Merge pull request #1 from wada811/feature/support-enum-and-custom-de…

…legate

Support enum and custom delegate

ViewModel-SavedState-ktx/build.gradle

@@ -12,5 +12,6 @@ android {
 
 dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
-    api 'androidx.lifecycle:lifecycle-viewmodel-savedstate:1.0.0-alpha05'
+    implementation 'androidx.lifecycle:lifecycle-livedata:2.2.0-beta01'
+    api 'androidx.lifecycle:lifecycle-viewmodel-savedstate:1.0.0-beta01'
 }

ViewModel-SavedState-ktx/src/main/java/com/wada811/viewmodelsavedstate/Bundle.kt

@@ -0,0 +1,6 @@
+package com.wada811.viewmodelsavedstate
+
+import android.os.Bundle
+
+@Suppress("unused")
+fun <T : Enum<T>> Bundle.putEnum(key: String, enum: T) = this.putInt(key, enum.toInt())

ViewModel-SavedState-ktx/src/main/java/com/wada811/viewmodelsavedstate/EnumConverter.kt

@@ -0,0 +1,5 @@
+package com.wada811.viewmodelsavedstate
+
+internal fun <T> Int?.toEnum(enumClass: Class<T>): T? = this?.let { enumClass.enumConstants!![this] }
+internal fun <T> T?.toInt(): Int? = (this as? Enum<*>)?.ordinal
+internal fun <T : Enum<T>> T.toInt(): Int = this.ordinal

ViewModel-SavedState-ktx/src/main/java/com/wada811/viewmodelsavedstate/Intent.kt

@@ -0,0 +1,6 @@
+package com.wada811.viewmodelsavedstate
+
+import android.content.Intent
+
+@Suppress("unused")
+fun <T : Enum<T>> Intent.putEnumExtra(key: String, enum: T) = this.putExtra(key, enum.toInt())

ViewModel-SavedState-ktx/src/main/java/com/wada811/viewmodelsavedstate/SavedStateViewModel.kt

@@ -1,5 +1,6 @@
 package com.wada811.viewmodelsavedstate
 
+import androidx.lifecycle.MediatorLiveData
 import androidx.lifecycle.MutableLiveData
 import androidx.lifecycle.SavedStateHandle
 import androidx.lifecycle.ViewModel
@@ -9,38 +10,118 @@ import kotlin.reflect.KProperty
 
 @Suppress("unused")
 abstract class SavedStateViewModel(private val savedStateHandle: SavedStateHandle) : ViewModel() {
-    protected fun <T> savedStateProperty(key: String? = null): ReadWriteProperty<SavedStateViewModel, T> {
-        return SavedStateProperty(savedStateHandle, key)
+    @Suppress("DEPRECATION")
+    protected inline fun <reified T> savedStateProperty(key: String? = null): ReadWriteProperty<SavedStateViewModel, T> {
+        return if (T::class.java.isEnum) _savedStateEnumProperty(T::class.java, key) else _savedStateBundleProperty(key)
     }
 
-    protected fun <T> savedStateLiveData(key: String? = null): ReadOnlyProperty<SavedStateViewModel, MutableLiveData<T>> {
+    @Suppress("FunctionName")
+    @Deprecated("Use savedStateProperty<T>(key)", ReplaceWith("savedStateProperty(key)"), DeprecationLevel.WARNING)
+    protected fun <T> _savedStateBundleProperty(key: String? = null): ReadWriteProperty<SavedStateViewModel, T> {
+        return savedStateProperty<T, T>({ it }, { it }, key)
+    }
+
+    @Suppress("FunctionName", "UNCHECKED_CAST")
+    @Deprecated("Use savedStateProperty<T>(key)", ReplaceWith("savedStateProperty(key)"), DeprecationLevel.WARNING)
+    protected fun <T> _savedStateEnumProperty(enumClass: Class<T>, key: String?): ReadWriteProperty<SavedStateViewModel, T> {
+        return savedStateProperty<Int?, T>({ it.toEnum(enumClass) as T }, { it.toInt() }, key)
+    }
+
+    @Suppress("MemberVisibilityCanBePrivate")
+    protected fun <T, R> savedStateProperty(deserialize: (T) -> R, serialize: (R) -> T, key: String? = null): ReadWriteProperty<SavedStateViewModel, R> {
+        return SavedStateProperty(savedStateHandle, key, deserialize, serialize)
+    }
+
+    @Suppress("DEPRECATION")
+    protected inline fun <reified T> savedStateLiveData(key: String? = null): ReadOnlyProperty<SavedStateViewModel, MutableLiveData<T>> {
+        return if (T::class.java.isEnum) _savedStateEnumLiveData(T::class.java, key) else _savedStateBundleLiveData(key)
+    }
+
+    @Suppress("FunctionName")
+    @Deprecated("Use savedStateLiveData<T>(key)", ReplaceWith("savedStateLiveData(key)"), DeprecationLevel.WARNING)
+    protected fun <T> _savedStateBundleLiveData(key: String? = null): ReadOnlyProperty<SavedStateViewModel, MutableLiveData<T>> {
         return SavedStateLiveData(savedStateHandle, key)
     }
 
-    internal class SavedStateProperty<T>(
+    @Suppress("FunctionName", "UNCHECKED_CAST")
+    @Deprecated("Use savedStateLiveData<T>(key)", ReplaceWith("savedStateLiveData(key)"), DeprecationLevel.WARNING)
+    protected fun <T> _savedStateEnumLiveData(enumClass: Class<T>, key: String?): ReadOnlyProperty<SavedStateViewModel, MutableLiveData<T>> {
+        return savedStateLiveData<Int?, T>({ it.toEnum(enumClass) as T }, { it.toInt() }, key)
+    }
+
+    @Suppress("MemberVisibilityCanBePrivate")
+    protected fun <T, R> savedStateLiveData(deserialize: (T) -> R, serialize: (R) -> T, key: String? = null): ReadOnlyProperty<SavedStateViewModel, MutableLiveData<R>> {
+        return SavedStateDelegatedLiveData(savedStateHandle, key, deserialize, serialize)
+    }
+
+    private class SavedStateProperty<T, R>(
         private val savedStateHandle: SavedStateHandle,
-        private val key: String? = null
-    ) : ReadWriteProperty<SavedStateViewModel, T> {
+        private val key: String?,
+        private val deserialize: (T) -> R,
+        private val serialize: (R) -> T
+    ) : ReadWriteProperty<SavedStateViewModel, R> {
+
         @Suppress("RemoveExplicitTypeArguments", "UNCHECKED_CAST")
-        override fun getValue(thisRef: SavedStateViewModel, property: KProperty<*>): T {
-            return savedStateHandle.get<T>(key ?: property.name) as T
+        override fun getValue(thisRef: SavedStateViewModel, property: KProperty<*>): R {
+            return deserialize(savedStateHandle.get<T>(key ?: property.name) as T)
         }
 
-        override fun setValue(thisRef: SavedStateViewModel, property: KProperty<*>, value: T) {
-            savedStateHandle.set(key ?: property.name, value)
+        override fun setValue(thisRef: SavedStateViewModel, property: KProperty<*>, value: R) {
+            savedStateHandle.set(key ?: property.name, serialize(value))
         }
     }
 
-    internal class SavedStateLiveData<T>(
+    private class SavedStateLiveData<T>(
         private val savedStateHandle: SavedStateHandle,
-        private val key: String? = null
+        private val key: String?
     ) : ReadOnlyProperty<SavedStateViewModel, MutableLiveData<T>> {
         override fun getValue(thisRef: SavedStateViewModel, property: KProperty<*>): MutableLiveData<T> {
             return savedStateHandle.getLiveData(key ?: property.name)
         }
     }
 
-    companion object {
-        private const val KEY_TEXT = "text"
+    private class SavedStateDelegatedLiveData<T, R>(
+        private val savedStateHandle: SavedStateHandle,
+        private val key: String?,
+        private val deserialize: (T) -> R,
+        private val serialize: (R) -> T
+    ) : ReadOnlyProperty<SavedStateViewModel, MutableLiveData<R>> {
+        private var savedStateLiveData: MutableLiveData<R>? = null
+
+        override fun getValue(thisRef: SavedStateViewModel, property: KProperty<*>): MutableLiveData<R> {
+            if (savedStateLiveData == null) {
+                savedStateLiveData = SavedStateLiveData(savedStateHandle, key ?: property.name, deserialize, serialize)
+            }
+            return savedStateLiveData!!
+        }
+
+        @Suppress("UNCHECKED_CAST")
+        private class SavedStateLiveData<T, R>(
+            savedStateHandle: SavedStateHandle,
+            key: String,
+            private val deserialize: (T) -> R,
+            private val serialize: (R) -> T
+        ) : MediatorLiveData<R>() {
+            private val liveData: MutableLiveData<T> = savedStateHandle.getLiveData<T>(key)
+
+            init {
+                value = deserialize(liveData.value as T)
+                addSource(liveData) {
+                    value = deserialize(it as T)
+                }
+            }
+
+            override fun getValue(): R {
+                return deserialize(liveData.value as T)
+            }
+
+            override fun setValue(value: R) {
+                super.setValue(value)
+                val serializedValue = serialize(value)
+                if (liveData.value != serializedValue) {
+                    liveData.value = serializedValue
+                }
+            }
+        }
     }
 }

sample/build.gradle

@@ -34,10 +34,10 @@ dependencies {
     implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
 
     implementation 'androidx.appcompat:appcompat:1.1.0'
-    implementation 'androidx.activity:activity:1.1.0-alpha03'
-    implementation 'androidx.activity:activity-ktx:1.1.0-alpha03'
-    implementation 'androidx.fragment:fragment:1.2.0-alpha04'
-    implementation 'androidx.fragment:fragment-ktx:1.2.0-alpha04'
+    implementation 'androidx.activity:activity:1.1.0-beta01'
+    implementation 'androidx.activity:activity-ktx:1.1.0-beta01'
+    implementation 'androidx.fragment:fragment:1.2.0-beta01'
+    implementation 'androidx.fragment:fragment-ktx:1.2.0-beta01'
     implementation project(':ViewModel-SavedState-ktx')
     implementation 'com.github.wada811:DataBinding-ktx:2.0.2'
     implementation 'androidx.constraintlayout:constraintlayout:1.1.3'

sample/src/main/java/com/wada811/viewmodelsavedstate/sample/SampleActivity.kt

@@ -7,6 +7,7 @@ import android.widget.Toast
 import androidx.activity.viewModels
 import androidx.appcompat.app.AppCompatActivity
 import com.wada811.databinding.dataBinding
+import com.wada811.viewmodelsavedstate.sample.SampleViewModel.CountUpValue
 import com.wada811.viewmodelsavedstate.sample.databinding.SampleActivityBinding
 
 class SampleActivity : AppCompatActivity() {
@@ -21,9 +22,22 @@ class SampleActivity : AppCompatActivity() {
         binding.viewModel = viewModel
         binding.activityCountText.text = "$count"
         binding.countUpButton.setOnClickListener {
-            binding.activityCountText.text = "${++count}"
+            count += viewModel.countUpValueEnumLiveData.value?.count ?: 0
+            binding.activityCountText.text = "$count"
             viewModel.countUp()
         }
+        binding.plusOneButton.setOnCheckedChangeListener { _, isChecked ->
+            if (isChecked) {
+                binding.plusTenButton.isChecked = false
+            }
+            viewModel.countUpValueIntLiveData.value = if (isChecked) CountUpValue.ONE.ordinal else null
+        }
+        binding.plusTenButton.setOnCheckedChangeListener { _, isChecked ->
+            if (isChecked) {
+                binding.plusOneButton.isChecked = false
+            }
+            viewModel.countUpValueEnumLiveData.value = if (isChecked) CountUpValue.TEN else null
+        }
         binding.rotateButton.setOnClickListener {
             viewModel.appendLog("Activity::rotate")
             requestedOrientation = when (requestedOrientation) {

sample/src/main/java/com/wada811/viewmodelsavedstate/sample/SampleViewModel.kt

@@ -7,29 +7,35 @@ import androidx.lifecycle.SavedStateHandle
 import com.wada811.viewmodelsavedstate.SavedStateViewModel
 
 class SampleViewModel(savedStateHandle: SavedStateHandle) : SavedStateViewModel(savedStateHandle) {
+    enum class CountUpValue(val count: Int) {
+        ONE(1),
+        TEN(10)
+    }
+
     private var viewModelCount = MutableLiveData(0)
     var viewModelCountText: LiveData<String> = MediatorLiveData<String>().also { liveData ->
         liveData.addSource(viewModelCount) { count ->
             liveData.value = "$count"
         }
     }
-
-    val savedStateCount: MutableLiveData<Int> by savedStateLiveData(SampleViewModel::savedStateCount.name)
+    val countUpValueIntLiveData: MutableLiveData<Int?> by savedStateLiveData(this::countUpValueEnumLiveData.name)
+    val countUpValueEnumLiveData: MutableLiveData<CountUpValue?> by savedStateLiveData()
+    val savedStateCount: MutableLiveData<Int> by savedStateLiveData()
     var savedStateCountText: LiveData<String> = MediatorLiveData<String>().also { liveData ->
         liveData.addSource(savedStateCount) { count ->
             liveData.value = "$count"
         }
     }
 
-    val log: MutableLiveData<String> by savedStateLiveData(SampleViewModel::log.name)
+    val log: MutableLiveData<String> by savedStateLiveData()
 
     init {
         appendLog("ViewModel::init")
     }
 
     fun countUp() {
-        viewModelCount.value = viewModelCount.value?.plus(1)
-        savedStateCount.value = savedStateCount.value?.plus(1)
+        viewModelCount.value = viewModelCount.value?.plus(CountUpValue.values().firstOrNull { it.ordinal == countUpValueIntLiveData.value }?.count ?: 0)
+        savedStateCount.value = savedStateCount.value?.plus(countUpValueEnumLiveData.value?.count ?: 0)
     }
 
     fun appendLog(text: String) {