Desktop webview support with JavaFX

composeApp/build.gradle.kts

@@ -1,4 +1,5 @@
 import com.android.build.api.variant.FilterConfiguration.FilterType.ABI
+import org.gradle.internal.os.OperatingSystem
 import org.jetbrains.compose.ExperimentalComposeLibrary
 import org.jetbrains.compose.desktop.application.dsl.TargetFormat
 import org.jetbrains.kotlin.gradle.ExperimentalKotlinGradlePluginApi
@@ -123,6 +124,14 @@ kotlin {
                 implementation(files("./src/desktopMain/libs/oonimkall.jar"))
                 implementation(compose.desktop.currentOs)
                 implementation(libs.bundles.desktop)
+
+                // As JavaFX have platform-specific dependencies, we need to add them manually
+                val fxParts = listOf("base", "graphics", "controls", "media", "web", "swing")
+                val jvmVersion = 17
+                val fxSuffix = getJavaFxSuffix()
+                fxParts.forEach {
+                    implementation("org.openjfx:javafx-$it:$jvmVersion:$fxSuffix")
+                }
             }
         }
         // Testing
@@ -542,3 +551,14 @@ fun isFdroidTaskRequested(): Boolean {
 fun isDebugTaskRequested(): Boolean {
     return gradle.startParameter.taskRequests.flatMap { it.args }.any { it.contains("Debug") }
 }
+
+fun getJavaFxSuffix(): String {
+    val os = OperatingSystem.current()
+    val arch = System.getProperty("os.arch")
+    return when {
+        os.isMacOsX -> if (arch == "aarch64") "mac-aarch64" else "mac"
+        os.isWindows -> "win"
+        os.isLinux -> if (arch == "aarch64") "linux-aarch64" else "linux"
+        else -> throw IllegalStateException("Unknown OS: $os")
+    }
+}

composeApp/src/androidMain/kotlin/org/ooni/probe/ui/shared/OoniWebView.kt → composeApp/src/androidMain/kotlin/org/ooni/probe/ui/shared/OoniWebView.android.kt

@@ -12,7 +12,6 @@ import android.webkit.WebView
 import android.webkit.WebViewClient
 import androidx.activity.compose.BackHandler
 import androidx.compose.runtime.Composable
-import androidx.compose.runtime.getValue
 import androidx.compose.ui.Modifier
 import androidx.compose.ui.viewinterop.AndroidView
 

composeApp/src/desktopMain/kotlin/org/ooni/probe/ui/shared/OoniWebView.desktop.kt

@@ -2,11 +2,130 @@ package org.ooni.probe.ui.shared
 
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.awt.SwingPanel
+import javafx.application.Platform
+import javafx.concurrent.Worker
+import javafx.embed.swing.JFXPanel
+import javafx.scene.Scene
+import javafx.scene.layout.StackPane
+import javafx.scene.web.WebView
+import java.net.URL
+import kotlin.io.encoding.Base64
 
 @Composable
 actual fun OoniWebView(
     controller: OoniWebViewController,
     modifier: Modifier,
     allowedDomains: List<String>,
 ) {
+    val event = controller.rememberNextEvent()
+
+    SwingPanel(
+        factory = {
+            controller.state = OoniWebViewController.State.Initializing
+
+            JFXPanel().apply {
+                Platform.setImplicitExit(false) // Otherwise, webView will not show the second time
+                Platform.runLater {
+
+                    val webView = WebView().apply {
+                        isVisible = true
+                        @Suppress("SetJavaScriptEnabled")
+                        engine.isJavaScriptEnabled = true
+
+                        // Set up load listeners
+                        engine.loadWorker.stateProperty().addListener { _, _, newValue ->
+                            when (newValue) {
+                                Worker.State.SCHEDULED -> {
+                                    controller.state = OoniWebViewController.State.Loading(0f)
+                                }
+
+                                Worker.State.RUNNING -> {
+                                    val progress = engine.loadWorker.progress
+                                    controller.state =
+                                        OoniWebViewController.State.Loading(progress.toFloat())
+                                }
+
+                                Worker.State.SUCCEEDED -> {
+                                    controller.state = OoniWebViewController.State.Successful
+                                    controller.canGoBack = engine.history.currentIndex > 0
+                                }
+
+                                Worker.State.FAILED -> {
+                                    controller.state = OoniWebViewController.State.Failure
+                                    controller.canGoBack = engine.history.currentIndex > 0
+                                }
+
+                                else -> {}
+                            }
+                        }
+
+                        // Domain restriction
+                        engine.locationProperty().addListener { _, _, newLocation ->
+                            try {
+                                val host = URL(newLocation).host
+                                val allowed = allowedDomains.any { domain ->
+                                    host.matches(Regex("^(.*\\.)?$domain$"))
+                                }
+
+                                if (!allowed) {
+                                    engine.load("about:blank")
+                                }
+                            } catch (e: Exception) {
+                                // Invalid URL, ignore
+                            }
+                            controller.canGoBack = engine.history.currentIndex > 0
+                        }
+
+                        val css = """
+                            body {
+                                -ms-overflow-style: none;  /* Internet Explorer 10+ */
+                                scrollbar-width: none;  /* Firefox */
+                            }
+                            body::-webkit-scrollbar {
+                                display: none;  /* Safari and Chrome */
+                            }
+                        """.trimIndent()
+                        val cssData = Base64.encode(css.encodeToByteArray())
+                        engine.userStyleSheetLocation =
+                            "data:text/css;charset=utf-8;base64,$cssData"
+                    }
+
+                    val root = StackPane()
+                    root.children.add(webView)
+                    this.scene = Scene(root)
+                }
+            }
+        },
+        modifier = modifier,
+        update = { jfxPanel ->
+            Platform.runLater {
+                val root = jfxPanel.scene?.root as? StackPane
+                val webView = (root?.children?.get(0) as? WebView) ?: return@runLater
+                when (event) {
+                    is OoniWebViewController.Event.Load -> {
+                        val headers = event.additionalHttpHeaders.entries.joinToString {
+                            "\n${it.key}: it.value"
+                        }
+                        // Hack to send HTTP headers by taking advantage of userAgent
+                        webView.engine.userAgent = "ooni$headers"
+                        webView.engine.load(event.url)
+                    }
+
+                    OoniWebViewController.Event.Reload -> {
+                        webView.engine.reload()
+                    }
+
+                    OoniWebViewController.Event.Back -> {
+                        if (webView.engine.history.currentIndex > 0) {
+                            webView.engine.history.go(-1)
+                        }
+                    }
+
+                    null -> Unit
+                }
+                event?.let(controller::onEventHandled)
+            }
+        },
+    )
 }