Autofill kotlin sample: Improve kotlin style.

Bug: 38182790
Test: manual

Change-Id: I8250c1de268f2dcff7f3aca459a1a6c0a484a844

16 files changed, 221 insertions, 205 deletions

diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/CommonUtil.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/CommonUtil.kt
index e2839e92..c64a6707 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/CommonUtil.kt
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/CommonUtil.kt
@@ -16,6 +16,8 @@
 package com.example.android.autofillframework
 
 import android.os.Bundle
+import com.google.gson.Gson
+import com.google.gson.GsonBuilder
 import java.util.Arrays
 
 object CommonUtil {
@@ -49,4 +51,8 @@ object CommonUtil {
         bundleToString(builder, data)
         return builder.toString()
     }
+
+    fun createGson(): Gson {
+        return GsonBuilder().excludeFieldsWithoutExposeAnnotation().setPrettyPrinting().create()
+    }
 }
\ No newline at end of file
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/CreditCardActivity.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/CreditCardActivity.kt
index c8136ed3..88e28b44 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/CreditCardActivity.kt
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/CreditCardActivity.kt
@@ -34,30 +34,31 @@ class CreditCardActivity : AppCompatActivity() {
 
     private val CC_EXP_YEARS_COUNT = 5
 
-    private val years: Array<CharSequence?> = arrayOfNulls<CharSequence>(CC_EXP_YEARS_COUNT)
-
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.credit_card_activity)
 
         // Create an ArrayAdapter using the string array and a default spinner layout
-        val dayAdapter = ArrayAdapter.createFromResource(this, R.array.day_array, android.R.layout.simple_spinner_item)
-        // Specify the layout to use when the list of choices appears
-        dayAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item)
-        // Apply the adapter to the spinner
-        expirationDay.adapter = dayAdapter
+        expirationDay.adapter = ArrayAdapter.createFromResource(this, R.array.day_array,
+                android.R.layout.simple_spinner_item).apply {
+            // Specify the layout to use when the list of choices appears
+            setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item)
+        }
 
-        val monthAdapter = ArrayAdapter.createFromResource(this, R.array.month_array, android.R.layout.simple_spinner_item)
-        monthAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item)
-        expirationMonth.adapter = monthAdapter
+        expirationMonth.adapter = ArrayAdapter.createFromResource(this, R.array.month_array,
+                android.R.layout.simple_spinner_item).apply {
+            setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item)
+        }
 
         val year = Calendar.getInstance().get(Calendar.YEAR)
-        for (i in years.indices) {
-            years[i] = Integer.toString(year + i)
-        }
-        expirationYear.adapter =
-                object : ArrayAdapter<CharSequence?>(this, android.R.layout.simple_spinner_item, years) {
-                    override fun getAutofillOptions(): Array<CharSequence?> {
+
+        val years = (0 until CC_EXP_YEARS_COUNT)
+                .map {Integer.toString(year + it)}
+                .toTypedArray<CharSequence>()
+
+        expirationYear.adapter = object : ArrayAdapter<CharSequence?>(this,
+                android.R.layout.simple_spinner_item, years) {
+                    override fun getAutofillOptions(): Array<CharSequence> {
                         return years
                     }
                 }
@@ -77,15 +78,12 @@ class CreditCardActivity : AppCompatActivity() {
      * any new data.
      */
     private fun submitCcInfo() {
-        val intent = WelcomeActivity.getStartActivityIntent(this)
-        startActivity(intent)
+        startActivity(WelcomeActivity.getStartActivityIntent(this))
         finish()
     }
 
     companion object {
-        fun getStartActivityIntent(context: Context): Intent {
-            val intent = Intent(context, CreditCardActivity::class.java)
-            return intent
-        }
+        fun getStartActivityIntent(context: Context) =
+                Intent(context, CreditCardActivity::class.java)
     }
 }
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/CustomVirtualView.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/CustomVirtualView.kt
index c737fe4c..36c43439 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/CustomVirtualView.kt
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/CustomVirtualView.kt
@@ -21,7 +21,6 @@ import android.graphics.Color
 import android.graphics.Paint
 import android.graphics.Paint.Style
 import android.graphics.Rect
-import android.text.TextUtils
 import android.util.AttributeSet
 import android.util.Log
 import android.util.SparseArray
@@ -32,6 +31,7 @@ import android.view.autofill.AutofillManager
 import android.view.autofill.AutofillValue
 import android.widget.EditText
 import android.widget.TextView
+import com.example.android.autofillframework.CommonUtil.TAG
 import com.example.android.autofillframework.CommonUtil.bundleToString
 import com.example.android.autofillframework.R
 import java.util.Arrays
@@ -42,33 +42,30 @@ import java.util.Arrays
  */
 class CustomVirtualView(context: Context, attrs: AttributeSet) : View(context, attrs) {
 
-    private val mLines = ArrayList<Line>()
-    private val mItems = SparseArray<Item>()
-    private val mAfm: AutofillManager = context.getSystemService(AutofillManager::class.java)
-
-    private var mFocusedLine: Line? = null
-    private val mTextPaint: Paint = Paint()
-    private val mTextHeight: Int = 90
-    private val mTopMargin: Int = 100
-    private val mLeftMargin: Int = 100
-    private val mVerticalGap: Int = 10
-    private val mLineLength: Int = mTextHeight + mVerticalGap
-    private val mFocusedColor: Int = Color.RED
-    private val mUnfocusedColor: Int = Color.BLACK
-
-    private val mUsernameLine: Line
-    private val mPasswordLine: Line
-
-    init {
-        mTextPaint.style = Style.FILL
-        mTextPaint.textSize = mTextHeight.toFloat()
-        mUsernameLine = addLine("usernameField", context.getString(R.string.username_label),
-                arrayOf(View.AUTOFILL_HINT_USERNAME), "         ", true)
-        mPasswordLine = addLine("passwordField", context.getString(R.string.password_label),
-                arrayOf(View.AUTOFILL_HINT_PASSWORD), "         ", false)
-
-        Log.d(TAG, "Text height: " + mTextHeight)
+    val usernameText: CharSequence
+        get() = usernameLine.fieldTextItem.text
+    val passwordText: CharSequence
+        get() = passwordLine.fieldTextItem.text
+    private var nextId: Int = 0
+    private val lines = ArrayList<Line>()
+    private val items = SparseArray<Item>()
+    private val autofillManager = context.getSystemService(AutofillManager::class.java)
+    private var focusedLine: Line? = null
+    private val textHeight = 90
+    private val textPaint = Paint().apply {
+        style = Style.FILL
+        textSize = textHeight.toFloat()
     }
+    private val topMargin = 100
+    private val leftMargin = 100
+    private val verticalGap = 10
+    private val lineLength = textHeight + verticalGap
+    private val focusedColor = Color.RED
+    private val unfocusedColor = Color.BLACK
+    private val usernameLine = addLine("usernameField", context.getString(R.string.username_label),
+            arrayOf(View.AUTOFILL_HINT_USERNAME), "         ", true)
+    private val passwordLine = addLine("passwordField", context.getString(R.string.password_label),
+            arrayOf(View.AUTOFILL_HINT_PASSWORD), "         ", false)
 
     override fun autofill(values: SparseArray<AutofillValue>) {
         // User has just selected a Dataset from the list of autofill suggestions.
@@ -76,15 +73,15 @@ class CustomVirtualView(context: Context, attrs: AttributeSet) : View(context, a
         // to fill a specific autofillable view. Now we have to update the UI based on the
         // AutofillValues in the list.
         Log.d(TAG, "autofill(): " + values)
-        for (i in 0..values.size() - 1) {
+        for (i in 0 until values.size()) {
             val id = values.keyAt(i)
             val value = values.valueAt(i)
-            mItems[id]?.let { item ->
-                if (item.editable) {
+            items[id]?.apply {
+                if (editable) {
                     // Set the item's text to the text wrapped in the AutofillValue.
-                    item.text = value.textValue
+                    text = value.textValue
                 } else {
-                    Log.w(TAG, "Item for autofillId $id is not editable: $item")
+                    Log.w(TAG, "Item for autofillId $id is not editable: $this")
                 }
             }
         }
@@ -94,24 +91,23 @@ class CustomVirtualView(context: Context, attrs: AttributeSet) : View(context, a
     override fun onProvideAutofillVirtualStructure(structure: ViewStructure, flags: Int) {
         // Build a ViewStructure to pack in AutoFillService requests.
         structure.setClassName(javaClass.name)
-        val childrenSize = mItems.size()
+        val childrenSize = items.size()
         Log.d(TAG, "onProvideAutofillVirtualStructure(): flags = " + flags + ", items = "
                 + childrenSize + ", extras: " + bundleToString(structure.extras))
         var index = structure.addChildCount(childrenSize)
-        for (i in 0..childrenSize - 1) {
-            val item = mItems.valueAt(i)
+        for (i in 0 until childrenSize) {
+            val item = items.valueAt(i)
             Log.d(TAG, "Adding new child at index $index: $item")
-            val child = structure.newChild(index)
-            child.setAutofillId(structure.getAutofillId(), item.id)
-            child.setAutofillHints(item.hints)
-            child.setAutofillType(item.type)
-            child.setDataIsSensitive(!item.sanitized)
-            if (TextUtils.getTrimmedLength(item.text) > 0) {
-                child.setAutofillValue(AutofillValue.forText(item.text))
+            structure.newChild(index).apply {
+                setAutofillId(structure.autofillId, item.id)
+                setAutofillHints(item.hints)
+                setAutofillType(item.type)
+                setDataIsSensitive(!item.sanitized)
+                setAutofillValue(AutofillValue.forText(item.text))
+                setFocused(item.focused)
+                setId(item.id, context.packageName, null, item.line.idEntry)
+                setClassName(item.className)
             }
-            child.setFocused(item.focused)
-            child.setId(item.id, context.packageName, null, item.line.idEntry)
-            child.setClassName(item.className)
             index++
         }
     }
@@ -119,74 +115,71 @@ class CustomVirtualView(context: Context, attrs: AttributeSet) : View(context, a
     override fun onDraw(canvas: Canvas) {
         super.onDraw(canvas)
 
-        Log.d(TAG, "onDraw: " + mLines.size + " lines; canvas:" + canvas)
+        Log.d(TAG, "onDraw: " + lines.size + " lines; canvas:" + canvas)
         var x: Float
-        var y = (mTopMargin + mLineLength).toFloat()
-        for (line in mLines) {
-            x = mLeftMargin.toFloat()
-            Log.v(TAG, "Drawing '" + line + "' at " + x + "x" + y)
-            mTextPaint.color = if (line.fieldTextItem.focused) mFocusedColor else mUnfocusedColor
-            val readOnlyText = line.labelItem.text.toString() + ":  ["
-            val writeText = line.fieldTextItem.text.toString() + "]"
+        var y = (topMargin + lineLength).toFloat()
+
+        lines.forEach {
+            x = leftMargin.toFloat()
+            Log.v(TAG, "Drawing $it at x=$x, y=$y")
+            textPaint.color = if (it.fieldTextItem.focused) focusedColor else unfocusedColor
+            val readOnlyText = it.labelItem.text.toString() + ":  ["
+            val writeText = it.fieldTextItem.text.toString() + "]"
             // Paints the label first...
-            canvas.drawText(readOnlyText, x, y, mTextPaint)
+            canvas.drawText(readOnlyText, x, y, textPaint)
             // ...then paints the edit text and sets the proper boundary
-            val deltaX = mTextPaint.measureText(readOnlyText)
+            val deltaX = textPaint.measureText(readOnlyText)
             x += deltaX
-            line.bounds.set(x.toInt(), (y - mLineLength).toInt(),
-                    (x + mTextPaint.measureText(writeText)).toInt(), y.toInt())
-            Log.d(TAG, "setBounds(" + x + ", " + y + "): " + line.bounds)
-            canvas.drawText(writeText, x, y, mTextPaint)
-            y += mLineLength.toFloat()
+            it.bounds.set(x.toInt(), (y - lineLength).toInt(),
+                    (x + textPaint.measureText(writeText)).toInt(), y.toInt())
+            Log.d(TAG, "setBounds(" + x + ", " + y + "): " + it.bounds)
+            canvas.drawText(writeText, x, y, textPaint)
+            y += lineLength.toFloat()
         }
     }
 
     override fun onTouchEvent(event: MotionEvent): Boolean {
         val y = event.y.toInt()
-        Log.d(TAG, "Touched: y=$y, range=$mLineLength, top=$mTopMargin")
-        var lowerY = mTopMargin
+        Log.d(TAG, "Touched: y=$y, range=$lineLength, top=$topMargin")
+        var lowerY = topMargin
         var upperY = -1
-        for (i in mLines.indices) {
-            upperY = lowerY + mLineLength
-            val line = mLines[i]
-            Log.d(TAG, "Line $i ranges from $lowerY to $upperY")
-            if (lowerY <= y && y <= upperY) {
-                Log.d(TAG, "Removing focus from " + mFocusedLine)
-                mFocusedLine?.changeFocus(false)
+        for (line in lines) {
+            upperY = lowerY + lineLength
+            Log.d(TAG, "Line $line ranges from $lowerY to $upperY")
+            if (y in lowerY..upperY) {
+                Log.d(TAG, "Removing focus from " + focusedLine)
+                focusedLine?.changeFocus(false)
                 Log.d(TAG, "Changing focus to " + line)
-                mFocusedLine = line
-                mFocusedLine?.changeFocus(true)
+                focusedLine = line.apply { changeFocus(true) }
                 invalidate()
                 break
             }
-            lowerY += mLineLength
+            lowerY += lineLength
         }
         return super.onTouchEvent(event)
     }
 
-    val usernameText: CharSequence
-        get() = mUsernameLine.fieldTextItem.text
-
-    val passwordText: CharSequence
-        get() = mPasswordLine.fieldTextItem.text
-
     fun resetFields() {
-        mUsernameLine.reset()
-        mPasswordLine.reset()
+        usernameLine.reset()
+        passwordLine.reset()
         postInvalidate()
     }
 
-    private fun addLine(idEntry: String, label: String, hints: Array<String>, text: String, sanitized: Boolean): Line {
-        val line = Line(idEntry, label, hints, text, sanitized)
-        mLines.add(line)
-        mItems.put(line.labelItem.id, line.labelItem)
-        mItems.put(line.fieldTextItem.id, line.fieldTextItem)
-        return line
+    private fun addLine(idEntry: String, label: String, hints: Array<String>, text: String,
+            sanitized: Boolean) = Line(idEntry, label, hints, text, sanitized).also {
+        lines.add(it)
+        items.apply {
+            put(it.labelItem.id, it.labelItem)
+            put(it.fieldTextItem.id, it.fieldTextItem)
+        }
     }
 
-    private class Item internal constructor(val line: Line, val id: Int, val hints: Array<String>?,
-            val type: Int, var text: CharSequence,
-            val editable: Boolean, val sanitized: Boolean) {
+    private inner class Item internal constructor(
+            val line: Line,
+            val id: Int,
+            val hints: Array<String>?,
+            val type: Int, var text: CharSequence, val editable: Boolean,
+            val sanitized: Boolean) {
         var focused = false
 
         override fun toString(): String {
@@ -213,15 +206,15 @@ class CustomVirtualView(context: Context, attrs: AttributeSet) : View(context, a
             if (focused) {
                 val absBounds = absCoordinates
                 Log.d(TAG, "focus gained on " + fieldTextItem.id + "; absBounds=" + absBounds)
-                mAfm.notifyViewEntered(this@CustomVirtualView, fieldTextItem.id, absBounds)
+                autofillManager.notifyViewEntered(this@CustomVirtualView, fieldTextItem.id, absBounds)
             } else {
                 Log.d(TAG, "focus lost on " + fieldTextItem.id)
-                mAfm.notifyViewExited(this@CustomVirtualView, fieldTextItem.id)
+                autofillManager.notifyViewExited(this@CustomVirtualView, fieldTextItem.id)
             }
         }
 
-        private // Must offset the boundaries so they're relative to the CustomView.
-        val absCoordinates: Rect
+        private val absCoordinates: Rect
+                // Must offset the boundaries so they're relative to the CustomView.
             get() {
                 val offset = IntArray(2)
                 getLocationOnScreen(offset)
@@ -242,11 +235,4 @@ class CustomVirtualView(context: Context, attrs: AttributeSet) : View(context, a
                     fieldTextItem.focused
         }
     }
-
-    companion object {
-
-        private val TAG = "CustomView"
-
-        private var nextId: Int = 0
-    }
 }
\ No newline at end of file
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/InfoButton.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/InfoButton.kt
index 3a2c0e3d..5b480b8d 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/InfoButton.kt
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/InfoButton.kt
@@ -21,8 +21,11 @@ import android.support.v7.widget.AppCompatImageButton
 import android.util.AttributeSet
 import com.example.android.autofillframework.R
 
-class InfoButton @JvmOverloads constructor(context: Context, attrs: AttributeSet? = null,
-        defStyleAttr: Int = 0) : AppCompatImageButton(context, attrs, defStyleAttr) {
+class InfoButton @JvmOverloads constructor(
+        context: Context,
+        attrs: AttributeSet? = null,
+        defStyleAttr: Int = 0
+) : AppCompatImageButton(context, attrs, defStyleAttr) {
 
     init {
         val typedArray = context.obtainStyledAttributes(attrs, R.styleable.InfoButton,
@@ -34,8 +37,7 @@ class InfoButton @JvmOverloads constructor(context: Context, attrs: AttributeSet
 
     fun setInfoText(infoText: String) {
         setOnClickListener {
-            AlertDialog.Builder(this@InfoButton.context)
-                    .setMessage(infoText).create().show()
+            AlertDialog.Builder(this@InfoButton.context).setMessage(infoText).create().show()
         }
     }
 }
\ No newline at end of file
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/NavigationItem.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/NavigationItem.kt
index 0701e146..be09a99a 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/NavigationItem.kt
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/NavigationItem.kt
@@ -29,8 +29,11 @@ import kotlinx.android.synthetic.main.navigation_item.view.buttonLabel
 import kotlinx.android.synthetic.main.navigation_item.view.cardView
 import kotlinx.android.synthetic.main.navigation_item.view.infoButton
 
-class NavigationItem @JvmOverloads constructor(context: Context, attrs: AttributeSet? = null,
-        defStyleAttr: Int = 0) : FrameLayout(context, attrs, defStyleAttr) {
+class NavigationItem @JvmOverloads constructor(
+        context: Context,
+        attrs: AttributeSet? = null,
+        defStyleAttr: Int = 0
+) : FrameLayout(context, attrs, defStyleAttr) {
 
     init {
         val typedArray = context.obtainStyledAttributes(attrs, R.styleable.NavigationItem,
@@ -43,13 +46,17 @@ class NavigationItem @JvmOverloads constructor(context: Context, attrs: Attribut
         typedArray.recycle()
         LayoutInflater.from(context).inflate(R.layout.navigation_item, this)
         logoDrawable?.setColorFilter(imageColor, PorterDuff.Mode.SRC_IN)
-        buttonLabel.text = labelText
-        buttonLabel.setCompoundDrawablesRelativeWithIntrinsicBounds(logoDrawable, null, null, null)
-        infoButton.setOnClickListener {
-            AlertDialog.Builder(this@NavigationItem.context)
-                    .setMessage(infoText).create().show()
+        buttonLabel.apply {
+            text = labelText
+            setCompoundDrawablesRelativeWithIntrinsicBounds(logoDrawable, null, null, null)
+        }
+        infoButton.apply {
+            setOnClickListener {
+                AlertDialog.Builder(this@NavigationItem.context)
+                        .setMessage(infoText).create().show()
+            }
+            setColorFilter(imageColor)
         }
-        infoButton.setColorFilter(imageColor)
     }
 
     fun setNavigationButtonClickListener(l: View.OnClickListener?) {
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/StandardAutoCompleteSignInActivity.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/StandardAutoCompleteSignInActivity.kt
index 21eb4d70..2e154fbf 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/StandardAutoCompleteSignInActivity.kt
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/app/StandardAutoCompleteSignInActivity.kt
@@ -33,9 +33,9 @@ import kotlinx.android.synthetic.main.login_with_autocomplete_activity.passwordF
 import kotlinx.android.synthetic.main.login_with_autocomplete_activity.usernameField
 
 class StandardAutoCompleteSignInActivity : AppCompatActivity() {
-    private var mAutofillReceived = false
-    private var mAutofillCallback: AutofillManager.AutofillCallback? = null
-    private var mAutofillManager: AutofillManager? = null
+    private var autofillReceived = false
+    private lateinit var autofillCallback: AutofillManager.AutofillCallback
+    private lateinit var autofillManager: AutofillManager
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -44,8 +44,8 @@ class StandardAutoCompleteSignInActivity : AppCompatActivity() {
 
         login.setOnClickListener { submitLogin() }
         clear.setOnClickListener { resetFields() }
-        mAutofillCallback = MyAutofillCallback()
-        mAutofillManager = getSystemService(AutofillManager::class.java)
+        autofillCallback = MyAutofillCallback()
+        autofillManager = getSystemService(AutofillManager::class.java)
         val mockAutocompleteAdapter = ArrayAdapter.createFromResource(this, R.array.mock_autocomplete_sign_in_suggestions,
                 android.R.layout.simple_dropdown_item_1line)
         usernameField.setAdapter(mockAutocompleteAdapter)
@@ -53,12 +53,12 @@ class StandardAutoCompleteSignInActivity : AppCompatActivity() {
 
     override fun onResume() {
         super.onResume()
-        mAutofillManager?.registerCallback(mAutofillCallback)
+        autofillManager.registerCallback(autofillCallback)
     }
 
     override fun onPause() {
         super.onPause()
-        mAutofillManager?.unregisterCallback(mAutofillCallback)
+        autofillManager.unregisterCallback(autofillCallback)
     }
 
     private fun resetFields() {
@@ -96,11 +96,13 @@ class StandardAutoCompleteSignInActivity : AppCompatActivity() {
             if (view is AutoCompleteTextView) {
                 when (event) {
                     AutofillManager.AutofillCallback.EVENT_INPUT_UNAVAILABLE,
-                    AutofillManager.AutofillCallback.EVENT_INPUT_HIDDEN -> if (!mAutofillReceived) {
-                        view.showDropDown()
+                    AutofillManager.AutofillCallback.EVENT_INPUT_HIDDEN -> {
+                        if (!autofillReceived) {
+                            view.showDropDown()
+                        }
                     }
                     AutofillManager.AutofillCallback.EVENT_INPUT_SHOWN -> {
-                        mAutofillReceived = true
+                        autofillReceived = true
                         view.setAdapter(null)
                     }
                     else -> Log.d(TAG, "Unexpected callback: " + event)
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/AuthActivity.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/AuthActivity.kt
index eea17992..e02a311a 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/AuthActivity.kt
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/AuthActivity.kt
@@ -46,7 +46,7 @@ import kotlinx.android.synthetic.main.multidataset_service_auth_activity.master_
  */
 class AuthActivity : AppCompatActivity() {
 
-    private var mReplyIntent: Intent? = null
+    private var replyIntent: Intent? = null
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
@@ -70,8 +70,8 @@ class AuthActivity : AppCompatActivity() {
     }
 
     override fun finish() {
-        if (mReplyIntent != null) {
-            setResult(Activity.RESULT_OK, mReplyIntent)
+        if (replyIntent != null) {
+            setResult(Activity.RESULT_OK, replyIntent)
         } else {
             setResult(Activity.RESULT_CANCELED)
         }
@@ -80,7 +80,7 @@ class AuthActivity : AppCompatActivity() {
 
     private fun onFailure() {
         Log.w(TAG, "Failed auth.")
-        mReplyIntent = null
+        replyIntent = null
     }
 
     private fun onSuccess() {
@@ -90,7 +90,7 @@ class AuthActivity : AppCompatActivity() {
         val parser = StructureParser(structure)
         parser.parseForFill()
         val autofillFields = parser.autofillFields
-        mReplyIntent = Intent()
+        replyIntent = Intent()
         val clientFormDataMap = SharedPrefsAutofillRepository
                 .getFilledAutofillFieldCollection(this, autofillFields.focusedAutofillHints, autofillFields.allAutofillHints)
         if (forResponse) {
@@ -106,11 +106,11 @@ class AuthActivity : AppCompatActivity() {
     }
 
     private fun setResponseIntent(fillResponse: FillResponse) {
-        mReplyIntent?.putExtra(EXTRA_AUTHENTICATION_RESULT, fillResponse)
+        replyIntent?.putExtra(EXTRA_AUTHENTICATION_RESULT, fillResponse)
     }
 
     private fun setDatasetIntent(dataset: Dataset) {
-        mReplyIntent?.putExtra(EXTRA_AUTHENTICATION_RESULT, dataset)
+        replyIntent?.putExtra(EXTRA_AUTHENTICATION_RESULT, dataset)
     }
 
     companion object {
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/AutofillFieldMetadata.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/AutofillFieldMetadata.kt
index f894a18b..bf12c574 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/AutofillFieldMetadata.kt
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/AutofillFieldMetadata.kt
@@ -28,7 +28,7 @@ class AutofillFieldMetadata(view: ViewNode) {
     var saveType = 0
         private set
 
-    val autofillHints: Array<String> = view.autofillHints.filter(AutofillHelper::isValidHint).toTypedArray()
+    val autofillHints = view.autofillHints.filter(AutofillHelper::isValidHint).toTypedArray()
     val autofillId: AutofillId = view.autofillId
     val autofillType: Int = view.autofillType
     val autofillOptions: Array<CharSequence>? = view.autofillOptions
@@ -42,8 +42,12 @@ class AutofillFieldMetadata(view: ViewNode) {
      * When the [ViewNode] is a list that the user needs to choose a string from (i.e. a spinner),
      * this is called to return the index of a specific item in the list.
      */
-    fun getAutofillOptionIndex(value: CharSequence): Int? {
-        return autofillOptions?.indexOf(value)
+    fun getAutofillOptionIndex(value: CharSequence): Int {
+        if (autofillOptions != null) {
+            return autofillOptions.indexOf(value)
+        } else {
+            return -1
+        }
     }
 
     private fun updateSaveTypeFromHints() {
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/AutofillFieldMetadataCollection.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/AutofillFieldMetadataCollection.kt
index 4aa3e1fd..1044ec78 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/AutofillFieldMetadataCollection.kt
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/AutofillFieldMetadataCollection.kt
@@ -21,11 +21,13 @@ import android.view.autofill.AutofillId
  * Data structure that stores a collection of `AutofillFieldMetadata`s. Contains all of the client's `View`
  * hierarchy autofill-relevant metadata.
  */
-data class AutofillFieldMetadataCollection(val autofillIds: java.util.ArrayList<AutofillId> = java.util.ArrayList<AutofillId>(),
-        val allAutofillHints: java.util.ArrayList<String> = java.util.ArrayList<String>(),
-        val focusedAutofillHints: java.util.ArrayList<String> = java.util.ArrayList<String>()) {
+data class AutofillFieldMetadataCollection @JvmOverloads constructor(
+        val autofillIds: ArrayList<AutofillId> = ArrayList<AutofillId>(),
+        val allAutofillHints: ArrayList<String> = ArrayList<String>(),
+        val focusedAutofillHints: ArrayList<String> = ArrayList<String>()
+) {
 
-    private val autofillHintsToFieldsMap = java.util.HashMap<String, MutableList<AutofillFieldMetadata>>()
+    private val autofillHintsToFieldsMap = HashMap<String, MutableList<AutofillFieldMetadata>>()
     var saveType = 0
         private set
 
@@ -37,9 +39,10 @@ data class AutofillFieldMetadataCollection(val autofillIds: java.util.ArrayList<
         if (autofillFieldMetadata.isFocused) {
             focusedAutofillHints.addAll(hintsList)
         }
-        autofillFieldMetadata.autofillHints.forEach { autofillHint ->
-            autofillHintsToFieldsMap[autofillHint] = autofillHintsToFieldsMap[autofillHint] ?: java.util.ArrayList<AutofillFieldMetadata>()
-            autofillHintsToFieldsMap[autofillHint]?.add(autofillFieldMetadata)
+        autofillFieldMetadata.autofillHints.forEach {
+            val fields = autofillHintsToFieldsMap[it] ?: ArrayList<AutofillFieldMetadata>()
+            autofillHintsToFieldsMap[it] = fields
+            fields.add(autofillFieldMetadata)
         }
     }
 
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/StructureParser.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/StructureParser.kt
index f185b8ea..e5042101 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/StructureParser.kt
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/StructureParser.kt
@@ -27,12 +27,11 @@ import com.example.android.autofillframework.multidatasetservice.model.FilledAut
  * AssistStructure from the client Activity, representing its View hierarchy. In this sample, it
  * parses the hierarchy and collects autofill metadata from {@link ViewNode}s along the way.
  */
-internal class StructureParser(private val mStructure: AssistStructure) {
+internal class StructureParser(private val autofillStructure: AssistStructure) {
     val autofillFields = AutofillFieldMetadataCollection()
     var filledAutofillFieldCollection: FilledAutofillFieldCollection = FilledAutofillFieldCollection()
         private set
 
-
     fun parseForFill() {
         parse(true)
     }
@@ -45,13 +44,11 @@ internal class StructureParser(private val mStructure: AssistStructure) {
      * Traverse AssistStructure and add ViewNode metadata to a flat list.
      */
     private fun parse(forFill: Boolean) {
-        Log.d(TAG, "Parsing structure for " + mStructure.activityComponent)
-        val nodes = mStructure.windowNodeCount
+        Log.d(TAG, "Parsing structure for " + autofillStructure.activityComponent)
+        val nodes = autofillStructure.windowNodeCount
         filledAutofillFieldCollection = FilledAutofillFieldCollection()
-        for (i in 0..nodes - 1) {
-            val node = mStructure.getWindowNodeAt(i)
-            val view = node.rootViewNode
-            parseLocked(forFill, view)
+        for (i in 0 until nodes) {
+            parseLocked(forFill, autofillStructure.getWindowNodeAt(i).rootViewNode)
         }
     }
 
@@ -66,10 +63,9 @@ internal class StructureParser(private val mStructure: AssistStructure) {
             }
         }
         val childrenSize = viewNode.childCount
-        if (childrenSize > 0) {
-            for (i in 0..childrenSize - 1) {
-                parseLocked(forFill, viewNode.getChildAt(i))
-            }
+        for (i in 0 until childrenSize) {
+            parseLocked(forFill, viewNode.getChildAt(i))
+
         }
     }
 }
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/datasource/AutofillRepository.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/datasource/AutofillRepository.kt
index 00a7d8df..4cb5ab87 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/datasource/AutofillRepository.kt
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/datasource/AutofillRepository.kt
@@ -31,7 +31,8 @@ interface AutofillRepository {
     /**
      * Saves LoginCredential under this datasetName.
      */
-    fun saveFilledAutofillFieldCollection(context: Context, filledAutofillFieldCollection: FilledAutofillFieldCollection)
+    fun saveFilledAutofillFieldCollection(context: Context,
+            filledAutofillFieldCollection: FilledAutofillFieldCollection)
 
     /**
      * Clears all data.
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/datasource/SharedPrefsAutofillRepository.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/datasource/SharedPrefsAutofillRepository.kt
index 98119152..1e7ed0da 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/datasource/SharedPrefsAutofillRepository.kt
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/datasource/SharedPrefsAutofillRepository.kt
@@ -18,6 +18,7 @@ package com.example.android.autofillframework.multidatasetservice.datasource
 import android.content.Context
 import android.content.SharedPreferences
 import android.util.ArraySet
+import com.example.android.autofillframework.CommonUtil
 import com.example.android.autofillframework.multidatasetservice.model.FilledAutofillFieldCollection
 import com.google.gson.Gson
 import com.google.gson.GsonBuilder
@@ -43,19 +44,19 @@ object SharedPrefsAutofillRepository : AutofillRepository {
         var hasDataForFocusedAutofillHints = false
         val clientFormDataMap = HashMap<String, FilledAutofillFieldCollection>()
         val clientFormDataStringSet = getAllAutofillDataStringSet(context)
+        val gson = GsonBuilder().excludeFieldsWithoutExposeAnnotation().setPrettyPrinting().create()
+        val type = object : TypeToken<FilledAutofillFieldCollection>() {}.type
         for (clientFormDataString in clientFormDataStringSet) {
-            val type = object : TypeToken<FilledAutofillFieldCollection>() {}.type
-            val gson: Gson = GsonBuilder().excludeFieldsWithoutExposeAnnotation().setPrettyPrinting().create()
-            gson.fromJson<FilledAutofillFieldCollection>(clientFormDataString, type)?.let { clientFormData ->
-                if (clientFormData.helpsWithHints(focusedAutofillHints)) {
+            gson.fromJson<FilledAutofillFieldCollection>(clientFormDataString, type)?.let {
+                if (it.helpsWithHints(focusedAutofillHints)) {
                     // Saved data has data relevant to at least 1 of the hints associated with the
                     // View in focus.
                     hasDataForFocusedAutofillHints = true
-                    clientFormData.datasetName?.let { datasetName ->
-                        if (clientFormData.helpsWithHints(allAutofillHints)) {
+                    it.datasetName?.let { datasetName ->
+                        if (it.helpsWithHints(allAutofillHints)) {
                             // Saved data has data relevant to at least 1 of these hints associated with any
                             // of the Views in the hierarchy.
-                            clientFormDataMap.put(datasetName, clientFormData)
+                            clientFormDataMap.put(datasetName, it)
                         }
                     }
                 }
@@ -72,7 +73,7 @@ object SharedPrefsAutofillRepository : AutofillRepository {
         val datasetName = "dataset-" + getDatasetNumber(context)
         filledAutofillFieldCollection.datasetName = datasetName
         val allAutofillData = getAllAutofillDataStringSet(context)
-        val gson: Gson = GsonBuilder().excludeFieldsWithoutExposeAnnotation().setPrettyPrinting().create()
+        val gson = CommonUtil.createGson()
         allAutofillData.add(gson.toJson(filledAutofillFieldCollection).toString())
         saveAllAutofillDataStringSet(context, allAutofillData)
         incrementDatasetNumber(context)
@@ -86,7 +87,8 @@ object SharedPrefsAutofillRepository : AutofillRepository {
         return getPrefs(context).getStringSet(CLIENT_FORM_DATA_KEY, ArraySet<String>())
     }
 
-    private fun saveAllAutofillDataStringSet(context: Context, allAutofillDataStringSet: Set<String>) {
+    private fun saveAllAutofillDataStringSet(context: Context,
+            allAutofillDataStringSet: Set<String>) {
         getPrefs(context).edit().putStringSet(CLIENT_FORM_DATA_KEY, allAutofillDataStringSet).apply()
     }
 
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/model/FilledAutofillField.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/model/FilledAutofillField.kt
index 64617ccf..7421cbcd 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/model/FilledAutofillField.kt
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/model/FilledAutofillField.kt
@@ -33,24 +33,23 @@ class FilledAutofillField(viewNode: AssistStructure.ViewNode) {
     @Expose
     var toggleValue: Boolean? = null
 
-    val autofillHints: Array<String> =
-            viewNode.autofillHints.filter(AutofillHelper::isValidHint).toTypedArray()
+    val autofillHints = viewNode.autofillHints.filter(AutofillHelper::isValidHint).toTypedArray()
 
     init {
-        viewNode.autofillValue?.let { autofillValue ->
-            if (autofillValue.isList) {
-                val index = autofillValue.listValue
+        viewNode.autofillValue?.let {
+            if (it.isList) {
+                val index = it.listValue
                 viewNode.autofillOptions?.let { autofillOptions ->
                     if (autofillOptions.size > index) {
                         textValue = autofillOptions[index].toString()
                     }
                 }
-            } else if (autofillValue.isDate) {
-                dateValue = autofillValue.dateValue
-            } else if (autofillValue.isText) {
+            } else if (it.isDate) {
+                dateValue = it.dateValue
+            } else if (it.isText) {
                 // Using toString of AutofillValue.getTextValue in order to save it to
                 // SharedPreferences.
-                textValue = autofillValue.textValue.toString()
+                textValue = it.textValue.toString()
             } else {
             }
         }
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/model/FilledAutofillFieldCollection.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/model/FilledAutofillFieldCollection.kt
index 2de46809..cef29185 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/model/FilledAutofillFieldCollection.kt
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/model/FilledAutofillFieldCollection.kt
@@ -30,8 +30,11 @@ import java.util.HashMap
  * FilledAutofillFieldCollection is the model that represents all of the form data on a client app's page, plus the
  * dataset name associated with it.
  */
-class FilledAutofillFieldCollection constructor(@Expose var datasetName: String? = null,
-        @Expose private val hintMap: HashMap<String, FilledAutofillField> = HashMap<String, FilledAutofillField>()) {
+class FilledAutofillFieldCollection @JvmOverloads constructor(
+        @Expose var datasetName: String? = null,
+        @Expose private val hintMap: HashMap<String, FilledAutofillField> = HashMap<String,
+                FilledAutofillField>()
+) {
 
     /**
      * Sets values for a list of autofillHints.
@@ -60,9 +63,12 @@ class FilledAutofillFieldCollection constructor(@Expose var datasetName: String?
                 val savedAutofillValue = hintMap[hint]
                 when (autofillType) {
                     View.AUTOFILL_TYPE_LIST -> {
-                        savedAutofillValue?.textValue?.let(autofillField::getAutofillOptionIndex)?.let { index ->
-                            datasetBuilder.setValue(autofillId, AutofillValue.forList(index))
-                            setValueAtLeastOnce = true
+                        savedAutofillValue?.textValue?.let {
+                            val index = autofillField.getAutofillOptionIndex(it)
+                            if (index != -1) {
+                                datasetBuilder.setValue(autofillId, AutofillValue.forList(index))
+                                setValueAtLeastOnce = true
+                            }
                         }
                     }
                     View.AUTOFILL_TYPE_DATE -> {
diff --git a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/settings/SettingsActivity.kt b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/settings/SettingsActivity.kt
index e314ccd7..5004fa26 100644
--- a/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/settings/SettingsActivity.kt
+++ b/input/autofill/AutofillFramework/kotlinApp/Application/src/main/java/com/example/android/autofillframework/multidatasetservice/settings/SettingsActivity.kt
@@ -70,9 +70,11 @@ class SettingsActivity : AppCompatActivity() {
                 settings_auth_credentials_label,
                 settings_auth_credentials_icon,
                 View.OnClickListener {
-                    MyPreferences.getMasterPassword(this@SettingsActivity)?.let {
+                    if (MyPreferences.getMasterPassword(this@SettingsActivity) != null) {
                         buildCurrentCredentialsDialog().show()
-                    } ?: buildNewCredentialsDialog().show()
+                    } else {
+                        buildNewCredentialsDialog().show()
+                    }
                 })
     }
 
@@ -132,10 +134,12 @@ class SettingsActivity : AppCompatActivity() {
     private fun setupSettingsSwitch(container: ViewGroup, switchLabelView: TextView, switchView: Switch, checked: Boolean,
             checkedChangeListener: CompoundButton.OnCheckedChangeListener) {
         val switchLabel = switchLabelView.text.toString()
-        switchView.contentDescription = switchLabel
-        switchView.isChecked = checked
+        with(switchView) {
+            contentDescription = switchLabel
+            isChecked = checked
+            setOnCheckedChangeListener (checkedChangeListener)
+        }
         container.setOnClickListener { switchView.performClick() }
-        switchView.setOnCheckedChangeListener(checkedChangeListener)
     }
 
     private fun setupSettingsButton(container: ViewGroup, buttonLabelView: TextView, imageView: ImageView,
diff --git a/input/autofill/AutofillFramework/kotlinApp/README.md b/input/autofill/AutofillFramework/kotlinApp/README.md
index 45ac76da..282a1ea2 100644
--- a/input/autofill/AutofillFramework/kotlinApp/README.md
+++ b/input/autofill/AutofillFramework/kotlinApp/README.md
@@ -72,14 +72,14 @@ order to provide this view hierarchy data to the Autofill service.
 override fun onProvideAutofillVirtualStructure(structure: ViewStructure, flags: Int) {
     // Build a ViewStructure to pack in AutoFillService requests.
     structure.setClassName(javaClass.name)
-    val childrenSize = mItems.size()
+    val childrenSize = items.size()
     Log.d(TAG, "onProvideAutofillVirtualStructure(): flags = " + flags + ", items = "
             + childrenSize + ", extras: " + bundleToString(structure.extras))
     var index = structure.addChildCount(childrenSize)
     // Traverse through the view hierarchy, including virtual child views. For each view, we
     // need to set the relevant autofill metadata and add it to the ViewStructure.
     for (i in 0..childrenSize - 1) {
-        val item = mItems.valueAt(i)
+        val item = items.valueAt(i)
         Log.d(TAG, "Adding new child at index $index: $item")
         val child = structure.newChild(index)
         child.setAutofillId(structure, item.id)
@@ -113,7 +113,7 @@ override fun autofill(values: SparseArray<AutofillValue>) {
     for (i in 0..values.size() - 1) {
         val id = values.keyAt(i)
         val value = values.valueAt(i)
-        mItems[id]?.let { item ->
+        items[id]?.let { item ->
             if (item.editable) {
                 // Set the item's text to the text wrapped in the AutofillValue.
                 item.text = value.textValue