ComposeNativeWebView is a Compose Multiplatform WebView whose API design and mobile implementations (Android & iOS) are intentionally derived almost verbatim from KevinnZou/compose-webview-multiplatform.

Package namespace:

dev.nucleusframework.webview.*

⚠️ Breaking change (v1.0.0+) — migrating from pre-Nucleus / Wry builds

1. Classpath / package — rename imports and package references:

   • io.github.kdroidfilter.webview.* → dev.nucleusframework.webview.*
   • Maven coordinates: io.github.kdroidfilter:… → dev.nucleusframework:composewebview

2. Desktop is Tao-only — the old Wry desktop backend is removed. Desktop WebView requires the Nucleus Tao backend (NativeView):

   • App entry: nucleusApplication(backend = NucleusBackend.Tao) { … }
   • Dependencies: Nucleus application + decorated-window-tao (Swing/Compose Desktop without Tao will not host the WebView)

   Why Tao? Native WebViews are opaque platform surfaces. Tao’s NativeView embeds them in the same window stack as Compose, so you can draw Compose UI on top of the WebView (toolbars, dialogs, loading overlays, chrome) instead of fighting a separate HWND/GTK child. You also get the rest of Tao’s desktop stack (decorated window, title bar, input routing, multiplatform windowing) in one path.

Android, iOS and WasmJs keep the same API shape; only the package and Maven group change.

Reused on purpose

• API surface (WebViewState, WebViewNavigator, settings, callbacks, mental model)
• Android implementation (android.webkit.WebView)
• iOS implementation (WKWebView)
• Overall behavior and semantics

If you already know compose-webview-multiplatform, you already know how to use this.

What ComposeNativeWebView adds

• Multiplatform packaging under NucleusFramework (dev.nucleusframework)
• WasmJs target via IFrame
• Desktop (JVM) via Nucleus Tao + NativeView (Linux WebKit2GTK; macOS WKWebView; Windows WebView2)

• Android: android.webkit.WebView
• iOS: WKWebView
• WasmJs: org.w3c.dom.HTMLIFrameElement
• Desktop: Nucleus Tao NativeView (requires nucleusApplication / Tao backend).
  • Linux: WebKit2GTK (libcompose_webview_linux.so)
  • Windows: WebView2 CompositionController + DirectComposition (compose_webview_windows.dll; needs WebView2 Runtime / Edge)
  • macOS: WKWebView (libcompose_webview_macos.dylib)

@Composable
fun App() {
  val state = rememberWebViewState("https://example.com")
  WebView(state, Modifier.fillMaxSize()) {
    // Optional Compose overlay on top of the native WebView
    // (NativeView content slot on desktop; Box overlay elsewhere).
  }
}

That’s it.

dependencies {
  implementation("dev.nucleusframework:composewebview:<version>")
}

Same artifact for Android, iOS, Desktop and WasmJs.

VisualSuiteApp + suiteCatalog() live in e2e-shared commonMain. Every platform host runs that same suite against a real WebView:

Cases that need a platform-only capability (history on Wasm, isolated native profiles on desktop, pixel screenshots, …) are Skipped with a reason — not Failed — so the catalog stays identical.

Same pure-logic packages on JVM / Android host / iOS simulator / Wasm browser:

COMMON='--tests dev.nucleusframework.webview.jsbridge.* --tests dev.nucleusframework.webview.web.* --tests dev.nucleusframework.webview.request.* --tests dev.nucleusframework.webview.cookie.* --tests dev.nucleusframework.webview.setting.*'
./gradlew :webview-compose:jvmTest $COMMON
./gradlew :webview-compose:testDebugUnitTest $COMMON
./gradlew :webview-compose:iosSimulatorArm64Test $COMMON   # macOS
./gradlew :webview-compose:wasmJsBrowserTest $COMMON

• loadUrl(url, headers)
• loadHtml(html)
• loadHtmlFile(fileName, readType)

• navigateBack(), navigateForward()
• reload(), stopLoading()
• canGoBack, canGoForward

• isLoading
• loadingState
• lastLoadedUrl
• pageTitle

Unified cookie API:

state.cookieManager.setCookie(...)
state.cookieManager.getCookies(url)
state.cookieManager.removeCookies(url)
state.cookieManager.removeAllCookies()

navigator.evaluateJavaScript("document.title = 'Hello'")

• injected automatically after page load
• callback-based
• works on Android / iOS / WasmJs / Desktop (Linux WebKit)

window.kmpJsBridge.callNative("echo", {...}, callback)

Intercept navigator-initiated navigations only:

override fun onInterceptUrlRequest(
  request: WebRequest,
  navigator: WebViewNavigator
): WebRequestInterceptResult

Useful for:

• blocking URLs
• app-driven routing
• security rules

val state = rememberWebViewState(
  url = "https://example.com"
) {
  customUserAgentString = "MyApp/1.0"
}

Supports:

• URL
• inline HTML
• resource files

val navigator = rememberWebViewNavigator()
WebView(state, navigator)

Commands:

• loadUrl
• loadHtml
• loadHtmlFile
• evaluateJavaScript

state.webSettings.customUserAgentString = "MyApp/1.2.3"

state.webSettings.logSeverity = KLogSeverity.Debug

• webview-compose/ → Compose Multiplatform API + platform actuals + commonTest
• e2e-shared/ → shared multiplatform visual e2e suite (VisualSuiteApp)
• e2e-desktop/, e2e-android/, e2e-wasmJs/, iosApp/ → platform hosts for that suite

• RequestInterceptor does not intercept sub-resources
• Desktop: requires Nucleus Tao (nucleusApplication + decorated-window-tao). Linux (WebKit2GTK), macOS (WKWebView) and Windows (WebView2) are fully wired.
• WasmJs:
  • Navigation back and forward is not available in the IFrame
  • The IFrame will work only if the target website has appropriately configured its CORS
  • JS can be executed only on the same origin
  • Cookies can be set only for the parent destination (when the destination of the iframe is the same as the parent destination)

• API inspiration: KevinnZou/compose-webview-multiplatform