Cacao: Add TabViewController

src/main/kotlin/net/shadowfacts/cacao/view/View.kt

@@ -11,6 +11,7 @@ import no.birkett.kiwi.Constraint
 import no.birkett.kiwi.Solver
 import java.lang.RuntimeException
 import java.util.*
+import kotlin.collections.HashSet
 
 /**
  * The base Cacao View class. Provides layout anchors, properties, and helper methods.
@@ -27,11 +28,16 @@ open class View() {
 	*/
 	var window: Window? = null
 
+	private val solverDelegate = ObservableLateInitProperty<Solver> {
+		for (v in subviews) {
+			v.solver = it
+		}
+	}
 	/**
 	 * The constraint solver used by the [net.shadowfacts.cacao.Window] this view belongs to.
 	 * Not initialized until [wasAdded] called, using it before that will throw a runtime exception.
 	 */
-	lateinit var solver: Solver
+	var solver: Solver by solverDelegate
 
 	/**
 	 * Layout anchor for the left edge of this view in the window's coordinate system.
@@ -167,7 +173,9 @@ open class View() {
 		subviewsSortedByZIndex = subviews.sortedBy(View::zIndex)
 
 		view.superview = this
-		view.solver = solver
+		if (solverDelegate.isInitialized) {
+			view.solver = solver
+		}
 		view.window = window
 
 		view.wasAdded()
@@ -182,16 +190,34 @@ open class View() {
 	 * @throws RuntimeException If the given [view] is not a subview of this view.
 	 */
 	fun removeSubview(view: View) {
-		if (view.superview != this) {
+		if (view.superview !== this) {
 			throw RuntimeException("Cannot remove subview whose superview is not this view")
 		}
-		solver.constraints.filter { constraint ->
-			constraint.getVariables().any { it is LayoutVariable && it.owner == view }
-		}.forEach(solver::removeConstraint)
+
+
 		_subviews.remove(view)
 		subviewsSortedByZIndex = subviews.sortedBy(View::zIndex)
 
 		view.superview = null
+
+		// we need to remove constraints for this subview that cross the boundary between the subview and ourself
+		val constraintsToRemove = solver.constraints.filter { constraint ->
+			val variables = constraint.getVariables().mapNotNull { it as? LayoutVariable }
+
+			for (a in 0 until variables.size - 1) {
+				for (b in a + 1 until variables.size) {
+					// if the variable views have no common ancestor after the removed view's superview is unset,
+					// the constraint crossed the this<->view boundary and should be removed
+					val ancestor = LowestCommonAncestor.find(variables[a].owner, variables[b].owner, View::superview)
+					if (ancestor == null) {
+						return@filter true
+					}
+				}
+			}
+			false
+		}
+		constraintsToRemove.forEach(solver::removeConstraint)
+
 		// todo: does this need to be reset
 //		view.solver = null
 		view.window = null
@@ -254,7 +280,7 @@ open class View() {
 	}
 
 	private fun updateIntrinsicContentSizeConstraints(old: Size?, new: Size?) {
-		if (!usesConstraintBasedLayout || !this::solver.isInitialized) return
+		if (!usesConstraintBasedLayout || !solverDelegate.isInitialized) return
 
 		if (old != null) {
 			solver.removeConstraint(intrinsicContentSizeWidthConstraint!!)
@@ -273,14 +299,14 @@ open class View() {
 	 * If overridden, the super-class method must be called.
 	 */
 	open fun didLayout() {
-		subviews.forEach(View::didLayout)
-
 		if (usesConstraintBasedLayout) {
 			val superviewLeft = superview?.leftAnchor?.value ?: 0.0
 			val superviewTop = superview?.topAnchor?.value ?: 0.0
 			frame = Rect(leftAnchor.value - superviewLeft, topAnchor.value - superviewTop, widthAnchor.value, heightAnchor.value)
 			bounds = Rect(0.0, 0.0, widthAnchor.value, heightAnchor.value)
 		}
+
+		subviews.forEach(View::didLayout)
 	}
 
 	/**

src/main/kotlin/net/shadowfacts/cacao/view/button/AbstractButton.kt

@@ -86,16 +86,9 @@ abstract class AbstractButton<Impl: AbstractButton<Impl>>(val content: View, val
 
 		RenderHelper.fill(matrixStack, bounds, backgroundColor)
 
-		var currentBackground: View? = background
-		if (mouse in bounds) {
-			currentBackground = hoveredBackground ?: currentBackground
-		}
-		if (disabled) {
-			currentBackground = disabledBackground ?: currentBackground
-		}
 		// don't need to convert mouse to background coordinate system
 		// the edges are all pinned, so the coordinate space is the same
-		currentBackground?.draw(matrixStack, mouse, delta)
+		getCurrentBackground(mouse)?.draw(matrixStack, mouse, delta)
 
 		val mouseInContent = convert(mouse, to = content)
 		content.draw(matrixStack, mouseInContent, delta)
@@ -117,4 +110,14 @@ abstract class AbstractButton<Impl: AbstractButton<Impl>>(val content: View, val
 		return true
 	}
 
+	protected open fun getCurrentBackground(mouse: Point): View? {
+		return if (disabled) {
+			disabledBackground ?: background
+		} else if (mouse in bounds) {
+			hoveredBackground ?: background
+		} else {
+			background
+		}
+	}
+
 }

src/main/kotlin/net/shadowfacts/cacao/viewcontroller/TabViewController.kt

@@ -0,0 +1,160 @@
+package net.shadowfacts.cacao.viewcontroller
+
+import net.minecraft.text.Text
+import net.minecraft.util.Identifier
+import net.shadowfacts.cacao.geometry.Axis
+import net.shadowfacts.cacao.geometry.Point
+import net.shadowfacts.cacao.geometry.Rect
+import net.shadowfacts.cacao.geometry.Size
+import net.shadowfacts.cacao.util.MouseButton
+import net.shadowfacts.cacao.util.texture.NinePatchTexture
+import net.shadowfacts.cacao.util.texture.Texture
+import net.shadowfacts.cacao.view.NinePatchView
+import net.shadowfacts.cacao.view.StackView
+import net.shadowfacts.cacao.view.TextureView
+import net.shadowfacts.cacao.view.View
+import net.shadowfacts.cacao.view.button.AbstractButton
+import net.shadowfacts.kiwidsl.dsl
+
+/**
+ * @author shadowfacts
+ */
+class TabViewController<T: TabViewController.Tab>(
+	val tabs: Array<T>,
+	initalTab: T = tabs.first()
+): ViewController() {
+
+	interface Tab {
+		val tabView: View
+		val tooltip: Text?
+		val controller: ViewController
+	}
+
+	var currentTab: T = initalTab
+		private set
+
+	private lateinit var tabButtons: List<TabButton<T>>
+
+	private lateinit var outerStack: StackView
+	private lateinit var tabStack: StackView
+	private lateinit var tabVCContainer: View
+
+	override fun viewDidLoad() {
+		super.viewDidLoad()
+
+		// padding is -4 so tab button texture overlaps with panel BG as expected
+		outerStack = StackView(Axis.VERTICAL, StackView.Distribution.FILL, -4.0)
+		view.addSubview(outerStack)
+
+		tabStack = StackView(Axis.HORIZONTAL, StackView.Distribution.FILL)
+		tabStack.zIndex = 1.0
+		outerStack.addArrangedSubview(tabStack)
+
+		tabVCContainer = View()
+		outerStack.addArrangedSubview(tabVCContainer)
+
+		tabButtons = tabs.mapIndexed { index, tab ->
+			val btn = TabButton(tab)
+			btn.handler = this::selectTab
+			if (tab == currentTab) {
+				btn.setSelected(true)
+			}
+			btn
+		}
+		// todo: batch calls to addArrangedSubview
+		tabButtons.forEach(tabStack::addArrangedSubview)
+
+		// spacer
+		tabStack.addArrangedSubview(View())
+
+		val background = NinePatchView(NinePatchTexture.PANEL_BG)
+		background.zIndex = -1.0
+		tabVCContainer.addSubview(background)
+
+		embedChild(currentTab.controller, tabVCContainer)
+
+		view.solver.dsl {
+			outerStack.leftAnchor equalTo view.leftAnchor
+			outerStack.rightAnchor equalTo view.rightAnchor
+			outerStack.topAnchor equalTo view.topAnchor
+			outerStack.bottomAnchor equalTo view.bottomAnchor
+
+			background.leftAnchor equalTo tabVCContainer.leftAnchor
+			background.rightAnchor equalTo tabVCContainer.rightAnchor
+			background.topAnchor equalTo tabVCContainer.topAnchor
+			background.bottomAnchor equalTo tabVCContainer.bottomAnchor
+		}
+	}
+
+	private fun selectTab(button: TabButton<T>) {
+		val oldTab = currentTab
+		currentTab = button.tab
+
+		// todo: unselect old button
+		tabButtons.forEach { it.setSelected(false) }
+		oldTab.controller.removeFromParent()
+
+		button.setSelected(true)
+		embedChild(currentTab.controller, tabVCContainer)
+		// todo: setNeedsLayout
+		window!!.layout()
+	}
+
+	private class TabButton<T: Tab>(
+		val tab: T,
+	): AbstractButton<TabButton<T>>(
+		tab.tabView,
+		padding = 2.0
+	) {
+		companion object {
+			val BACKGROUND = Identifier("textures/gui/container/creative_inventory/tabs.png")
+		}
+
+		private var selected = false
+		private var backgroundView = TextureView(Texture(BACKGROUND, 0, 0))
+
+		init {
+			intrinsicContentSize = Size(28.0, 32.0)
+			background = null
+			hoveredBackground = null
+			disabledBackground = null
+		}
+
+		override fun wasAdded() {
+			super.wasAdded()
+			backgroundView.usesConstraintBasedLayout = false
+			backgroundView.frame = Rect(0.0, 0.0, 28.0, 32.0)
+			addSubview(backgroundView)
+		}
+
+		override fun didLayout() {
+			super.didLayout()
+			updateBackgroundTexture()
+		}
+
+		fun setSelected(selected: Boolean) {
+			this.selected = selected
+			updateBackgroundTexture()
+		}
+
+		override fun getCurrentBackground(mouse: Point) = backgroundView
+
+		override fun mouseClicked(point: Point, mouseButton: MouseButton): Boolean {
+			if (selected) return false
+			else return super.mouseClicked(point, mouseButton)
+		}
+
+		private fun updateBackgroundTexture() {
+			val v = if (selected) 32 else 0
+			val u = when {
+				superview == null -> 0
+				frame.left == 0.0 -> 0
+				frame.right == superview!!.bounds.right -> 140
+				else -> 28
+			}
+			backgroundView.texture = Texture(BACKGROUND, u, v)
+			backgroundView.frame = Rect(0.0, 0.0, 28.0, if (selected) 32.0 else 28.0)
+		}
+	}
+
+}

src/main/kotlin/net/shadowfacts/cacao/viewcontroller/ViewController.kt

@@ -23,6 +23,12 @@ abstract class ViewController {
 	 * b) this VC is added as a child of another view controller.
 	 */
 	var window: Window? = null
+		set(value) {
+			field = value
+			for (vc in children) {
+				vc.window = value
+			}
+		}
 
 	/**
 	 * Helper function for creating layout constraints in the domain of this VC's window.
@@ -70,6 +76,18 @@ abstract class ViewController {
 		view = View()
 	}
 
+	val isViewLoaded: Boolean
+		get() = ::view.isInitialized
+
+	/**
+	 * Calls [loadView] to load this controller's view only if it has not already been loaded.
+	 */
+	fun loadViewIfNeeded() {
+		if (!isViewLoaded) {
+			loadView()
+		}
+	}
+
 	/**
 	 * This method is called after the view is loaded, it's properties are initialized, and [View.wasAdded] has been
 	 * called.
@@ -149,7 +167,8 @@ abstract class ViewController {
 		viewController.parent = this
 		viewController.window = window
 		_children.add(viewController)
-		viewController.loadView()
+		val wasViewLoaded = viewController.isViewLoaded
+		viewController.loadViewIfNeeded()
 
 		container.addSubview(viewController.view)
 
@@ -162,7 +181,9 @@ abstract class ViewController {
 			}
 		}
 
-		viewController.viewDidLoad()
+		if (!wasViewLoaded) {
+			viewController.viewDidLoad()
+		}
 	}
 
 	/**
@@ -186,7 +207,6 @@ abstract class ViewController {
 	fun removeFromParent() {
 		parent?.removeChild(this)
 		view.removeFromSuperview()
-		// todo: remove view from superview
 	}
 
 }

src/main/kotlin/net/shadowfacts/cacao/window/Window.kt

@@ -86,7 +86,7 @@ open class Window(
 
 	fun wasAdded() {
 		viewController.window = this
-		viewController.loadView()
+		viewController.loadViewIfNeeded()
 
 		viewController.view.window = this
 		viewController.view.solver = solver

src/main/kotlin/net/shadowfacts/phycon/screen/TestCacaoScreen.kt

@@ -2,6 +2,7 @@ package net.shadowfacts.phycon.screen
 
 import net.minecraft.client.MinecraftClient
 import net.minecraft.text.LiteralText
+import net.minecraft.text.Text
 import net.minecraft.util.Identifier
 import net.shadowfacts.cacao.CacaoScreen
 import net.shadowfacts.cacao.window.Window
@@ -12,6 +13,7 @@ import net.shadowfacts.cacao.util.texture.NinePatchTexture
 import net.shadowfacts.cacao.util.texture.Texture
 import net.shadowfacts.cacao.view.*
 import net.shadowfacts.cacao.view.button.Button
+import net.shadowfacts.cacao.viewcontroller.TabViewController
 import net.shadowfacts.cacao.viewcontroller.ViewController
 import net.shadowfacts.kiwidsl.dsl
 
@@ -21,48 +23,104 @@ import net.shadowfacts.kiwidsl.dsl
 class TestCacaoScreen: CacaoScreen() {
 
 	init {
-		val viewController = object: ViewController() {
-			override fun loadView() {
-				view = View()
-			}
+//		val viewController = object: ViewController() {
+//			override fun loadView() {
+//				view = View()
+//			}
+//
+//			override fun viewDidLoad() {
+//				super.viewDidLoad()
+//
+//				val stack = view.addSubview(StackView(Axis.VERTICAL, StackView.Distribution.CENTER, spacing = 4.0)).apply {
+//					backgroundColor = Color.WHITE
+//				}
+//				val birch = stack.addArrangedSubview(TextureView(Texture(Identifier("textures/block/birch_log_top.png"), 0, 0, 16, 16))).apply {
+//					intrinsicContentSize = Size(50.0, 50.0)
+//				}
+//				val ninePatch = stack.addArrangedSubview(NinePatchView(NinePatchTexture.PANEL_BG)).apply {
+//					intrinsicContentSize = Size(75.0, 100.0)
+//				}
+//				val red = stack.addArrangedSubview(View()).apply {
+//					intrinsicContentSize = Size(50.0, 50.0)
+//					backgroundColor = Color.RED
+//				}
+//
+//				val label = Label(LiteralText("Test"), wrappingMode = Label.WrappingMode.NO_WRAP).apply {
+////					textColor = Color.BLACK
+//				}
+////				stack.addArrangedSubview(label)
+//				val button = red.addSubview(Button(label))
+//
+//				view.solver.dsl {
+//					stack.topAnchor equalTo 0
+//					stack.centerXAnchor equalTo window!!.centerXAnchor
+//					stack.widthAnchor equalTo 100
+//
+//
+//					button.centerXAnchor equalTo red.centerXAnchor
+//					button.centerYAnchor equalTo red.centerYAnchor
+////					label.heightAnchor equalTo 9
+//					button.heightAnchor equalTo 20
+//				}
+//
+//			}
+//		}
+//		addWindow(Window(viewController))
 
+		val viewController = object: ViewController() {
 			override fun viewDidLoad() {
 				super.viewDidLoad()
 
-				val stack = view.addSubview(StackView(Axis.VERTICAL, StackView.Distribution.CENTER, spacing = 4.0)).apply {
-					backgroundColor = Color.WHITE
-				}
-				val birch = stack.addArrangedSubview(TextureView(Texture(Identifier("textures/block/birch_log_top.png"), 0, 0, 16, 16))).apply {
-					intrinsicContentSize = Size(50.0, 50.0)
-				}
-				val ninePatch = stack.addArrangedSubview(NinePatchView(NinePatchTexture.PANEL_BG)).apply {
-					intrinsicContentSize = Size(75.0, 100.0)
-				}
-				val red = stack.addArrangedSubview(View()).apply {
-					intrinsicContentSize = Size(50.0, 50.0)
-					backgroundColor = Color.RED
-				}
-
-				val label = Label(LiteralText("Test"), wrappingMode = Label.WrappingMode.NO_WRAP).apply {
-//					textColor = Color.BLACK
-				}
-//				stack.addArrangedSubview(label)
-				val button = red.addSubview(Button(label))
+				val tabs = arrayOf(
+					Tab(Label("A"), AViewController()),
+					Tab(Label("B"), BViewController()),
+				)
+				val tabVC = TabViewController(tabs)
+				embedChild(tabVC, pinEdges = false)
 
 				view.solver.dsl {
-					stack.topAnchor equalTo 0
-					stack.centerXAnchor equalTo window!!.centerXAnchor
-					stack.widthAnchor equalTo 100
-
-
-					button.centerXAnchor equalTo red.centerXAnchor
-					button.centerYAnchor equalTo red.centerYAnchor
-//					label.heightAnchor equalTo 9
-					button.heightAnchor equalTo 20
+					tabVC.view.centerXAnchor equalTo view.centerXAnchor
+					tabVC.view.centerYAnchor equalTo view.centerYAnchor
+					tabVC.view.widthAnchor equalTo 200
+					tabVC.view.heightAnchor equalTo 150
 				}
 			}
 		}
 		addWindow(Window(viewController))
 	}
 
+	data class Tab(
+		override val tabView: View,
+		override val controller: ViewController,
+		override val tooltip: Text? = null
+	): TabViewController.Tab
+
+	class AViewController: ViewController() {
+		override fun viewDidLoad() {
+			super.viewDidLoad()
+			val button = Button(Label("A content")) {
+				println("A pressed")
+			}
+			view.addSubview(button)
+			view.solver.dsl {
+				button.centerXAnchor equalTo view.centerXAnchor
+				button.centerYAnchor equalTo view.centerYAnchor
+			}
+		}
+	}
+
+	class BViewController: ViewController() {
+		override fun viewDidLoad() {
+			super.viewDidLoad()
+			val button = Button(Label("B content")) {
+				println("B pressed")
+			}
+			view.addSubview(button)
+			view.solver.dsl {
+				button.centerXAnchor equalTo view.centerXAnchor
+				button.centerYAnchor equalTo view.centerYAnchor
+			}
+		}
+	}
+
 }

src/test/kotlin/net/shadowfacts/cacao/util/LCATest.kt

@@ -19,6 +19,14 @@ class LCATest {
 		assertEquals(parent, LowestCommonAncestor.find(child, parent, Node::parent))
 	}
 
+	@Test
+	fun testNestedParent() {
+		val parent = Node("parent", null)
+		val middle = Node("middle", parent)
+		val child = Node("child", middle)
+		assertEquals(parent, LowestCommonAncestor.find(parent, child, Node::parent))
+	}
+
 	@Test
 	fun testSiblings() {
 		val root = Node("root", null)