add RvmSavedStateDelegates

Author: Alex

reactiveviewmodel/build.gradle

@@ -44,7 +44,7 @@ afterEvaluate {
             release(MavenPublication) {
                 from components.release
                 groupId = 'com.alexdeww.reactiveviewmodel'
-                version = '2.4.1'
+                version = '2.4.2'
             }
         }
     }

reactiveviewmodel/src/main/java/com/alexdeww/reactiveviewmodel/core/RvmSavedStateDelegates.kt

@@ -0,0 +1,127 @@
+package com.alexdeww.reactiveviewmodel.core
+
+import androidx.lifecycle.SavedStateHandle
+import com.alexdeww.reactiveviewmodel.core.property.State
+import com.alexdeww.reactiveviewmodel.widget.BaseVisualControl
+import com.alexdeww.reactiveviewmodel.widget.FormatterAction
+import com.alexdeww.reactiveviewmodel.widget.InputControl
+import com.alexdeww.reactiveviewmodel.widget.RatingControl
+import kotlin.properties.ReadOnlyProperty
+import kotlin.properties.ReadWriteProperty
+import kotlin.reflect.KProperty
+
+fun <T> SavedStateHandle.delegate(
+    initValue: (thisRef: ReactiveViewModel, stateHandle: SavedStateHandle, key: String) -> T
+): ReadWriteProperty<ReactiveViewModel, T> = SavedStateProperty(this, initValue)
+
+fun <T : Any> SavedStateHandle.value(
+    initialValue: T? = null
+): ReadWriteProperty<ReactiveViewModel, T?> = delegate { _, stateHandle, key ->
+    if (stateHandle.contains(key)) stateHandle[key]
+    else initialValue
+}
+
+fun <T : Any> SavedStateHandle.valueNonNull(
+    defaultValue: T
+): ReadWriteProperty<ReactiveViewModel, T> = delegate { _, stateHandle, key ->
+    stateHandle[key] ?: defaultValue
+}
+
+fun <T : Any> SavedStateHandle.state(
+    initialValue: T? = null,
+    debounceInterval: Long? = null
+): ReadOnlyProperty<ReactiveViewModel, State<T>> = delegate { thisRef, stateHandle, key ->
+    val state = State(stateHandle[key] ?: initialValue, debounceInterval)
+    thisRef.run { state.viewFlowable.subscribe { stateHandle[key] = it }.disposeOnCleared() }
+    state
+}
+
+fun SavedStateHandle.inputControl(
+    initialText: String = "",
+    hideErrorOnUserInput: Boolean = true,
+    formatter: FormatterAction? = null,
+    initialEnabled: Boolean = true,
+    initialVisibility: BaseVisualControl.Visibility = BaseVisualControl.Visibility.VISIBLE
+): ReadOnlyProperty<ReactiveViewModel, InputControl> = delegate { thisRef, stateHandle, key ->
+    val textKey = "$key.text"
+    val errorKey = "$key.error"
+    val enabledKey = "$key.enabled"
+    val visibilityKey = "$key.visibility"
+    val control = InputControl(
+        initialText = stateHandle[textKey] ?: initialText,
+        hideErrorOnUserInput = hideErrorOnUserInput,
+        formatter = formatter,
+        initialEnabled = stateHandle[enabledKey] ?: initialEnabled,
+        initialVisibility = stateHandle[visibilityKey] ?: initialVisibility
+    )
+    thisRef.run {
+        control.value.viewFlowable
+            .subscribe { stateHandle[textKey] = it }
+            .disposeOnCleared()
+        control.error.viewFlowable
+            .subscribe { stateHandle[errorKey] = it }
+            .disposeOnCleared()
+        control.enabled.viewFlowable
+            .subscribe { stateHandle[enabledKey] = it }
+            .disposeOnCleared()
+        control.visibility.viewFlowable
+            .subscribe { stateHandle[visibilityKey] = it }
+            .disposeOnCleared()
+    }
+    control
+}
+
+fun SavedStateHandle.ratingControl(
+    initialValue: Float = 0f,
+    initialEnabled: Boolean = true,
+    initialVisibility: BaseVisualControl.Visibility = BaseVisualControl.Visibility.VISIBLE
+): ReadOnlyProperty<ReactiveViewModel, RatingControl> = delegate { thisRef, stateHandle, key ->
+    val ratingKey = "$key.rating"
+    val enabledKey = "$key.enabled"
+    val visibilityKey = "$key.visibility"
+    val control = RatingControl(
+        initialValue = stateHandle[ratingKey] ?: initialValue,
+        initialEnabled = stateHandle[enabledKey] ?: initialEnabled,
+        initialVisibility = stateHandle[visibilityKey] ?: initialVisibility
+    )
+    thisRef.run {
+        control.value.viewFlowable
+            .subscribe { stateHandle[ratingKey] = it }
+            .disposeOnCleared()
+        control.enabled.viewFlowable
+            .subscribe { stateHandle[enabledKey] = it }
+            .disposeOnCleared()
+        control.visibility.viewFlowable
+            .subscribe { stateHandle[visibilityKey] = it }
+            .disposeOnCleared()
+    }
+    control
+}
+
+@PublishedApi
+internal class SavedStateProperty<T>(
+    private val savedStateHandle: SavedStateHandle,
+    private val initValue: (thisRef: ReactiveViewModel, stateHandle: SavedStateHandle, key: String) -> T
+) : ReadWriteProperty<ReactiveViewModel, T> {
+
+    private object NoneValue
+
+    private var value: Any? = NoneValue
+
+    @Suppress("UNCHECKED_CAST")
+    override fun getValue(thisRef: ReactiveViewModel, property: KProperty<*>): T {
+        if (value === NoneValue) {
+            value = initValue(thisRef, savedStateHandle, getStateKey(thisRef, property))
+        }
+        return value as T
+    }
+
+    override fun setValue(thisRef: ReactiveViewModel, property: KProperty<*>, value: T) {
+        this.value = value
+        savedStateHandle[getStateKey(thisRef, property)] = value
+    }
+
+    private fun getStateKey(thisRef: ReactiveViewModel, property: KProperty<*>): String =
+        "${thisRef::class.java.simpleName}.${property.name}"
+
+}