[Editor] Create project structure panel scaffolding

editor/src/main/kotlin/com/bartlomiejpluta/base/editor/main/view/MainView.kt

@@ -13,6 +13,7 @@ class MainView : View("BASE Game Editor") {
    private val projectContext: ProjectContext by di()
 
    private val mainMenuView = find<MainMenuView>()
+   private val projectStructureView = find<ProjectStructureView>()
 
    init {
       projectContext.projectProperty.addListener { _, _, project ->
@@ -35,5 +36,7 @@ class MainView : View("BASE Game Editor") {
             }
          }
       }
+
+      left = projectStructureView.root
    }
 }

editor/src/main/kotlin/com/bartlomiejpluta/base/editor/main/view/ProjectStructureView.kt

@@ -0,0 +1,60 @@
+package com.bartlomiejpluta.base.editor.main.view
+
+import com.bartlomiejpluta.base.editor.map.asset.GameMapAsset
+import com.bartlomiejpluta.base.editor.project.context.ProjectContext
+import com.bartlomiejpluta.base.editor.util.fx.BindingUtil
+import javafx.beans.property.SimpleStringProperty
+import javafx.collections.ObservableList
+import javafx.scene.control.TreeItem
+import org.kordamp.ikonli.javafx.FontIcon
+import tornadofx.*
+
+
+class ProjectStructureView : View() {
+   private val projectContext: ProjectContext by di()
+
+   private val structureMaps = StructureCategory("Maps")
+
+   private val structureRoot = StructureCategory(name = "Project", items = observableListOf(structureMaps))
+
+   init {
+      projectContext.projectProperty.addListener { _, _, project ->
+         project?.let {
+            structureRoot.nameProperty.bind(it.nameProperty)
+            BindingUtil.bindMapValues(structureMaps.items, project.maps)
+            root.refresh()
+         }
+      }
+   }
+
+   override val root = treeview<Any> {
+      root = TreeItem(structureRoot)
+
+      cellFormat {
+         graphic = when(it) {
+            structureRoot -> FontIcon("fa-cog")
+            is StructureCategory -> FontIcon("fa-folder")
+            is GameMapAsset -> FontIcon("fa-map")
+            else -> null
+         }
+
+         text = when (it) {
+            is StructureCategory -> it.name
+            is GameMapAsset -> it.name
+            else -> throw IllegalStateException("Unsupported structure item type")
+         }
+      }
+
+      populate {
+         when (val value = it.value) {
+            is StructureCategory -> value.items
+            else -> null
+         }
+      }
+   }
+
+   private class StructureCategory(name: String = "", var items: ObservableList<out Any> = observableListOf()) {
+      val nameProperty = SimpleStringProperty(name)
+      val name by nameProperty
+   }
+}

editor/src/main/kotlin/com/bartlomiejpluta/base/editor/util/fx/BindingUtil.kt

@@ -0,0 +1,27 @@
+package com.bartlomiejpluta.base.editor.util.fx
+
+import javafx.beans.binding.Bindings
+import javafx.collections.MapChangeListener
+import javafx.collections.ObservableList
+import javafx.collections.ObservableMap
+import tornadofx.observableListOf
+
+object BindingUtil {
+   fun <K, V> observableMapValues(map: ObservableMap<out K, out V>) = observableListOf<V>().apply {
+      addAll(map.values)
+
+      // FIXME:
+      // It's not really efficient way to track map updates by clearing all
+      // and putting it all over again, however it preserves the original map order.
+      // The efficiency should be sufficient for the project purposes (there are no any expectations
+      // to store a very large collections in here - if the need arose it should be immediately improved).
+      map.addListener(MapChangeListener {
+         clear()
+         addAll(map.values)
+      })
+   }
+
+   fun <K, V> bindMapValues(target: ObservableList<out V>, map: ObservableMap<out K, out V>) {
+      Bindings.bindContent(target, observableMapValues(map))
+   }
+}