redwood/CHANGELOG.md

Change Log

Unreleased

Fixed:

• Fix memory leaks in UIView layout components (UIViewBox, UIViewFlexContainer, RedwoodUIView)
• Fix memory leak in HostProtocolAdapter

These leaks affected some Treehouse-based screens and prevented UI components and their associated memory from being released after dismissal.

0.19.0

This will be the final release of Redwood for the foreseeable future. Development will be discontinued at this time.

New:

• Focus API. Redwood has a new FocusRequester to focus a widget.

Changed:

• Android libraries now have a minimum SDK level of 23.
• iOS x64 targets are no longer supported.
• Use AndroidX collection and Compose runtime artifacts, which are now fully multiplatform. A dependency constraint to the JetBrains Compose runtime version 1.9.0 has been added, which is the first version that is empty and itself now points to AndroidX.

Fixed:

• Don't measure the height of RedwoodUIView as zero when measured with sizeThatFits() or intrinsicContentSize(). We had been using UIStackView which doesn't support these functions.
• Correctly signal RedwoodUIView size changes of to callers who measure it with intrinsicContentSize().
• The Redwood Gradle plugin is now compatible with Gradle 9.1.
• Don't incorrectly size items to 0 when using the Flex() modifier on a Wrap container.

0.18.0 - 2025-08-01

New:

• Schema @Widgets can now set internalComposable = true to have their @Composable functions generated as internal. This will require that you define a public version in the main sources of the module which generates the functions. This can be used to hide old widgets that should no longer be used, create more complex widget protocols away from callers, and to conditionally split implementation between two bindings, for example.
• UI changes which come from Treehouse are now converted to their final value on a background thread. Previously JSON deserialization happened on the background thread to an intermediate model, but mapping that model to the final value still occurred on the main thread.

Changed:

• Schema dependencies can now be a graph (i.e., dependencies can have their own dependencies), but the entire transitive set needs to be redeclared on the root schema (for the protocol to work properly).
• Compose UI widget type has been changed from @Composable () -> Unit to @Composable (Modifier) -> Unit to support unscoped modifiers.
• JVM and Android artifacts now target Java 11 bytecode, as the upstream Compose dependencies now all target Java 11.
• The host protocol type has been renamed from ProtocolFactory to HostProtocol. An instance of HostProtocol is now required when constructing a TreehouseAppFactory.
• Enforce that event properties declared in your schema always return Unit.
• In-development snapshots are now published to the Central Portal Snapshots repository at https://central.sonatype.com/repository/maven-snapshots/.

Fixed:

• Don't double insets on insets-aware UIViews. Previously we offered the same insets via two mechanisms, which could result in double insets.
• Don't conflate CrossAxisAlignment.Stretch with Contraint.Fill. We had a bug where CrossAxisAlignment.Stretch would cause children to fill their parent container.
• Honor the inbound max width for Row and Column layouts using Constraint.Wrap on iOS. This is necessary for child components that can wrap, like text.
• Using "stretch" cross-axis alignment on a lazy list now works correctly in Compose UI.

Upgraded:

• Kotlin 2.2.0
• Zipline 1.21.0

0.17.0 - 2025-01-30

Breaking:

• Treehouse hosts running Redwood 0.11.0 or older are not longer actively supported. They will continue to work, but they will experience indefinite memory leaks of native widgets.
• Old, deprecated overloads of ZiplineTreehouseUi.start have been removed. The new overloads have been available since Redwood 0.8.0 for over a year.

New:

• UIConfiguration.viewInsets tracks the safe area of the specific RedwoodView being targeted. This is currently implemented for views on Android and UIViews on iOS.
• ConsumeInsets {} composable consumes insets. Most applications should call this in their root composable function.
• Add TestRedwoodComposition.setContentAndSnapshot function which is a fused version of setContent and awaitSnapshot, except that it guarantees the returned snapshot is the result of the initial composition of the content without any additional frames sent.

Fixed:

• Fix inconsistency in margin application between ComposeUiBox and ViewBox.
• Add support for the Height modifier in ComposeUiBox.
• Add support for the Width modifier in ComposeUiBox.
• Call DisposableEffect when a screen is unbound. We were only calling these when the effect was removed from the composition.
• Support movableContentOf in Treehouse (and generally in the Redwood protocol). Note: this requires the host be running version 0.17.0 or newer.
• Fix case where Column and Row would not update their intrinsic size on iOS if they are not a child of another Column or Row.

0.16.0 - 2024-11-19

New:

• Redwood publishes what's happening in bound content through the new Content.State type.
• Accept a ZiplineHttpClient in TreehouseAppFactory on Android.

Changed:

• Drop support for non-incremental layouts in Row and Column.
• Support for @Default annotation has now been removed, as detailed in the 0.15.0 release.

Fixed:

• Fix a layout bug where children of fixed-with Row containers were assigned the wrong width.
• Fix inconsistencies between iOS and Android for Column and Row layouts.
• Fix a layout bug where Row and Column layouts reported the wrong dimensions if their subviews could wrap.
• Correctly update the layout when a Box's child's modifiers are removed.
• Fix a layout bug where children of Box containers were not measured properly.
• Fix a bug where LazyColumn didn't honor child widget resizes.

Breaking:

• Replace CodeListener with a new DynamicContentWidgetFactory API. Now loading and crashed views work like all other child widgets.

0.15.0 - 2024-09-30

New:

• Default expressions can now be used directly in the schema rather than using the @Default annotation. The annotation has been deprecated, and will be removed in the next release.
• EventListener.Factory.close() is called by TreehouseApp.close() to release any resources held by the factory.
• Lambda parameter names defined in the schema are now propagated to the generated composable and widget interface.
• ResizableWidget is an interface that UIView widgets must use if their intrinsic sizes may change dynamically. It notifies any enclosing parent views to trigger a new layout.

Changed:

• Removed Wasm JS target. We are not ready to support it yet.

Fixed:

• Breaking the last remaining retain cycle in UIViewLazyList.
• Don't leak the DisplayLink when a TreehouseApp is stopped on iOS.
• Correctly handle dynamic size changes for child widgets of Box, Column, and Row.
• Don't clip elements of Column and Row layouts whose unbounded size exceeds the container size.
• Correctly implement margins for Box on iOS.
• Correctly handle dynamic updates to modifiers on Column and Row.

0.14.0 - 2024-08-29

New:

• Source-based schema parser is now the default. The useFir Gradle property has been removed.
• TreehouseAppFactory accepts a LeakDetector which can be used to notify you of reference leaks for native UI nodes, Zipline instances, Redwood's own internal wrappers, and more.
• Introduce a LoadingStrategy interface to manage LazyList preloading.
• Optimize encoding modifiers in Kotlin/JS.

Changed:

• In Treehouse, events from the UI are now serialized on a background thread. This means that there is both a delay and a thread change between when a UI binding sends an event and when that object is converted to JSON. All arguments to events must not be mutable and support property reads on any thread. Best practice is for all event arguments to be completely immutable.
• ProtocolFactory interface is now sealed as arbitrary subtypes were never supported. Only schema-generated subtypes should be used.
• UIViewLazyList doesn't crash with a NullPointerException if cells are added, removed, and re-added without being reused.
• Change UiConfiguration.viewportSize to be nullable. A null viewportSize indicates the viewport's size has not been resolved yet.

Fixed:

• Breaking content: UIView retain cycle in UIViewLazyList's LazyListContainerCell.
• Update ProtocolNode widget IDs when recycling widgets. This was causing pooled nodes to be leaked.

Breaking:

• The TreehouseApp.spec property is removed. Most callers should be able to use TreehouseApp.name instead. This is necessary to avoid a retain cycle.

Upgraded:

• Kotlin 2.0.20
• Zipline 1.17.0

0.13.0 - 2024-07-25

New:

• Wasm JS added as a target for common Redwood modules. There is no Treehouse support today.
• Add onScroll property to Row and Column. This property is invoked when overflow = Overflow.Scroll and the container is scrolled.
• Add Px class to represent a raw pixel value in the host's coordinate system.
• New source-based schema parser can be enabled with redwood { useFir = true } in your schema module. Please report and failures to the issue tracker. This parser will become the default in 0.14.0.

Changed:

• The TreehouseApp type is now an abstract class. This should make it easier to write unit tests for code that integrates Treehouse.
• The TreehouseApp.Spec.bindServices() function is now suspending.
• The TreehouseAppFactory function now accepts a Zipline LoaderEventListener parameter.

Fixed:

• Using a data object for a widget of modifier no longer causes schema parsing to crash.
• Ensuring LazyList's itemsBefore and itemsAfter properties are always within [0, itemCount], to prevent IndexOutOfBoundsException crashes.
• Don't crash in LazyList when a scroll and content change occur in the same update.
• Updating a flex container's margin now works correctly for Yoga-based layouts.

Breaking:

• The TreehouseApp.Factory.dispatchers property is removed, and callers should migrate to TreehouseApp.dispatchers. With this update each TreehouseApp has its own private thread so a shared dispatchers property no longer fits our implementation. -TreehouseApp.Spec.bindServices() now accepts a TreehouseApp parameter.

Upgraded:

• Zipline 1.16.0

0.12.0 - 2024-06-18

New:

• Upgrade to Kotlin 2.0!
• Added a basic DOM-based LazyList implementation. -TreehouseApp.close() stops the app and prevents it from being started again later.
• Added UiConfiguration.layoutDirection to support reading the host's layout direction.
• New redwood-bom artifact can be used to ensure all Redwood artifacts use the same version. See Gradle's documentation on how to use the BOM in your build.

Changed:

• The app.cash.redwood Gradle plugin has been removed. This plugin did two things: apply the Compose compiler and add a dependency on the redwood-compose artifact. The Compose compiler can now be added by applying the org.jetbrains.kotlin.plugin.compose Gradle plugin. Dependencies on Redwood artifacts can be added manually.
• Removed deprecated typealiases for generated -WidgetFactories type which was renamed to -WidgetSystem in 0.10.0.
• Removed deprecated Modifier.flex extension function which is now supported natively by Row and Column since 0.8.0.
• Removed deprecated TreehouseWidgetView and TreehouseUIKitView type aliases for TreehouseLayout and TreehouseUIView which were renamed in 0.7.0.
• Removed deprecated TreehouseAppFactory functions with the old FileSystem and Path order which were changed in 0.11.0.
• Rename the two types named ProtocolBridge to ProtocolHost and ProtocolGuest.

Fixed:

• Fix memory leaks caused by reference cycles on iOS. We got into trouble mixing garbage-collected Kotlin objects with reference-counted Swift objects.

Breaking: -TreehouseApp.zipline is now a StateFlow<Zipline?> instead of a Zipline?. -CodeListener.onCodeDetached() replaces onUncaughtException(). The new function is called whenever code stops driving a view for any reason. The new function accepts a Throwable? that is non-null if it's detached due to exception. -Content.awaitContent() now accepts an optional Int parameter for the number of updates to observe before the function returns.

• MacOS targets have been removed from all modules.

Upgraded:

• Kotlin 2.0.0
• Zipline 1.13.0
• kotlinx.serialization 1.7.0

Gradle plugin removed

This version of Redwood removes the custom Gradle plugin in favor of the official JetBrains Compose compiler plugin which ships as part of Kotlin itself. Each module in which you had previously applied the app.cash.redwood plugin should be changed to apply org.jetbrains.kotlin.plugin.compose instead. The Redwood dependencies will no longer be added as a result of the plugin change, and so any module which references Redwoods APIs should add those dependencies explicitly.

For posterity, the Kotlin version compatibility table and compiler version customization for our old Redwood Gradle plugin will be archived here:

Redwood 0.12.0 Gradle plugin Kotlin compatibility table

Since Kotlin compiler plugins are an unstable API, certain versions of Redwood only work with certain versions of Kotlin.

Kotlin	Redwood
1.9.24	0.11.0
1.9.23	0.10.0
1.9.22	0.8.0 - 0.9.0
1.9.10	0.7.0
1.9.0	0.6.0
1.8.22	0.5.0
1.8.20	0.3.0 - 0.4.0
1.7.20	0.1.0 - 0.2.1

Redwood 0.12.0 Gradle plugin Compose compiler customization instructions

Each version of Redwood ships with a specific JetBrains Compose compiler version which works with a single version of Kotlin (see version table above). Newer versions of the Compose compiler or alternate Compose compilers can be specified using the Gradle extension.

To use a new version of the JetBrains Compose compiler version:

redwood {
  kotlinCompilerPlugin.set("1.4.8")
}

To use an alternate Compose compiler dependency:

redwood {
  kotlinCompilerPlugin.set("com.example:custom-compose-compiler:1.0.0")
}

0.11.0 - 2024-05-15

New:

• Added toDebugString method for WidgetValue and List<WidgetValue> which returns a formatted string of a widget's children and properties, useful for test debugging.

Changed:

• Removed generated typealiases for package names which changed in 0.10.0.
• In UIViewLazyList's UITableView, adding special-case handling for programmatic scroll-to-top calls.
• APIs accepting a FileSystem and Path now have the FileSystem coming before the Path in the parameter list. Compatibility functions are retained for this version, but will be removed in the next version.
• Change LazyListState to be scroll-aware, reducing the size of the preload window while actively scrolling, and optimizing the preload window once the scroll has completed.

Fixed:

• Work around a problem with our memory-leak fix where our old LazyList code would crash when its placeholders were unexpectedly removed.
• Avoid calling into the internal Zipline instance from the UI thread on startup. This would manifest as weird native crashes due to multiple threads mutating shared memory.
• In UIViewLazyList, fix UInt to UIColor conversion math used for pullRefreshContentColor.
• In YogaUIView's setScrollEnabled method, only call setNeedsLayout if the scrollEnabled value is actually changing.
• In YogaUIView's layoutNodes method, return early for nested YogaUIViews to prevent redundant frame calculations.

Upgraded:

• Zipline 1.10.1.

This version works with Kotlin 1.9.24 by default.

0.10.0 - 2024-04-05

New:

• Compose UI implementation for Box.
• Layout modifier support for HTML DOM layouts.
• Unscoped modifiers provide a global hook for side-effecting behavior on native views. For example, create a background color modifier which changes the platform-native UI node through a factory function.
• Widget.Children interface now exposes widgets: List<Widget<W>> property. Most subtypes were already exposing this individually.

Changed:

• Disable klib signature clash checks for JS compilations. These occasionally occur as a result of Compose compiler behavior, and are safe to disable (the first-party JetBrains Compose Gradle plugin also disables them).
• onModifierChanged callback in Widget.Children now receives the index and the Widget instance affected by the change.
• The package of 'redwood-protocol-host' changed to app.cash.redwood.protocol.host. This should not affect end-users as its types are mostly for internal use.
• The entire redwood-yoga artifact's public API has been annotated with an opt-in annotation indicating that it's only for Redwood internal use and is not stable.
• Revert: Don't block touch events to non-subviews below a Row, Column, or Box in the iOS UIView implementation. This matches the behavior of the Android View and Compose UI implementations.
• The generated "widget factories" type (e.g., MySchemaWidgetFactories) is now called a "widget system" (e.g., MySchemaWidgetSystem). Sometimes it was also referred to as a "provider" in parameter names. A @Deprecated typealias is generated for now, but will be removed in the future.
• The package names of some generated code has changed. Deprecated typealiases are generated in the old locations for public types and functions, but those will be removed in the next release.
  • Testing code is now under your.package.testing.
  • Protocol guest code is now under your.package.protocol.guest.
  • Protocol host code is now under your.package.protocol.host.
• The 'app.cash.redwood.generator.compose.protocol' and 'app.cash.redwood.generator.widget.protocol' Gradle plugins are now deprecated and will be removed in the next release. Use 'app.cash.redwood.generator.protocol.guest' and 'app.cash.redwood.generator.protocol.host', respectively.
• The 'redwood-tooling-codegen' CLI flags for protocol codegen have changed from --compose-protocol and --widget-protocol to --protocol-guest and --protocol-host, respectively.
• Entrypoints to the protocol on the host-side and guest-side now require supplying the version of Redwood in use on the other side in order to ensure compatibility and work around any bugs in older versions. This uses a new RedwoodVersion type, and will be automatically wired if using our Treehouse artifacts.

Fixed:

• Fix failure to release JS resources when calling CoroutineScope is being cancelled
• JVM targets now correctly link against Java 8 APIs. Previously they produced Java 8 bytecode, but linked against the compile JDK's APIs (21). This allowed linking against newer APIs that might not exist on older runtimes, which is no longer possible. Android targets which also produce Java 8 bytecode were not affected.
• Fix the View implementation of Box to wrap its width and height by default. This matches the behavior of the UIView implementation and all other layout widgets.
• Fix the UIView implementation of Box not updating when some of its parameters are changed.
• Fix Modifier.size not being applied to children inside a Box.
• Fix Margin not being applied to the UIView implementation of Box.
• The View implementation of Box now applies start/end margins correctly in RTL, and does not crash if set before the native view was attached.
• Fix the backgroundColor for UIViewLazyList to be transparent. This matches the behavior of the other LazyList platform implementations.
• Fix TreehouseUIView to size itself according to the size of its subview.
• In UIViewLazyList, adding beginUpdates/endUpdates calls to insertRows/deleteRows, and wrapping changes in UIView.performWithoutAnimation blocks.
• Fix memory leak in 'protocol-guest' and 'protocol-host' where child nodes beneath a removed node were incorrectly retained in an internal map indefinitely. The guest protocol code has been updated to work around this memory leak when deployed to old hosts by sending individual remove operations for each node in the subtree.
• Ensure that Zipline services are not closed prematurely when disposing a Treehouse UI.
• In UIViewLazyList, don't remove subviews from hierarchy during prepareForReuse call

This version works with Kotlin 1.9.23 by default.

0.9.0 - 2024-02-28

Changed:

• Added Modifier parameter to RedwoodContent which is applied to the root Box into which content is rendered (https://android.googlesource.com/platform/frameworks/support/+/androidx-main/compose/docs/compose-api-guidelines.md#elements-accept-and-respect-a-modifier-parameter).
• The parameter order of LazyRow and LazyColumn have changed to reflect Compose best practices (https://android.googlesource.com/platform/frameworks/support/+/androidx-main/compose/docs/compose-api-guidelines.md#elements-accept-and-respect-a-modifier-parameter).
• The parameter order of TreehouseContent has changed to reflect Compose best practices (https://android.googlesource.com/platform/frameworks/support/+/androidx-main/compose/docs/compose-api-guidelines.md#elements-accept-and-respect-a-modifier-parameter).
• The render function of ComposeWidgetChildren has been renamed to Render to reflect Compose best practices (https://android.googlesource.com/platform/frameworks/support/+/androidx-main/compose/docs/compose-api-guidelines.md#naming-unit-composable-functions-as-entities).
• Disable decoy generation for JS target to make compatible with JetBrains Compose 1.6. This is an ABI-breaking change, so all Compose-based libraries targeting JS will also need to have been recompiled.

Fixed:

• Don't block touch events to non-subviews below a Row, Column, or Box in the iOS UIView implementation. This matches the behavior of the Android View and Compose UI implementations.

This version works with Kotlin 1.9.22 by default.

0.8.0 - 2024-02-22

New:

• flex(double) modifier for layouts which acts as a weight along the main axis.
• Allow reserving widget, modifier, property, and children tags in the schema. This can be used to document old items which no longer exist and prevent their values from accidentally being reused.
• Add dangerZone { } DSL to the redwood { } Gradle extension which allows enabling Compose reports and metrics. Currently these features break build caching as Compose forces the use of absolute paths in the Kotlin compiler arguments when in use (hence why they're marked as dangerous).
• BackHandler composable provides a callback for handling hardware back affordances (currently only on Android).
• Expose frameClock on StandardAppLifecycle to allow monitoring host frames.
• CodeListener.onUncaughtException notifies of any uncaught exceptions which occur in Treehouse guest code.
• Preview: Add Box widget which stacks children on top of each other. This is currently only implemented for Android views and iOS UIKit.
• Support rememberSaveable in plain Redwood compositions.
• Programmatic scrolls on LazyListState can now set animated=true for an animated scroll.
• Add ziplineCreated, manifestReady, and codeLoadSkippedNotFresh event callbacks to Treehouse EventListener.

Changed:

• The Treehouse Zipline disk cache directory is no longer within the cache directory on Android. This ensures it can't be cleared while the app is running. Zipline automatically constrains the directory to a maximum size so old entires will still be purged automatically.
• Set the Zipline thread's stack size to 8MiB on Android to match iOS.
• Use margin-inline-start and margin-inline-end for the start and end margin, respectively, for the HTML DOM layout bindings.
• TestRedwoodComposition now accepts only the initial UiConfiuration and exposes a MutableStateFlow for changing its value over time.
• TreehouseLayout now defines a default ID to allow state saving and restoration to work. Note that this will only work when a single instance is present in the hierarchy. If you have multiple, supply your own unique IDs.
• Emoji Search sample applications now bundle the latest guest code at compile-time and do not require the server running to work.
• The built-in RedwoodView for HTMLElement now reports density changes to the UiConfiguration.
• Redwood protocol modules have been renamed to 'guest' and 'host' to match Treehouse conventions.
• Suppress deprecation warnings in generated code. This code often refers to user types which may be deprecated, and should not cause additional warnings.
• TreehouseAppContent.preload is now idempotent.
• LazyList on iOS has changed from UICollectionView to UITableView, and changes to the backing data are now reported granularly rather than reloading everything.
• Allow arbitrary serializable content within rememberSaveable inside Treehouse.
• Add a TreehouseApp argument to CodeListener. Combined with the new uncaught exception callback, this provides an easy way to restart a Treehouse application on a crash.
• EventListener.Factory instances are now supplied as part of a TreehouseApp instead of a TreehouseAppFactory. This more closely scopes them with the lifetime of the Zipline instance.

Fixed:

• Ensure changes to modifiers notify their parent widget when using Treehouse.
• Explicitly mark the generated scope objects as @Stable to prevent needless recomposition.
• Dispose the old composition when the RedwoodContent composable recomposes or is removed from the composition.
• Ensure UIViewChildren indexes children using typedArrangedSubviews when removing views from a UIStackView.
• Correctly parse data object modifiers in the schema.
• Remember the default CodeListener for TreehouseContent to avoid unneccessary recomposition on creation.
• When calling TreehouseUi.start, fall back to older API signature when newer one does not match. This is needed because an addiitonal parameter was added in newer versions, but older guest code may have the old signature.
• Persist saved values from Treehouse without jumping back to the UI thread which allows proper restoration after a config change.
• Reset the requested widths and heights of a layout in the underlying Yoga engine when the size is invalidated. This ensures that the engine will properly measure changed content the grows and shrinks in either dimension.

This version works with Kotlin 1.9.22 by default.

0.7.0 - 2023-09-13

New:

• Expose viewport size and density in UiConfiguration.
• RedwoodView and platform-specific subtypes provide a turnkey view into which a RedwoodComposition can be rendered. TreehouseView now extends RedwoodView.

Changed:

• Remove support for the Kotlin/JS plugin (org.jetbrains.kotlin.js). This plugin is deprecated and projects should be migrated to Kotlin multiplatform plugin (org.jetbrains.kotlin.multiplatform).
• Some TreehouseView subtypes were renamed to better match platform conventions:
  • TreehouseWidgetView is now TreehouseLayout for Android.
  • TreehouseUIKitView is now TreehouseUIView for iOS.
• UIViewChildren now supports UIStackView automatically.
• Package name of types in 'lazylayout-dom' artifact is now lazylayout instead of just layout.

This version works with Kotlin 1.9.10 by default.

0.6.0 - 2023-08-10

New:

• Support for specifying custom Compose compiler versions. This will allow you to use the latest version of Redwood with newer versions of Kotlin than it explicitly supports.

  See the README for more information.

• LazyList can now be programmatically scrolled through its ScrollItemIndex parameter.

• Pull-to-refresh indicator color on LazyList is now customizable through pullRefreshContentColor parameter.

Changes:

• Many public types have been migrated away from data class to regular classes with equals/hashCode/toString(). If you were relying on destructuring or copy() for these types you will need to migrate to doing this manually.

Fix:

• The emoji search browser sample no longer crashes on first load.
• Lots of rendering and performance fixes for UIKit version of LazyList
  • Only measure items which are visible in the active viewport.
  • Remove some default item spacing imposed by the backing UICollectionViewFlowLayout.
  • Share most of the internal bookkeeping logic with the Android implementations for consistency and correctness.
  • Placeholders are now correctly sized along the main axis.

This version works with Kotlin 1.9.0 by default.

0.5.0 - 2023-07-05

This release marks Redwood's "beta" period which provides slightly more stability guarantees than before. All future releases up to (but NOT including) 1.0 will have protocol and service compatibility with older versions. In practice, what this means is that you can use Redwood 0.6 (and beyond) to compile and deploy Treehouse guest code which will run inside a Treehouse host from Redwood 0.5.

Redwood still reserves the right to make binary- and source-incompatible changes within the host code or within the guest code.

New:

• The relevant tags and names from your schema will now automatically be tracked in an API file and changes will be validated to be backwards-compatible. The redwoodApiGenerate Gradle task will generate or update the file, and the redwoodApiCheck task will validate the current schema as part of the check lifecycle task.
• width, height, and size modifiers allow precise control over widget size within Redwood layout.
• Preliminary support for rememberSaveable within Treehouse guest code with persistence only available on Android hosts.

Changes:

• The flexbox implementation has changed from being a Kotlin port of the Google's Java flexbox layout to using Facebook's Yoga library.
• LazyList now has arguments for margin and cross-axis alignment (verticalAlignment for LazyRow, horizontalAlignment for LazyColumn)
• Remove the ability to use custom implementations of LazyList. Any missing functionality from the built-in versions should be filed as a feature request.
• The command-line tools (codegen, lint, schema) are now uploaded to Maven Central as standalone zip files in addition to each regular jar artifact for use with non-Gradle build systems.

Fixed:

• RTL layout direction is now supported by the Compose UI and View-based implementations of Redwood layout.

This version only works with Kotlin 1.8.22.

0.4.0 - 2023-06-09

New:

• Experimental support for refresh indicators on LazyRow and LazyColumn via refreshing boolean and onRefresh lambda. These are experimental because we expect refresh support to migrate to some kind of future support for widget decorators so that it can be applied to any widget.
• DisplayLinkClock is available for iOS and MacOS users of Redwood. (Treehouse already had a frame clock for iOS).
• A WidgetValue (or List<WidgetValue>) produced from the generated testing function's awaitSnapshot() can now be converted to a SnapshotChangeList which can be serialized to JSON. That JSON can then later be deserialized and applied to a TreehouseView to recreate a full view hierarchy from any state. This is useful for unit testing widget implementations, screenshot testing, and more.
• Widget implementations can implement the ChangeListener interface to receive an onEndChanges() callback which occurs after all property or event lambda changes in that batch. This can help reduce thrashing in response to changes to multiple properties or event lambdas at once.
• LazyRow and LazyColumn now support a placeholder composable slot which will be used with Treehouse when a new item is displayed but before its content has loaded. Additionally, the size of these widgets can now be controlled through width and height constraints.

Changes:

• LayoutModifier has been renamed to Modifier.

• UI primitives like Dp, Density, and Margin have moved from Treehouse into the Redwood runtime (in the app.cash.redwood.ui package).

• HostConfiguration has moved from Treehouse into the Redwood runtime (in the app.cash.redwood.ui package) and is now called UiConfiguration.

• Composables running in Treehouse now run on a background thread on iOS. Previously they were running on the main thread. Interactions with UIKit still occur on the main thread.

• RedwoodContent function for hosting a Redwood composable within Compose UI has moved into a new redwood-composeui artifact as it will soon require a Compose UI dependency.

• The generated testing function now returns the value which was returned from the testing lambda.

  Before:

  suspend fun ExampleTester(body: suspend TestRedwoodComposition.() -> Unit)
  

  Now:

  suspend fun <R> ExampleTester(body: suspend TestRedwoodComposition.() -> R): R
  

• The Redwood and Treehouse frame clocks now send actual values for the frame time instead of 0.

Fixed:

• Widgets which accept nullable lambdas for events now receive an initial null value when no lambda is set. Previously a null would only be seen after a non-null lambda.
• Reduce binary impact of each widget's composable function by eliminating a large error string generated by the Kotlin compiler for an error case whose occurrence was impossible.
• The iOS implementation of Row, Column, Spacer, and UIViewChildren now react to size and child view changes more accurately according to UIKit norms.

This version only works with Kotlin 1.8.20.

0.3.0 - 2023-05-15

New:

• Support for testing Composables with new test-specific code generation. Use the 'app.cash.redwood.generator.testing' plugin to generate a lambda-accepting entrypoint function (such as ExampleTester()). Inside the lambda you can await snapshots of the values which would be bound to the UI widgets at that time.
• Redwood Layout now contains a Spacer which can be used to create negative space separately from padding (which otherwise disappears when the item disappears).
• The host's safe area insets are now included in HostConfiguration. Note that these are global values which should only be applied when a view is known to be occupying the full window size.
• Use the host's native frame rate to trigger recomposition inside of Treehouse. Pending snapshot changes are also required for recomposition to occur.

Changes:

• Widgets are now created, populated, and attached to the native view hierarchy in a different order than before. Previously widget was created, attached to its parent, and then its properties were all set followed by any language modifiers. Now, the widget is created, all of its properties and layout modifiers are set, and then it is added to its parent. Additionally, widgets are added to their parents in a bottom-up manner. Code like Row { Column { Text } } will see Text be added to Column before Column is added to `Row.
• 'redwood-treehouse' module has been split into '-shared', '-guest', and '-host' modules to more cleanly delineate where each is used. "Host" is the native application and "guess" is code running inside the Zipline JS VM.
• Schema dependencies are not longer parsed when loading a schema. Instead, a JSON representation is loaded from the classpath which contains the parsed structure of the dependency. As a result, the module which contains the schema files must apply the 'app.cash.redwood.schema' plugin in order to create this JSON.
• Redwood Layout's Padding type is now called Margin.
• Both Redwood's own API as well as code generated from your schema is now annotated with @ObjCName to create better-looking APIs in Objective-C (and Swift).
• The @Deprecated annotation on a widget or its properties will now propagate into the generated Composable and widget interface.
• Event types are no longer always nullable. They will now respect the nullability in the schema.
• Layout modifiers are now generated into a 'modifier' subpackage.

Fixed:

• Redwood Layout Constraints are now correctly propagated into HTML.

This version only works with Kotlin 1.8.20.

0.2.1 - 2023-01-31

Changed:

• Do not use a ScrollView/HorizontalScrollView as the parent container for View-based Row and Column display when the container is not scrollable (the default). Use a FrameLayout instead.

Fixed:

• Actually publish the redwood-treehouse-composeui artifact.

This version only works with Kotlin 1.7.20.

0.2.0 - 2023-01-30

New:

• redwood-layout-dom module provides HTML implementations of Row and Column.
• Lazy layout's schema artifacts are now published and can be used by other projects.
• Expose concurrentDownloads parameter for TreehouseApp.Factory. The default is 8.
• Add moduleLoadStart and moduleLoadEnd events to Treehouse's EventListener.

Changed:

• Compile with Android API 33.
• Counter sample now uses shared Row and Column layouts rather than its own unspecified one.
• JSON serialization on the Compose-side of Treehouse is now faster and emits dramatically less code than before.
• Create a dedicated CoroutineScope for each TreehouseView. When a view leaves, its coroutines can now be immediately canceled without waiting for anything on the application-side.
• TreehouseLauncher is now called TreehouseApp.Factory. Additionally, when you create() a TreehouseApp from a factory you must also call start() for it to actually start.
• Use platform-specific collections types in JS for the Compose-side of Treehouse. This is faster, more memory-efficient, and produces less code.
• Update to Zipline 0.9.15.

Fixed:

• Do not expose Gradle Configurations created by our plugin. This ensures they are not candidates for downstream modules to match against when declaring a dependency on a project using the plugin.
• Change when the Treehouse FrameClock is closed to avoid crashing on updates.

This version only works with Kotlin 1.7.20.

0.1.0 - 2022-12-23

Initial release.

This version only works with Kotlin 1.7.20.