCircleView.kt b/application/vlc-android/src/org/videolan/vlc/gui/view/HalfCircleView.kt
index 51180044e..4fb96f33c 100644
--- a/application/vlc-android/src/org/videolan/vlc/gui/view/HalfCircleView.kt
+++ b/application/vlc-android/src/org/videolan/vlc/gui/view/HalfCircleView.kt
@@ -6,8 +6,8 @@ import android.graphics.Paint
 import android.util.AttributeSet
 import android.view.View
 import androidx.core.content.ContextCompat
-import org.videolan.vlc.R
 import org.videolan.tools.Settings
+import org.videolan.vlc.R
 
 class HalfCircleView : View {
     private var isLeft: Boolean = true
@@ -49,11 +49,11 @@ class HalfCircleView : View {
         }
     }
 
-    override fun onDraw(canvas: Canvas?) {
+    override fun onDraw(canvas: Canvas) {
         if (!Settings.showTvUi) {
             val cx = if (isLeft) -width else width * 2
             val cy = height / 2
-            canvas?.drawCircle(cx.toFloat(), cy.toFloat(), width.toFloat()*2, paint)
+            canvas.drawCircle(cx.toFloat(), cy.toFloat(), width.toFloat()*2, paint)
         }
         super.onDraw(canvas)
     }
diff --git a/application/vlc-android/src/org/videolan/vlc/gui/view/PlayerProgress.kt b/application/vlc-android/src/org/videolan/vlc/gui/view/PlayerProgress.kt
index 421c75415..e6fb2680b 100644
--- a/application/vlc-android/src/org/videolan/vlc/gui/view/PlayerProgress.kt
+++ b/application/vlc-android/src/org/videolan/vlc/gui/view/PlayerProgress.kt
@@ -25,7 +25,11 @@
 package org.videolan.vlc.gui.view
 
 import android.content.Context
-import android.graphics.*
+import android.graphics.Canvas
+import android.graphics.Paint
+import android.graphics.Path
+import android.graphics.RectF
+import android.graphics.Region
 import android.util.AttributeSet
 import android.view.View
 import androidx.core.content.ContextCompat
@@ -73,7 +77,7 @@ class PlayerProgress : View {
         paintProgress.isAntiAlias = true
     }
 
-    override fun onDraw(canvas: Canvas?) {
+    override fun onDraw(canvas: Canvas) {
         val left = (width.toFloat() - progressWidth.toFloat()) / 2
         val right = width - left
         val top = yOffset.toFloat()
@@ -83,18 +87,18 @@ class PlayerProgress : View {
         //draw background
         roundedRectanglePath(left, top, right, bottom, radius, radius)
         paintBackground.setShadowLayer(6F,0F,0F, shadowColor)
-        canvas?.drawPath(path, paintBackground)
+        canvas.drawPath(path, paintBackground)
         paintBackground.clearShadowLayer()
         paintBackground.color = 0x00000000
-        canvas?.drawPath(path, paintBackground)
+        canvas.drawPath(path, paintBackground)
         paintBackground.color = backgroundColor
-        canvas?.drawPath(path, paintBackground)
+        canvas.drawPath(path, paintBackground)
 
         //draw progress
         val clipTop = yOffset + (bottom - top) * (1 - progressPercent)
         rectProgress.set(left, clipTop, right, bottom)
 
-        canvas?.withClip(rectProgress) {
+        canvas.withClip(rectProgress) {
             clipRect(rectProgress)
         }
 
@@ -112,7 +116,7 @@ class PlayerProgress : View {
         firstClippingRegion.op(secondClippingRegion, Region.Op.INTERSECT)
 
         paintProgress.color = progressColor
-        canvas?.drawPath(firstClippingRegion.boundaryPath, paintProgress)
+        canvas.drawPath(firstClippingRegion.boundaryPath, paintProgress)
 
         //draw boost
         if (isDouble && progressPercent > 0.5) {
@@ -133,7 +137,7 @@ class PlayerProgress : View {
             firstClippingRegion.op(secondClippingRegion, Region.Op.INTERSECT)
 
             paintProgress.color = boostColor
-            canvas?.drawPath(firstClippingRegion.boundaryPath, paintProgress)
+            canvas.drawPath(firstClippingRegion.boundaryPath, paintProgress)
         }
 
         super.onDraw(canvas)
diff --git a/application/vlc-android/src/org/videolan/vlc/gui/view/WidgetHandleView.kt b/application/vlc-android/src/org/videolan/vlc/gui/view/WidgetHandleView.kt
index 9daf6d617..236a97d6b 100644
--- a/application/vlc-android/src/org/videolan/vlc/gui/view/WidgetHandleView.kt
+++ b/application/vlc-android/src/org/videolan/vlc/gui/view/WidgetHandleView.kt
@@ -59,7 +59,7 @@ class WidgetHandleView : View {
         paint.isAntiAlias = true
     }
 
-    override fun onDraw(canvas: Canvas?) {
+    override fun onDraw(canvas: Canvas) {
         val padding = 8.dp.toFloat()
         val viewWidth = width
         //3.56 is the known ratio of the [R.drawable.vlc_widget_mini] image. 6.dp is two times the stroke size
@@ -68,12 +68,12 @@ class WidgetHandleView : View {
         val height = height - padding
         paint.strokeWidth = 3.dp.toFloat()
         paint.style = Paint.Style.STROKE
-        canvas?.drawRoundRect(hPadding, padding, viewWidth - hPadding, height, 12.dp.toFloat(), 12.dp.toFloat(), paint)
+        canvas.drawRoundRect(hPadding, padding, viewWidth - hPadding, height, 12.dp.toFloat(), 12.dp.toFloat(), paint)
         paint.style = Paint.Style.FILL
-        canvas?.drawCircle(hPadding, padding + (height / 2), 6.dp.toFloat(), paint)
-        canvas?.drawCircle(hPadding + (width.toFloat() / 2), padding, 6.dp.toFloat(), paint)
-        canvas?.drawCircle(hPadding + width.toFloat(), padding + (height / 2), 6.dp.toFloat(), paint)
-        canvas?.drawCircle(hPadding + (width.toFloat() / 2), height, 6.dp.toFloat(), paint)
+        canvas.drawCircle(hPadding, padding + (height / 2), 6.dp.toFloat(), paint)
+        canvas.drawCircle(hPadding + (width.toFloat() / 2), padding, 6.dp.toFloat(), paint)
+        canvas.drawCircle(hPadding + width.toFloat(), padding + (height / 2), 6.dp.toFloat(), paint)
+        canvas.drawCircle(hPadding + (width.toFloat() / 2), height, 6.dp.toFloat(), paint)
         super.onDraw(canvas)
     }
 }
\ No newline at end of file
diff --git a/build.gradle b/build.gradle
index 2aa890912..25df4be2c 100644
--- a/build.gradle
+++ b/build.gradle
@@ -46,7 +46,7 @@ ext {
     medialibraryVersion = vlcMajorVersion == 3 ? '0.13.13-rc10' : '0.13.13-vlc4-rc10'
     minSdkVersion = 17
     targetSdkVersion = 34
-    compileSdkVersion = 33
+    compileSdkVersion = 34
     buildToolsVersion = '33.0.1'
     androidxLegacyVersion = '1.0.0'
     androidxCoreVersion = '1.7.0'