Shuffle things around for cleaner layering (#164)

The 'layout' package is now a standalone widget tree. The 'ui' package is now only composables. The root package contains all the code for integration and Compose.

mosaic-runtime/src/commonMain/kotlin/com/jakewharton/mosaic/layout/NoContentMeasurePolicy.kt

@@ -1,5 +0,0 @@
-package com.jakewharton.mosaic.layout
-
-public fun interface NoContentMeasurePolicy {
-	public fun NoContentMeasureScope.measure(): MeasureResult
-}

mosaic-runtime/src/commonMain/kotlin/com/jakewharton/mosaic/layout/NoContentMeasureScope.kt

@@ -1,19 +0,0 @@
-package com.jakewharton.mosaic.layout
-
-public sealed class NoContentMeasureScope {
-	public fun layout(
-		width: Int,
-		height: Int,
-	): MeasureResult {
-		return LayoutResult(width, height)
-	}
-
-	private class LayoutResult(
-		override val width: Int,
-		override val height: Int,
-	) : MeasureResult {
-		override fun placeChildren() {}
-	}
-
-	internal companion object : NoContentMeasureScope()
-}

mosaic-runtime/src/commonMain/kotlin/com/jakewharton/mosaic/layout/Node.kt

@@ -1,14 +1,7 @@
-package com.jakewharton.mosaic
+package com.jakewharton.mosaic.layout
 
-import androidx.compose.runtime.AbstractApplier
+import com.jakewharton.mosaic.TextCanvas
-import androidx.compose.runtime.Applier
+import com.jakewharton.mosaic.TextSurface
-import androidx.compose.runtime.Composable
-import androidx.compose.runtime.ReusableComposeNode
-import com.jakewharton.mosaic.layout.Measurable
-import com.jakewharton.mosaic.layout.MeasurePolicy
-import com.jakewharton.mosaic.layout.MeasureResult
-import com.jakewharton.mosaic.layout.MeasureScope
-import com.jakewharton.mosaic.layout.Placeable
 import com.jakewharton.mosaic.layout.Placeable.PlacementScope
 
 internal fun interface DrawPolicy {
@@ -148,87 +141,4 @@ internal class MosaicNode(
 	fun paintStatics(statics: MutableList<TextSurface>) = staticPaintPolicy?.run { performPaintStatics(statics) }
 
 	override fun toString() = debugPolicy.run { renderDebug() }
-
-	companion object {
-		val Factory: () -> MosaicNode = {
-			MosaicNode(
-				measurePolicy = ThrowingPolicy,
-				drawPolicy = ThrowingPolicy,
-				staticPaintPolicy = ThrowingPolicy,
-				debugPolicy = ThrowingPolicy,
-			)
-		}
-
-		fun root(): MosaicNode {
-			return MosaicNode(
-				measurePolicy = { measurables ->
-					var width = 0
-					var height = 0
-					val placeables = measurables.map { measurable ->
-						measurable.measure().also {
-							width = maxOf(width, it.width)
-							height = maxOf(height, it.height)
-						}
-					}
-					layout(width, height) {
-						for (placeable in placeables) {
-							placeable.place(0, 0)
-						}
-					}
-				},
-				drawPolicy = null,
-				staticPaintPolicy = StaticPaintPolicy.Children,
-				debugPolicy = {
-					children.joinToString(separator = "\n")
-				}
-			)
-		}
-
-		private val ThrowingPolicy = object : MeasurePolicy, DrawPolicy, StaticPaintPolicy, DebugPolicy {
-			override fun MeasureScope.measure(measurables: List<Measurable>) = throw AssertionError()
-			override fun performDraw(canvas: TextCanvas) = throw AssertionError()
-			override fun MosaicNode.performPaintStatics(statics: MutableList<TextSurface>) = throw AssertionError()
-			override fun MosaicNode.renderDebug() = throw AssertionError()
-		}
-	}
-}
-
-@Composable
-internal inline fun Node(
-	content: @Composable () -> Unit = {},
-	measurePolicy: MeasurePolicy,
-	drawPolicy: DrawPolicy?,
-	staticPaintPolicy: StaticPaintPolicy?,
-	debugPolicy: DebugPolicy,
-) {
-	ReusableComposeNode<MosaicNode, Applier<Any>>(
-		factory = MosaicNode.Factory,
-		update = {
-			set(measurePolicy) { this.measurePolicy = measurePolicy }
-			set(drawPolicy) { this.drawPolicy = drawPolicy }
-			set(staticPaintPolicy) { this.staticPaintPolicy = staticPaintPolicy }
-			set(debugPolicy) { this.debugPolicy = debugPolicy }
-		},
-		content = content,
-	)
-}
-
-internal class MosaicNodeApplier(root: MosaicNode) : AbstractApplier<MosaicNode>(root) {
-	override fun insertTopDown(index: Int, instance: MosaicNode) {
-		// Ignored, we insert bottom-up.
-	}
-
-	override fun insertBottomUp(index: Int, instance: MosaicNode) {
-		current.children.add(index, instance)
-	}
-
-	override fun remove(index: Int, count: Int) {
-		current.children.remove(index, count)
-	}
-
-	override fun move(from: Int, to: Int, count: Int) {
-		current.children.move(from, to, count)
-	}
-
-	override fun onClear() {}
 }

mosaic-runtime/src/commonMain/kotlin/com/jakewharton/mosaic/mosaic.kt

@@ -1,10 +1,13 @@
 package com.jakewharton.mosaic
 
+import androidx.compose.runtime.AbstractApplier
 import androidx.compose.runtime.BroadcastFrameClock
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.Composition
 import androidx.compose.runtime.Recomposer
 import androidx.compose.runtime.snapshots.Snapshot
+import com.jakewharton.mosaic.layout.MosaicNode
+import com.jakewharton.mosaic.layout.StaticPaintPolicy
 import kotlin.time.ExperimentalTime
 import kotlinx.coroutines.CompletableDeferred
 import kotlinx.coroutines.CoroutineScope
@@ -26,7 +29,7 @@ internal fun mosaicNodes(content: @Composable () -> Unit): MosaicNode {
 	val job = Job()
 	val composeContext = clock + job
 
-	val rootNode = MosaicNode.root()
+	val rootNode = createRootNode()
 	val recomposer = Recomposer(composeContext)
 	val composition = Composition(MosaicNodeApplier(rootNode), recomposer)
 
@@ -64,7 +67,7 @@ public suspend fun runMosaic(body: suspend MosaicScope.() -> Unit): Unit = corou
 	val job = Job(coroutineContext[Job])
 	val composeContext = coroutineContext + clock + job
 
-	val rootNode = MosaicNode.root()
+	val rootNode = createRootNode()
 	val recomposer = Recomposer(composeContext)
 	val composition = Composition(MosaicNodeApplier(rootNode), recomposer)
 
@@ -136,3 +139,48 @@ public suspend fun runMosaic(body: suspend MosaicScope.() -> Unit): Unit = corou
 	job.cancel()
 	composition.dispose()
 }
+
+internal fun createRootNode(): MosaicNode {
+	return MosaicNode(
+		measurePolicy = { measurables ->
+			var width = 0
+			var height = 0
+			val placeables = measurables.map { measurable ->
+				measurable.measure().also {
+					width = maxOf(width, it.width)
+					height = maxOf(height, it.height)
+				}
+			}
+			layout(width, height) {
+				for (placeable in placeables) {
+					placeable.place(0, 0)
+				}
+			}
+		},
+		drawPolicy = null,
+		staticPaintPolicy = StaticPaintPolicy.Children,
+		debugPolicy = {
+			children.joinToString(separator = "\n")
+		}
+	)
+}
+
+internal class MosaicNodeApplier(root: MosaicNode) : AbstractApplier<MosaicNode>(root) {
+	override fun insertTopDown(index: Int, instance: MosaicNode) {
+		// Ignored, we insert bottom-up.
+	}
+
+	override fun insertBottomUp(index: Int, instance: MosaicNode) {
+		current.children.add(index, instance)
+	}
+
+	override fun remove(index: Int, count: Int) {
+		current.children.remove(index, count)
+	}
+
+	override fun move(from: Int, to: Int, count: Int) {
+		current.children.move(from, to, count)
+	}
+
+	override fun onClear() {}
+}

mosaic-runtime/src/commonMain/kotlin/com/jakewharton/mosaic/rendering.kt

@@ -1,5 +1,6 @@
 package com.jakewharton.mosaic
 
+import com.jakewharton.mosaic.layout.MosaicNode
 import kotlin.time.ExperimentalTime
 import kotlin.time.TimeMark
 import kotlin.time.TimeSource

mosaic-runtime/src/commonMain/kotlin/com/jakewharton/mosaic/ui/Column.kt

@@ -3,7 +3,6 @@
 package com.jakewharton.mosaic.ui
 
 import androidx.compose.runtime.Composable
-import com.jakewharton.mosaic.layout.Layout
 import kotlin.jvm.JvmName
 
 @Composable

mosaic-runtime/src/commonMain/kotlin/com/jakewharton/mosaic/ui/Layout.kt

@@ -1,13 +1,38 @@
 @file:JvmName("Layout")
 
-package com.jakewharton.mosaic.layout
+package com.jakewharton.mosaic.ui
 
 import androidx.compose.runtime.Composable
-import com.jakewharton.mosaic.DrawPolicy
+import com.jakewharton.mosaic.layout.DrawPolicy
-import com.jakewharton.mosaic.Node
+import com.jakewharton.mosaic.layout.Measurable
-import com.jakewharton.mosaic.StaticPaintPolicy
+import com.jakewharton.mosaic.layout.MeasurePolicy
+import com.jakewharton.mosaic.layout.MeasureResult
+import com.jakewharton.mosaic.layout.MeasureScope
+import com.jakewharton.mosaic.layout.StaticPaintPolicy
 import kotlin.jvm.JvmName
 
+internal fun interface NoContentMeasurePolicy {
+	fun NoContentMeasureScope.measure(): MeasureResult
+}
+
+internal sealed class NoContentMeasureScope {
+	fun layout(
+		width: Int,
+		height: Int,
+	): MeasureResult {
+		return LayoutResult(width, height)
+	}
+
+	private class LayoutResult(
+		override val width: Int,
+		override val height: Int,
+	) : MeasureResult {
+		override fun placeChildren() {}
+	}
+
+	internal companion object : NoContentMeasureScope()
+}
+
 @Composable
 internal fun Layout(
 	debugInfo: () -> String = { "Layout()" },

mosaic-runtime/src/commonMain/kotlin/com/jakewharton/mosaic/ui/Node.kt

@@ -0,0 +1,50 @@
+package com.jakewharton.mosaic.ui
+
+import androidx.compose.runtime.Applier
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.ReusableComposeNode
+import com.jakewharton.mosaic.TextCanvas
+import com.jakewharton.mosaic.TextSurface
+import com.jakewharton.mosaic.layout.DebugPolicy
+import com.jakewharton.mosaic.layout.DrawPolicy
+import com.jakewharton.mosaic.layout.Measurable
+import com.jakewharton.mosaic.layout.MeasurePolicy
+import com.jakewharton.mosaic.layout.MeasureScope
+import com.jakewharton.mosaic.layout.MosaicNode
+import com.jakewharton.mosaic.layout.StaticPaintPolicy
+
+@Composable
+internal inline fun Node(
+	content: @Composable () -> Unit = {},
+	measurePolicy: MeasurePolicy,
+	drawPolicy: DrawPolicy?,
+	staticPaintPolicy: StaticPaintPolicy?,
+	debugPolicy: DebugPolicy,
+) {
+	ReusableComposeNode<MosaicNode, Applier<Any>>(
+		factory = NodeFactory,
+		update = {
+			set(measurePolicy) { this.measurePolicy = measurePolicy }
+			set(drawPolicy) { this.drawPolicy = drawPolicy }
+			set(staticPaintPolicy) { this.staticPaintPolicy = staticPaintPolicy }
+			set(debugPolicy) { this.debugPolicy = debugPolicy }
+		},
+		content = content,
+	)
+}
+
+internal val NodeFactory: () -> MosaicNode = {
+	MosaicNode(
+		measurePolicy = ThrowingPolicy,
+		drawPolicy = ThrowingPolicy,
+		staticPaintPolicy = ThrowingPolicy,
+		debugPolicy = ThrowingPolicy,
+	)
+}
+
+private val ThrowingPolicy = object : MeasurePolicy, DrawPolicy, StaticPaintPolicy, DebugPolicy {
+	override fun MeasureScope.measure(measurables: List<Measurable>) = throw AssertionError()
+	override fun performDraw(canvas: TextCanvas) = throw AssertionError()
+	override fun MosaicNode.performPaintStatics(statics: MutableList<TextSurface>) = throw AssertionError()
+	override fun MosaicNode.renderDebug() = throw AssertionError()
+}

mosaic-runtime/src/commonMain/kotlin/com/jakewharton/mosaic/ui/Row.kt

@@ -3,7 +3,6 @@
 package com.jakewharton.mosaic.ui
 
 import androidx.compose.runtime.Composable
-import com.jakewharton.mosaic.layout.Layout
 import kotlin.jvm.JvmName
 
 @Composable

mosaic-runtime/src/commonMain/kotlin/com/jakewharton/mosaic/ui/Static.kt

@@ -8,7 +8,6 @@ import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
 import androidx.compose.runtime.setValue
 import androidx.compose.runtime.snapshots.SnapshotStateList
-import com.jakewharton.mosaic.Node
 import kotlin.jvm.JvmName
 
 /**

mosaic-runtime/src/commonMain/kotlin/com/jakewharton/mosaic/ui/Text.kt

@@ -4,7 +4,6 @@ package com.jakewharton.mosaic.ui
 
 import androidx.compose.runtime.Composable
 import androidx.compose.runtime.remember
-import com.jakewharton.mosaic.layout.Layout
 import com.jakewharton.mosaic.text.TextLayout
 import kotlin.jvm.JvmName
 

mosaic-runtime/src/commonTest/kotlin/com/jakewharton/mosaic/DebugRenderingTest.kt

@@ -1,6 +1,6 @@
 package com.jakewharton.mosaic
 
-import com.jakewharton.mosaic.layout.Layout
+import com.jakewharton.mosaic.ui.Layout
 import com.jakewharton.mosaic.ui.Row
 import com.jakewharton.mosaic.ui.Static
 import com.jakewharton.mosaic.ui.Text

mosaic-runtime/src/commonTest/kotlin/com/jakewharton/mosaic/LayoutTest.kt

@@ -1,8 +1,8 @@
 package com.jakewharton.mosaic
 
-import com.jakewharton.mosaic.layout.Layout
 import com.jakewharton.mosaic.layout.Measurable
 import com.jakewharton.mosaic.ui.Column
+import com.jakewharton.mosaic.ui.Layout
 import com.jakewharton.mosaic.ui.Row
 import com.jakewharton.mosaic.ui.Text
 import kotlin.test.Test

mosaic-runtime/src/commonTest/kotlin/com/jakewharton/mosaic/NodeApplierTest.kt

@@ -1,11 +1,14 @@
 package com.jakewharton.mosaic
 
 import androidx.compose.runtime.Applier
+import com.jakewharton.mosaic.layout.DebugPolicy
+import com.jakewharton.mosaic.layout.MosaicNode
+import com.jakewharton.mosaic.ui.NodeFactory
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
 class NodeApplierTest {
-	private val root = MosaicNode.root()
+	private val root = createRootNode()
 	private val applier = MosaicNodeApplier(root)
 
 	private fun <T> Applier<T>.insert(index: Int, instance: T) {
@@ -185,7 +188,7 @@ class NodeApplierTest {
 	}
 
 	private fun TextNode(name: String): MosaicNode {
-		return MosaicNode.Factory().apply {
+		return NodeFactory().apply {
 			debugPolicy = DebugPolicy { name }
 		}
 	}