Article

Changelog

Changes in each release.

0.4.0

systemImage and systemName parameters take an SFSymbol instead of a String. Constants are generated for every SF Symbol (SFSymbol.starFill, with availability in their KDoc); SFSymbol("name") covers custom or newer symbols. Migrate with systemImage = "star.fill" → systemImage = SFSymbol.starFill.
SwiftUIEnvironment exposes ColorScheme, DynamicTypeSize, UserInterfaceSizeClass and LayoutDirection instead of strings. An absent size class is now null (it used to be an empty string).

Label and ContentUnavailableView overloads that take an asset-catalog image with a LocalizedKey title. They used to clash with the systemImage overloads.

renderComposeSwiftUIPreviews links static frameworks that use C libraries, such as SQLDelight's SQLite driver. It passes the framework's linkerOpts to the preview host and strips dead code like Xcode does. If symbols are still missing, the error says to declare those libraries with linkerOpts.

renderComposeSwiftUIPreviews works with the configuration cache in modules that use Compose Multiplatform resources. It used to fail with "cannot serialize object of type AssembleTargetResourcesTask".
The IntelliJ plugin asks for an IDE restart after it is installed. Without the restart, the previews stayed blank.

IntelliJ IDEA / Android Studio plugin (intellij-plugin): Kotlin files with @Preview open in a code | preview split editor, with a gutter icon per preview. Previews are rendered with real SwiftUI on the iOS simulator by the new renderComposeSwiftUIPreviews Gradle task, and again on every save.

TextEditorView(TextEditor(text:)) was read-only: bindings inside nested values were sent to SwiftUI as constants. They now update the text and call the Kotlin onTextChange callback.

@Preview for Compose SwiftUI composables, rendered in Xcode's canvas. The Gradle plugin finds top-level, parameterless @Preview @Composable functions (any annotation named Preview works) and writes ComposeSwiftUIPreviews.swift next to the renderer, with one Swift #Preview per function and a ComposeSwiftUIPreviewGallery view that lists them all. The task is generateComposeSwiftUIPreviews.
LazyForEach(items, key) { item -> } for long lists: inside a List or a lazy stack, a row is composed only while SwiftUI shows it, and disposed when it scrolls away. A 10,000-row list now mounts in 28 ms instead of 909 ms on the iOS simulator, and a one-row change takes 0.4 ms instead of 4.5 ms.
A scenario benchmark (scripts/run_scenarios.sh): long lists (mount, scrolling, one-row change, every row changed) and animations, compared with plain SwiftUI using native @Observable models.
The sample app has two previews, a 5,000-row list and opens the preview gallery from its home screen.

Generated containers render their content through ChildrenView, and flushCompose() runs up to four passes so that state written by effects is shown in the same SwiftUI update.

UIKitView, UIViewControllerView, AppKitView and NSViewControllerView take a sizing parameter. NativeViewSizing.FitHeight sizes the embedded view to its content at the proposed width, so a paragraph of variable length is neither cut nor followed by a gap. FitContent uses the content's size in both directions. Fill, the default, keeps the previous behavior.
The same four functions take an update callback that runs on every recomposition, to push Kotlin state into the embedded view.

TabView(selection, onSelectionChange) and Tab(title, systemImage, value): the selected tab is Kotlin state, so code can switch tabs (for example a button in one tab that opens another). Tapping the tab bar calls onSelectionChange.
Mixed-style text: Text(StyledString), built with buildStyledString { withStyle(SpanStyle(...)) { append(...) } } like Compose's buildAnnotatedString. A SpanStyle sets color, font, font size, weight, design, italic, underline, strikethrough, monospaced, baseline offset and kerning. Nested styles merge. This replaces Text + Text and AttributedString, which Kotlin can't express.
The sample app shows both: a tab bar switched from Kotlin and a styled paragraph.

First release: SwiftUI views and modifiers generated from Apple's SDK for iOS, macOS, tvOS and watchOS, the Compose runtime host, viewModel { }, hand-written APIs for navigation, presentations, gestures, layouts and shapes, Navigation 3 NavDisplay, UIKit and AppKit embedding, and the dev.nucleusframework.compose-swiftui Gradle plugin.