ok

lib/src/main/kotlin/com/github/mnemotechnician/mkui/Layout.kt

@@ -14,7 +14,7 @@ import mindustry.ui.*
 
 private val tmpButtons = Seq<Button>(10); //used by buttonGroup
 
-/** Adds a table to the group, passes it to the lamda and returns the created table. */
+/** Adds a table constructed by a lambda to the group, passes it to the lamda and returns the created table. */
 inline fun Group.addTable(background: Drawable = Styles.none, constructor: Table.() -> Unit = {}): Table {
 	return if (this is Table) {
 		this.addTable(background, constructor).get() //tables work differently
@@ -26,13 +26,29 @@ inline fun Group.addTable(background: Drawable = Styles.none, constructor: Table
 	}
 }
 
-/** Adds a table to the existing table and returns the created table cell */
+/** Adds a table constructed by a lambda to the existing table and returns the created table cell */
 inline fun Table.addTable(background: Drawable = Styles.none, constructor: Table.() -> Unit = {}): Cell<Table> {
 	val t = Table(background)
 	t.constructor()
 	return add(t)
 }
 
+/** Adds a collapser constructed by a lambda to the existing table and returns the created cell */
+inline fun Table.addCollapser(background: Drawable = Styles.none, shown: Boolean = true, constructor: Table.() -> Unit = {}): Cell<Collapser> {
+	val table = Table(background)
+	table.constructor()
+
+	val col = Collapser(table, !shown)
+	return add(col)
+}
+
+/** Adds a collapser constructed by a lambda to the existing table and returns the created cell. Whether it's shown is determined by the lambda. */
+inline fun Table.addCollapser(background: Drawable = Styles.none, crossinline shown: () -> Boolean = { true }, animate: Boolean = false, constructor: Table.() -> Unit = {}): Cell<Collapser> {
+	val cell = addCollapser(background, shown(), constructor)
+	cell.get().setCollapsed(animate) { !shown() }
+	return cell;
+}
+
 /** Adds a constant label to the table and returns the created cell */
 inline fun Table.addLabel(text: String, style: Label.LabelStyle = Styles.defaultLabel, wrap: Boolean = false, ellipsis: String? = null): Cell<Label> {
 	val label = Label(text, style)
@@ -101,7 +117,8 @@ inline fun Table.addImage(crossinline provider: () -> Drawable): Cell<Image> {
 	return add(i)
 }
 
-/** Creates a toggle button constructed by a lambda and returns the created cell. The style MUST support checked state. Ontoggle is called whenever the button is toggled. */
+/** Creates a toggle button constructed by a lambda and returns the created cell. Ontoggle is called whenever the button is toggled.
+ *  @throws IllegalArgumentException when the providen style doesn't support checked state */
 inline fun Table.toggleButton(constructor: Button.() -> Unit, toggleableStyle: Button.ButtonStyle = Styles.togglet, crossinline ontoggle: Button.(Boolean) -> Unit): Cell<Button> {
 	if (toggleableStyle.checked == null) throw IllegalArgumentException("This style does not support checked state!")
 

lib/src/main/kotlin/com/github/mnemotechnician/mkui/windows/Window.kt

@@ -6,6 +6,9 @@ import com.github.mnemotechnician.mkui.*
 /** A class that represents a floating on-screen window that the user can drag and interact with. */
 abstract class Window {
 
+	/** The root of the window */
+	lateinit internal var rootTable: Table
+
 	/** The table this window is assigned to. Initialized when the window is created. */
 	lateinit var table: Table
 		internal set

lib/src/main/kotlin/com/github/mnemotechnician/mkui/windows/WindowManager.kt

@@ -1,6 +1,7 @@
 package com.github.mnemotechnician.mkui.windows
 
 import arc.*
+import arc.math.*
 import arc.util.*
 import arc.struct.*
 import arc.scene.event.*
@@ -27,43 +28,62 @@ object WindowManager {
 		}
 
 		Events.run(EventType.Trigger.update) {
-			windows.each { it.onUpdate() }
+			windows.each {
+				//keep in stage
+				val root = it.rootTable
+				val pos = root.localToParentCoordinates(Tmp.v1.set(0f, 0f));
+
+				root.setPosition(
+					Mathf.clamp(pos.x, root.getPrefWidth() / 2, windowGroup.width - root.getPrefWidth() / 2),
+					Mathf.clamp(pos.y, root.getPrefHeight() / 2, windowGroup.height - root.getPrefHeight() / 2)
+				);
+
+				it.onUpdate()
+			}
 		}
 	}
 
 	/** Constructs & registers the window */
 	fun createWindow(window: Window) {
 		val windowTable = Table(Styles.black5).apply {
-			//tob bar — name, buttons and also a way to drag the table
+			lateinit var collapser: Collapser
+
+			window.rootTable = this
+
+			//top bar — name, buttons and also a way to drag the table
 			addTable(Styles.black3) {
 				addLabel({ window.name }, ellipsis = "...").fillX()
+
 				//collapse/show
 				textToggle("-", Styles.togglet) {
 					childAs<Label>(0).setText(if (it) "[accent]=" else "[accent]-")
 
+					collapser.toggle()
 					window.isCollapsed = it
 					window.onToggle(it)
-
-					TODO("collapsing is not yet implemented")
 				}
 
 				dragged { x, y ->
+					val oldPos = window.rootTable.localToParentCoordinates(Tmp.v1.set(x, y))
+					window.rootTable.setPosition(oldPos.x, oldPos.y)
+
 					window.onDrag()
-					TODO("dragging is not yet implemented")
 				}
 			}.fillX().marginBottom(5f)
 
 			row()
 
 			//main container
-			addTable {
+			collapser = addCollapser(animate = true) {
+				setClip(true)
+
 				window.table = this
 				window.onCreate()
-			}
+			}.pad(5f).get()
 		}
 
 		windowGroup.addChild(windowTable)
-		windowTable.setPosition(windowGroup.width / 2, windowGroup.height / 2)
+		windowTable.setPosition(Core.scene.width / 2, Core.scene.height / 2)
 
 		windows.add(window)
 	}