diff --git a/conductor/src/main/java/com/bluelinelabs/conductor/internal/ViewAttachHandler.java b/conductor/src/main/java/com/bluelinelabs/conductor/internal/ViewAttachHandler.java
deleted file mode 100644
index 8d7064f7..00000000
--- a/conductor/src/main/java/com/bluelinelabs/conductor/internal/ViewAttachHandler.java
+++ /dev/null
@@ -1,151 +0,0 @@
-package com.bluelinelabs.conductor.internal;
-
-import android.view.View;
-import android.view.View.OnAttachStateChangeListener;
-import android.view.ViewGroup;
-
-public class ViewAttachHandler implements OnAttachStateChangeListener {
-
-    private enum ReportedState {
-        VIEW_DETACHED,
-        ACTIVITY_STOPPED,
-        ATTACHED
-    }
-
-    public interface ViewAttachListener {
-        void onAttached();
-        void onDetached(boolean fromActivityStop);
-        void onViewDetachAfterStop();
-    }
-
-    private interface ChildAttachListener {
-        void onAttached();
-    }
-
-    private boolean rootAttached = false;
-    boolean childrenAttached = false;
-    private boolean activityStopped = false;
-    private ReportedState reportedState = ReportedState.VIEW_DETACHED;
-    private ViewAttachListener attachListener;
-    OnAttachStateChangeListener childOnAttachStateChangeListener;
-
-    public ViewAttachHandler(ViewAttachListener attachListener) {
-        this.attachListener = attachListener;
-    }
-
-    @Override
-    public void onViewAttachedToWindow(final View v) {
-        if (rootAttached) {
-            return;
-        }
-
-        rootAttached = true;
-        listenForDeepestChildAttach(v, new ChildAttachListener() {
-            @Override
-            public void onAttached() {
-                childrenAttached = true;
-                reportAttached();
-            }
-        });
-    }
-
-    @Override
-    public void onViewDetachedFromWindow(View v) {
-        rootAttached = false;
-        if (childrenAttached) {
-            childrenAttached = false;
-            reportDetached(false);
-        }
-    }
-
-    public void listenForAttach(final View view) {
-        view.addOnAttachStateChangeListener(this);
-    }
-
-    public void unregisterAttachListener(View view) {
-        view.removeOnAttachStateChangeListener(this);
-
-        if (childOnAttachStateChangeListener != null && view instanceof ViewGroup) {
-            findDeepestChild((ViewGroup)view).removeOnAttachStateChangeListener(childOnAttachStateChangeListener);
-            childOnAttachStateChangeListener = null;
-        }
-    }
-
-    public void onActivityStarted() {
-        activityStopped = false;
-        reportAttached();
-    }
-
-    public void onActivityStopped() {
-        activityStopped = true;
-        reportDetached(true);
-    }
-
-    void reportAttached() {
-        if (rootAttached && childrenAttached && !activityStopped && reportedState != ReportedState.ATTACHED) {
-            reportedState = ReportedState.ATTACHED;
-            attachListener.onAttached();
-        }
-    }
-
-    private void reportDetached(boolean detachedForActivity) {
-        boolean wasDetachedForActivity = reportedState == ReportedState.ACTIVITY_STOPPED;
-
-        if (detachedForActivity) {
-            reportedState = ReportedState.ACTIVITY_STOPPED;
-        } else {
-            reportedState = ReportedState.VIEW_DETACHED;
-        }
-
-        if (wasDetachedForActivity && !detachedForActivity) {
-            attachListener.onViewDetachAfterStop();
-        } else {
-            attachListener.onDetached(detachedForActivity);
-        }
-    }
-
-    private void listenForDeepestChildAttach(final View view, final ChildAttachListener attachListener) {
-        if (!(view instanceof ViewGroup)) {
-            attachListener.onAttached();
-            return;
-        }
-
-        ViewGroup viewGroup = (ViewGroup)view;
-        if (viewGroup.getChildCount() == 0) {
-            attachListener.onAttached();
-            return;
-        }
-
-        childOnAttachStateChangeListener = new OnAttachStateChangeListener() {
-            boolean attached = false;
-
-            @Override
-            public void onViewAttachedToWindow(View v) {
-                if (!attached && childOnAttachStateChangeListener != null) {
-                    attached = true;
-                    attachListener.onAttached();
-                    v.removeOnAttachStateChangeListener(this);
-                    childOnAttachStateChangeListener = null;
-                }
-            }
-
-            @Override
-            public void onViewDetachedFromWindow(View v) { }
-        };
-        findDeepestChild(viewGroup).addOnAttachStateChangeListener(childOnAttachStateChangeListener);
-    }
-
-    private View findDeepestChild(ViewGroup viewGroup) {
-        if (viewGroup.getChildCount() == 0) {
-            return viewGroup;
-        }
-
-        View lastChild = viewGroup.getChildAt(viewGroup.getChildCount() - 1);
-        if (lastChild instanceof ViewGroup) {
-            return findDeepestChild((ViewGroup)lastChild);
-        } else {
-            return lastChild;
-        }
-    }
-
-}
diff --git a/conductor/src/main/java/com/bluelinelabs/conductor/internal/ViewAttachHandler.kt b/conductor/src/main/java/com/bluelinelabs/conductor/internal/ViewAttachHandler.kt
new file mode 100644
index 00000000..6c3a8091
--- /dev/null
+++ b/conductor/src/main/java/com/bluelinelabs/conductor/internal/ViewAttachHandler.kt
@@ -0,0 +1,130 @@
+package com.bluelinelabs.conductor.internal
+
+import android.view.View
+import android.view.ViewGroup
+
+class ViewAttachHandler(private val attachListener: ViewAttachListener) : View.OnAttachStateChangeListener {
+    private enum class ReportedState {
+        VIEW_DETACHED, ACTIVITY_STOPPED, ATTACHED
+    }
+
+    interface ViewAttachListener {
+        fun onAttached()
+        fun onDetached(fromActivityStop: Boolean)
+        fun onViewDetachAfterStop()
+    }
+
+    private interface ChildAttachListener {
+        fun onAttached()
+    }
+
+    private var rootAttached = false
+    private var activityStopped = false
+    private var reportedState = ReportedState.VIEW_DETACHED
+
+    var childrenAttached = false
+    var childOnAttachStateChangeListener: View.OnAttachStateChangeListener? = null
+
+    override fun onViewAttachedToWindow(v: View) {
+        if (rootAttached) {
+            return
+        }
+        rootAttached = true
+        listenForDeepestChildAttach(v, object : ChildAttachListener {
+            override fun onAttached() {
+                childrenAttached = true
+                reportAttached()
+            }
+        })
+    }
+
+    override fun onViewDetachedFromWindow(v: View) {
+        rootAttached = false
+        if (childrenAttached) {
+            childrenAttached = false
+            reportDetached(false)
+        }
+    }
+
+    fun listenForAttach(view: View) {
+        view.addOnAttachStateChangeListener(this)
+    }
+
+    fun unregisterAttachListener(view: View) {
+        view.removeOnAttachStateChangeListener(this)
+        val childOnAttachStateChangeListener = childOnAttachStateChangeListener ?: return
+        if (view is ViewGroup) {
+            findDeepestChild(view).removeOnAttachStateChangeListener(childOnAttachStateChangeListener)
+            this.childOnAttachStateChangeListener = null
+        }
+    }
+
+    fun onActivityStarted() {
+        activityStopped = false
+        reportAttached()
+    }
+
+    fun onActivityStopped() {
+        activityStopped = true
+        reportDetached(true)
+    }
+
+    fun reportAttached() {
+        if (rootAttached && childrenAttached && !activityStopped && reportedState != ReportedState.ATTACHED) {
+            reportedState = ReportedState.ATTACHED
+            attachListener.onAttached()
+        }
+    }
+
+    private fun reportDetached(detachedForActivity: Boolean) {
+        val wasDetachedForActivity = reportedState == ReportedState.ACTIVITY_STOPPED
+
+        reportedState = if (detachedForActivity) ReportedState.ACTIVITY_STOPPED else ReportedState.VIEW_DETACHED
+
+        if (wasDetachedForActivity && !detachedForActivity) {
+            attachListener.onViewDetachAfterStop()
+        } else {
+            attachListener.onDetached(detachedForActivity)
+        }
+    }
+
+    private fun listenForDeepestChildAttach(view: View, attachListener: ChildAttachListener) {
+        if (view !is ViewGroup) {
+            attachListener.onAttached()
+            return
+        }
+
+        if (view.childCount == 0) {
+            attachListener.onAttached()
+            return
+        }
+
+        childOnAttachStateChangeListener = object : View.OnAttachStateChangeListener {
+            var attached = false
+            override fun onViewAttachedToWindow(v: View) {
+                if (!attached && childOnAttachStateChangeListener != null) {
+                    attached = true
+                    attachListener.onAttached()
+                    v.removeOnAttachStateChangeListener(this)
+                    childOnAttachStateChangeListener = null
+                }
+            }
+
+            override fun onViewDetachedFromWindow(v: View) {}
+        }
+        findDeepestChild(view).addOnAttachStateChangeListener(childOnAttachStateChangeListener)
+    }
+
+    private fun findDeepestChild(viewGroup: ViewGroup): View {
+        if (viewGroup.childCount == 0) {
+            return viewGroup
+        }
+        val lastChild = viewGroup.getChildAt(viewGroup.childCount - 1)
+        return if (lastChild is ViewGroup) {
+            findDeepestChild(lastChild)
+        } else {
+            lastChild
+        }
+    }
+
+}