CategoryMapper.kt

import javafx.beans.property.SimpleListProperty
import javafx.beans.property.SimpleObjectProperty
import javafx.collections.FXCollections
import javafx.collections.ObservableList
import javafx.scene.control.SelectionMode
import javafx.scene.control.TreeItem
import javafx.scene.text.Font
import tornadofx.*

fun main() {
  launch<DemoApp>()
}

class DemoApp : App(CategoryMapperView::class)

data class DemoCategory(
  val id: String,
  val name: String,
  val subcategories: List<DemoCategory>? = null
)

class CategoryMapperViewModel : ViewModel() {

  val sourceProperty = SimpleListProperty<DemoCategory>()
  val targetProperty = SimpleListProperty<DemoCategory>()

  val sourceSelection = SimpleObjectProperty<DemoCategory>()
  val targetSelection = SimpleListProperty<DemoCategory>(FXCollections.observableArrayList(listOf()))

  init {
    sourceSelection.onChange {
      targetSelection.value.clear()
      // TODO: load targetSelection
      println("source selection changed... loading preselected target categories")
    }
    targetSelection.onChange { list: ObservableList<DemoCategory>? ->
      // .. store selected if sourceSelection.value != null
      list?.forEach { println(it) }
    }
    loadCategories()
  }

  private fun loadCategories() {
    // load async (demo purpose)
    sourceProperty.asyncItems {
      listOf(
        DemoCategory(
          "1", "Cars", listOf(
            DemoCategory("11", "BMW"),
            DemoCategory("12", "Meredes"),
            DemoCategory("13", "Ford")
          )
        ),
        DemoCategory(
          "2", "Fruits", listOf(
            DemoCategory("21", "Banana"),
            DemoCategory("22", "Apple"),
            DemoCategory("23", "Cherry")
          )
        ),
        DemoCategory(
          "3", "Cities", listOf(
            DemoCategory("31", "New York"),
            DemoCategory("32", "London"),
            DemoCategory("33", "Berlin")
          )
        )
      )
    }

    targetProperty.asyncItems {
      // load async (demo purpose)
      listOf(
        DemoCategory(
          "1", "Cars", listOf(
            DemoCategory("11", "BMW"),
            DemoCategory("12", "Meredes"),
            DemoCategory("13", "Ford")
          )
        ),
        DemoCategory(
          "2", "Fruits", listOf(
            DemoCategory("21", "Banana"),
            DemoCategory("22", "Apple"),
            DemoCategory("23", "Cherry")
          )
        ),
        DemoCategory(
          "3", "Cities", listOf(
            DemoCategory("31", "New York"),
            DemoCategory("32", "London"),
            DemoCategory("33", "Berlin")
          )
        )
      )
    }
  }
}

class CategoryMapperView : View() {

  private val viewmodel: CategoryMapperViewModel by inject()

  override val root = vbox {
    paddingAll = 8
    label("Categories") { font = Font.font(16.0) }
    hbox {
      treeview<DemoCategory> {
        root = TreeItem(DemoCategory("", "root"))
        isShowRoot = false
        cellFormat { text = it.name }
        populate { parent ->
          when (parent) {
            root -> viewmodel.sourceProperty
            else -> parent.value.subcategories
          }
        }
        root.isExpanded = true
        root.children.forEach { it.isExpanded = true }
        onUserSelect { viewmodel.sourceSelection.value = it }
      }
      treeview<DemoCategory> {
        selectionModel.selectionMode = SelectionMode.MULTIPLE
        root = TreeItem(DemoCategory("", "root"))
        isShowRoot = false
        cellFormat { text = "${it.name} (${it.id})" }
        populate { parent ->
          when (parent) {
            root -> viewmodel.targetProperty
            else -> parent.value.subcategories
          }
        }
        root.isExpanded = true
        root.children.forEach { it.isExpanded = true }

        // TMP solution
        onUserSelect {
          viewmodel.targetSelection.value = FXCollections.observableArrayList(
            selectionModel.selectedItems.map { it.value }
          )
        }

        // TODO: HOW to bind  viewmodel.targetSelection
        //       to selectionModel.selectedItems

      }
    }
  }
}