viewcompose-preview-core/com.viewcompose.preview.tooling

Package-level declarations

Types

Canonical artifact directory layout. IDs are path-safe by protocol validation.

@Serializable

data class PreviewArtifacts(val imagePath: String? = null, val renderTreePath: String? = null, val diagnosticsPath: String? = null)

Files emitted by a successful or partially successful render.

PreviewBuildInput

@Serializable

data class PreviewBuildInput(val kind: PreviewBuildInputKind, val paths: List<String>)

One deterministic, non-empty group of build inputs.

PreviewBuildInputKind

@Serializable

enum PreviewBuildInputKind : Enum<PreviewBuildInputKind>

Stable roles for files exported by the Gradle bridge.

PreviewBuildManifest

@Serializable

data class PreviewBuildManifest(val protocolVersion: Int = ViewComposePreviewProtocol.CURRENT_VERSION, val modulePath: String, val buildVariant: String, val namespace: String, val androidGradlePluginVersion: String, val minSdk: Int, val targetSdk: Int, val compileSdk: Int, val sdkDirectory: String, val mergedManifestPath: String, val artifactRootDirectory: String, val resourcePackageNames: List<String>, val inputs: List<PreviewBuildInput>, val inputFingerprint: String, val layoutlibCompatibilityFingerprint: String = inputFingerprint)

Fully resolved Android build target consumed by discovery, rendering, and IDE tooling.

PreviewClippingState

@Serializable

enum PreviewClippingState : Enum<PreviewClippingState>

PreviewCompositionLocal

@Serializable

data class PreviewCompositionLocal(val name: String, val value: String)

PreviewCompositionSnapshot

@Serializable

data class PreviewCompositionSnapshot(val invalidatedScopeCount: Int = 0, val recomposedScopeCount: Int = 0, val skippedScopeCount: Int = 0, val scopes: List<PreviewRecomposeScope> = emptyList())

PreviewConfiguration

@Serializable

data class PreviewConfiguration(val widthDp: Int = PreviewDefaults.WIDTH_DP, val heightDp: Int = PreviewDefaults.HEIGHT_DP, val density: Float = PreviewDefaults.DENSITY, val fontScale: Float = PreviewDefaults.FONT_SCALE, val localeTags: List<String> = listOf(PreviewDefaults.LOCALE_TAG), val layoutDirection: PreviewLayoutDirection = PreviewLayoutDirection.Ltr, val theme: PreviewTheme = PreviewTheme.Light, val apiLevel: Int? = null)

Fully resolved environment for one static preview render.

PreviewConfigurationAxis

@Serializable

data class PreviewConfigurationAxis(val id: String, val displayName: String, val options: List<PreviewConfigurationOption>)

One independently selectable dimension of a preview matrix.

PreviewConfigurationMatrix

@Serializable

data class PreviewConfigurationMatrix(val base: PreviewConfiguration = PreviewConfiguration(), val axes: List<PreviewConfigurationAxis>)

Deterministic Cartesian product used by Gradle, tests, and the IDE variant selector.

PreviewConfigurationOption

@Serializable

data class PreviewConfigurationOption(val id: String, val displayName: String, val override: PreviewConfigurationOverride)

One named choice on a preview matrix axis.

PreviewConfigurationOverride

@Serializable

data class PreviewConfigurationOverride(val widthDp: Int? = null, val heightDp: Int? = null, val density: Float? = null, val fontScale: Float? = null, val localeTags: List<String>? = null, val layoutDirection: PreviewLayoutDirection? = null, val theme: PreviewTheme? = null, val apiLevel: Int? = null)

Nullable configuration fields used by a matrix option to override a base configuration.

PreviewConfigurationPresets

object PreviewConfigurationPresets

Reusable axes covering the common first-party static preview configurations.

PreviewDefaults

object PreviewDefaults

Stable defaults shared by annotations, Gradle tooling, and render workers.

PreviewDescriptor

@Serializable

data class PreviewDescriptor(val id: String, val displayName: String, val group: String = "", val entryPoint: PreviewJvmEntryPoint, val variants: List<PreviewVariant>, val sourceLocation: PreviewSourceLocation? = null, val themeProviderClassName: String? = null)

IDE- and renderer-independent description of one preview function.

PreviewDescriptorCatalog

@Serializable

data class PreviewDescriptorCatalog(val protocolVersion: Int = ViewComposePreviewProtocol.CURRENT_VERSION, val modulePath: String, val buildVariant: String, val buildFingerprint: String, val descriptors: List<PreviewDescriptor>, val diagnostics: List<PreviewDiagnostic> = emptyList())

Machine-readable discovery result written even when individual preview functions are invalid.

PreviewDiagnostic

@Serializable

data class PreviewDiagnostic(val severity: PreviewDiagnosticSeverity, val message: String, val phase: String, val sourceLocation: PreviewSourceLocation? = null, val details: String? = null)

One structured compile, discovery, render, or export diagnostic.

PreviewDiagnosticSeverity

@Serializable

enum PreviewDiagnosticSeverity : Enum<PreviewDiagnosticSeverity>

PreviewFontScales

@Target(allowedTargets = [AnnotationTarget.FUNCTION, AnnotationTarget.ANNOTATION_CLASS])

@ViewComposePreview(name = "Font 100%", fontScale = 1.0)

@ViewComposePreview(name = "Font 130%", fontScale = 1.3)

@ViewComposePreview(name = "Font 200%", fontScale = 2.0)

annotation class PreviewFontScales

Built-in multi-preview for default, large, and maximum accessibility font scales.

PreviewJvmEntryPoint

@Serializable

data class PreviewJvmEntryPoint(val ownerClassName: String, val methodName: String, val methodDescriptor: String? = null)

Compiled JVM function that a render worker invokes for a preview.

PreviewLayoutBounds

@Serializable

data class PreviewLayoutBounds(val left: Int, val top: Int, val right: Int, val bottom: Int)

PreviewLayoutDiagnostic

@Serializable

data class PreviewLayoutDiagnostic(val kind: PreviewLayoutDiagnosticKind, val severity: PreviewDiagnosticSeverity, val className: String, val bounds: PreviewLayoutBounds, val visibleBounds: PreviewLayoutBounds? = null, val clippingAncestorClassName: String? = null, val clippingAncestorNodeId: String? = null, val clippingExpected: Boolean = false, val metrics: Map<String, Int> = emptyMap(), val nodeId: String? = null, val sourceCallSites: List<PreviewSourceCallSite> = emptyList(), val synthetic: Boolean = false)

One source-aware layout condition captured after Android measure and layout complete.

PreviewLayoutDiagnosticKind

@Serializable

enum PreviewLayoutDiagnosticKind : Enum<PreviewLayoutDiagnosticKind>

PreviewLayoutDirection

@Serializable

enum PreviewLayoutDirection : Enum<PreviewLayoutDirection>

Explicit layout direction used for a deterministic preview render.

PreviewLightDark

@Target(allowedTargets = [AnnotationTarget.FUNCTION, AnnotationTarget.ANNOTATION_CLASS])

@ViewComposePreview(name = "Light", theme = PreviewTheme.Light)

@ViewComposePreview(name = "Dark", theme = PreviewTheme.Dark)

annotation class PreviewLightDark

Built-in multi-preview for the framework Light and Dark token sets.

PreviewLtrRtl

@Target(allowedTargets = [AnnotationTarget.FUNCTION, AnnotationTarget.ANNOTATION_CLASS])

@ViewComposePreview(name = "LTR · en-US", localeTag = "en-US", layoutDirection = PreviewLayoutDirection.Ltr)

@ViewComposePreview(name = "RTL · ar-EG", localeTag = "ar-EG", layoutDirection = PreviewLayoutDirection.Rtl)

annotation class PreviewLtrRtl

Built-in multi-preview for LTR English and RTL Arabic environments.

PreviewNativeViewNode

@Serializable

data class PreviewNativeViewNode(val className: String, val bounds: PreviewLayoutBounds, val measuredWidth: Int, val measuredHeight: Int, val visibility: String, val visibleBounds: PreviewLayoutBounds? = null, val clippingState: PreviewClippingState = PreviewClippingState.NotClipped, val clippingAncestorClassName: String? = null, val clippingAncestorNodeId: String? = null, val clippingExpected: Boolean = false, val properties: Map<String, String> = emptyMap(), val nodeId: String? = null, val sourceCallSites: List<PreviewSourceCallSite> = emptyList(), val synthetic: Boolean = false, val children: List<PreviewNativeViewNode> = emptyList())

One laid-out Android View captured after the static preview root completes measure and layout.

PreviewNodeBindingStats

@Serializable

data class PreviewNodeBindingStats(val rebound: Int = 0, val patched: Int = 0, val skipped: Int = 0)

PreviewPatchRecord

@Serializable

data class PreviewPatchRecord(val operation: String, val type: String, val key: String? = null, val parentKey: String? = null, val index: Int, val moved: Boolean = false, val detail: String? = null, val nodeId: String? = null, val sourceCallSites: List<PreviewSourceCallSite> = emptyList(), val synthetic: Boolean = false)

PreviewPhaseTiming

@Serializable

data class PreviewPhaseTiming(val phase: String, val durationMillis: Long)

One deterministic phase measurement emitted by the isolated render pipeline.

PreviewPhoneTablet

@Target(allowedTargets = [AnnotationTarget.FUNCTION, AnnotationTarget.ANNOTATION_CLASS])

@ViewComposePreview(name = "Phone", widthDp = 411, heightDp = 891)

@ViewComposePreview(name = "Tablet", widthDp = 800, heightDp = 1280)

annotation class PreviewPhoneTablet

Built-in multi-preview for common phone and tablet canvas sizes.

PreviewProtocolJson

object PreviewProtocolJson

Canonical JSON codec shared by Gradle, render workers, tests, and the Android Studio plugin.

PreviewRecomposeScope

@Serializable

data class PreviewRecomposeScope(val path: String, val signature: String, val depth: Int, val reasons: List<String> = emptyList(), val recomposed: Boolean, val skipped: Boolean, val locals: List<PreviewCompositionLocal> = emptyList(), val sourceCallSites: List<PreviewSourceCallSite> = emptyList())

PreviewRenderRequest

@Serializable

data class PreviewRenderRequest(val protocolVersion: Int = ViewComposePreviewProtocol.CURRENT_VERSION, val requestId: String, val descriptor: PreviewDescriptor, val variantId: String, val modulePath: String, val buildVariant: String, val buildFingerprint: String, val outputDirectory: String)

One isolated static render request.

PreviewRenderResponse

@Serializable

data class PreviewRenderResponse(val protocolVersion: Int = ViewComposePreviewProtocol.CURRENT_VERSION, val requestId: String, val previewId: String, val variantId: String, val status: PreviewRenderStatus, val artifacts: PreviewArtifacts? = null, val diagnostics: List<PreviewDiagnostic> = emptyList(), val durationMillis: Long? = null, val phaseTimings: List<PreviewPhaseTiming> = emptyList())

Response returned by an isolated preview worker.

PreviewRenderSnapshot

@Serializable

data class PreviewRenderSnapshot(val stats: PreviewRenderStats = PreviewRenderStats(), val structure: PreviewRenderStructure = PreviewRenderStructure(), val warnings: List<String> = emptyList(), val tree: List<PreviewRenderTreeNode> = emptyList(), val nativeViewTree: List<PreviewNativeViewNode> = emptyList(), val layoutDiagnostics: List<PreviewLayoutDiagnostic> = emptyList(), val patches: List<PreviewPatchRecord> = emptyList(), val composition: PreviewCompositionSnapshot = PreviewCompositionSnapshot())

Platform-neutral diagnostics emitted beside a static preview image.

PreviewRenderStats

@Serializable

data class PreviewRenderStats(val inserts: Int = 0, val reuses: Int = 0, val removals: Int = 0, val reboundNodes: Int = 0, val patchedNodes: Int = 0, val skippedBindings: Int = 0, val skippedSubtrees: Int = 0, val bindingsByType: Map<String, PreviewNodeBindingStats> = emptyMap())

PreviewRenderStatus

@Serializable

enum PreviewRenderStatus : Enum<PreviewRenderStatus>

Stable preview worker outcome. Failures are data rather than thrown across the process boundary.

PreviewRenderStructure

@Serializable

data class PreviewRenderStructure(val vnodeCount: Int = 0, val mountedNodeCount: Int = 0, val maxVNodeDepth: Int = 0, val maxMountedDepth: Int = 0)

PreviewRenderTreeNode

@Serializable

data class PreviewRenderTreeNode(val type: String, val key: String? = null, val nodeId: String? = null, val sourceCallSites: List<PreviewSourceCallSite> = emptyList(), val synthetic: Boolean = false, val children: List<PreviewRenderTreeNode> = emptyList())

PreviewSourceCallSite

@Serializable

data class PreviewSourceCallSite(val className: String, val methodName: String, val fileName: String, val lineNumber: Int)

One JVM line-table call site associated with a preview node.

PreviewSourceLocation

@Serializable

data class PreviewSourceLocation(val filePath: String, val line: Int, val column: Int = 1, val symbolName: String? = null)

Source location used for diagnostics and IDE navigation.

PreviewTheme

@Serializable

enum PreviewTheme : Enum<PreviewTheme>

Explicit day/night resource mode used for a deterministic preview render.

PreviewVariant

@Serializable

data class PreviewVariant(val id: String, val displayName: String, val configuration: PreviewConfiguration)

Named configuration presented as one selectable preview variant.

PreviewWorkerBatchCommand

@Serializable

data class PreviewWorkerBatchCommand(val protocolVersion: Int = ViewComposePreviewProtocol.CURRENT_VERSION, val commands: List<PreviewWorkerCommand>)

Bounded collection of isolated render commands executed sequentially by one short-lived host. The host process still exits after the batch, preventing Layoutlib state from leaking into Gradle or Android Studio while avoiding one JVM startup per gallery tile.

PreviewWorkerCommand

@Serializable

data class PreviewWorkerCommand(val protocolVersion: Int = ViewComposePreviewProtocol.CURRENT_VERSION, val buildManifestPath: String, val renderRequestPath: String, val renderResponsePath: String, val layoutlibRuntimeRoot: String, val layoutlibResourcesRoot: String, val renderClasspath: List<String> = emptyList())

One self-contained command consumed by the isolated Layoutlib host.

ViewComposePreview

@Target(allowedTargets = [AnnotationTarget.FUNCTION, AnnotationTarget.ANNOTATION_CLASS])

@Repeatable(value = ViewComposePreviews::class)

annotation class ViewComposePreview(val name: String = "", val group: String = "", val widthDp: Int = PreviewDefaults.WIDTH_DP, val heightDp: Int = PreviewDefaults.HEIGHT_DP, val density: Float = PreviewDefaults.DENSITY, val fontScale: Float = PreviewDefaults.FONT_SCALE, val localeTag: String = PreviewDefaults.LOCALE_TAG, val layoutDirection: PreviewLayoutDirection = PreviewLayoutDirection.Ltr, val theme: PreviewTheme = PreviewTheme.Light, val apiLevel: Int = PreviewDefaults.UNSPECIFIED_API_LEVEL)

Marks a top-level or static ViewCompose DSL function as a tooling preview entry point.

ViewComposePreviewProtocol

object ViewComposePreviewProtocol

Versioned boundary between Gradle/IDE clients and an isolated preview render worker.

ViewComposePreviews

@Target(allowedTargets = [AnnotationTarget.FUNCTION, AnnotationTarget.ANNOTATION_CLASS])

annotation class ViewComposePreviews(val value: Array<ViewComposePreview>)

JVM container used for repeatable ViewComposePreview declarations.

ViewComposePreviewThemeProvider

@Target(allowedTargets = [AnnotationTarget.CLASS])

annotation class ViewComposePreviewThemeProvider

Selects the single application-owned theme provider used by static previews in one module.

Properties

isAutoHeight

val PreviewConfiguration.isAutoHeight: Boolean

Whether the screenshot canvas may grow beyond viewportHeightDp.

MAX_PREVIEW_WORKER_BATCH_SIZE

const val MAX_PREVIEW_WORKER_BATCH_SIZE: Int = 8

viewportHeightDp

val PreviewConfiguration.viewportHeightDp: Int

Concrete device height used by Android resources and the first layout pass.

Functions

toPreviewConfiguration

fun ViewComposePreview.toPreviewConfiguration(): PreviewConfiguration

Converts annotation values into the resolved, host-independent preview configuration.