diff --git a/.idea/checkstyle-idea.xml b/.idea/checkstyle-idea.xml
index f81f7a5a..59202c05 100644
--- a/.idea/checkstyle-idea.xml
+++ b/.idea/checkstyle-idea.xml
@@ -4,7 +4,7 @@
     <option name="configuration">
       <map>
         <entry key="active-configuration" value="PROJECT_RELATIVE:$PROJECT_DIR$/config/checkstyle/checkstyle.xml:Checkstyle" />
-        <entry key="checkstyle-version" value="8.16" />
+        <entry key="checkstyle-version" value="8.23" />
         <entry key="copy-libs" value="false" />
         <entry key="location-0" value="BUNDLED:(bundled):Sun Checks" />
         <entry key="location-1" value="BUNDLED:(bundled):Google Checks" />
diff --git a/README.md b/README.md
index dbe35d40..e87fc3a3 100644
--- a/README.md
+++ b/README.md
@@ -59,79 +59,70 @@ Add the `SpeedDialView` to your layout:
 
 #### Action items
 Add the items to the `SpeedDialView`:
-```java
-SpeedDialView speedDialView = findViewById(R.id.speedDial);
+```kotlin
+val speedDialView = findViewById<SpeedDialView>(R.id.speedDial)
 speedDialView.addActionItem(
-        new SpeedDialActionItem.Builder(R.id.fab_link, R.drawable.ic_link_white_24dp)
-                .create()
-);
-
+    SpeedDialActionItem.Builder(R.id.fab_no_label, R.drawable.ic_link_white_24dp)
+        .create())
 ```
 
 If the color customization is not requested, it is also possible to inflate the Action items
 form a Menu Resource:
-```java
-speedDialView.inflate(R.menu.menu_speed_dial);
+```kotlin
+speedDialView.inflate(R.menu.menu_speed_dial)
 ```
 Only the attributes `android:id`, `android:icon` and `android:title` are supported.
 
 #### Click listeners
 Add the click listeners:
-```java
-speedDialView.setOnActionSelectedListener(new SpeedDialView.OnActionSelectedListener() {
-    @Override
-    public boolean onActionSelected(SpeedDialActionItem speedDialActionItem) {
-        switch (speedDialActionItem.getId()) {
-            case R.id.fab_link:
-                showToast("Link action clicked!");
-                return false; // true to keep the Speed Dial open
-            default:
-                return false;
+```kotlin
+speedDialView.setOnActionSelectedListener(SpeedDialView.OnActionSelectedListener { actionItem ->
+    when (actionItem.id) {
+        R.id.fab_no_label -> {
+            showToast("No label action clicked!\nClosing with animation")
+            speedDialView.close() // To close the Speed Dial with animation
+            return@OnActionSelectedListener true // false will close it without animation
         }
     }
-});
+    false
+})
 ```
 
 ### Optional steps
 #### Add the main action click listener
-```java
-speedDialView.setOnChangeListener(new SpeedDialView.OnChangeListener() {
-    @Override
-    public void onMainActionSelected() {
-        // Call your main action here
-        return false; // true to keep the Speed Dial open
+```kotlin
+speedDialView.setOnChangeListener(object : SpeedDialView.OnChangeListener {
+    override fun onMainActionSelected(): Boolean {
+        showToast("Main action clicked!")
+        return false // True to keep the Speed Dial open
     }
 
-    @Override
-    public void onToggleChanged(boolean isOpen) {
-        Log.d(TAG, "Speed dial toggle state changed. Open = " + isOpen);
+    override fun onToggleChanged(isOpen: Boolean) {
+        Log.d(TAG, "Speed dial toggle state changed. Open = $isOpen")
     }
-});
+})
 ```
 
 #### Customizing the items
 The `SpeedDialActionItem.Builder` provides several setters to customize the aspect of one item:
 
-```java
-mSpeedDialView.addActionItem(
-        new SpeedDialActionItem.Builder(R.id.fab_custom_color, R.drawable.ic_custom_color)
-                .setFabBackgroundColor(ResourcesCompat.getColor(getResources(), R.color.material_white_1000, getTheme()))
-                .setFabImageTintColor(ResourcesCompat.getColor(getResources(), R.color.inbox_primary, getTheme()))
-                .setLabel(getString(R.string.label_custom_color))
-                .setLabelColor(Color.WHITE)
-                .setLabelBackgroundColor(ResourcesCompat.getColor(getResources(), R.color.inbox_primary, getTheme()))
-                .setLabelClickable(false)
-                .create()
-);
+```kotlin
+speedDialView.addActionItem(SpeedDialActionItem.Builder(R.id.fab_custom_color, drawable)
+        .setFabBackgroundColor(ResourcesCompat.getColor(getResources(), R.color.material_white_1000, getTheme()))
+        .setFabImageTintColor(ResourcesCompat.getColor(getResources(), R.color.inbox_primary, getTheme()))
+        .setLabel(getString(R.string.label_custom_color))
+        .setLabelColor(Color.WHITE)
+        .setLabelBackgroundColor(ResourcesCompat.getColor(getResources(), R.color.inbox_primary, getTheme()))
+        .setLabelClickable(false)
+        .create())
 ```
 Is is also possible to specify a theme to easily change the FAB background and ripple effect color:
 
-```java
-mSpeedDialView.addActionItem(
-        new SpeedDialActionItem.Builder(R.id.fab_custom_theme, R.drawable.ic_theme_white_24dp)
-                .setLabel(getString(R.string.label_custom_theme))
-                .setTheme(R.style.AppTheme_Purple)
-                .create());
+```kotlin
+speedDialView.addActionItem(SpeedDialActionItem.Builder(R.id.fab_custom_theme, R.drawable.ic_theme_white_24dp)
+        .setLabel(getString(R.string.label_custom_theme))
+        .setTheme(R.style.AppTheme_Purple)
+        .create())
 ```
 ```xml
 <style name="AppTheme.Purple" parent="AppTheme">
@@ -162,9 +153,9 @@ and then provide the instance of that layout to the `SpeedDialView`:
     app:sdOverlayLayout="@id/overlay" />
 ```
 or
-```java
-SpeedDialOverlayLayout overlayLayout = findViewById(R.id.overlay);
-mSpeedDialView.setSpeedDialOverlayLayout(overlayLayout);
+```kotlin
+val overlayLayout = findViewById<SpeedDialOverlayLayout>(R.id.overlay)
+speedDialView.setSpeedDialOverlayLayout(overlayLayout)
 ```
 
 #### Hiding the FAB when scrolling a `RecyclerView` or a `NestedScrollView`
@@ -180,20 +171,20 @@ the convenience string resource `@string/speeddial_scrolling_view_snackbar_behav
 ```
 
 Or programmatically:
-```java
-CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) speedDialView.getLayoutParams();
-params.setBehavior(new SpeedDialView.ScrollingViewSnackbarBehavior());
-speedDialView.requestLayout();
+```kotlin
+val params = speedDialView.layoutParams as CoordinatorLayout.LayoutParams
+params.behavior = SpeedDialView.ScrollingViewSnackbarBehavior()
+speedDialView.requestLayout()
 ```
 
 NB: for the behaviors to work, `SpeedDialView` needs to be a direct child of `CoordinatorLayout`
 
 #### Disabling `SnackbarBehavior`
 Since the `SnackbarBehavior` is enabled by default and, afaik, it is not possible to remove a Behavior, simply use apply the `SpeedDialView.NoBehavior` instead:
-```java
-CoordinatorLayout.LayoutParams params = (CoordinatorLayout.LayoutParams) speedDialView.getLayoutParams();
-params.setBehavior(new SpeedDialView.NoBehavior());
-speedDialView.requestLayout();
+```kotlin
+val params = speedDialView.layoutParams as CoordinatorLayout.LayoutParams
+params.behavior = SpeedDialView.NoBehavior()
+speedDialView.requestLayout()
 ```
 
 ### Sample project
@@ -250,7 +241,7 @@ This project is based on [floating-action-menu by ArthurGhazaryan](https://githu
 
 ## Licenses
 ```
-Copyright 2018 Roberto Leinardi.
+Copyright 2019 Roberto Leinardi.
 
 Licensed to the Apache Software Foundation (ASF) under one or more contributor
 license agreements.  See the NOTICE file distributed with this work for
diff --git a/build.gradle b/build.gradle
index 06a8dadf..b66778ee 100644
--- a/build.gradle
+++ b/build.gradle
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 apply from: rootProject.file('versions-plugin.gradle')
+apply from: rootProject.file('detekt.gradle')
 apply plugin: "se.bjurr.violations.violation-comments-to-github-gradle-plugin"
 
 buildscript {
@@ -22,6 +23,7 @@ buildscript {
         addRepos(repositories)
     }
     dependencies {
+        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$versions.kotlin"
         classpath "com.android.tools.build:gradle:$versions.android_gradle_plugin"
         classpath "com.leinardi.android:android-checkstyle-plugin:$versions.android_checkstyle_plugin"
         classpath "com.github.dcendents:android-maven-gradle-plugin:$versions.android_maven_gradle_plugin"
@@ -29,6 +31,7 @@ buildscript {
         classpath "com.github.ben-manes:gradle-versions-plugin:$versions.gradle_versions_plugin"
         classpath "se.bjurr.violations:violation-comments-to-github-gradle-plugin:$versions.violations_plugin"
         classpath "net.ltgt.gradle:gradle-errorprone-plugin:$versions.errorprone_plugin"
+        classpath "io.gitlab.arturbosch.detekt:detekt-gradle-plugin:$versions.detekt"
         // NOTE: Do not place your application dependencies here; they belong
         // in the individual module build.gradle files
     }
diff --git a/checkstyle.gradle b/checkstyle.gradle
index e5f1d7a1..54c13994 100644
--- a/checkstyle.gradle
+++ b/checkstyle.gradle
@@ -20,5 +20,5 @@ checkstyle {
     ignoreFailures = false // Whether this task will ignore failures and continue running the build.
     configFile rootProject.file('config/checkstyle/checkstyle.xml')
     // The Checkstyle configuration file to use.
-    toolVersion = '8.16' // The version of Checkstyle you want to be used
+    toolVersion = '8.23' // The version of Checkstyle you want to be used
 }
diff --git a/config/detekt/config.yml b/config/detekt/config.yml
new file mode 100644
index 00000000..c190a585
--- /dev/null
+++ b/config/detekt/config.yml
@@ -0,0 +1,561 @@
+build:
+  maxIssues: 1 # Custom
+  weights:
+    complexity: 1 # Custom
+    # LongParameterList: 1
+    style: 1 # Custom
+    comments: 1 # Custom
+    empty-blocks: 1 # Custom
+    exceptions: 1 # Custom
+    naming: 1 # Custom
+    performance: 1 # Custom
+    potential-bugs: 1 # Custom
+
+processors:
+  active: true
+  exclude:
+  # - 'FunctionCountProcessor'
+  # - 'PropertyCountProcessor'
+  # - 'ClassCountProcessor'
+  # - 'PackageCountProcessor'
+  # - 'KtFileCountProcessor'
+
+console-reports:
+  active: true
+  exclude:
+  #  - 'ProjectStatisticsReport'
+  #  - 'ComplexityReport'
+  #  - 'NotificationReport'
+  #  - 'FindingsReport'
+  #  - 'BuildFailureReport'
+
+comments:
+  active: true
+  excludes: "**/modules/test-*/**" # Custom
+  CommentOverPrivateFunction:
+    active: false
+  CommentOverPrivateProperty:
+    active: false
+  EndOfSentenceFormat:
+    active: false
+    endOfSentenceFormat: ([.?!][ \t\n\r\f<])|([.?!:]$)
+  UndocumentedPublicClass:
+    active: false
+    searchInNestedClass: true
+    searchInInnerClass: true
+    searchInInnerObject: true
+    searchInInnerInterface: true
+  UndocumentedPublicFunction:
+    active: false
+
+complexity:
+  active: true
+  ComplexCondition:
+    active: true
+    threshold: 6 # Custom
+  ComplexInterface:
+    active: false
+    threshold: 10
+    includeStaticDeclarations: false
+  ComplexMethod:
+    active: true
+    threshold: 20 # Custom
+    ignoreSingleWhenExpression: true # Custom
+    ignoreSimpleWhenEntries: false
+  LabeledExpression:
+    active: false
+    ignoredLabels: ""
+  LargeClass:
+    active: true
+    threshold: 600
+  LongMethod:
+    active: true
+    threshold: 60
+    excludes: "**/modules/test-*/**,**/src/test*/**,**/src/androidTest*/**,**/*Test.kt" # Custom
+  LongParameterList:
+    active: false # Custom
+    threshold: 6
+    ignoreDefaultParameters: false
+  MethodOverloading:
+    active: false
+    threshold: 6
+  NestedBlockDepth:
+    active: true
+    threshold: 4
+  StringLiteralDuplication:
+    active: false
+    excludes: "**/modules/test-*/**" # Custom
+    threshold: 3
+    ignoreAnnotation: true
+    excludeStringsWithLessThan5Characters: true
+    ignoreStringsRegex: '$^'
+  TooManyFunctions:
+    active: false # Custom
+    excludes: "**/modules/test-*/**" # Custom
+    thresholdInFiles: 11
+    thresholdInClasses: 11
+    thresholdInInterfaces: 11
+    thresholdInObjects: 11
+    thresholdInEnums: 11
+    ignoreDeprecated: false
+    ignorePrivate: false
+    ignoreOverridden: false
+
+empty-blocks:
+  active: true
+  EmptyCatchBlock:
+    active: true
+    allowedExceptionNameRegex: "^(_|(ignore|expected).*)"
+  EmptyClassBlock:
+    active: true
+  EmptyDefaultConstructor:
+    active: true
+  EmptyDoWhileBlock:
+    active: true
+  EmptyElseBlock:
+    active: true
+  EmptyFinallyBlock:
+    active: true
+  EmptyForBlock:
+    active: true
+  EmptyFunctionBlock:
+    active: true
+    ignoreOverriddenFunctions: false
+  EmptyIfBlock:
+    active: true
+  EmptyInitBlock:
+    active: true
+  EmptyKtFile:
+    active: true
+  EmptySecondaryConstructor:
+    active: true
+  EmptyWhenBlock:
+    active: true
+  EmptyWhileBlock:
+    active: true
+
+exceptions:
+  active: true
+  ExceptionRaisedInUnexpectedLocation:
+    active: true # Custom
+    methodNames: 'toString,hashCode,equals,finalize'
+  InstanceOfCheckForException:
+    active: false
+    excludes: "**/modules/test-*/**" # Custom
+  NotImplementedDeclaration:
+    active: false
+  PrintStackTrace:
+    active: true # Custom
+  RethrowCaughtException:
+    active: false
+  ReturnFromFinally:
+    active: false
+  SwallowedException:
+    active: false
+    ignoredExceptionTypes: 'InterruptedException,NumberFormatException,ParseException,MalformedURLException'
+  ThrowingExceptionFromFinally:
+    active: true # Custom
+  ThrowingExceptionInMain:
+    active: false
+  ThrowingExceptionsWithoutMessageOrCause:
+    active: true # Custom
+    exceptions: 'IllegalArgumentException,IllegalStateException,IOException'
+  ThrowingNewInstanceOfSameException:
+    active: false
+  TooGenericExceptionCaught:
+    active: true
+    excludes: "**/modules/test-*/**" # Custom
+    exceptionNames:
+      - ArrayIndexOutOfBoundsException
+      - Error
+      - Exception
+      - IllegalMonitorStateException
+      - NullPointerException
+      - IndexOutOfBoundsException
+      - RuntimeException
+      - Throwable
+    allowedExceptionNameRegex: "^(_|(ignore|expected).*)"
+  TooGenericExceptionThrown:
+    active: true
+    exceptionNames:
+      - Error
+      - Exception
+      - Throwable
+      - RuntimeException
+
+formatting:
+  active: true
+  android: true # Custom
+  autoCorrect: true
+  excludes: "**/modules/test-*/**" # Custom
+  AnnotationOnSeparateLine:
+    active: false
+  ChainWrapping:
+    active: true
+    autoCorrect: true
+  CommentSpacing:
+    active: true
+    autoCorrect: true
+  Filename:
+    active: true
+  FinalNewline:
+    active: true
+    autoCorrect: true
+  ImportOrdering:
+    active: false
+  Indentation:
+    active: false
+    indentSize: 4
+    continuationIndentSize: 4
+  MaximumLineLength:
+    active: true
+    maxLineLength: 120 # Custom
+  ModifierOrdering:
+    active: true
+    autoCorrect: true
+  MultiLineIfElse:
+    active: true
+    autoCorrect: true
+  NoBlankLineBeforeRbrace:
+    active: false # Custom
+    autoCorrect: true
+  NoConsecutiveBlankLines:
+    active: true
+    autoCorrect: true
+  NoEmptyClassBody:
+    active: true
+    autoCorrect: true
+  NoItParamInMultilineLambda:
+    active: false
+  NoLineBreakAfterElse:
+    active: true
+    autoCorrect: true
+  NoLineBreakBeforeAssignment:
+    active: true
+    autoCorrect: true
+  NoMultipleSpaces:
+    active: true
+    autoCorrect: true
+    excludes: "**/modules/test-*/**,**/src/test*/**,**/src/androidTest*/**,**/*Test.kt" # Custom
+  NoSemicolons:
+    active: true
+    autoCorrect: true
+  NoTrailingSpaces:
+    active: true
+    autoCorrect: true
+    excludes: "**/modules/test-*/**,**/src/test*/**,**/src/androidTest*/**,**/*Test.kt" # Custom
+  NoUnitReturn:
+    active: true
+    autoCorrect: true
+  NoUnusedImports:
+    active: true
+    autoCorrect: true
+  NoWildcardImports:
+    active: true
+    autoCorrect: true
+  PackageName:
+    active: true
+    autoCorrect: true
+  ParameterListWrapping:
+    active: true
+    autoCorrect: true
+    indentSize: 4
+  SpacingAroundColon:
+    active: true
+    autoCorrect: true
+  SpacingAroundComma:
+    active: true
+    autoCorrect: true
+  SpacingAroundCurly:
+    active: true
+    autoCorrect: true
+  SpacingAroundDot:
+    active: true
+    autoCorrect: true
+  SpacingAroundKeyword:
+    active: true
+    autoCorrect: true
+    excludes: "**/modules/test-*/**,**/src/test*/**,**/src/androidTest*/**,**/*Test.kt" # Custom
+  SpacingAroundOperators:
+    active: true
+    autoCorrect: true
+  SpacingAroundParens:
+    active: true
+    autoCorrect: true
+  SpacingAroundRangeOperator:
+    active: true
+    autoCorrect: true
+  SpacingAroundUnaryOperators:
+    active: true
+    autoCorrect: true
+  StringTemplate:
+    active: true
+    autoCorrect: true
+
+naming:
+  active: true
+  ClassNaming:
+    active: true
+    excludes: "**/modules/test-*/**" # Custom
+    classPattern: '[A-Z$][a-zA-Z0-9$]*'
+  ConstructorParameterNaming:
+    active: true
+    excludes: "**/modules/test-*/**" # Custom
+    parameterPattern: '([a-ln-z]|m[a-z])[A-Za-z0-9]*' # Custom
+    privateParameterPattern: '([a-ln-z]|m[a-z])[A-Za-z0-9]*' # Custom
+    excludeClassPattern: '$^'
+  EnumNaming:
+    active: true
+    excludes: "**/modules/test-*/**" # Custom
+    enumEntryPattern: '^[A-Z][_A-Z0-9]*' # Custom
+  ForbiddenClassName:
+    active: false
+    excludes: "**/modules/test-*/**" # Custom
+    forbiddenName: ''
+  FunctionMaxLength:
+    active: false
+    excludes: "**/modules/test-*/**" # Custom
+    maximumFunctionNameLength: 30
+  FunctionMinLength:
+    active: false
+    excludes: "**/modules/test-*/**" # Custom
+    minimumFunctionNameLength: 3
+  FunctionNaming:
+    active: true
+    excludes: "**/modules/test-*/**,**/src/test*/**,**/src/androidTest*/**,**/*Test.kt" # Custom
+    functionPattern: '^([a-z$][a-zA-Z$0-9]*)|(`.*`)$'
+    excludeClassPattern: '$^'
+    ignoreOverridden: true
+  FunctionParameterNaming:
+    active: true
+    excludes: "**/modules/test-*/**" # Custom
+    parameterPattern: '([a-ln-z]|m[a-z])[A-Za-z0-9]*' # Custom
+    excludeClassPattern: '$^'
+    ignoreOverriddenFunctions: true
+  InvalidPackageDeclaration:
+    active: false
+    rootPackage: ''
+  MatchingDeclarationName:
+    active: false # Custom
+  MemberNameEqualsClassName:
+    active: true # Custom
+    ignoreOverriddenFunction: true
+  ObjectPropertyNaming:
+    active: true
+    excludes: "**/modules/test-*/**" # Custom
+    constantPattern: '[A-Za-z][_A-Za-z0-9]*'
+    propertyPattern: '[A-Za-z][_A-Za-z0-9]*'
+    privatePropertyPattern: '(_)?[A-Za-z][_A-Za-z0-9]*'
+  PackageNaming:
+    active: true
+    excludes: "**/modules/test-*/**" # Custom
+    packagePattern: '^[a-z]+(\.[a-z][a-z0-9]*)*$' # Custom
+  TopLevelPropertyNaming:
+    active: true
+    excludes: "**/modules/test-*/**" # Custom
+    constantPattern: '[A-Z][_A-Z0-9]*'
+    propertyPattern: '[A-Za-z][_A-Za-z0-9]*'
+    privatePropertyPattern: '(_)?[A-Za-z][_A-Za-z0-9]*' # Custom
+  VariableMaxLength:
+    active: false
+    excludes: "**/modules/test-*/**" # Custom
+    maximumVariableNameLength: 64
+  VariableMinLength:
+    active: false
+    excludes: "**/modules/test-*/**" # Custom
+    minimumVariableNameLength: 1
+  VariableNaming:
+    active: true
+    excludes: "**/modules/test-*/**" # Custom
+    variablePattern: '(_)?([a-ln-z]|m[a-z])[A-Za-z0-9]*' # Custom
+    privateVariablePattern: '(_)?([a-ln-z]|m[a-z])[A-Za-z0-9]*' # Custom
+    excludeClassPattern: '$^'
+    ignoreOverridden: true
+
+performance:
+  active: true
+  ArrayPrimitive:
+    active: true # Custom
+  ForEachOnRange:
+    active: true
+    excludes: "**/modules/test-*/**" # Custom
+  SpreadOperator:
+    active: false # Custom
+    excludes: "**/modules/test-*/**" # Custom
+  UnnecessaryTemporaryInstantiation:
+    active: true
+
+potential-bugs:
+  active: true
+  DuplicateCaseInWhenExpression:
+    active: true
+  EqualsAlwaysReturnsTrueOrFalse:
+    active: false
+  EqualsWithHashCodeExist:
+    active: true
+  ExplicitGarbageCollectionCall:
+    active: true
+  InvalidRange:
+    active: true # Custom
+  IteratorHasNextCallsNextMethod:
+    active: false
+  IteratorNotThrowingNoSuchElementException:
+    active: false
+  LateinitUsage:
+    active: true # Custom
+    excludes: "**/modules/test-*/**,**/src/test*/**,**/src/androidTest*/**,**/*Test.kt" # Custom
+    excludeAnnotatedProperties: "Inject" # Custom
+    ignoreOnClassesPattern: "(.*Activity|.*Fragment|.*Adapter|.*ViewModel|.*ViewModelObservable|.*Sdk)" # Custom
+  MissingWhenCase:
+    active: false
+  RedundantElseInWhen:
+    active: false
+  UnconditionalJumpStatementInLoop:
+    active: false
+  UnreachableCode:
+    active: true
+  UnsafeCallOnNullableType:
+    active: true # Custom
+  UnsafeCast:
+    active: false
+  UselessPostfixExpression:
+    active: true # Custom
+  WrongEqualsTypeParameter:
+    active: true # Custom
+
+style:
+  active: true
+  CollapsibleIfStatements:
+    active: true # Custom
+  DataClassContainsFunctions:
+    active: true # Custom
+    conversionFunctionPrefix: 'to'
+  DataClassShouldBeImmutable:
+    active: false
+  EqualsNullCall:
+    active: true # Custom
+  EqualsOnSignatureLine:
+    active: false
+  ExplicitItLambdaParameter:
+    active: true # Custom
+  ExpressionBodySyntax:
+    active: false
+    includeLineWrapping: false
+  ForbiddenComment:
+    active: true
+    values: 'TODO' # Custom
+  ForbiddenImport:
+    active: true # Custom
+    imports: ''
+  ForbiddenVoid:
+    active: true # Custom
+    ignoreOverridden: false
+  FunctionOnlyReturningConstant:
+    active: false
+    ignoreOverridableFunction: true
+    excludedFunctions: 'describeContents'
+  LibraryCodeMustSpecifyReturnType:
+    active: false
+  LoopWithTooManyJumpStatements:
+    active: false
+    maxJumpCount: 1
+  MagicNumber:
+    active: true
+    excludes: "**/modules/test-*/**,**/src/test*/**,**/src/androidTest*/**,**/*Test.kt" # Custom
+    ignoreNumbers: '-1,0,1,2'
+    ignoreHashCodeFunction: false # Custom
+    ignorePropertyDeclaration: true # Custom
+    ignoreConstantDeclaration: true
+    ignoreCompanionObjectPropertyDeclaration: true
+    ignoreAnnotation: false
+    ignoreNamedArgument: true
+    ignoreEnums: true # Custom
+    ignoreRanges: false
+  MandatoryBracesIfStatements:
+    active: true # Custom
+  MaxLineLength:
+    active: true
+    excludes: "**/modules/test-*/**" # Custom
+    maxLineLength: 120 # Custom
+    excludePackageStatements: true
+    excludeImportStatements: true
+    excludeCommentStatements: false
+  MayBeConst:
+    active: true # Custom
+  ModifierOrder:
+    active: true
+  NestedClassesVisibility:
+    active: true # Custom
+  NewLineAtEndOfFile:
+    active: true
+  NoTabs:
+    active: true # Custom
+  OptionalAbstractKeyword:
+    active: true
+  OptionalUnit:
+    active: false
+  OptionalWhenBraces:
+    active: false
+  PreferToOverPairSyntax:
+    active: false
+  ProtectedMemberInFinalClass:
+    active: true # Custom
+  RedundantVisibilityModifierRule:
+    active: true # Custom
+  ReturnCount:
+    active: true
+    max: 5 # Custom
+    excludedFunctions: "equals"
+    excludeLabeled: false
+    excludeReturnFromLambda: true
+  SafeCast:
+    active: true
+  SerialVersionUIDInSerializableClass:
+    active: false
+  SpacingBetweenPackageAndImports:
+    active: true # Custom
+  ThrowsCount:
+    active: true
+    max: 2
+  TrailingWhitespace:
+    active: true # Custom
+  UnderscoresInNumericLiterals:
+    active: false
+    acceptableDecimalLength: 5
+  UnnecessaryAbstractClass:
+    active: false
+    excludeAnnotatedClasses: "dagger.Module"
+  UnnecessaryApply:
+    active: false
+  UnnecessaryInheritance:
+    active: false
+  UnnecessaryLet:
+    active: true # Custom
+  UnnecessaryParentheses:
+    active: true # Custom
+  UntilInsteadOfRangeTo:
+    active: false
+  UnusedImports:
+    active: true # Custom
+  UnusedPrivateClass:
+    active: false
+  UnusedPrivateMember:
+    active: false
+    allowedNames: "(_|ignored|expected|serialVersionUID)"
+  UseCheckOrError:
+    active: false
+  UseDataClass:
+    active: true # Custom
+    excludeAnnotatedClasses: ""
+  UseRequire:
+    active: false
+  UselessCallOnNotNull:
+    active: false
+  UtilityClassWithPublicConstructor:
+    active: true # Custom
+  VarCouldBeVal:
+    active: true # Custom
+  WildcardImport:
+    active: true
+    excludes: "**/modules/test-*/**" # Custom
+    excludeImports: 'java.util.*,kotlinx.android.synthetic.*'
diff --git a/dependencies.gradle b/dependencies.gradle
index 8249e936..59d278ae 100644
--- a/dependencies.gradle
+++ b/dependencies.gradle
@@ -29,12 +29,13 @@ versions.androidx_cardview = "1.0.0"
 versions.androidx_constraintlayout = "1.1.3"
 versions.androidx_recyclerview = "1.0.0"
 versions.constraint_layout = "1.1.3"
+versions.detekt = "1.0.0-RC16"
 versions.errorprone_plugin = "0.0.15"
 versions.espresso = "3.0.1"
 versions.gradle_bintray_plugin = "1.8.4"
 versions.gradle_versions_plugin = "0.24.0"
 versions.junit = "4.12"
-versions.kotlin = "1.2"
+versions.kotlin = "1.3.41"
 versions.material = "1.0.0"
 versions.mockito = "2.13.3"
 versions.mockito_all = "1.10.19"
diff --git a/detekt.gradle b/detekt.gradle
new file mode 100644
index 00000000..122ced9f
--- /dev/null
+++ b/detekt.gradle
@@ -0,0 +1,31 @@
+/*
+ * Copyright 2019 Roberto Leinardi.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+apply plugin: 'io.gitlab.arturbosch.detekt'
+
+detekt {
+    toolVersion = rootProject.ext.versions.detekt
+    input = files(rootDir)
+    config = rootProject.files('config/detekt/config.yml')
+}
+
+dependencies {
+    detektPlugins "io.gitlab.arturbosch.detekt:detekt-formatting:${versions.detekt}"
+}
+
+tasks.getByName('detekt') {
+    exclude("**/build/generated/**")
+}
diff --git a/library/src/main/java/com/leinardi/android/speeddial/FabWithLabelView.java b/library/src/main/java/com/leinardi/android/speeddial/FabWithLabelView.java
index c441d169..7e94dcf7 100644
--- a/library/src/main/java/com/leinardi/android/speeddial/FabWithLabelView.java
+++ b/library/src/main/java/com/leinardi/android/speeddial/FabWithLabelView.java
@@ -37,7 +37,6 @@
 import androidx.annotation.Nullable;
 import androidx.cardview.widget.CardView;
 import androidx.core.content.res.ResourcesCompat;
-import androidx.core.graphics.drawable.DrawableCompat;
 import androidx.core.widget.ImageViewCompat;
 import com.google.android.material.floatingactionbutton.FloatingActionButton;
 import com.leinardi.android.speeddial.SpeedDialView.OnActionSelectedListener;
diff --git a/library/src/main/java/com/leinardi/android/speeddial/SpeedDialView.java b/library/src/main/java/com/leinardi/android/speeddial/SpeedDialView.java
index a741e49f..56cdb8b8 100755
--- a/library/src/main/java/com/leinardi/android/speeddial/SpeedDialView.java
+++ b/library/src/main/java/com/leinardi/android/speeddial/SpeedDialView.java
@@ -19,6 +19,7 @@
 import android.content.Context;
 import android.content.res.ColorStateList;
 import android.content.res.TypedArray;
+import android.graphics.Bitmap;
 import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
 import android.os.Build;
@@ -806,7 +807,10 @@ private void toggle(boolean show, boolean animate) {
     private void updateMainFabDrawable(boolean animate) {
         if (isOpen()) {
             if (mMainFabOpenedDrawable != null) {
-                mMainFab.setImageDrawable(mMainFabOpenedDrawable);
+                // This is a workaround. I don't know why if I set directly the rotated Drawable with `setImageDrawable`
+                // it will be transparent/empty on Android API 16 (works on API 27, haven't tested other versions).
+                Bitmap bitmap = UiUtils.getBitmapFromDrawable(mMainFabOpenedDrawable);
+                mMainFab.setImageBitmap(bitmap);
             }
             UiUtils.rotateForward(mMainFab, getMainFabAnimationRotateAngle(), animate);
         } else {
diff --git a/sample/build.gradle b/sample/build.gradle
index 5af30f17..72b14ddb 100755
--- a/sample/build.gradle
+++ b/sample/build.gradle
@@ -15,6 +15,8 @@
  */
 
 apply plugin: 'com.android.application'
+apply plugin: 'kotlin-android'
+apply plugin: 'kotlin-android-extensions'
 apply from: rootProject.file('checkstyle.gradle')
 
 android {
@@ -69,6 +71,7 @@ android {
 dependencies {
     implementation project(':library')
 //    implementation "com.leinardi.android:speed-dial:${build_versions.version_name}"
+    implementation"org.jetbrains.kotlin:kotlin-stdlib-jdk7:$versions.kotlin"
     implementation "androidx.appcompat:appcompat:$versions.androidx_appcompat"
     implementation "androidx.recyclerview:recyclerview:$versions.androidx_recyclerview"
     implementation "androidx.constraintlayout:constraintlayout:$versions.androidx_constraintlayout"
diff --git a/sample/src/main/java/com/leinardi/android/speeddial/sample/CustomAdapter.java b/sample/src/main/java/com/leinardi/android/speeddial/sample/CustomAdapter.java
deleted file mode 100644
index cb1fcc43..00000000
--- a/sample/src/main/java/com/leinardi/android/speeddial/sample/CustomAdapter.java
+++ /dev/null
@@ -1,90 +0,0 @@
-/*
- * Copyright 2019 Roberto Leinardi.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.leinardi.android.speeddial.sample;
-
-import android.util.Log;
-import android.view.LayoutInflater;
-import android.view.View;
-import android.view.ViewGroup;
-import android.widget.TextView;
-
-import androidx.recyclerview.widget.RecyclerView;
-
-/**
- * Provide views to RecyclerView with data from mDataSet.
- */
-public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.ViewHolder> {
-    private static final String TAG = "CustomAdapter";
-
-    private String[] mDataSet;
-
-    /**
-     * Initialize the dataset of the Adapter.
-     *
-     * @param dataSet String[] containing the data to populate views to be used by RecyclerView.
-     */
-    public CustomAdapter(String[] dataSet) {
-        mDataSet = dataSet;
-    }
-
-    // Create new views (invoked by the layout manager)
-    @Override
-    public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int viewType) {
-        // Create a new view.
-        View v = LayoutInflater.from(viewGroup.getContext())
-                .inflate(com.leinardi.android.speeddial.sample.R.layout.text_row_item, viewGroup, false);
-
-        return new ViewHolder(v);
-    }
-
-    // Replace the contents of a view (invoked by the layout manager)
-    @Override
-    public void onBindViewHolder(ViewHolder viewHolder, final int position) {
-        // Get element from your dataset at this position and replace the contents of the view
-        // with that element
-        viewHolder.getTextView().setText(mDataSet[position]);
-    }
-
-    // Return the size of your dataset (invoked by the layout manager)
-    @Override
-    public int getItemCount() {
-        return mDataSet.length;
-    }
-
-    /**
-     * Provide a reference to the type of views that you are using (custom ViewHolder)
-     */
-    public static class ViewHolder extends RecyclerView.ViewHolder {
-        private final TextView mTextView;
-
-        public ViewHolder(View v) {
-            super(v);
-            // Define click listener for the ViewHolder's View.
-            v.setOnClickListener(new View.OnClickListener() {
-                @Override
-                public void onClick(View v) {
-                    Log.d(TAG, "Element " + getAdapterPosition() + " clicked.");
-                }
-            });
-            mTextView = v.findViewById(R.id.textView);
-        }
-
-        public TextView getTextView() {
-            return mTextView;
-        }
-    }
-}
diff --git a/sample/src/main/java/com/leinardi/android/speeddial/sample/CustomAdapter.kt b/sample/src/main/java/com/leinardi/android/speeddial/sample/CustomAdapter.kt
new file mode 100644
index 00000000..881cd72f
--- /dev/null
+++ b/sample/src/main/java/com/leinardi/android/speeddial/sample/CustomAdapter.kt
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2019 Roberto Leinardi.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.leinardi.android.speeddial.sample
+
+import android.util.Log
+import android.view.LayoutInflater
+import android.view.View
+import android.view.ViewGroup
+import android.widget.TextView
+
+import androidx.recyclerview.widget.RecyclerView
+
+/**
+ * Provide views to RecyclerView with data from dataSet.
+ */
+class CustomAdapter(private val dataSet: Array<String>) : RecyclerView.Adapter<CustomAdapter.ViewHolder>() {
+
+    override fun onCreateViewHolder(viewGroup: ViewGroup, viewType: Int): ViewHolder {
+        return ViewHolder(LayoutInflater.from(viewGroup.context)
+                .inflate(R.layout.text_row_item, viewGroup, false))
+    }
+
+    override fun onBindViewHolder(viewHolder: ViewHolder, position: Int) {
+        viewHolder.textView.text = dataSet[position]
+    }
+
+    override fun getItemCount() = dataSet.size
+
+    /**
+     * Provide a reference to the type of views that you are using (custom ViewHolder)
+     */
+    class ViewHolder(v: View) : RecyclerView.ViewHolder(v) {
+        val textView: TextView
+
+        init {
+            // Define click listener for the ViewHolder's View.
+            v.setOnClickListener { Log.d(TAG, "Element $adapterPosition clicked.") }
+            textView = v.findViewById(R.id.textView)
+        }
+    }
+
+    companion object {
+        private const val TAG = "CustomAdapter"
+    }
+}
diff --git a/sample/src/main/java/com/leinardi/android/speeddial/sample/MainActivity.java b/sample/src/main/java/com/leinardi/android/speeddial/sample/MainActivity.java
deleted file mode 100755
index fb4f2060..00000000
--- a/sample/src/main/java/com/leinardi/android/speeddial/sample/MainActivity.java
+++ /dev/null
@@ -1,193 +0,0 @@
-/*
- * Copyright 2019 Roberto Leinardi.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.leinardi.android.speeddial.sample;
-
-import android.content.Intent;
-import android.graphics.Color;
-import android.graphics.drawable.Drawable;
-import android.os.Bundle;
-import android.util.Log;
-import android.view.Menu;
-import android.view.MenuItem;
-
-import androidx.appcompat.content.res.AppCompatResources;
-import androidx.core.content.res.ResourcesCompat;
-import com.leinardi.android.speeddial.FabWithLabelView;
-import com.leinardi.android.speeddial.SpeedDialActionItem;
-import com.leinardi.android.speeddial.SpeedDialView;
-import com.leinardi.android.speeddial.sample.usecases.BaseUseCaseActivity;
-import com.leinardi.android.speeddial.sample.usecases.UseCasesActivity;
-
-/**
- * Sample project
- */
-@SuppressWarnings("PMD") // sample project with long methods
-public class MainActivity extends BaseUseCaseActivity {
-    private static final String TAG = MainActivity.class.getSimpleName();
-    private static final int ADD_ACTION_POSITION = 4;
-    private SpeedDialView mSpeedDialView;
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        initSpeedDial(savedInstanceState == null);
-
-    }
-
-    private void initSpeedDial(boolean addActionItems) {
-        mSpeedDialView = findViewById(R.id.speedDial);
-
-        if (addActionItems) {
-            mSpeedDialView.addActionItem(new SpeedDialActionItem.Builder(R.id.fab_no_label, R.drawable
-                    .ic_link_white_24dp)
-                    .create());
-
-            Drawable drawable = AppCompatResources.getDrawable(MainActivity.this, R.drawable.ic_custom_color);
-            FabWithLabelView fabWithLabelView = mSpeedDialView.addActionItem(new SpeedDialActionItem.Builder(R.id
-                    .fab_custom_color, drawable)
-                    .setFabImageTintColor(ResourcesCompat.getColor(getResources(), R.color.inbox_primary, getTheme()))
-                    .setLabel(R.string.label_custom_color)
-                    .setLabelColor(Color.WHITE)
-                    .setLabelBackgroundColor(ResourcesCompat.getColor(getResources(), R.color.inbox_primary,
-                            getTheme()))
-                    .create());
-            if (fabWithLabelView != null) {
-                fabWithLabelView.setSpeedDialActionItem(fabWithLabelView.getSpeedDialActionItemBuilder()
-                        .setFabBackgroundColor(ResourcesCompat.getColor(getResources(), R.color.material_white_1000,
-                                getTheme()))
-                        .create());
-            }
-
-            mSpeedDialView.addActionItem(new SpeedDialActionItem.Builder(R.id.fab_long_label, R.drawable
-                    .ic_lorem_ipsum)
-                    .setLabel("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor " +
-                            "incididunt ut labore et dolore magna aliqua.")
-                    .create());
-
-            drawable = AppCompatResources.getDrawable(MainActivity.this, R.drawable.ic_add_white_24dp);
-            mSpeedDialView.addActionItem(new SpeedDialActionItem.Builder(R.id.fab_add_action, drawable)
-                    .setFabBackgroundColor(ResourcesCompat.getColor(getResources(), R.color.material_green_500,
-                            getTheme()))
-                    .setLabel(R.string.label_add_action)
-                    .setLabelBackgroundColor(Color.TRANSPARENT)
-                    .create());
-
-            mSpeedDialView.addActionItem(new SpeedDialActionItem.Builder(R.id.fab_custom_theme, R.drawable
-                    .ic_theme_white_24dp)
-                    .setLabel(getString(R.string.label_custom_theme))
-                    .setTheme(R.style.AppTheme_Purple)
-                    .create());
-
-        }
-
-        //Set main action clicklistener.
-        mSpeedDialView.setOnChangeListener(new SpeedDialView.OnChangeListener() {
-            @Override
-            public boolean onMainActionSelected() {
-                showToast("Main action clicked!");
-                return false; // True to keep the Speed Dial open
-            }
-
-            @Override
-            public void onToggleChanged(boolean isOpen) {
-                Log.d(TAG, "Speed dial toggle state changed. Open = " + isOpen);
-            }
-        });
-
-        //Set option fabs clicklisteners.
-        mSpeedDialView.setOnActionSelectedListener(new SpeedDialView.OnActionSelectedListener() {
-            @Override
-            public boolean onActionSelected(SpeedDialActionItem actionItem) {
-                switch (actionItem.getId()) {
-                    case R.id.fab_no_label:
-                        showToast("No label action clicked!\nClosing with animation");
-                        mSpeedDialView.close(); // To close the Speed Dial with animation
-                        return true; // false will close it without animation
-                    case R.id.fab_long_label:
-                        showSnackbar(actionItem.getLabel(MainActivity.this) + " clicked!");
-                        break;
-                    case R.id.fab_custom_color:
-                        showToast(actionItem.getLabel(MainActivity.this) + " clicked!\nClosing without animation.");
-                        return false; // closes without animation (same as mSpeedDialView.close(false); return false;)
-                    case R.id.fab_custom_theme:
-                        showToast(actionItem.getLabel(MainActivity.this) + " clicked!");
-                        break;
-                    case R.id.fab_add_action:
-                        mSpeedDialView.addActionItem(new SpeedDialActionItem.Builder(R.id.fab_replace_action,
-                                R.drawable.ic_replace_white_24dp)
-                                .setFabBackgroundColor(ResourcesCompat.getColor(getResources(), R.color
-                                                .material_orange_500,
-                                        getTheme()))
-                                .setLabel(getString(R.string.label_replace_action))
-                                .create(), ADD_ACTION_POSITION);
-                        break;
-                    case R.id.fab_replace_action:
-                        mSpeedDialView.replaceActionItem(new SpeedDialActionItem.Builder(R.id
-                                .fab_remove_action,
-                                R.drawable.ic_delete_white_24dp)
-                                .setLabel(getString(R.string.label_remove_action))
-                                .setFabBackgroundColor(ResourcesCompat.getColor(getResources(), R.color.inbox_accent,
-                                        getTheme()))
-                                .create(), ADD_ACTION_POSITION);
-                        break;
-                    case R.id.fab_remove_action:
-                        mSpeedDialView.removeActionItemById(R.id.fab_remove_action);
-                        break;
-                    default:
-                        break;
-                }
-                return true; // To keep the Speed Dial open
-            }
-        });
-
-    }
-
-    @Override
-    public boolean onCreateOptionsMenu(Menu menu) {
-        getMenuInflater().inflate(R.menu.menu_main, menu);
-        return true;
-    }
-
-    @Override
-    public void onBackPressed() {
-        //Closes menu if its opened.
-        if (mSpeedDialView.isOpen()) {
-            mSpeedDialView.close();
-        } else {
-            super.onBackPressed();
-        }
-
-    }
-
-    @Override
-    public boolean onOptionsItemSelected(MenuItem item) {
-        int id = item.getItemId();
-
-        //noinspection SimplifiableIfStatement
-        if (id == R.id.action_use_cases) {
-            startActivity(new Intent(MainActivity.this, UseCasesActivity.class));
-            return true;
-        }
-
-        return super.onOptionsItemSelected(item);
-    }
-
-    @Override
-    protected int getLayoutRes() {
-        return R.layout.activity_main;
-    }
-}
diff --git a/sample/src/main/java/com/leinardi/android/speeddial/sample/MainActivity.kt b/sample/src/main/java/com/leinardi/android/speeddial/sample/MainActivity.kt
new file mode 100755
index 00000000..b2af1a0a
--- /dev/null
+++ b/sample/src/main/java/com/leinardi/android/speeddial/sample/MainActivity.kt
@@ -0,0 +1,158 @@
+/*
+ * Copyright 2019 Roberto Leinardi.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.leinardi.android.speeddial.sample
+
+import android.content.Intent
+import android.graphics.Color
+import android.os.Bundle
+import android.util.Log
+import android.view.Menu
+import android.view.MenuItem
+import androidx.appcompat.content.res.AppCompatResources
+import androidx.core.content.res.ResourcesCompat
+import com.leinardi.android.speeddial.SpeedDialActionItem
+import com.leinardi.android.speeddial.SpeedDialView
+import com.leinardi.android.speeddial.sample.usecases.BaseUseCaseActivity
+import com.leinardi.android.speeddial.sample.usecases.UseCasesActivity
+
+/**
+ * Sample project
+ */
+@Suppress("LongMethod", "ComplexMethod", "MagicNumber") // sample project with long methods
+class MainActivity : BaseUseCaseActivity() {
+    override val layoutRes = R.layout.activity_main
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        initSpeedDial(savedInstanceState == null)
+    }
+
+    private fun initSpeedDial(addActionItems: Boolean) {
+        if (addActionItems) {
+            speedDialView.addActionItem(SpeedDialActionItem.Builder(R.id.fab_no_label, R.drawable
+                    .ic_link_white_24dp)
+                    .create())
+
+            var drawable = AppCompatResources.getDrawable(this@MainActivity, R.drawable.ic_custom_color)
+            val fabWithLabelView = speedDialView.addActionItem(SpeedDialActionItem.Builder(R.id
+                    .fab_custom_color, drawable)
+                    .setFabImageTintColor(ResourcesCompat.getColor(resources, R.color.inbox_primary, theme))
+                    .setLabel(R.string.label_custom_color)
+                    .setLabelColor(Color.WHITE)
+                    .setLabelBackgroundColor(ResourcesCompat.getColor(resources, R.color.inbox_primary,
+                            theme))
+                    .create())
+            fabWithLabelView?.apply {
+                speedDialActionItem = speedDialActionItemBuilder
+                        .setFabBackgroundColor(ResourcesCompat.getColor(resources, R.color.material_white_1000, theme))
+                        .create()
+            }
+
+            speedDialView.addActionItem(SpeedDialActionItem.Builder(R.id.fab_long_label, R.drawable
+                    .ic_lorem_ipsum)
+                    .setLabel("Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor " +
+                            "incididunt ut labore et dolore magna aliqua.")
+                    .create())
+
+            drawable = AppCompatResources.getDrawable(this@MainActivity, R.drawable.ic_add_white_24dp)
+            speedDialView.addActionItem(SpeedDialActionItem.Builder(R.id.fab_add_action, drawable)
+                    .setFabBackgroundColor(ResourcesCompat.getColor(resources, R.color.material_green_500, theme))
+                    .setLabel(R.string.label_add_action)
+                    .setLabelBackgroundColor(Color.TRANSPARENT)
+                    .create())
+
+            speedDialView.addActionItem(SpeedDialActionItem.Builder(R.id.fab_custom_theme, R.drawable
+                    .ic_theme_white_24dp)
+                    .setLabel(getString(R.string.label_custom_theme))
+                    .setTheme(R.style.AppTheme_Purple)
+                    .create())
+        }
+
+        // Set main action clicklistener.
+        speedDialView.setOnChangeListener(object : SpeedDialView.OnChangeListener {
+            override fun onMainActionSelected(): Boolean {
+                showToast("Main action clicked!")
+                return false // True to keep the Speed Dial open
+            }
+
+            override fun onToggleChanged(isOpen: Boolean) {
+                Log.d(TAG, "Speed dial toggle state changed. Open = $isOpen")
+            }
+        })
+
+        // Set option fabs clicklisteners.
+        speedDialView.setOnActionSelectedListener(SpeedDialView.OnActionSelectedListener { actionItem ->
+            when (actionItem.id) {
+                R.id.fab_no_label -> {
+                    showToast("No label action clicked!\nClosing with animation")
+                    speedDialView.close() // To close the Speed Dial with animation
+                    return@OnActionSelectedListener true // false will close it without animation
+                }
+                R.id.fab_long_label -> showSnackbar(actionItem.getLabel(this@MainActivity) + " clicked!")
+                R.id.fab_custom_color -> {
+                    showToast(actionItem.getLabel(this@MainActivity) + " clicked!\nClosing without animation.")
+                    // closes without animation (same as speedDialView.close(false); return false;)
+                    return@OnActionSelectedListener false
+                }
+                R.id.fab_custom_theme -> showToast(actionItem.getLabel(this@MainActivity) + " clicked!")
+                R.id.fab_add_action -> speedDialView.addActionItem(SpeedDialActionItem.Builder(R.id.fab_replace_action,
+                        R.drawable.ic_replace_white_24dp)
+                        .setFabBackgroundColor(ResourcesCompat.getColor(resources, R.color
+                                .material_orange_500,
+                                theme))
+                        .setLabel(getString(R.string.label_replace_action))
+                        .create(), ADD_ACTION_POSITION)
+                R.id.fab_replace_action -> speedDialView.replaceActionItem(SpeedDialActionItem.Builder(R.id
+                        .fab_remove_action,
+                        R.drawable.ic_delete_white_24dp)
+                        .setLabel(getString(R.string.label_remove_action))
+                        .setFabBackgroundColor(ResourcesCompat.getColor(resources, R.color.inbox_accent,
+                                theme))
+                        .create(), ADD_ACTION_POSITION)
+                R.id.fab_remove_action -> speedDialView.removeActionItemById(R.id.fab_remove_action)
+            }
+            true // To keep the Speed Dial open
+        })
+    }
+
+    override fun onCreateOptionsMenu(menu: Menu): Boolean {
+        menuInflater.inflate(R.menu.menu_main, menu)
+        return true
+    }
+
+    override fun onBackPressed() {
+        // Closes menu if its opened.
+        if (speedDialView.isOpen) {
+            speedDialView.close()
+        } else {
+            super.onBackPressed()
+        }
+    }
+
+    override fun onOptionsItemSelected(item: MenuItem): Boolean {
+        if (item.itemId == R.id.action_use_cases) {
+            startActivity(Intent(this@MainActivity, UseCasesActivity::class.java))
+            return true
+        }
+        return super.onOptionsItemSelected(item)
+    }
+
+    companion object {
+        private val TAG = MainActivity::class.java.simpleName
+        private const val ADD_ACTION_POSITION = 4
+    }
+}
diff --git a/sample/src/main/java/com/leinardi/android/speeddial/sample/usecases/BaseUseCaseActivity.java b/sample/src/main/java/com/leinardi/android/speeddial/sample/usecases/BaseUseCaseActivity.java
deleted file mode 100644
index 2bd439e8..00000000
--- a/sample/src/main/java/com/leinardi/android/speeddial/sample/usecases/BaseUseCaseActivity.java
+++ /dev/null
@@ -1,198 +0,0 @@
-/*
- * Copyright 2019 Roberto Leinardi.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.leinardi.android.speeddial.sample.usecases;
-
-import android.os.Bundle;
-import android.os.SystemClock;
-import android.view.MenuInflater;
-import android.view.MenuItem;
-import android.view.View;
-import android.widget.Toast;
-
-import androidx.annotation.LayoutRes;
-import androidx.annotation.Nullable;
-import androidx.appcompat.app.AppCompatActivity;
-import androidx.appcompat.widget.ActionMenuView;
-import androidx.appcompat.widget.Toolbar;
-import androidx.coordinatorlayout.widget.CoordinatorLayout;
-import androidx.core.content.res.ResourcesCompat;
-import androidx.recyclerview.widget.LinearLayoutManager;
-import androidx.recyclerview.widget.RecyclerView;
-import com.google.android.material.snackbar.Snackbar;
-import com.leinardi.android.speeddial.SpeedDialActionItem;
-import com.leinardi.android.speeddial.SpeedDialView;
-import com.leinardi.android.speeddial.UiUtils;
-import com.leinardi.android.speeddial.sample.BuildConfig;
-import com.leinardi.android.speeddial.sample.CustomAdapter;
-import com.leinardi.android.speeddial.sample.R;
-
-public abstract class BaseUseCaseActivity extends AppCompatActivity {
-    private static final int DATASET_COUNT = 60;
-    private String[] mDataset;
-    private CoordinatorLayout mCoordinatorLayout;
-    private Toast mToast;
-    private Snackbar mSnackbar;
-    private SpeedDialView mSpeedDial;
-    private RecyclerView mRecyclerView;
-    private CustomAdapter mCustomAdapter;
-
-    @Override
-    protected void onCreate(@Nullable Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(getLayoutRes());
-        mCoordinatorLayout = findViewById(R.id.coordinatorLayout);
-        initToolbar();
-        initRecyclerView();
-        mSpeedDial = findViewById(R.id.speedDial);
-    }
-
-    @LayoutRes
-    protected abstract int getLayoutRes();
-
-    private void initToolbar() {
-        Toolbar toolbar = findViewById(R.id.toolbar);
-        toolbar.setSubtitle(getString(R.string.app_version, BuildConfig.VERSION_NAME));
-        setSupportActionBar(toolbar);
-
-        Toolbar toolbarBottom = findViewById(R.id.toolbar_bottom);
-        toolbarBottom.setContentInsetsAbsolute(0, 0);
-        ActionMenuView actionMenuView = findViewById(R.id.amvMenu);
-        if (actionMenuView != null) {
-            actionMenuView.setOnMenuItemClickListener(new ActionMenuView.OnMenuItemClickListener() {
-                @Override
-                public boolean onMenuItemClick(MenuItem item) {
-                    int id = item.getItemId();
-                    //noinspection SimplifiableIfStatement
-                    if (id == R.id.action_show) {
-                        if (mSpeedDial.getVisibility() == View.VISIBLE) {
-                            mSpeedDial.hide();
-                        } else {
-                            mSpeedDial.show();
-                        }
-                    } else if (id == R.id.action_snack) {
-                        showSnackbar("Test snackbar");
-                    } else if (id == R.id.action_add_item) {
-                        mSpeedDial.addActionItem(new SpeedDialActionItem.Builder((int) SystemClock.uptimeMillis(),
-                                R.drawable.ic_pencil_alt_white_24dp).create());
-                    } else if (id == R.id.action_remove_item) {
-                        int size = mSpeedDial.getActionItems().size();
-                        if (size > 0) {
-                            mSpeedDial.removeActionItem(size - 1);
-                        }
-                    } else if (id == R.id.action_expansion_mode_top) {
-                        mSpeedDial.setExpansionMode(SpeedDialView.ExpansionMode.TOP);
-                    } else if (id == R.id.action_expansion_mode_left) {
-                        mSpeedDial.setExpansionMode(SpeedDialView.ExpansionMode.LEFT);
-                    } else if (id == R.id.action_expansion_mode_bottom) {
-                        mSpeedDial.setExpansionMode(SpeedDialView.ExpansionMode.BOTTOM);
-                    } else if (id == R.id.action_expansion_mode_right) {
-                        mSpeedDial.setExpansionMode(SpeedDialView.ExpansionMode.RIGHT);
-                    } else if (id == R.id.action_rotation_angle_0) {
-                        mSpeedDial.setMainFabAnimationRotateAngle(0);
-                    } else if (id == R.id.action_rotation_angle_45) {
-                        mSpeedDial.setMainFabAnimationRotateAngle(45);
-                    } else if (id == R.id.action_rotation_angle_90) {
-                        mSpeedDial.setMainFabAnimationRotateAngle(90);
-                    } else if (id == R.id.action_rotation_angle_180) {
-                        mSpeedDial.setMainFabAnimationRotateAngle(180);
-                    } else if (id == R.id.action_main_fab_background_color_closed_primary) {
-                        mSpeedDial.setMainFabClosedBackgroundColor(UiUtils.getPrimaryColor(BaseUseCaseActivity.this));
-                    } else if (id == R.id.action_main_fab_background_color_closed_orange) {
-                        mSpeedDial.setMainFabClosedBackgroundColor(
-                                ResourcesCompat.getColor(getResources(), R.color.material_orange_500, getTheme()));
-                    } else if (id == R.id.action_main_fab_background_color_closed_purple) {
-                        mSpeedDial.setMainFabClosedBackgroundColor(
-                                ResourcesCompat.getColor(getResources(), R.color.material_purple_500, getTheme()));
-                    } else if (id == R.id.action_main_fab_background_color_closed_white) {
-                        mSpeedDial.setMainFabClosedBackgroundColor(
-                                ResourcesCompat.getColor(getResources(), R.color.material_white_1000, getTheme()));
-                    } else if (id == R.id.action_main_fab_background_color_closed_none) {
-                        mSpeedDial.setMainFabClosedBackgroundColor(0);
-                    } else if (id == R.id.action_main_fab_background_color_opened_primary) {
-                        mSpeedDial.setMainFabOpenedBackgroundColor(UiUtils.getPrimaryColor(BaseUseCaseActivity.this));
-                    } else if (id == R.id.action_main_fab_background_color_opened_orange) {
-                        mSpeedDial.setMainFabOpenedBackgroundColor(
-                                ResourcesCompat.getColor(getResources(), R.color.material_orange_500, getTheme()));
-                    } else if (id == R.id.action_main_fab_background_color_opened_purple) {
-                        mSpeedDial.setMainFabOpenedBackgroundColor(
-                                ResourcesCompat.getColor(getResources(), R.color.material_purple_500, getTheme()));
-                    } else if (id == R.id.action_main_fab_background_color_opened_white) {
-                        mSpeedDial.setMainFabOpenedBackgroundColor(
-                                ResourcesCompat.getColor(getResources(), R.color.material_white_1000, getTheme()));
-                    } else if (id == R.id.action_main_fab_background_color_opened_none) {
-                        mSpeedDial.setMainFabOpenedBackgroundColor(0);
-                    } else if (id == R.id.action_toggle_list) {
-                        if (mRecyclerView.getAdapter() == null) {
-                            mRecyclerView.setAdapter(mCustomAdapter);
-                        } else {
-                            mRecyclerView.setAdapter(null);
-                        }
-                    } else if (id == R.id.action_toggle_reverse_animation) {
-                        mSpeedDial.setUseReverseAnimationOnClose(!mSpeedDial.getUseReverseAnimationOnClose());
-                    }
-                    return true;
-                }
-            });
-
-            MenuInflater inflater = getMenuInflater();
-            // use amvMenu here
-            inflater.inflate(R.menu.menu_base_use_case, actionMenuView.getMenu());
-        }
-    }
-
-    private void initRecyclerView() {
-        initDataset();
-        mRecyclerView = findViewById(R.id.recyclerView);
-        if (mRecyclerView != null) {
-            mCustomAdapter = new CustomAdapter(mDataset);
-            // Set CustomAdapter as the adapter for RecyclerView.
-            mRecyclerView.setAdapter(mCustomAdapter);
-            RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(this);
-            mRecyclerView.setLayoutManager(layoutManager);
-        }
-    }
-
-    protected void showToast(String text) {
-        if (mToast != null) {
-            mToast.cancel();
-        }
-        mToast = Toast.makeText(getApplicationContext(), text, Toast.LENGTH_LONG);
-        mToast.show();
-    }
-
-    protected void showSnackbar(String text) {
-        mSnackbar = Snackbar.make(mCoordinatorLayout, text, Snackbar.LENGTH_SHORT);
-        mSnackbar.setAction("Close", new View.OnClickListener() {
-            @Override
-            public void onClick(View view) {
-                mSnackbar.dismiss();
-            }
-        });
-        mSnackbar.show();
-    }
-
-    /**
-     * Generates Strings for RecyclerView's adapter. This data would usually come
-     * from a local content provider or remote server.
-     */
-    private void initDataset() {
-        mDataset = new String[DATASET_COUNT];
-        for (int i = 0; i < DATASET_COUNT; i++) {
-            mDataset[i] = "This is element #" + i;
-        }
-    }
-}
diff --git a/sample/src/main/java/com/leinardi/android/speeddial/sample/usecases/BaseUseCaseActivity.kt b/sample/src/main/java/com/leinardi/android/speeddial/sample/usecases/BaseUseCaseActivity.kt
new file mode 100644
index 00000000..e3ca834a
--- /dev/null
+++ b/sample/src/main/java/com/leinardi/android/speeddial/sample/usecases/BaseUseCaseActivity.kt
@@ -0,0 +1,192 @@
+/*
+ * Copyright 2019 Roberto Leinardi.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.leinardi.android.speeddial.sample.usecases
+
+import android.os.Bundle
+import android.os.SystemClock
+import android.view.View
+import android.widget.Toast
+import androidx.annotation.LayoutRes
+import androidx.appcompat.app.AppCompatActivity
+import androidx.appcompat.widget.ActionMenuView
+import androidx.appcompat.widget.Toolbar
+import androidx.coordinatorlayout.widget.CoordinatorLayout
+import androidx.core.content.res.ResourcesCompat
+import androidx.recyclerview.widget.LinearLayoutManager
+import androidx.recyclerview.widget.RecyclerView
+import com.google.android.material.snackbar.Snackbar
+import com.leinardi.android.speeddial.SpeedDialActionItem
+import com.leinardi.android.speeddial.SpeedDialView
+import com.leinardi.android.speeddial.UiUtils
+import com.leinardi.android.speeddial.sample.BuildConfig
+import com.leinardi.android.speeddial.sample.CustomAdapter
+import com.leinardi.android.speeddial.sample.R
+
+abstract class BaseUseCaseActivity : AppCompatActivity() {
+    private val coordinatorLayout by lazy { findViewById<CoordinatorLayout>(R.id.coordinatorLayout) }
+    protected val speedDialView: SpeedDialView by lazy { findViewById<SpeedDialView>(R.id.speedDial) }
+    private val recyclerView by lazy { findViewById<RecyclerView>(R.id.recyclerView) }
+    private var dataset = emptyArray<String>()
+    private var toast: Toast? = null
+    private var snackbar: Snackbar? = null
+    private var customAdapter: CustomAdapter? = null
+
+    @get:LayoutRes
+    protected abstract val layoutRes: Int
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(layoutRes)
+        initToolbar()
+        initRecyclerView()
+    }
+
+    @Suppress("LongMethod", "ComplexMethod", "MagicNumber")
+    private fun initToolbar() {
+        val toolbar = findViewById<Toolbar>(R.id.toolbar)
+        toolbar.subtitle = getString(R.string.app_version, BuildConfig.VERSION_NAME)
+        setSupportActionBar(toolbar)
+
+        val toolbarBottom = findViewById<Toolbar>(R.id.toolbar_bottom)
+        toolbarBottom.setContentInsetsAbsolute(0, 0)
+        val actionMenuView = findViewById<ActionMenuView>(R.id.amvMenu)
+        if (actionMenuView != null) {
+            actionMenuView.setOnMenuItemClickListener { item ->
+                val id = item.itemId
+
+                when (id) {
+                    R.id.action_show -> if (speedDialView.visibility == View.VISIBLE) {
+                        speedDialView.hide()
+                    } else {
+                        speedDialView.show()
+                    }
+                    R.id.action_snack -> showSnackbar("Test snackbar")
+                    R.id.action_add_item ->
+                        speedDialView.addActionItem(SpeedDialActionItem.Builder(
+                                SystemClock.uptimeMillis().toInt(),
+                                R.drawable.ic_pencil_alt_white_24dp).create()
+                        )
+                    R.id.action_remove_item -> {
+                        val size = speedDialView.actionItems.size
+                        if (size > 0) {
+                            speedDialView.removeActionItem(size - 1)
+                        }
+                    }
+                    R.id.action_expansion_mode_top ->
+                        speedDialView.expansionMode = SpeedDialView.ExpansionMode.TOP
+                    R.id.action_expansion_mode_left ->
+                        speedDialView.expansionMode = SpeedDialView.ExpansionMode.LEFT
+                    R.id.action_expansion_mode_bottom ->
+                        speedDialView.expansionMode = SpeedDialView.ExpansionMode.BOTTOM
+                    R.id.action_expansion_mode_right ->
+                        speedDialView.expansionMode = SpeedDialView.ExpansionMode.RIGHT
+                    R.id.action_rotation_angle_0 -> speedDialView.mainFabAnimationRotateAngle = 0f
+                    R.id.action_rotation_angle_45 -> speedDialView.mainFabAnimationRotateAngle = 45f
+                    R.id.action_rotation_angle_90 -> speedDialView.mainFabAnimationRotateAngle = 90f
+                    R.id.action_rotation_angle_180 -> speedDialView.mainFabAnimationRotateAngle = 180f
+                    R.id.action_main_fab_background_color_closed_primary ->
+                        speedDialView.mainFabClosedBackgroundColor = UiUtils.getPrimaryColor(
+                                this@BaseUseCaseActivity)
+                    R.id.action_main_fab_background_color_closed_orange ->
+                        speedDialView.mainFabClosedBackgroundColor = ResourcesCompat.getColor(
+                                resources,
+                                R.color.material_orange_500,
+                                theme)
+                    R.id.action_main_fab_background_color_closed_purple ->
+                        speedDialView.mainFabClosedBackgroundColor = ResourcesCompat.getColor(
+                                resources,
+                                R.color.material_purple_500,
+                                theme)
+                    R.id.action_main_fab_background_color_closed_white ->
+                        speedDialView.mainFabClosedBackgroundColor = ResourcesCompat.getColor(
+                                resources,
+                                R.color.material_white_1000,
+                                theme)
+                    R.id.action_main_fab_background_color_closed_none ->
+                        speedDialView.mainFabClosedBackgroundColor = 0
+                    R.id.action_main_fab_background_color_opened_primary ->
+                        speedDialView.mainFabOpenedBackgroundColor = UiUtils.getPrimaryColor(
+                                this@BaseUseCaseActivity)
+                    R.id.action_main_fab_background_color_opened_orange ->
+                        speedDialView.mainFabOpenedBackgroundColor = ResourcesCompat.getColor(
+                                resources,
+                                R.color.material_orange_500,
+                                theme)
+                    R.id.action_main_fab_background_color_opened_purple ->
+                        speedDialView.mainFabOpenedBackgroundColor = ResourcesCompat.getColor(
+                                resources,
+                                R.color.material_purple_500,
+                                theme)
+                    R.id.action_main_fab_background_color_opened_white ->
+                        speedDialView.mainFabOpenedBackgroundColor = ResourcesCompat.getColor(
+                                resources,
+                                R.color.material_white_1000,
+                                theme)
+                    R.id.action_main_fab_background_color_opened_none ->
+                        speedDialView.mainFabOpenedBackgroundColor = 0
+                    R.id.action_toggle_list -> if (recyclerView.adapter == null) {
+                        recyclerView.adapter = customAdapter
+                    } else {
+                        recyclerView.adapter = null
+                    }
+                    R.id.action_toggle_reverse_animation ->
+                        speedDialView.useReverseAnimationOnClose = !speedDialView.useReverseAnimationOnClose
+                }
+                true
+            }
+
+            val inflater = menuInflater
+            // use amvMenu here
+            inflater.inflate(R.menu.menu_base_use_case, actionMenuView.menu)
+        }
+    }
+
+    private fun initRecyclerView() {
+        initDataset()
+        customAdapter = CustomAdapter(dataset)
+        // Set CustomAdapter as the adapter for RecyclerView.
+        recyclerView.adapter = customAdapter
+        val layoutManager = LinearLayoutManager(this)
+        recyclerView.layoutManager = layoutManager
+    }
+
+    protected fun showToast(text: String) {
+        toast?.cancel()
+        toast = Toast.makeText(applicationContext, text, Toast.LENGTH_LONG)
+        checkNotNull(toast).show()
+    }
+
+    protected fun showSnackbar(text: String) {
+        snackbar = Snackbar.make(coordinatorLayout, text, Snackbar.LENGTH_SHORT)
+        checkNotNull(snackbar).apply {
+            setAction("Close") { dismiss() }
+            show()
+        }
+    }
+
+    /**
+     * Generates Strings for RecyclerView's adapter. This data would usually come
+     * from a local content provider or remote server.
+     */
+    private fun initDataset() {
+        dataset = Array(DATASET_COUNT) { "This is element #$it" }
+    }
+
+    companion object {
+        private const val DATASET_COUNT = 60
+    }
+}
diff --git a/sample/src/main/java/com/leinardi/android/speeddial/sample/usecases/UseCase1Activity.java b/sample/src/main/java/com/leinardi/android/speeddial/sample/usecases/UseCase1Activity.kt
similarity index 69%
rename from sample/src/main/java/com/leinardi/android/speeddial/sample/usecases/UseCase1Activity.java
rename to sample/src/main/java/com/leinardi/android/speeddial/sample/usecases/UseCase1Activity.kt
index 45c1f95d..e93437ad 100644
--- a/sample/src/main/java/com/leinardi/android/speeddial/sample/usecases/UseCase1Activity.java
+++ b/sample/src/main/java/com/leinardi/android/speeddial/sample/usecases/UseCase1Activity.kt
@@ -14,13 +14,10 @@
  * limitations under the License.
  */
 
-package com.leinardi.android.speeddial.sample.usecases;
+package com.leinardi.android.speeddial.sample.usecases
 
-import com.leinardi.android.speeddial.sample.R;
+import com.leinardi.android.speeddial.sample.R
 
-public class UseCase1Activity extends BaseUseCaseActivity {
-    @Override
-    protected int getLayoutRes() {
-        return R.layout.activity_use_case_1;
-    }
+class UseCase1Activity : BaseUseCaseActivity() {
+    override val layoutRes = R.layout.activity_use_case_1
 }
diff --git a/sample/src/main/java/com/leinardi/android/speeddial/sample/usecases/UseCasesActivity.java b/sample/src/main/java/com/leinardi/android/speeddial/sample/usecases/UseCasesActivity.java
deleted file mode 100644
index 10cde11e..00000000
--- a/sample/src/main/java/com/leinardi/android/speeddial/sample/usecases/UseCasesActivity.java
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright 2019 Roberto Leinardi.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package com.leinardi.android.speeddial.sample.usecases;
-
-import android.content.Intent;
-import android.os.Bundle;
-import androidx.appcompat.app.AppCompatActivity;
-import androidx.appcompat.widget.Toolbar;
-
-import com.leinardi.android.speeddial.SpeedDialActionItem;
-import com.leinardi.android.speeddial.SpeedDialView;
-import com.leinardi.android.speeddial.sample.R;
-
-public class UseCasesActivity extends AppCompatActivity {
-
-    @Override
-    protected void onCreate(Bundle savedInstanceState) {
-        super.onCreate(savedInstanceState);
-        setContentView(R.layout.activity_use_cases);
-        Toolbar toolbar = findViewById(R.id.toolbar);
-        setSupportActionBar(toolbar);
-
-        SpeedDialView speedDialView = findViewById(R.id.speedDial);
-
-        speedDialView.inflate(R.menu.menu_use_cases);
-        speedDialView.open();
-
-        speedDialView.setOnActionSelectedListener(new SpeedDialView.OnActionSelectedListener() {
-            @Override
-            public boolean onActionSelected(SpeedDialActionItem actionItem) {
-                startActivity(new Intent(UseCasesActivity.this, UseCase1Activity.class));
-                return true;
-            }
-        });
-    }
-}
diff --git a/sample/src/main/java/com/leinardi/android/speeddial/sample/usecases/UseCasesActivity.kt b/sample/src/main/java/com/leinardi/android/speeddial/sample/usecases/UseCasesActivity.kt
new file mode 100644
index 00000000..e4050034
--- /dev/null
+++ b/sample/src/main/java/com/leinardi/android/speeddial/sample/usecases/UseCasesActivity.kt
@@ -0,0 +1,40 @@
+/*
+ * Copyright 2019 Roberto Leinardi.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.leinardi.android.speeddial.sample.usecases
+
+import android.content.Intent
+import android.os.Bundle
+import androidx.appcompat.app.AppCompatActivity
+import androidx.appcompat.widget.Toolbar
+import com.leinardi.android.speeddial.SpeedDialView
+import com.leinardi.android.speeddial.sample.R
+
+class UseCasesActivity : AppCompatActivity() {
+
+    override fun onCreate(savedInstanceState: Bundle?) {
+        super.onCreate(savedInstanceState)
+        setContentView(R.layout.activity_use_cases)
+        setSupportActionBar(findViewById<Toolbar>(R.id.toolbar))
+        val speedDialView = findViewById<SpeedDialView>(R.id.speedDial)
+        speedDialView.inflate(R.menu.menu_use_cases)
+        speedDialView.open()
+        speedDialView.setOnActionSelectedListener {
+            startActivity(Intent(this@UseCasesActivity, UseCase1Activity::class.java))
+            true
+        }
+    }
+}