Wizard: rework UI components for settings

#KT-35712 fixed

idea/idea-new-project-wizard/src/org/jetbrains/kotlin/tools/projectWizard/wizard/ui/components/CheckboxComponent.kt

@@ -0,0 +1,32 @@
+package org.jetbrains.kotlin.tools.projectWizard.wizard.ui.components
+
+import com.intellij.ui.components.JBCheckBox
+import com.intellij.ui.components.JBTextField
+import org.jetbrains.kotlin.tools.projectWizard.core.ValuesReadingContext
+import org.jetbrains.kotlin.tools.projectWizard.core.entity.SettingValidator
+import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.textField
+
+class CheckboxComponent(
+    valuesReadingContext: ValuesReadingContext,
+    labelText: String? = null,
+    initialValue: Boolean? = null,
+    validator: SettingValidator<Boolean>? = null,
+    onValueUpdate: (Boolean) -> Unit = {}
+) : UIComponent<Boolean>(
+    valuesReadingContext,
+    labelText,
+    validator,
+    onValueUpdate
+) {
+    override val uiComponent: JBCheckBox = JBCheckBox(labelText, initialValue ?: false).apply {
+        addChangeListener {
+            fireValueUpdated(this@apply.isSelected)
+        }
+    }
+
+    override fun updateUiValue(newValue: Boolean) = safeUpdateUi {
+        uiComponent.isSelected = newValue
+    }
+
+    override fun getUiValue(): Boolean = uiComponent.isSelected
+}

idea/idea-new-project-wizard/src/org/jetbrains/kotlin/tools/projectWizard/wizard/ui/components/DropDownComponent.kt

@@ -3,46 +3,34 @@ package org.jetbrains.kotlin.tools.projectWizard.wizard.ui.components
 import com.intellij.openapi.ui.ComboBox
 import com.intellij.ui.ColoredListCellRenderer
 import com.intellij.ui.SimpleTextAttributes
+import org.jetbrains.kotlin.tools.projectWizard.core.ValuesReadingContext
 import org.jetbrains.kotlin.tools.projectWizard.core.entity.SettingValidator
 import org.jetbrains.kotlin.tools.projectWizard.core.entity.ValidationResult
-import org.jetbrains.kotlin.tools.projectWizard.core.ValuesReadingContext
 import org.jetbrains.kotlin.tools.projectWizard.core.entity.settingValidator
-import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.Component
-import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.panel
-import java.awt.BorderLayout
-import javax.swing.JComponent
 import org.jetbrains.kotlin.tools.projectWizard.settings.DisplayableSettingItem
-import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.setting.ValidationIndicator
 import org.jetbrains.kotlin.utils.addToStdlib.safeAs
 import java.awt.event.ItemEvent
-import javax.swing.DefaultComboBoxModel
 import javax.swing.Icon
 import javax.swing.JList
 
 class DropDownComponent<T : DisplayableSettingItem>(
     private val valuesReadingContext: ValuesReadingContext,
-    private val initialValues: List<T> = emptyList(),
+    initialValues: List<T> = emptyList(),
     labelText: String? = null,
-    private val filter: (T) -> Boolean = { true },
+    filter: (T) -> Boolean = { true },
     private val validator: SettingValidator<T> = settingValidator { ValidationResult.OK },
     private val iconProvider: (T) -> Icon? = { null },
-    private val onAnyValueUpdate: (T) -> Unit = {}
-) : Component() {
+    onValueUpdate: (T) -> Unit = {}
+) : UIComponent<T>(
+    valuesReadingContext,
+    labelText,
+    validator,
+    onValueUpdate
+) {
     @Suppress("UNCHECKED_CAST")
-
-    private val validationIndicator = ValidationIndicator(defaultText = labelText, showText = true)
-
-    private var allowFireEventWhenValueUpdated: Boolean = true
-
-    private fun withoutActionFiring(action: () -> Unit) {
-        val initialAllowFireEventWhenValueUpdated = allowFireEventWhenValueUpdated
-        allowFireEventWhenValueUpdated = false
-        action()
-        allowFireEventWhenValueUpdated = initialAllowFireEventWhenValueUpdated
-    }
-
-    @Suppress("UNCHECKED_CAST")
-    private val comboBox = ComboBox<T>().apply {
+    override val uiComponent: ComboBox<T> = ComboBox<T>(
+        initialValues.filter(filter).toTypedArray<DisplayableSettingItem>() as Array<T>
+    ).apply {
         renderer = object : ColoredListCellRenderer<T>() {
             override fun customizeCellRenderer(
                 list: JList<out T>,
@@ -69,55 +57,19 @@ class DropDownComponent<T : DisplayableSettingItem>(
             }
         }
 
-        addItemListener { e ->
-            if (e?.stateChange == ItemEvent.SELECTED) {
-                value = e.item as T
+        addItemListener { event ->
+            if (event?.stateChange == ItemEvent.SELECTED) {
+                @Suppress("UNCHECKED_CAST")
+                (event.item as? T)?.let(::fireValueUpdated)
             }
         }
     }
 
-    override fun onInit() {
-        super.onInit()
-        updateValues(initialValues)
-    }
-
-    fun updateValues(newValues: List<T>) {
-        val newValuesFiltered = newValues.filter(filter)
-        val oldValue = comboBox.selectedItem
-        withoutActionFiring {
-            @Suppress("UNCHECKED_CAST")
-            comboBox.model = DefaultComboBoxModel(newValuesFiltered.toTypedArray<DisplayableSettingItem>() as Array<T>)
-        }
-
-        if (oldValue !in newValuesFiltered) {
-            newValuesFiltered.firstOrNull()?.let { newValue ->
-                value = newValuesFiltered.first()
-            }
-        }
-    }
-
-    override val component: JComponent = panel {
-        add(validationIndicator, BorderLayout.NORTH)
-        add(comboBox, BorderLayout.CENTER)
+    override fun updateUiValue(newValue: T) = safeUpdateUi {
+        uiComponent.selectedItem = newValue
     }
 
     @Suppress("UNCHECKED_CAST")
-    var value: T
-        get() = comboBox.selectedItem as T
-        set(value) {
-            comboBox.selectedItem = value
-            fireValueChanged(value)
-        }
-
-    private fun fireValueChanged(newValue: T) {
-        validate(newValue)
-        if (allowFireEventWhenValueUpdated) {
-            onAnyValueUpdate(newValue)
-        }
-    }
-
-    fun validate(value: T = this.value) {
-        validationIndicator.validationState = validator.validate(valuesReadingContext, value)
-    }
+    override fun getUiValue(): T = uiComponent.selectedItem as T
 }
 

idea/idea-new-project-wizard/src/org/jetbrains/kotlin/tools/projectWizard/wizard/ui/components/PathFieldComponent.kt

@@ -6,24 +6,32 @@ import com.intellij.openapi.ui.TextFieldWithBrowseButton
 import org.jetbrains.kotlin.tools.projectWizard.core.entity.StringValidator
 import org.jetbrains.kotlin.tools.projectWizard.core.entity.ValidationResult
 import org.jetbrains.kotlin.tools.projectWizard.core.ValuesReadingContext
+import org.jetbrains.kotlin.tools.projectWizard.core.entity.SettingValidator
+import org.jetbrains.kotlin.tools.projectWizard.core.entity.settingValidator
 import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.Component
 import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.panel
 import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.setting.ValidationIndicator
 import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.textField
 import java.awt.BorderLayout
+import java.nio.file.Path
+import java.nio.file.Paths
+import javax.swing.Icon
 import javax.swing.JComponent
 
 class PathFieldComponent(
-    private val valuesReadingContext: ValuesReadingContext,
-    private val initialText: String = "",
-    labelText: String? = "",
-    private val validator: StringValidator = org.jetbrains.kotlin.tools.projectWizard.core.entity.settingValidator {  ValidationResult.OK },
-    private val onSuccessValueUpdate: (String) -> Unit = {},
-    private val onAnyValueUpdate: (String) -> Unit = {}
-) : Component() {
-    private val validationIndicator = ValidationIndicator(defaultText = labelText, showText = true)
-    private val pathField = TextFieldWithBrowseButton(
-        textField(initialText, this::fireValueChanged)
+    valuesReadingContext: ValuesReadingContext,
+    labelText: String? = null,
+    initialValue: Path? = null,
+    validator: SettingValidator<Path>? = null,
+    onValueUpdate: (Path) -> Unit = {}
+) : UIComponent<Path>(
+    valuesReadingContext,
+    labelText,
+    validator,
+    onValueUpdate
+) {
+    override val uiComponent: TextFieldWithBrowseButton = TextFieldWithBrowseButton(
+        textField(initialValue?.toString().orEmpty()) { path -> fireValueUpdated(Paths.get(path)) }
     ).apply {
         addBrowseFolderListener(
             TextBrowseFolderListener(
@@ -33,33 +41,9 @@ class PathFieldComponent(
         )
     }
 
-    override val component: JComponent = panel {
-        add(validationIndicator, BorderLayout.NORTH)
-        add(pathField, BorderLayout.CENTER)
+    override fun updateUiValue(newValue: Path)= safeUpdateUi {
+        uiComponent.text = newValue.toString()
     }
 
-
-    var value: String
-        get() = pathField.text
-        set(value) {
-            pathField.text = value
-            fireValueChanged(value)
-        }
-
-    private fun fireValueChanged(text: String) {
-        validate(text)
-        if (validationIndicator.validationState == ValidationResult.OK) {
-            onSuccessValueUpdate(text)
-        }
-        onAnyValueUpdate(text)
-    }
-
-    override fun onInit() {
-        super.onInit()
-        validate(initialText)
-    }
-
-    private fun validate(text: String) {
-        validationIndicator.validationState = validator.validate(valuesReadingContext, text)
-    }
+    override fun getUiValue(): Path = Paths.get(uiComponent.text)
 }

idea/idea-new-project-wizard/src/org/jetbrains/kotlin/tools/projectWizard/wizard/ui/components/TextFieldComponent.kt

@@ -1,54 +1,27 @@
 package org.jetbrains.kotlin.tools.projectWizard.wizard.ui.components
 
-import org.jetbrains.kotlin.tools.projectWizard.core.entity.StringValidator
-import org.jetbrains.kotlin.tools.projectWizard.core.entity.ValidationResult
+import com.intellij.ui.components.JBTextField
 import org.jetbrains.kotlin.tools.projectWizard.core.ValuesReadingContext
-import org.jetbrains.kotlin.tools.projectWizard.core.entity.settingValidator
-import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.Component
-import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.panel
-import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.setting.ValidationIndicator
+import org.jetbrains.kotlin.tools.projectWizard.core.entity.SettingValidator
 import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.textField
-import java.awt.BorderLayout
-import javax.swing.JComponent
 
 class TextFieldComponent(
-    private val valuesReadingContext: ValuesReadingContext,
-    private val initialText: String = "",
-    labelText: String? = "",
-    private val validator: StringValidator = settingValidator { ValidationResult.OK },
-    private val onSuccessValueUpdate: (String) -> Unit = {},
-    private val onAnyValueUpdate: (String) -> Unit = {}
-) : Component() {
-    private val validationIndicator = ValidationIndicator(defaultText = labelText, showText = true)
-    private val textField = textField(initialText, this::fireValueChanged)
+    valuesReadingContext: ValuesReadingContext,
+    labelText: String? = null,
+    initialValue: String? = null,
+    validator: SettingValidator<String>? = null,
+    onValueUpdate: (String) -> Unit = {}
+) : UIComponent<String>(
+    valuesReadingContext,
+    labelText,
+    validator,
+    onValueUpdate
+) {
+    override val uiComponent: JBTextField = textField(initialValue.orEmpty(), ::fireValueUpdated)
 
-    override val component: JComponent = panel {
-        add(validationIndicator, BorderLayout.NORTH)
-        add(textField, BorderLayout.CENTER)
+    override fun updateUiValue(newValue: String) = safeUpdateUi {
+        uiComponent.text = newValue
     }
 
-
-    var value: String
-        get() = textField.text
-        set(value) {
-            textField.text = value
-            fireValueChanged(value)
-        }
-
-    private fun fireValueChanged(text: String) {
-        validate(text)
-        if (validationIndicator.validationState == ValidationResult.OK) {
-            onSuccessValueUpdate(text)
-        }
-        onAnyValueUpdate(text)
-    }
-
-    override fun onInit() {
-        super.onInit()
-        validate(initialText)
-    }
-
-    private fun validate(text: String) {
-        validationIndicator.validationState = validator.validate(valuesReadingContext, text)
-    }
+    override fun getUiValue(): String = uiComponent.text
 }

idea/idea-new-project-wizard/src/org/jetbrains/kotlin/tools/projectWizard/wizard/ui/components/UIComponent.kt

@@ -0,0 +1,69 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.tools.projectWizard.wizard.ui.components
+
+import org.jetbrains.kotlin.tools.projectWizard.core.ValuesReadingContext
+import org.jetbrains.kotlin.tools.projectWizard.core.entity.Setting
+import org.jetbrains.kotlin.tools.projectWizard.core.entity.SettingType
+import org.jetbrains.kotlin.tools.projectWizard.core.entity.SettingValidator
+import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.DynamicComponent
+import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.panel
+import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.setting.ValidationIndicator
+import java.awt.BorderLayout
+import javax.swing.JComponent
+
+abstract class UIComponent<V : Any>(
+    private val valuesReadingContext: ValuesReadingContext,
+    labelText: String? = null,
+    private val validator: SettingValidator<V>? = null,
+    private val onValueUpdate: (V) -> Unit = {}
+) : DynamicComponent(valuesReadingContext) {
+    private val validationIndicator = if (validator != null)
+        ValidationIndicator(defaultText = labelText, showText = true)
+    else null
+
+    protected abstract val uiComponent: JComponent
+
+    abstract fun updateUiValue(newValue: V)
+    abstract fun getUiValue(): V
+
+    private var allowEventFiring = true
+
+    protected fun fireValueUpdated(value: V) {
+        if (allowEventFiring) {
+            onValueUpdate(value)
+        }
+        validate(value)
+    }
+
+    override fun onInit() {
+        super.onInit()
+        validate(getUiValue())
+    }
+
+    final override val component: JComponent by lazy(LazyThreadSafetyMode.NONE) {
+        panel {
+            validationIndicator?.let { add(it, BorderLayout.NORTH) }
+            add(uiComponent, BorderLayout.CENTER)
+        }
+    }
+
+    protected fun safeUpdateUi(updater: () -> Unit) {
+        val allowEventFiringSaved = allowEventFiring
+        allowEventFiring = false
+        updater()
+        allowEventFiring = allowEventFiringSaved
+    }
+
+    fun validate(value: V) {
+        if (validator == null) return
+        if (validationIndicator == null) return
+        validationIndicator.validationState = validator.validate(valuesReadingContext, value)
+    }
+}
+
+fun <V: Any> UIComponent<V>.valueForSetting(setting: Setting<V, SettingType<V>>): V =
+    setting.defaultValue ?:  getUiValue()

idea/idea-new-project-wizard/src/org/jetbrains/kotlin/tools/projectWizard/wizard/ui/firstStep/BuildSystemTypeSettingComponent.kt

@@ -11,39 +11,37 @@ import org.jetbrains.kotlin.tools.projectWizard.plugins.buildSystem.BuildSystemP
 import org.jetbrains.kotlin.tools.projectWizard.plugins.buildSystem.BuildSystemType
 import org.jetbrains.kotlin.tools.projectWizard.plugins.kotlin.KotlinPlugin
 import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.components.DropDownComponent
+import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.components.valueForSetting
 import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.panel
 import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.setting.SettingComponent
+import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.setting.UIComponentDelegatingSettingComponent
 import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.setting.ValidationIndicator
 import java.awt.BorderLayout
 
 
 class BuildSystemTypeSettingComponent(
     private val valuesReadingContext: ValuesReadingContext
-) : SettingComponent<BuildSystemType, DropDownSettingType<BuildSystemType>>(
+) : UIComponentDelegatingSettingComponent<BuildSystemType, DropDownSettingType<BuildSystemType>>(
     BuildSystemPlugin::type.reference,
     valuesReadingContext
 ) {
-    override val validationIndicator: ValidationIndicator? = null
-    private val listComponent = DropDownComponent(
+    override val uiComponent: DropDownComponent<BuildSystemType> = DropDownComponent(
         valuesReadingContext,
         setting.type.values,
         labelText = "Build System",
         filter = { value -> setting.type.filter(valuesReadingContext, reference, value) },
         validator = setting.validator,
         iconProvider = BuildSystemType::icon,
-        onAnyValueUpdate = { value = it }
+        onValueUpdate = { value = it }
     ).asSubComponent()
 
-    override val component = panel {
-        add(listComponent.component, BorderLayout.CENTER)
-    }
 
     override fun onValueUpdated(reference: SettingReference<*, *>?) {
         super.onValueUpdated(reference)
         if (reference == KotlinPlugin::projectKind.reference) {
-            listComponent.component.updateUI()
+            uiComponent.component.updateUI()
         }
-        listComponent.validate()
+        value?.let(uiComponent::validate)
     }
 }
 

idea/idea-new-project-wizard/src/org/jetbrains/kotlin/tools/projectWizard/wizard/ui/secondStep/ModuleSettingsComponent.kt

@@ -24,7 +24,7 @@ class ModuleSettingsComponent(valuesReadingContext: ValuesReadingContext) : Dyna
     private val nameField = TextFieldComponent(
         valuesReadingContext,
         labelText = "Name",
-        onAnyValueUpdate = { value ->
+        onValueUpdate = { value ->
             module?.name = value
             eventManager.fireListeners(null)
         },
@@ -52,7 +52,7 @@ class ModuleSettingsComponent(valuesReadingContext: ValuesReadingContext) : Dyna
         }
 
     private fun updateModule(module: Module) {
-        nameField.value = module.name
+        nameField.updateUiValue(module.name)
         nameField.component.isVisible = module.kind != ModuleKind.target
                 || module.configurator.moduleType != ModuleType.common
 

idea/idea-new-project-wizard/src/org/jetbrains/kotlin/tools/projectWizard/wizard/ui/setting/DefaultSettingComponent.kt

@@ -1,69 +1,59 @@
 package org.jetbrains.kotlin.tools.projectWizard.wizard.ui.setting
 
 import com.intellij.openapi.ui.ComboBox
-import com.intellij.ui.components.JBCheckBox
 import org.jetbrains.kotlin.tools.projectWizard.core.ValuesReadingContext
-import org.jetbrains.kotlin.tools.projectWizard.settings.DisplayableSettingItem
 import org.jetbrains.kotlin.tools.projectWizard.core.entity.*
+import org.jetbrains.kotlin.tools.projectWizard.settings.DisplayableSettingItem
 import org.jetbrains.kotlin.tools.projectWizard.settings.version.Version
-import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.components.DropDownComponent
-import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.components.PathFieldComponent
-import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.components.TextFieldComponent
+import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.components.*
 import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.label
 import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.panel
 import java.awt.BorderLayout
 import java.awt.event.ItemEvent
 import java.nio.file.Path
-import java.nio.file.Paths
 import javax.swing.DefaultComboBoxModel
 import javax.swing.JComponent
 
 
-sealed class DefaultSettingComponent<V : Any, T : SettingType<V>>(
-    reference: SettingReference<V, T>,
-    valuesReadingContext: ValuesReadingContext
-) : SettingComponent<V, T>(reference, valuesReadingContext) {
-    companion object {
-        @Suppress("UNCHECKED_CAST")
-        fun <V : Any, T : SettingType<V>> create(
-            setting: SettingReference<V, T>,
-            valuesReadingContext: ValuesReadingContext
-        ): DefaultSettingComponent<V, T> = when (setting.type) {
-            VersionSettingType::class ->
-                VersionSettingComponent(
-                    setting as SettingReference<Version, VersionSettingType>,
-                    valuesReadingContext
-                ) as DefaultSettingComponent<V, T>
-            BooleanSettingType::class ->
-                BooleanSettingComponent(
-                    setting as SettingReference<Boolean, BooleanSettingType>,
-                    valuesReadingContext
-                ) as DefaultSettingComponent<V, T>
-            DropDownSettingType::class ->
-                DropdownSettingComponent(
-                    setting as SettingReference<DisplayableSettingItem, DropDownSettingType<DisplayableSettingItem>>,
-                    valuesReadingContext
-                ) as DefaultSettingComponent<V, T>
-            StringSettingType::class ->
-                StringSettingComponent(
-                    setting as SettingReference<String, StringSettingType>,
-                    valuesReadingContext
-                ) as DefaultSettingComponent<V, T>
-            PathSettingType::class ->
-                PathSettingComponent(
-                    setting as SettingReference<Path, PathSettingType>,
-                    valuesReadingContext
-                ) as DefaultSettingComponent<V, T>
-            else -> TODO(setting.type.qualifiedName!!)
-        }
+object DefaultSettingComponent {
+    @Suppress("UNCHECKED_CAST")
+    fun <V : Any, T : SettingType<V>> create(
+        setting: SettingReference<V, T>,
+        valuesReadingContext: ValuesReadingContext
+    ): SettingComponent<V, T> = when (setting.type) {
+        VersionSettingType::class ->
+            VersionSettingComponent(
+                setting as SettingReference<Version, VersionSettingType>,
+                valuesReadingContext
+            ) as SettingComponent<V, T>
+        BooleanSettingType::class ->
+            BooleanSettingComponent(
+                setting as SettingReference<Boolean, BooleanSettingType>,
+                valuesReadingContext
+            ) as SettingComponent<V, T>
+        DropDownSettingType::class ->
+            DropdownSettingComponent(
+                setting as SettingReference<DisplayableSettingItem, DropDownSettingType<DisplayableSettingItem>>,
+                valuesReadingContext
+            ) as SettingComponent<V, T>
+        StringSettingType::class ->
+            StringSettingComponent(
+                setting as SettingReference<String, StringSettingType>,
+                valuesReadingContext
+            ) as SettingComponent<V, T>
+        PathSettingType::class ->
+            PathSettingComponent(
+                setting as SettingReference<Path, PathSettingType>,
+                valuesReadingContext
+            ) as SettingComponent<V, T>
+        else -> TODO(setting.type.qualifiedName!!)
     }
 }
 
-
 class VersionSettingComponent(
     reference: SettingReference<Version, VersionSettingType>,
     valuesReadingContext: ValuesReadingContext
-) : DefaultSettingComponent<Version, VersionSettingType>(reference, valuesReadingContext) {
+) : SettingComponent<Version, VersionSettingType>(reference, valuesReadingContext) {
     private val settingLabel = label(setting.title)
     private val comboBox = ComboBox<Version>().apply {
         addItemListener { e ->
@@ -98,94 +88,68 @@ class VersionSettingComponent(
     }
 }
 
+
 class DropdownSettingComponent(
     reference: SettingReference<DisplayableSettingItem, DropDownSettingType<DisplayableSettingItem>>,
     private val valuesReadingContext: ValuesReadingContext
-) : DefaultSettingComponent<DisplayableSettingItem, DropDownSettingType<DisplayableSettingItem>>(
+) : UIComponentDelegatingSettingComponent<DisplayableSettingItem, DropDownSettingType<DisplayableSettingItem>>(
     reference,
     valuesReadingContext
 ) {
-    private val dropDownComponent = DropDownComponent(
-        valuesReadingContext,
-        setting.type.values,
+    override val uiComponent = DropDownComponent(
+        valuesReadingContext = valuesReadingContext,
+        initialValues = setting.type.values,
+        validator = setting.validator,
         filter = { value -> setting.type.filter(valuesReadingContext, reference, value) },
         labelText = setting.title,
-        onAnyValueUpdate = { newValue ->
-            value = newValue
-        }
+        onValueUpdate = { newValue -> value = newValue }
     ).asSubComponent()
-
-    override val validationIndicator: ValidationIndicator? = null
-    override val component: JComponent = dropDownComponent.component
 }
 
 class BooleanSettingComponent(
     reference: SettingReference<Boolean, BooleanSettingType>,
     valuesReadingContext: ValuesReadingContext
-) : DefaultSettingComponent<Boolean, BooleanSettingType>(reference, valuesReadingContext) {
-    private val checkBox = JBCheckBox(setting.title).apply {
-        addChangeListener {
-            value = this@apply.isSelected
-        }
-    }
-
-    override fun onValueUpdated(reference: SettingReference<*, *>?) {
-        super.onValueUpdated(reference)
-        checkBox.isSelected = value ?: false
-    }
-
-    override val validationIndicator = ValidationIndicator(showText = false)
-
-    override val component: JComponent by lazy(LazyThreadSafetyMode.NONE) {
-        panel {
-            // TODO add validation indicator
-            add(checkBox, BorderLayout.CENTER)
-        }
-    }
+) : UIComponentDelegatingSettingComponent<Boolean, BooleanSettingType>(
+    reference,
+    valuesReadingContext
+) {
+    override val uiComponent = CheckboxComponent(
+        valuesReadingContext = valuesReadingContext,
+        labelText = setting.title,
+        initialValue = null,
+        validator = setting.validator,
+        onValueUpdate = { newValue -> value = newValue }
+    ).asSubComponent()
 }
 
 class StringSettingComponent(
     reference: SettingReference<String, StringSettingType>,
     valuesReadingContext: ValuesReadingContext,
     showLabel: Boolean = true
-) : DefaultSettingComponent<String, StringSettingType>(reference, valuesReadingContext) {
-    private val textFieldComponent = TextFieldComponent(
-        valuesReadingContext,
-        setting.defaultValue.orEmpty(),
+) : UIComponentDelegatingSettingComponent<String, StringSettingType>(
+    reference,
+    valuesReadingContext
+) {
+    override val uiComponent = TextFieldComponent(
+        valuesReadingContext = valuesReadingContext,
+        initialValue = null,
         labelText = if (showLabel) setting.title else null,
         validator = setting.validator,
-        onAnyValueUpdate = {
-            value = it
-        }
+        onValueUpdate = { newValue -> value = newValue }
     ).asSubComponent()
-
-    override val validationIndicator: ValidationIndicator? = null
-
-    override fun onInit() {
-        super.onInit()
-        textFieldComponent.value = value.orEmpty()
-    }
-
-    override val component = textFieldComponent.component
 }
 
 class PathSettingComponent(
     reference: SettingReference<Path, PathSettingType>,
     valuesReadingContext: ValuesReadingContext
-) : DefaultSettingComponent<Path, PathSettingType>(reference, valuesReadingContext) {
-    private val pathFieldComponent = PathFieldComponent(
-        valuesReadingContext,
-        "",
-        setting.title,
-        validator = settingValidator { path ->
-            setting.validator.validate(this, Paths.get(path))
-        },
-        onAnyValueUpdate = {
-            value = Paths.get(it)
-        }
+) : UIComponentDelegatingSettingComponent<Path, PathSettingType>(
+    reference,
+    valuesReadingContext
+) {
+    override val uiComponent = PathFieldComponent(
+        valuesReadingContext = valuesReadingContext,
+        labelText = setting.title,
+        validator = settingValidator { path -> setting.validator.validate(this, path) },
+        onValueUpdate = { newValue -> value = newValue }
     ).asSubComponent()
-
-    override val validationIndicator: ValidationIndicator? = null
-
-    override val component = pathFieldComponent.component
 }

idea/idea-new-project-wizard/src/org/jetbrains/kotlin/tools/projectWizard/wizard/ui/setting/UIComponentDelegatingSettingComponent.kt

@@ -0,0 +1,35 @@
+/*
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.tools.projectWizard.wizard.ui.setting
+
+import org.jetbrains.kotlin.tools.projectWizard.core.ValuesReadingContext
+import org.jetbrains.kotlin.tools.projectWizard.core.entity.SettingReference
+import org.jetbrains.kotlin.tools.projectWizard.core.entity.SettingType
+import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.components.UIComponent
+import org.jetbrains.kotlin.tools.projectWizard.wizard.ui.components.valueForSetting
+import javax.swing.JComponent
+
+abstract class UIComponentDelegatingSettingComponent<V : Any, T : SettingType<V>>(
+    reference: SettingReference<V, T>,
+    valuesReadingContext: ValuesReadingContext
+) : SettingComponent<V, T>(reference, valuesReadingContext) {
+    abstract val uiComponent: UIComponent<V>
+
+    // As there is one in UIComponent
+    override val validationIndicator: ValidationIndicator? = null
+
+    override fun onInit() {
+        super.onInit()
+        if (value == null) {
+            if (value == null) {
+                value = uiComponent.valueForSetting(setting)
+            }
+        }
+        value?.let(uiComponent::updateUiValue)
+    }
+
+    override val component: JComponent by lazy(LazyThreadSafetyMode.NONE) { uiComponent.component }
+}