diff --git a/.gitignore b/.gitignore
index 32beabc..63e2526 100644
--- a/.gitignore
+++ b/.gitignore
@@ -88,4 +88,5 @@ lint/tmp/
 *.hprof
 
 # Signing
-keystore.properties
\ No newline at end of file
+keystore.properties
+.idea/
diff --git a/dependencies.gradle b/dependencies.gradle
index 1b9e647..0f6297b 100644
--- a/dependencies.gradle
+++ b/dependencies.gradle
@@ -1,11 +1,11 @@
 ext.versions = [
-    kotlin              : '1.5.21',
-    core_ktx            : '1.6.0',
-    appcompat           : '1.3.1',
-    constraintlayout    : '2.1.0',
-    material            : '1.4.0',
+    kotlin              : '1.4.32',
+    core_ktx            : '1.3.2',
+    appcompat           : '1.2.0',
+    constraintlayout    : '2.0.4',
+    material            : '1.3.0',
     lifecycle           : '2.3.0',
-    exoplayer           : '2.15.0'
+    exoplayer           : '2.15.1'
 ]
 
 ext.build = [
diff --git a/doubletapplayerview/src/main/java/com/github/vkay94/dtpv/PlayerDoubleTapListener.java b/doubletapplayerview/src/main/java/com/github/vkay94/dtpv/PlayerDoubleTapListener.kt
similarity index 59%
rename from doubletapplayerview/src/main/java/com/github/vkay94/dtpv/PlayerDoubleTapListener.java
rename to doubletapplayerview/src/main/java/com/github/vkay94/dtpv/PlayerDoubleTapListener.kt
index cdfaaa2..f183d33 100644
--- a/doubletapplayerview/src/main/java/com/github/vkay94/dtpv/PlayerDoubleTapListener.java
+++ b/doubletapplayerview/src/main/java/com/github/vkay94/dtpv/PlayerDoubleTapListener.kt
@@ -1,37 +1,36 @@
-package com.github.vkay94.dtpv;
-
-public interface PlayerDoubleTapListener {
+package com.github.vkay94.dtpv
 
+interface PlayerDoubleTapListener {
     /**
      * Called when double tapping starts, after double tap gesture
      *
      * @param posX x tap position on the root view
      * @param posY y tap position on the root view
      */
-    default void onDoubleTapStarted(float posX, float posY) { }
+    fun onDoubleTapStarted(posX: Float, posY: Float) {}
 
     /**
      * Called for each ongoing tap (also single tap) (MotionEvent#ACTION_DOWN)
      * when double tap started and still in double tap mode defined
-     * by {@link DoubleTapPlayerView#getDoubleTapDelay()}
+     * by [DoubleTapPlayerView.getDoubleTapDelay]
      *
      * @param posX x tap position on the root view
      * @param posY y tap position on the root view
      */
-    default void onDoubleTapProgressDown(float posX, float posY) { }
+    fun onDoubleTapProgressDown(posX: Float, posY: Float) {}
 
     /**
      * Called for each ongoing tap (also single tap) (MotionEvent#ACTION_UP}
      * when double tap started and still in double tap mode defined
-     * by {@link DoubleTapPlayerView#getDoubleTapDelay()}
+     * by [DoubleTapPlayerView.getDoubleTapDelay]
      *
      * @param posX x tap position on the root view
      * @param posY y tap position on the root view
      */
-    default void onDoubleTapProgressUp(float posX, float posY) { }
+    fun onDoubleTapProgressUp(posX: Float, posY: Float) {}
 
     /**
-     * Called when {@link DoubleTapPlayerView#getDoubleTapDelay()} is over
+     * Called when [DoubleTapPlayerView.getDoubleTapDelay] is over
      */
-    default void onDoubleTapFinished() { }
+    fun onDoubleTapFinished() {}
 }
\ No newline at end of file