View <-> LiveData connection tweaks, some re-org

app/src/main/kotlin/com/afollestad/nocknock/ui/addsite/AddSiteActivity.kt

@@ -21,12 +21,12 @@ import android.widget.ArrayAdapter
 import androidx.appcompat.app.AppCompatActivity
 import com.afollestad.nocknock.R
 import com.afollestad.nocknock.data.model.ValidationMode
-import com.afollestad.nocknock.viewcomponents.ext.attachLiveData
 import com.afollestad.nocknock.viewcomponents.ext.conceal
 import com.afollestad.nocknock.viewcomponents.ext.onLayout
-import com.afollestad.nocknock.viewcomponents.ext.toViewError
+import com.afollestad.nocknock.viewcomponents.livedata.attachLiveData
-import com.afollestad.nocknock.viewcomponents.ext.toViewText
+import com.afollestad.nocknock.viewcomponents.livedata.toViewError
-import com.afollestad.nocknock.viewcomponents.ext.toViewVisibility
+import com.afollestad.nocknock.viewcomponents.livedata.toViewText
+import com.afollestad.nocknock.viewcomponents.livedata.toViewVisibility
 import kotlinx.android.synthetic.main.activity_addsite.checkIntervalLayout
 import kotlinx.android.synthetic.main.activity_addsite.doneBtn
 import kotlinx.android.synthetic.main.activity_addsite.inputName
@@ -88,9 +88,11 @@ class AddSiteActivity : AppCompatActivity() {
         .toViewError(this, responseTimeoutInput)
 
     // Validation mode
-    responseValidationMode.attachLiveData(this, viewModel.validationMode,
+    responseValidationMode.attachLiveData(
-        { ValidationMode.fromIndex(it) },
+        lifecycleOwner = this,
-        { it.toIndex() }
+        data = viewModel.validationMode,
+        outTransformer = { ValidationMode.fromIndex(it) },
+        inTransformer = { it.toIndex() }
     )
     viewModel.onValidationSearchTermError()
         .toViewError(this, responseValidationSearchTerm)
@@ -98,7 +100,11 @@ class AddSiteActivity : AppCompatActivity() {
         .toViewText(this, validationModeDescription)
 
     // Validation search term
-    responseValidationSearchTerm.attachLiveData(this, viewModel.validationSearchTerm)
+    responseValidationSearchTerm.attachLiveData(
+        lifecycleOwner = this,
+        data = viewModel.validationSearchTerm,
+        pullInChanges = false
+    )
     viewModel.onValidationSearchTermVisibility()
         .toViewVisibility(this, responseValidationSearchTerm)
 

app/src/main/kotlin/com/afollestad/nocknock/ui/addsite/AddSiteViewModel.kt

@@ -32,8 +32,8 @@ import com.afollestad.nocknock.data.model.ValidationMode.TERM_SEARCH
 import com.afollestad.nocknock.data.putSite
 import com.afollestad.nocknock.engine.validation.ValidationManager
 import com.afollestad.nocknock.ui.ScopedViewModel
+import com.afollestad.nocknock.utilities.livedata.map
 import com.afollestad.nocknock.viewcomponents.ext.isNullOrLessThan
-import com.afollestad.nocknock.viewcomponents.ext.map
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
@@ -50,7 +50,9 @@ class AddSiteViewModel(
   // Public properties
   val name = MutableLiveData<String>()
   val url = MutableLiveData<String>()
-  val timeout = MutableLiveData<Int>()
+  val timeout = MutableLiveData<Int>().apply {
+    this.value = 10000
+  }
   val validationMode = MutableLiveData<ValidationMode>()
   val validationSearchTerm = MutableLiveData<String>()
   val validationScript = MutableLiveData<String>()
@@ -214,8 +216,8 @@ class AddSiteViewModel(
     )
     return Site(
         id = 0,
-        name = name.value!!,
+        name = name.value!!.trim(),
-        url = url.value!!,
+        url = url.value!!.trim(),
         settings = newSettings,
         lastResult = null
     )

app/src/main/kotlin/com/afollestad/nocknock/ui/viewsite/ViewSiteActivity.kt

@@ -26,12 +26,12 @@ import com.afollestad.nocknock.broadcasts.StatusUpdateIntentReceiver
 import com.afollestad.nocknock.data.model.Site
 import com.afollestad.nocknock.data.model.ValidationMode
 import com.afollestad.nocknock.utilities.providers.IntentProvider
-import com.afollestad.nocknock.viewcomponents.ext.attachLiveData
+import com.afollestad.nocknock.viewcomponents.livedata.attachLiveData
 import com.afollestad.nocknock.viewcomponents.ext.dimenFloat
 import com.afollestad.nocknock.viewcomponents.ext.onScroll
-import com.afollestad.nocknock.viewcomponents.ext.toViewError
+import com.afollestad.nocknock.viewcomponents.livedata.toViewError
-import com.afollestad.nocknock.viewcomponents.ext.toViewText
+import com.afollestad.nocknock.viewcomponents.livedata.toViewText
-import com.afollestad.nocknock.viewcomponents.ext.toViewVisibility
+import com.afollestad.nocknock.viewcomponents.livedata.toViewVisibility
 import kotlinx.android.synthetic.main.activity_viewsite.checkIntervalLayout
 import kotlinx.android.synthetic.main.activity_viewsite.disableChecksButton
 import kotlinx.android.synthetic.main.activity_viewsite.doneBtn
@@ -102,9 +102,12 @@ class ViewSiteActivity : AppCompatActivity() {
         .toViewError(this, responseTimeoutInput)
 
     // Validation mode
-    responseValidationMode.attachLiveData(this, viewModel.validationMode,
+    responseValidationMode.attachLiveData(
-        { ValidationMode.fromIndex(it) },
+        lifecycleOwner = this,
-        { it.toIndex() })
+        data = viewModel.validationMode,
+        outTransformer = { ValidationMode.fromIndex(it) },
+        inTransformer = { it.toIndex() }
+    )
     viewModel.onValidationSearchTermError()
         .toViewError(this, responseValidationSearchTerm)
     viewModel.onValidationModeDescription()

app/src/main/kotlin/com/afollestad/nocknock/ui/viewsite/ViewSiteViewModel.kt

@@ -38,10 +38,10 @@ import com.afollestad.nocknock.engine.validation.ValidationManager
 import com.afollestad.nocknock.notifications.NockNotificationManager
 import com.afollestad.nocknock.ui.ScopedViewModel
 import com.afollestad.nocknock.utilities.ext.formatDate
+import com.afollestad.nocknock.utilities.livedata.map
+import com.afollestad.nocknock.utilities.livedata.zip
 import com.afollestad.nocknock.utilities.providers.StringProvider
 import com.afollestad.nocknock.viewcomponents.ext.isNullOrLessThan
-import com.afollestad.nocknock.viewcomponents.ext.map
-import com.afollestad.nocknock.viewcomponents.ext.zip
 import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
@@ -232,8 +232,8 @@ class ViewSiteViewModel(
   @VisibleForTesting(otherwise = PRIVATE)
   fun getValidationArgs(): String? {
     return when (validationMode.value) {
-      TERM_SEARCH -> validationSearchTerm.value
+      TERM_SEARCH -> validationSearchTerm.value?.trim()
-      JAVASCRIPT -> validationScript.value
+      JAVASCRIPT -> validationScript.value?.trim()
       else -> null
     }
   }
@@ -310,8 +310,8 @@ class ViewSiteViewModel(
         disabled = false
     )
     return site.copy(
-        name = name.value!!,
+        name = name.value!!.trim(),
-        url = url.value!!,
+        url = url.value!!.trim(),
         settings = newSettings
     )
         .withStatus(status = WAITING)

app/src/main/res/layout/activity_addsite.xml

@@ -93,7 +93,7 @@
 
         <include layout="@layout/include_divider"/>
 
-        <com.afollestad.nocknock.viewcomponents.interval.CheckIntervalLayout
+        <com.afollestad.nocknock.viewcomponents.interval.ValidationIntervalLayout
             android:id="@+id/checkIntervalLayout"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"

app/src/main/res/layout/activity_viewsite.xml

@@ -115,7 +115,7 @@
             android:layout_marginTop="@dimen/content_inset_less"
             />
 
-        <com.afollestad.nocknock.viewcomponents.interval.CheckIntervalLayout
+        <com.afollestad.nocknock.viewcomponents.interval.ValidationIntervalLayout
             android:id="@+id/checkIntervalLayout"
             android:layout_width="match_parent"
             android:layout_height="wrap_content"

app/src/test/kotlin/com/afollestad/nocknock/ui/addsite/AddSiteViewModelTest.kt

@@ -24,7 +24,7 @@ import com.afollestad.nocknock.data.model.ValidationMode.STATUS_CODE
 import com.afollestad.nocknock.data.model.ValidationMode.TERM_SEARCH
 import com.afollestad.nocknock.engine.validation.ValidationManager
 import com.afollestad.nocknock.mockDatabase
-import com.afollestad.nocknock.test
+import com.afollestad.nocknock.utilities.livedata.test
 import com.google.common.truth.Truth.assertThat
 import com.nhaarman.mockitokotlin2.any
 import com.nhaarman.mockitokotlin2.argumentCaptor

app/src/test/kotlin/com/afollestad/nocknock/ui/main/MainViewModelTest.kt

@@ -23,7 +23,7 @@ import com.afollestad.nocknock.MOCK_MODEL_3
 import com.afollestad.nocknock.engine.validation.ValidationManager
 import com.afollestad.nocknock.mockDatabase
 import com.afollestad.nocknock.notifications.NockNotificationManager
-import com.afollestad.nocknock.test
+import com.afollestad.nocknock.utilities.livedata.test
 import com.nhaarman.mockitokotlin2.mock
 import com.nhaarman.mockitokotlin2.verify
 import kotlinx.coroutines.Dispatchers

app/src/test/kotlin/com/afollestad/nocknock/ui/viewsite/ViewSiteViewModelTest.kt

@@ -31,7 +31,7 @@ import com.afollestad.nocknock.data.model.ValidationResult
 import com.afollestad.nocknock.engine.validation.ValidationManager
 import com.afollestad.nocknock.mockDatabase
 import com.afollestad.nocknock.notifications.NockNotificationManager
-import com.afollestad.nocknock.test
+import com.afollestad.nocknock.utilities.livedata.test
 import com.afollestad.nocknock.utilities.providers.StringProvider
 import com.google.common.truth.Truth
 import com.google.common.truth.Truth.assertThat

common/build.gradle

@@ -20,7 +20,7 @@ android {
 
 dependencies {
   implementation 'androidx.annotation:annotation:' + versions.androidx
-  implementation 'androidx.appcompat:appcompat:' + versions.androidx
+  api 'androidx.lifecycle:lifecycle-extensions:' + versions.lifecycle
 
   implementation 'org.jetbrains.kotlin:kotlin-stdlib-jdk7:' + versions.kotlin
   api 'org.jetbrains.kotlinx:kotlinx-coroutines-core:' + versions.coroutines
@@ -30,9 +30,8 @@ dependencies {
   implementation 'org.mozilla:rhino:' + versions.rhino
 
   testImplementation 'junit:junit:' + versions.junit
-  testImplementation 'org.mockito:mockito-core:' + versions.mockito
-  testImplementation 'com.nhaarman.mockitokotlin2:mockito-kotlin:' + versions.mockitoKotlin
   testImplementation 'com.google.truth:truth:' + versions.truth
+  testImplementation 'androidx.arch.core:core-testing:' + versions.archTesting
 }
 
 apply from: '../spotless.gradle'

common/src/main/kotlin/com/afollestad/nocknock/utilities/ext/ViewExt.kt

@@ -18,9 +18,29 @@ package com.afollestad.nocknock.utilities.ext
 import android.text.Editable
 import android.text.TextWatcher
 import android.widget.EditText
+import androidx.annotation.IntRange
+import kotlin.math.min
 
-fun EditText.onTextChanged(cb: (String) -> Unit) {
+fun EditText.setTextAndMaintainSelection(text: CharSequence) {
+  val formerStart = min(selectionStart, text.length)
+  val formerEnd = min(selectionEnd, text.length)
+  setText(text)
+  if (formerEnd <= formerStart) {
+    setSelection(formerStart)
+  } else {
+    setSelection(formerStart, formerEnd)
+  }
+}
+
+fun EditText.onTextChanged(
+  @IntRange(from = 0, to = 10000) debounce: Int = 0,
+  cb: (String) -> Unit
+) {
   addTextChangedListener(object : TextWatcher {
+    val callbackRunner = Runnable {
+      cb(text.trim().toString())
+    }
+
     override fun afterTextChanged(s: Editable?) = Unit
 
     override fun beforeTextChanged(
@@ -35,6 +55,13 @@ fun EditText.onTextChanged(cb: (String) -> Unit) {
       start: Int,
       before: Int,
       count: Int
-    ) = cb(s.toString().trim())
+    ) {
+      removeCallbacks(callbackRunner)
+      if (debounce == 0) {
+        callbackRunner.run()
+      } else {
+        postDelayed(callbackRunner, debounce.toLong())
+      }
+    }
   })
 }

common/src/main/kotlin/com/afollestad/nocknock/utilities/livedata/Distinct.kt

@@ -0,0 +1,53 @@
+/**
+ * Designed and developed by Aidan Follestad (@afollestad)
+ *
+ * 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.afollestad.nocknock.utilities.livedata
+
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MediatorLiveData
+import androidx.lifecycle.Observer
+
+/** @author Aidan Follestad (@afollestad) */
+class DistinctLiveData<T>(source1: LiveData<T>) : MediatorLiveData<T>() {
+
+  private var isInitialized = false
+  private var lastValue: T? = null
+
+  init {
+    super.addSource(source1) {
+      if (!isInitialized) {
+        value = it
+        isInitialized = true
+        lastValue = it
+      } else if (lastValue != it) {
+        value = it
+        lastValue = it
+      }
+    }
+  }
+
+  override fun <S : Any?> addSource(
+    source: LiveData<S>,
+    onChanged: Observer<in S>
+  ) {
+    throw UnsupportedOperationException()
+  }
+
+  override fun <T : Any?> removeSource(toRemote: LiveData<T>) {
+    throw UnsupportedOperationException()
+  }
+}
+
+fun <T> LiveData<T>.distinct(): MediatorLiveData<T> = DistinctLiveData(this)

common/src/main/kotlin/com/afollestad/nocknock/utilities/livedata/LiveDataExt.kt

@@ -0,0 +1,25 @@
+/**
+ * Designed and developed by Aidan Follestad (@afollestad)
+ *
+ * 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.afollestad.nocknock.utilities.livedata
+
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.Transformations
+
+fun <X, Y> LiveData<X>.map(mapper: (X) -> Y) =
+  Transformations.map(this, mapper)!!
+
+fun <X, Y> LiveData<X>.switchMap(mapper: (X) -> LiveData<Y>) =
+  Transformations.switchMap(this, mapper)!!

common/src/main/kotlin/com/afollestad/nocknock/utilities/livedata/TestLiveData.kt

@@ -13,13 +13,11 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package com.afollestad.nocknock
+package com.afollestad.nocknock.utilities.livedata
 
 import androidx.annotation.CheckResult
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.Observer
-import com.google.common.truth.Truth.assertThat
-import com.google.common.truth.Truth.assertWithMessage
 
 /** @author Aidan Follestad (@afollestad) */
 class TestLiveData<T>(data: LiveData<T>) {
@@ -34,17 +32,32 @@ class TestLiveData<T>(data: LiveData<T>) {
   }
 
   fun assertNoValues() {
-    assertWithMessage("Expected no values, but got: $receivedValues").that(receivedValues)
+    if (receivedValues.isNotEmpty()) {
-        .isEmpty()
+      throw AssertionError("Expected no values, but got: $receivedValues")
+    }
   }
 
   fun assertValues(vararg assertValues: T) {
     val assertList = assertValues.toList()
-    assertThat(receivedValues).isEqualTo(assertList)
+    if (!assertList.contentEquals(receivedValues)) {
+      throw AssertionError("Expected $assertList\n\t\tBut got: $receivedValues")
+    }
     receivedValues.clear()
   }
 
   @CheckResult fun values(): List<T> = receivedValues
+
+  private fun List<T>.contentEquals(other: List<T>): Boolean {
+    if (this.size != other.size) {
+      return false
+    }
+    for ((index, value) in this.withIndex()) {
+      if (other[index] != value) {
+        return false
+      }
+    }
+    return true
+  }
 }
 
 @CheckResult fun <T> LiveData<T>.test() = TestLiveData(this)

common/src/main/kotlin/com/afollestad/nocknock/utilities/livedata/Zip.kt

@@ -0,0 +1,102 @@
+/**
+ * Designed and developed by Aidan Follestad (@afollestad)
+ *
+ * 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.afollestad.nocknock.utilities.livedata
+
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MediatorLiveData
+import androidx.lifecycle.Observer
+
+typealias Zipper<T, K, R> = (T, K) -> R
+
+/** @author Aidan Follestad (@afollestad) */
+class ZipLiveData<T, K, R>(
+  source1: LiveData<T>,
+  source2: LiveData<K>,
+  private val distinctUntilChanged: Boolean,
+  private val resetAfterEmission: Boolean,
+  private val zipper: Zipper<T, K, R>
+) : MediatorLiveData<R>() {
+
+  private var data1: T? = null
+  private var data2: K? = null
+  private var lastNotified: R? = null
+
+  init {
+    super.addSource(source1) {
+      if (data1 == it) return@addSource
+      data1 = it
+      maybeNotify()
+    }
+    super.addSource(source2) {
+      if (data2 == it) return@addSource
+      data2 = it
+      maybeNotify()
+    }
+  }
+
+  private fun maybeNotify() {
+    if (data1 != null && data2 != null) {
+      val zippedUp = zipper(data1!!, data2!!)
+
+      if (!distinctUntilChanged || zippedUp != lastNotified) {
+        value = zippedUp
+        lastNotified = zippedUp
+
+        if (resetAfterEmission) {
+          data1 = null
+          data2 = null
+        }
+      }
+    }
+  }
+
+  override fun <S : Any?> addSource(
+    source: LiveData<S>,
+    onChanged: Observer<in S>
+  ) {
+    throw UnsupportedOperationException()
+  }
+
+  override fun <T : Any?> removeSource(toRemote: LiveData<T>) {
+    throw UnsupportedOperationException()
+  }
+}
+
+fun <T, K, R> zip(
+  source1: LiveData<T>,
+  source2: LiveData<K>,
+  distinctUntilChanged: Boolean = true,
+  resetAfterEmission: Boolean = false,
+  zipper: Zipper<T, K, R>
+) = ZipLiveData(
+    source1 = source1,
+    source2 = source2,
+    distinctUntilChanged = distinctUntilChanged,
+    resetAfterEmission = resetAfterEmission,
+    zipper = zipper
+)
+
+fun <T, K> zip(
+  source1: LiveData<T>,
+  source2: LiveData<K>,
+  distinctUntilChanged: Boolean = true,
+  resetAfterEmission: Boolean = false
+) = zip(
+    source1 = source1,
+    source2 = source2,
+    distinctUntilChanged = distinctUntilChanged,
+    resetAfterEmission = resetAfterEmission,
+    zipper = { left, right -> Pair(left, right) })

common/src/test/kotlin/com/afollestad/nocknock/utilities/livedata/DistinctTest.kt

@@ -0,0 +1,47 @@
+/**
+ * Designed and developed by Aidan Follestad (@afollestad)
+ *
+ * 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.afollestad.nocknock.utilities.livedata
+
+import androidx.arch.core.executor.testing.InstantTaskExecutorRule
+import androidx.lifecycle.MutableLiveData
+import org.junit.Rule
+import org.junit.Test
+
+/** @author Aidan Follestad (@afollestad) */
+class DistinctTest {
+
+  @Rule @JvmField val rule = InstantTaskExecutorRule()
+
+  @Test fun filterLastValues() {
+    val data = MutableLiveData<String>()
+    val distinct = data.distinct()
+        .test()
+
+    data.postValue("Hello")
+    data.postValue("Hello")
+
+    data.postValue("Hi")
+    data.postValue("Hi")
+
+    data.postValue("Hello")
+
+    distinct.assertValues(
+        "Hello",
+        "Hi",
+        "Hello"
+    )
+  }
+}

common/src/test/kotlin/com/afollestad/nocknock/utilities/livedata/ZipTest.kt

@@ -0,0 +1,123 @@
+/**
+ * Designed and developed by Aidan Follestad (@afollestad)
+ *
+ * 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.afollestad.nocknock.utilities.livedata
+
+import androidx.arch.core.executor.testing.InstantTaskExecutorRule
+import androidx.lifecycle.MutableLiveData
+import org.junit.Rule
+import org.junit.Test
+
+/** @author Aidan Follestad (@afollestad) */
+class ZipTest {
+
+  @Rule @JvmField val rule = InstantTaskExecutorRule()
+
+  @Test fun test_withDistinct() {
+    val data1 = MutableLiveData<String>()
+    val data2 = MutableLiveData<Int>()
+    val zipped = zip(data1, data2, true)
+        .test()
+
+    data1.postValue("Hello")
+    data2.postValue(24)
+    zipped.assertValues(Pair("Hello", 24))
+
+    data1.postValue("Hello")
+    data2.postValue(24)
+    zipped.assertNoValues()
+  }
+
+  @Test fun test_noDistinct() {
+    val data1 = MutableLiveData<String>()
+    val data2 = MutableLiveData<Int>()
+    val zipped = zip(data1, data2, false)
+        .test()
+
+    data1.postValue("Hello")
+    data2.postValue(24)
+    zipped.assertValues(Pair("Hello", 24))
+
+    data1.postValue("Hi")
+    data2.postValue(24)
+    zipped.assertValues(Pair("Hi", 24))
+  }
+
+  @Test fun test_noDistinct_resetAfterEmission() {
+    val data1 = MutableLiveData<String>()
+    val data2 = MutableLiveData<Int>()
+    val zipped = zip(data1, data2, false, true)
+        .test()
+
+    data1.postValue("Hello")
+    data2.postValue(24)
+    zipped.assertValues(Pair("Hello", 24))
+
+    data1.postValue("Hi")
+    data2.postValue(50)
+    zipped.assertValues(Pair("Hi", 50))
+  }
+
+  @Test fun test_withDistinct_customZipper() {
+    val data1 = MutableLiveData<String>()
+    val data2 = MutableLiveData<Int>()
+    val zipped = zip(data1, data2, true,
+        zipper = { left, right ->
+          "$left $right"
+        }).test()
+
+    data1.postValue("Hello")
+    data2.postValue(24)
+    zipped.assertValues("Hello 24")
+
+    data1.postValue("Hello")
+    data2.postValue(24)
+    zipped.assertNoValues()
+  }
+
+  @Test fun test_noDistinct_customZipper() {
+    val data1 = MutableLiveData<String>()
+    val data2 = MutableLiveData<Int>()
+    val zipped = zip(data1, data2, false,
+        zipper = { left, right ->
+          "$left $right"
+        }).test()
+
+    data1.postValue("Hello")
+    data2.postValue(24)
+    zipped.assertValues("Hello 24")
+
+    data1.postValue("Hi")
+    data2.postValue(24)
+    zipped.assertValues("Hi 24")
+  }
+
+  @Test fun test_noDistinct_customZipper_resetAfterEmission() {
+    val data1 = MutableLiveData<String>()
+    val data2 = MutableLiveData<Int>()
+    val zipped = zip(data1, data2, false, true,
+        zipper = { left, right ->
+          "$left $right"
+        }).test()
+
+    data1.postValue("Hello")
+    data2.postValue(24)
+    zipped.assertValues("Hello 24")
+
+    data1.postValue("Hi")
+    data2.postValue(50)
+    zipped.assertValues("Hi 50")
+  }
+}

viewcomponents/src/main/java/com/afollestad/nocknock/viewcomponents/ext/LiveDataExt.kt

@@ -1,148 +0,0 @@
-/**
- * Designed and developed by Aidan Follestad (@afollestad)
- *
- * 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.afollestad.nocknock.viewcomponents.ext
-
-import android.view.View
-import android.widget.EditText
-import android.widget.Spinner
-import android.widget.TextView
-import androidx.lifecycle.LifecycleOwner
-import androidx.lifecycle.LiveData
-import androidx.lifecycle.MediatorLiveData
-import androidx.lifecycle.MutableLiveData
-import androidx.lifecycle.Observer
-import androidx.lifecycle.Transformations
-import com.afollestad.nocknock.utilities.ext.onTextChanged
-
-fun <X, Y> LiveData<X>.map(mapper: (X) -> Y) =
-  Transformations.map(this, mapper)!!
-
-fun <X, Y> LiveData<X>.switchMap(mapper: (X) -> LiveData<Y>) =
-  Transformations.switchMap(this, mapper)!!
-
-inline fun <reified T> EditText.attachLiveData(
-  lifecycleOwner: LifecycleOwner,
-  data: MutableLiveData<T>
-) {
-  // Out
-  when {
-    T::class == Int::class -> {
-      onTextChanged { data.postValue(it.trim().toInt() as T) }
-    }
-    T::class == Long::class -> {
-      onTextChanged { data.postValue(it.trim().toLong() as T) }
-    }
-    T::class == String::class -> {
-      onTextChanged { data.postValue(it.trim() as T) }
-    }
-    else -> {
-      throw IllegalArgumentException("Can't send EditText text changes into ${T::class}")
-    }
-  }
-  // In
-  data.observe(lifecycleOwner, Observer {
-    when {
-      T::class == Int::class -> setText(it as Int)
-      T::class == String::class -> setText(it as String)
-    }
-  })
-}
-
-fun <T> Spinner.attachLiveData(
-  lifecycleOwner: LifecycleOwner,
-  data: MutableLiveData<T>,
-  outTransformer: (Int) -> T,
-  inTransformer: (T) -> Int
-) {
-  // Out
-  onItemSelected { data.postValue(outTransformer(it)) }
-  // In
-  data.observe(lifecycleOwner, Observer {
-    setSelection(inTransformer(it))
-  })
-}
-
-fun LiveData<Int?>.toViewError(
-  owner: LifecycleOwner,
-  view: EditText
-) = observe(owner, Observer { error ->
-  view.error = if (error != null) {
-    view.resources.getString(error)
-  } else {
-    null
-  }
-})
-
-inline fun <reified T> LiveData<T>.toViewText(
-  owner: LifecycleOwner,
-  view: TextView
-) = observe(owner, Observer {
-  when {
-    T::class == Int::class -> view.setText(it as Int)
-    T::class == String::class -> view.text = it as String
-    else -> throw IllegalStateException("Cannot set ${T::class} as view text.")
-  }
-})
-
-fun LiveData<Boolean>.toViewVisibility(
-  owner: LifecycleOwner,
-  view: View
-) = observe(owner, Observer { view.showOrHide(it) })
-
-/** @author Aidan Follestad (@afollestad) */
-class ZipLiveData<T, K>(
-  source1: LiveData<T>,
-  source2: LiveData<K>
-) : MediatorLiveData<Pair<T, K>>() {
-
-  private var data1: T? = null
-  private var data2: K? = null
-
-  init {
-    super.addSource(source1) {
-      data1 = it
-      maybeNotify()
-    }
-    super.addSource(source2) {
-      data2 = it
-      maybeNotify()
-    }
-  }
-
-  private fun maybeNotify() {
-    if (data1 != null && data2 != null) {
-      value = Pair(data1!!, data2!!)
-    }
-  }
-
-  override fun <S : Any?> addSource(
-    source: LiveData<S>,
-    onChanged: Observer<in S>
-  ) {
-    throw UnsupportedOperationException()
-  }
-
-  override fun <T : Any?> removeSource(toRemote: LiveData<T>) {
-    throw UnsupportedOperationException()
-  }
-}
-
-fun <T, K> zip(
-  source1: LiveData<T>,
-  source2: LiveData<K>
-): MediatorLiveData<Pair<T, K>> {
-  return ZipLiveData(source1, source2)
-}

viewcomponents/src/main/java/com/afollestad/nocknock/viewcomponents/interval/CheckIntervalLayout.kt

@@ -1,133 +0,0 @@
-/**
- * Designed and developed by Aidan Follestad (@afollestad)
- *
- * 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.afollestad.nocknock.viewcomponents.interval
-
-import android.content.Context
-import android.util.AttributeSet
-import android.widget.ArrayAdapter
-import android.widget.LinearLayout
-import androidx.lifecycle.Lifecycle.State.DESTROYED
-import androidx.lifecycle.Lifecycle.State.RESUMED
-import androidx.lifecycle.Lifecycle.State.STARTED
-import androidx.lifecycle.LifecycleOwner
-import androidx.lifecycle.LifecycleRegistry
-import androidx.lifecycle.LiveData
-import androidx.lifecycle.MutableLiveData
-import androidx.lifecycle.Observer
-import com.afollestad.nocknock.utilities.ext.DAY
-import com.afollestad.nocknock.utilities.ext.HOUR
-import com.afollestad.nocknock.utilities.ext.MINUTE
-import com.afollestad.nocknock.utilities.ext.WEEK
-import com.afollestad.nocknock.utilities.ext.onTextChanged
-import com.afollestad.nocknock.viewcomponents.R.array
-import com.afollestad.nocknock.viewcomponents.R.layout
-import com.afollestad.nocknock.viewcomponents.ext.onItemSelected
-import kotlinx.android.synthetic.main.check_interval_layout.view.input
-import kotlinx.android.synthetic.main.check_interval_layout.view.spinner
-
-/** @author Aidan Follestad (@afollestad) */
-class CheckIntervalLayout(
-  context: Context,
-  attrs: AttributeSet? = null
-) : LinearLayout(context, attrs), LifecycleOwner {
-
-  companion object {
-    const val INDEX_MINUTE = 0
-    const val INDEX_HOUR = 1
-    const val INDEX_DAY = 2
-    const val INDEX_WEEK = 3
-  }
-
-  init {
-    orientation = VERTICAL
-    inflate(context, layout.check_interval_layout, this)
-  }
-
-  private lateinit var valueData: MutableLiveData<Int>
-  private lateinit var multiplierData: MutableLiveData<Long>
-
-  private val lifecycle = LifecycleRegistry(this)
-
-  override fun onFinishInflate() {
-    super.onFinishInflate()
-    val spinnerAdapter = ArrayAdapter(
-        context,
-        layout.list_item_spinner,
-        resources.getStringArray(array.interval_options)
-    )
-    spinnerAdapter.setDropDownViewResource(
-        layout.list_item_spinner_dropdown
-    )
-    spinner.adapter = spinnerAdapter
-    lifecycle.markState(STARTED)
-  }
-
-  override fun onAttachedToWindow() {
-    super.onAttachedToWindow()
-    lifecycle.markState(RESUMED)
-  }
-
-  override fun onDetachedFromWindow() {
-    lifecycle.markState(DESTROYED)
-    super.onDetachedFromWindow()
-  }
-
-  fun setError(error: String?) {
-    input.error = error
-  }
-
-  fun attach(
-    valueData: MutableLiveData<Int>,
-    multiplierData: MutableLiveData<Long>,
-    errorData: LiveData<Int?>
-  ) {
-    this.valueData = valueData
-    this.multiplierData = multiplierData
-
-    this.valueData.observe(this, Observer {
-      input.setText("$it")
-    })
-    this.multiplierData.observe(this, Observer { multiplier ->
-      val targetPos = when (multiplier) {
-        MINUTE -> 0
-        HOUR -> 1
-        DAY -> 2
-        WEEK -> 3
-        else -> throw IllegalStateException("Unknown multiplier: $multiplier")
-      }
-      if (spinner.selectedItemPosition != targetPos) {
-        spinner.setSelection(targetPos)
-      }
-    })
-
-    errorData.observe(this, Observer {
-      setError(if (it != null) resources.getString(it) else null)
-    })
-
-    input.onTextChanged { this.valueData.value = it.toInt() }
-    spinner.onItemSelected {
-      this.multiplierData.value = when (it) {
-        INDEX_MINUTE -> MINUTE
-        INDEX_HOUR -> HOUR
-        INDEX_DAY -> DAY
-        INDEX_WEEK -> WEEK
-        else -> throw IllegalStateException("Unknown multiplier index: $it")
-      }
-    }
-  }
-
-  override fun getLifecycle() = lifecycle
-}

viewcomponents/src/main/kotlin/com/afollestad/nocknock/viewcomponents/interval/ValidationIntervalLayout.kt

@@ -0,0 +1,101 @@
+/**
+ * Designed and developed by Aidan Follestad (@afollestad)
+ *
+ * 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.afollestad.nocknock.viewcomponents.interval
+
+import android.content.Context
+import android.util.AttributeSet
+import android.widget.ArrayAdapter
+import android.widget.LinearLayout
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MutableLiveData
+import com.afollestad.nocknock.utilities.ext.DAY
+import com.afollestad.nocknock.utilities.ext.HOUR
+import com.afollestad.nocknock.utilities.ext.MINUTE
+import com.afollestad.nocknock.utilities.ext.WEEK
+import com.afollestad.nocknock.viewcomponents.R.array
+import com.afollestad.nocknock.viewcomponents.R.layout
+import com.afollestad.nocknock.viewcomponents.livedata.attachLiveData
+import com.afollestad.nocknock.viewcomponents.livedata.lifecycleOwner
+import com.afollestad.nocknock.viewcomponents.livedata.toViewError
+import kotlinx.android.synthetic.main.validation_interval_layout.view.input
+import kotlinx.android.synthetic.main.validation_interval_layout.view.spinner
+
+/** @author Aidan Follestad (@afollestad) */
+class ValidationIntervalLayout(
+  context: Context,
+  attrs: AttributeSet? = null
+) : LinearLayout(context, attrs) {
+
+  companion object {
+    const val INDEX_MINUTE = 0
+    const val INDEX_HOUR = 1
+    const val INDEX_DAY = 2
+    const val INDEX_WEEK = 3
+  }
+
+  init {
+    orientation = VERTICAL
+    inflate(context, layout.validation_interval_layout, this)
+  }
+
+  override fun onFinishInflate() {
+    super.onFinishInflate()
+    val spinnerAdapter = ArrayAdapter(
+        context,
+        layout.list_item_spinner,
+        resources.getStringArray(array.interval_options)
+    )
+    spinnerAdapter.setDropDownViewResource(
+        layout.list_item_spinner_dropdown
+    )
+    spinner.adapter = spinnerAdapter
+  }
+
+  fun attach(
+    valueData: MutableLiveData<Int>,
+    multiplierData: MutableLiveData<Long>,
+    errorData: LiveData<Int?>
+  ) {
+    input.attachLiveData(lifecycleOwner(), valueData)
+    spinner.attachLiveData(
+        lifecycleOwner = lifecycleOwner(),
+        data = multiplierData,
+        inTransformer = {
+          when (it) {
+            MINUTE -> 0
+            HOUR -> 1
+            DAY -> 2
+            WEEK -> 3
+            else -> throw IllegalStateException("Unknown multiplier: $it")
+          }
+        },
+        outTransformer = {
+          when (it) {
+            INDEX_MINUTE -> MINUTE
+            INDEX_HOUR -> HOUR
+            INDEX_DAY -> DAY
+            INDEX_WEEK -> WEEK
+            else -> throw IllegalStateException("Unknown multiplier index: $it")
+          }
+        }
+    )
+    errorData.toViewError(lifecycleOwner(), this, ::setError)
+  }
+
+  private fun setError(error: String?) {
+    input.error = error
+  }
+}

viewcomponents/src/main/kotlin/com/afollestad/nocknock/viewcomponents/js/JavaScriptInputLayout.kt

@@ -18,22 +18,17 @@ package com.afollestad.nocknock.viewcomponents.js
 import android.content.Context
 import android.util.AttributeSet
 import android.widget.HorizontalScrollView
-import androidx.lifecycle.Lifecycle.State.CREATED
-import androidx.lifecycle.Lifecycle.State.DESTROYED
-import androidx.lifecycle.Lifecycle.State.RESUMED
-import androidx.lifecycle.LifecycleOwner
-import androidx.lifecycle.LifecycleRegistry
 import androidx.lifecycle.LiveData
 import androidx.lifecycle.MutableLiveData
-import androidx.lifecycle.Observer
-import com.afollestad.nocknock.utilities.ext.onTextChanged
 import com.afollestad.nocknock.viewcomponents.R.dimen
 import com.afollestad.nocknock.viewcomponents.R.layout
-import com.afollestad.nocknock.viewcomponents.R.string
 import com.afollestad.nocknock.viewcomponents.ext.dimenFloat
 import com.afollestad.nocknock.viewcomponents.ext.dimenInt
 import com.afollestad.nocknock.viewcomponents.ext.showOrHide
-import com.afollestad.nocknock.viewcomponents.ext.toViewVisibility
+import com.afollestad.nocknock.viewcomponents.livedata.attachLiveData
+import com.afollestad.nocknock.viewcomponents.livedata.lifecycleOwner
+import com.afollestad.nocknock.viewcomponents.livedata.toViewError
+import com.afollestad.nocknock.viewcomponents.livedata.toViewVisibility
 import kotlinx.android.synthetic.main.javascript_input_layout.view.error_text
 import kotlinx.android.synthetic.main.javascript_input_layout.view.userInput
 
@@ -41,10 +36,7 @@ import kotlinx.android.synthetic.main.javascript_input_layout.view.userInput
 class JavaScriptInputLayout(
   context: Context,
   attrs: AttributeSet? = null
-) : HorizontalScrollView(context, attrs), LifecycleOwner {
+) : HorizontalScrollView(context, attrs) {
-
-  private val lifecycle = LifecycleRegistry(this)
-  private lateinit var codeData: MutableLiveData<String>
 
   init {
     val contentInset = dimenInt(dimen.content_inset)
@@ -61,51 +53,20 @@ class JavaScriptInputLayout(
     inflate(context, layout.javascript_input_layout, this)
   }
 
-  override fun onFinishInflate() {
-    super.onFinishInflate()
-    lifecycle.markState(CREATED)
-  }
-
-  override fun onAttachedToWindow() {
-    super.onAttachedToWindow()
-    lifecycle.markState(RESUMED)
-  }
-
-  override fun onDetachedFromWindow() {
-    lifecycle.markState(DESTROYED)
-    super.onDetachedFromWindow()
-  }
-
-  fun setError(error: String?) {
-    error_text.showOrHide(error != null)
-    error_text.text = error
-  }
-
   fun attach(
     codeData: MutableLiveData<String>,
     errorData: LiveData<Int?>,
     visibility: LiveData<Boolean>
   ) {
-    this.codeData = codeData
+    userInput.attachLiveData(lifecycleOwner(), codeData)
-    this.codeData.observe(this, Observer {
+    errorData.toViewError(lifecycleOwner(), this, ::setError)
-      if (it.isNullOrEmpty()) {
+    visibility.toViewVisibility(lifecycleOwner(), this)
-        setDefaultCode()
-      } else {
-        userInput.setText(it)
-      }
-    })
-    errorData.observe(this, Observer {
-      setError(if (it != null) resources.getString(it) else null)
-    })
-    visibility.toViewVisibility(this, this)
-    userInput.onTextChanged { this.codeData.value = it }
   }
 
   fun clear() = userInput.setText("")
 
-  private fun setDefaultCode() = userInput.setText(
+  private fun setError(error: String?) {
-      string.default_js
+    error_text.showOrHide(error != null)
-  )
+    error_text.text = error
-
+  }
-  override fun getLifecycle() = lifecycle
 }

viewcomponents/src/main/kotlin/com/afollestad/nocknock/viewcomponents/livedata/LiveDataViewExt.kt

@@ -0,0 +1,120 @@
+/**
+ * Designed and developed by Aidan Follestad (@afollestad)
+ *
+ * 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.afollestad.nocknock.viewcomponents.livedata
+
+import android.view.View
+import android.widget.EditText
+import android.widget.Spinner
+import android.widget.TextView
+import androidx.lifecycle.LifecycleOwner
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.Observer
+import com.afollestad.nocknock.utilities.ext.onTextChanged
+import com.afollestad.nocknock.utilities.ext.setTextAndMaintainSelection
+import com.afollestad.nocknock.utilities.livedata.distinct
+import com.afollestad.nocknock.viewcomponents.ext.onItemSelected
+import com.afollestad.nocknock.viewcomponents.ext.showOrHide
+
+inline fun <reified T> EditText.attachLiveData(
+  lifecycleOwner: LifecycleOwner,
+  data: MutableLiveData<T>,
+  debounce: Int = 100,
+  pushOutChanges: Boolean = true,
+  pullInChanges: Boolean = false
+) {
+  // Initial value
+  if (T::class == String::class) {
+    data.value = this.text.trim().toString() as T
+  }
+  // Out
+  if (pushOutChanges) {
+    when {
+      T::class == Int::class -> {
+        onTextChanged(debounce) { data.postValue(it.trim().toInt() as T) }
+      }
+      T::class == Long::class -> {
+        onTextChanged(debounce) { data.postValue(it.trim().toLong() as T) }
+      }
+      T::class == String::class -> {
+        onTextChanged(debounce) { data.postValue(it as T) }
+      }
+      else -> {
+        throw IllegalArgumentException("Can't send EditText text changes into ${T::class}")
+      }
+    }
+  }
+  // In
+  if (pullInChanges) {
+    data.distinct()
+        .observe(lifecycleOwner, Observer {
+          when {
+            T::class == Int::class -> setText(it as Int)
+            T::class == String::class -> setTextAndMaintainSelection(it as String)
+          }
+        })
+  }
+}
+
+fun <T> Spinner.attachLiveData(
+  lifecycleOwner: LifecycleOwner,
+  data: MutableLiveData<T>,
+  outTransformer: (Int) -> T,
+  inTransformer: (T) -> Int
+) {
+  // Out
+  onItemSelected { data.postValue(outTransformer(it)) }
+  // In
+  data.distinct()
+      .observe(lifecycleOwner, Observer {
+        setSelection(inTransformer(it))
+      })
+}
+
+fun LiveData<Int?>.toViewError(
+  owner: LifecycleOwner,
+  view: View,
+  setter: (String?) -> Unit
+) = observe(owner, Observer { error ->
+  setter(
+      if (error != null) {
+        view.resources.getString(error)
+      } else {
+        null
+      }
+  )
+})
+
+fun LiveData<Int?>.toViewError(
+  owner: LifecycleOwner,
+  view: EditText
+) = toViewError(owner, view, view::setError)
+
+fun LiveData<*>.toViewText(
+  owner: LifecycleOwner,
+  view: TextView
+) = distinct().observe(owner, Observer {
+  when (it) {
+    is Int -> view.setText(it)
+    is String -> view.text = it
+    else -> throw IllegalStateException("Can't set $it to a text view.")
+  }
+})
+
+fun LiveData<Boolean>.toViewVisibility(
+  owner: LifecycleOwner,
+  view: View
+) = distinct().observe(owner, Observer { view.showOrHide(it) })

viewcomponents/src/main/kotlin/com/afollestad/nocknock/viewcomponents/livedata/ViewLifecycleOwner.kt

@@ -0,0 +1,59 @@
+/**
+ * Designed and developed by Aidan Follestad (@afollestad)
+ *
+ * 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.afollestad.nocknock.viewcomponents.livedata
+
+import android.view.View
+import android.view.View.OnAttachStateChangeListener
+import androidx.lifecycle.Lifecycle.State.CREATED
+import androidx.lifecycle.Lifecycle.State.DESTROYED
+import androidx.lifecycle.Lifecycle.State.RESUMED
+import androidx.lifecycle.Lifecycle.State.STARTED
+import androidx.lifecycle.LifecycleOwner
+import androidx.lifecycle.LifecycleRegistry
+import com.afollestad.nocknock.viewcomponents.R
+
+/** @author Aidan Follestad (@afollestad) */
+class ViewLifecycleOwner(view: View) : LifecycleOwner, OnAttachStateChangeListener {
+
+  private val lifecycleRegistry = LifecycleRegistry(this)
+
+  init {
+    view.addOnAttachStateChangeListener(this)
+  }
+
+  override fun getLifecycle() = lifecycleRegistry
+
+  override fun onViewAttachedToWindow(v: View?) {
+    lifecycleRegistry.markState(CREATED)
+    lifecycleRegistry.markState(STARTED)
+    lifecycleRegistry.markState(RESUMED)
+  }
+
+  override fun onViewDetachedFromWindow(v: View) {
+    lifecycleRegistry.markState(DESTROYED)
+  }
+}
+
+fun View.lifecycleOwner(): LifecycleOwner {
+  val tagOwner = getTag(R.id.view_lifecycle_registry) as? ViewLifecycleOwner
+  return if (tagOwner != null) {
+    tagOwner
+  } else {
+    val newOwner = ViewLifecycleOwner(this)
+    setTag(R.id.view_lifecycle_registry, newOwner)
+    newOwner
+  }
+}

viewcomponents/src/main/res/values/ids.xml

@@ -0,0 +1,4 @@
+<?xml version="1.0" encoding="utf-8"?>
+<resources>
+  <item format="integer" name="view_lifecycle_registry" type="id"/>
+</resources>