Add basic button implementation

.gitignore

@@ -1,4 +1,5 @@
 .DS_Store
+logs/
 
 # gradle
 

src/main/kotlin/net/shadowfacts/asmr/TestCacaoScreen.kt

@@ -5,12 +5,11 @@ import net.shadowfacts.cacao.CacaoScreen
 import net.shadowfacts.cacao.view.View
 import net.shadowfacts.cacao.Window
 import net.shadowfacts.cacao.geometry.Axis
-import net.shadowfacts.cacao.geometry.Point
 import net.shadowfacts.cacao.geometry.Size
 import net.shadowfacts.cacao.util.Color
-import net.shadowfacts.cacao.util.MouseButton
-import net.shadowfacts.cacao.util.RenderHelper
+import net.shadowfacts.cacao.view.Label
 import net.shadowfacts.cacao.view.StackView
+import net.shadowfacts.cacao.view.button.Button
 
 /**
  * @author shadowfacts
@@ -34,20 +33,12 @@ class TestCacaoScreen: CacaoScreen() {
 				intrinsicContentSize = Size(50.0, 50.0)
 				backgroundColor = Color(0x0000ff)
 			})
-			val purple = blue.addSubview(object: View() {
-				init {
-					intrinsicContentSize = Size(25.0, 25.0)
-					backgroundColor = Color(0x800080)
-				}
-
-				override fun mouseClicked(point: Point, mouseButton: MouseButton) {
-					println("hello world")
-				}
-
-				override fun drawContent(mouse: Point, delta: Float) {
-					if (mouse in bounds) {
-						RenderHelper.fill(bounds, Color.WHITE)
+			val purple = blue.addSubview(Button(Label("Hello, button!")).apply {
+				handler = {
+					println("$it clicked!")
 				}
+				background = View().apply {
+					backgroundColor = Color(0xebfc00)
 				}
 			})
 

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

@@ -219,14 +219,15 @@ open class View() {
 	/**
 	 * Called to draw this view.
 	 * This method should not be called directly, it is called by the parent view/window.
-	 * This method may not be overridden, use [drawContent] to draw any custom content.
+	 * This method generally should not be overridden, but it is left open for internal framework use.
+	 * Use [drawContent] to draw any custom content.
 	 *
 	 * @param mouse The position of the mouse in the coordinate system of this view.
 	 * @param delta The time since the last frame.
 	 */
-	fun draw(mouse: Point, delta: Float) {
+	open fun draw(mouse: Point, delta: Float) {
 		RenderHelper.pushMatrix()
-		RenderHelper.translate(frame.left, frame.top, 0.0)
+		RenderHelper.translate(frame.left, frame.top)
 
 		RenderHelper.fill(bounds, backgroundColor)
 

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

@@ -0,0 +1,115 @@
+package net.shadowfacts.cacao.view.button
+
+import net.shadowfacts.cacao.geometry.Point
+import net.shadowfacts.cacao.util.MouseButton
+import net.shadowfacts.cacao.util.RenderHelper
+import net.shadowfacts.cacao.view.View
+import net.shadowfacts.kiwidsl.dsl
+
+/**
+ * A abstract button class. Cannot be constructed directly, used for creating button implementations with their own logic.
+ * Use [Button] for a generic no-frills button.
+ *
+ * @author shadowfacts
+ * @param Impl The type of the concrete implementation of the button.
+ * 				Used to allow the [handler] to receive the exact button type that was constructed.
+ * @param content The [View] that provides the content of this button.
+ * 					Will be added as a subview of the button and laid out using constraints.
+ * @param padding The padding between the [content] and the edges of the button.
+ */
+abstract class AbstractButton<Impl: AbstractButton<Impl>>(val content: View, val padding: Double = 4.0): View() {
+
+	/**
+	 * The function that handles when this button is clicked.
+	 * The parameter is the type of the concrete button implementation that was used.
+	 */
+	var handler: ((Impl) -> Unit)? = null
+
+	/**
+	 * Whether the button is disabled.
+	 * Disabled buttons have a different background ([disabledBackground]) and do not receive click events.
+	 */
+	var disabled = false
+
+	/**
+	 * The normal background view to draw behind the button content. It will be added as a subview during [wasAdded],
+	 * so all background view properties must be specified prior to the button being added to a view hierarchy.
+	 *
+	 * The background will fill the entire button (going beneath the content [padding]).
+	 * There are also [hoveredBackground] and [disabledBackground] for those states.
+	 * If a [backgroundColor] is specified, it will be drawn behind the background View and thus not visible
+	 * unless the background view is not fully opaque.
+	 */
+	var background: View? = null
+	/**
+	 * The background to draw when the button is hovered over by the mouse.
+	 * If `null`, the normal [background] will be used.
+	 * @see background
+	 */
+	var hoveredBackground: View? = null
+	/**
+	 * The background to draw when the button is [disabled].
+	 * If `null`, the normal [background] will be used.
+	 * @see background
+	 */
+	var disabledBackground: View? = null
+
+	override fun wasAdded() {
+		solver.dsl {
+			addSubview(content)
+			content.leftAnchor equalTo (leftAnchor + padding)
+			content.rightAnchor equalTo (rightAnchor - padding)
+			content.topAnchor equalTo (topAnchor + padding)
+			content.bottomAnchor equalTo (bottomAnchor - padding)
+
+			listOfNotNull(background, hoveredBackground, disabledBackground).forEach {
+				addSubview(it)
+				it.leftAnchor equalTo leftAnchor
+				it.rightAnchor equalTo rightAnchor
+				it.topAnchor equalTo topAnchor
+				it.bottomAnchor equalTo bottomAnchor
+			}
+		}
+
+		super.wasAdded()
+	}
+
+	override fun draw(mouse: Point, delta: Float) {
+		RenderHelper.pushMatrix()
+		RenderHelper.translate(frame.left, frame.top)
+
+		RenderHelper.fill(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(mouse, delta)
+
+		val mouseInContent = convert(mouse, to = content)
+		content.draw(mouseInContent, delta)
+
+		// don't draw subviews, otherwise all background views + content will get drawn
+
+		RenderHelper.popMatrix()
+	}
+
+	override fun mouseClicked(point: Point, mouseButton: MouseButton) {
+		if (disabled) return
+
+		val handler = handler
+		if (handler != null) {
+			// We can perform an unchecked cast here because we are certain that Impl will be the concrete implementation
+			// of AbstractButton.
+			// For example, an implementing class may be defined as such: `class Button: AbstractButton<Button>`
+			@Suppress("UNCHECKED_CAST")
+			handler(this as Impl)
+		}
+	}
+
+}

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

@@ -0,0 +1,12 @@
+package net.shadowfacts.cacao.view.button
+
+import net.shadowfacts.cacao.view.View
+
+/**
+ * A simple button implementation that provides no additional logic.
+ *
+ * @author shadowfacts
+ * @param content The [View] that provides the content of this button.
+ * @param padding The padding between the [content] and the edges of the button.
+ */
+class Button(content: View, padding: Double = 4.0): AbstractButton<Button>(content, padding)

src/test/kotlin/net/shadowfacts/cacao/view/ButtonClickTests.kt

@@ -0,0 +1,70 @@
+package net.shadowfacts.cacao.view
+
+import net.shadowfacts.cacao.Window
+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.view.button.Button
+import net.shadowfacts.kiwidsl.dsl
+import org.junit.jupiter.api.Assertions.assertFalse
+import org.junit.jupiter.api.Assertions.assertTrue
+import org.junit.jupiter.api.BeforeEach
+import org.junit.jupiter.api.Test
+import java.util.concurrent.CompletableFuture
+
+/**
+ * @author shadowfacts
+ */
+class ButtonClickTests {
+
+	lateinit var window: Window
+
+	@BeforeEach
+	fun setup() {
+		window = Window()
+	}
+
+	@Test
+	fun testClickInsideButton() {
+		val clicked = CompletableFuture<Boolean>()
+		val content = View().apply {
+			intrinsicContentSize = Size(25.0, 25.0)
+		}
+		val button = window.addView(Button(content).apply {
+			handler = {
+				clicked.complete(true)
+			}
+		})
+		window.solver.dsl {
+			button.leftAnchor equalTo 0
+			button.topAnchor equalTo 0
+		}
+		window.layout()
+		window.mouseClicked(Point(5.0, 5.0), MouseButton.LEFT)
+
+		assertTrue(clicked.getNow(false))
+	}
+
+	@Test
+	fun testClickOutsideButton() {
+		val clicked = CompletableFuture<Boolean>()
+		val content = View().apply {
+			intrinsicContentSize = Size(25.0, 25.0)
+		}
+		val button = window.addView(Button(content).apply {
+			handler = {
+				clicked.complete(true)
+			}
+		})
+		window.solver.dsl {
+			button.leftAnchor equalTo 0
+			button.topAnchor equalTo 0
+		}
+		window.layout()
+		window.mouseClicked(Point(50.0, 50.0), MouseButton.LEFT)
+
+		assertFalse(clicked.getNow(false))
+	}
+
+}