Prevent unnecessary desktop WebView recreation during recomposition

webview-compose/src/androidMain/kotlin/io/github/kdroidfilter/webview/web/AndroidWebView.kt

@@ -8,20 +8,20 @@ import io.github.kdroidfilter.webview.util.KLogger
 import kotlinx.coroutines.CoroutineScope
 
 internal class AndroidWebView(
-    override val webView: WebView,
+    override val nativeWebView: WebView,
     override val scope: CoroutineScope,
     override val webViewJsBridge: WebViewJsBridge?,
 ) : IWebView {
     init {
         initWebView()
     }
 
-    override fun canGoBack(): Boolean = webView.canGoBack()
+    override fun canGoBack(): Boolean = nativeWebView.canGoBack()
 
-    override fun canGoForward(): Boolean = webView.canGoForward()
+    override fun canGoForward(): Boolean = nativeWebView.canGoForward()
 
     override fun loadUrl(url: String, additionalHttpHeaders: Map<String, String>) {
-        webView.loadUrl(url, additionalHttpHeaders)
+        nativeWebView.loadUrl(url, additionalHttpHeaders)
     }
 
     override suspend fun loadHtml(
@@ -32,7 +32,7 @@ internal class AndroidWebView(
         historyUrl: String?,
     ) {
         if (html == null) return
-        webView.loadDataWithBaseURL(baseUrl, html, mimeType, encoding, historyUrl)
+        nativeWebView.loadDataWithBaseURL(baseUrl, html, mimeType, encoding, historyUrl)
     }
 
     override suspend fun loadHtmlFile(fileName: String, readType: WebViewFileReadType) {
@@ -52,34 +52,35 @@ internal class AndroidWebView(
                 val selected =
                     candidates.firstOrNull { path ->
                         try {
-                            webView.context.assets.open(path).close()
+                            nativeWebView.context.assets.open(path).close()
                             true
                         } catch (_: Exception) {
                             false
                         }
                     } ?: candidates.first()
                 val url = "file:///android_asset/$selected"
-                webView.loadUrl(url)
+                nativeWebView.loadUrl(url)
                 KLogger.d(tag = "AndroidWebView") { "loadUrl $url (candidates: ${candidates.joinToString()})" }
             }
-            WebViewFileReadType.COMPOSE_RESOURCE_FILES -> webView.loadUrl(fileName)
+
+            WebViewFileReadType.COMPOSE_RESOURCE_FILES -> nativeWebView.loadUrl(fileName)
         }
     }
 
-    override fun goBack() = webView.goBack()
+    override fun goBack() = nativeWebView.goBack()
 
-    override fun goForward() = webView.goForward()
+    override fun goForward() = nativeWebView.goForward()
 
-    override fun reload() = webView.reload()
+    override fun reload() = nativeWebView.reload()
 
-    override fun stopLoading() = webView.stopLoading()
+    override fun stopLoading() = nativeWebView.stopLoading()
 
     override fun evaluateJavaScript(script: String, callback: ((String) -> Unit)?) {
         val androidScript = "javascript:$script"
         KLogger.d {
             "evaluateJavaScript: $androidScript"
         }
-        webView.evaluateJavascript(androidScript, callback)
+        nativeWebView.evaluateJavascript(androidScript, callback)
     }
 
     override fun injectJsBridge() {
@@ -97,7 +98,7 @@ internal class AndroidWebView(
     }
 
     override fun initJsBridge(webViewJsBridge: WebViewJsBridge) {
-        webView.addJavascriptInterface(this, "androidJsBridge")
+        nativeWebView.addJavascriptInterface(this, "androidJsBridge")
     }
 
     @JavascriptInterface

webview-compose/src/commonMain/kotlin/io/github/kdroidfilter/webview/web/IWebView.kt

@@ -9,7 +9,7 @@ expect class NativeWebView
  * Platform WebView abstraction.
  */
 interface IWebView {
-    val webView: NativeWebView
+    val nativeWebView: NativeWebView
 
     val scope: CoroutineScope
 

webview-compose/src/commonMain/kotlin/io/github/kdroidfilter/webview/web/WebViewState.kt

@@ -1,12 +1,6 @@
 package io.github.kdroidfilter.webview.web
 
-import androidx.compose.runtime.Composable
-import androidx.compose.runtime.Stable
-import androidx.compose.runtime.getValue
-import androidx.compose.runtime.mutableStateListOf
-import androidx.compose.runtime.mutableStateOf
-import androidx.compose.runtime.remember
-import androidx.compose.runtime.setValue
+import androidx.compose.runtime.*
 import androidx.compose.runtime.snapshots.SnapshotStateList
 import io.github.kdroidfilter.webview.cookie.CookieManager
 import io.github.kdroidfilter.webview.cookie.WebViewCookieManager
@@ -34,10 +28,8 @@ class WebViewState(
 
     val webSettings: WebSettings by mutableStateOf(WebSettings())
 
-    internal var webView by mutableStateOf<IWebView?>(null)
-
-    val nativeWebView: NativeWebView
-        get() = webView?.webView ?: error("WebView is not initialized")
+    var webView: IWebView? by mutableStateOf(null)
+        internal set
 
     val cookieManager: CookieManager by mutableStateOf(WebViewCookieManager())
 }

webview-compose/src/iosMain/kotlin/io/github/kdroidfilter/webview/web/IOSWebView.kt

@@ -5,33 +5,23 @@ import io.github.kdroidfilter.webview.jsbridge.WebViewJsBridge
 import io.github.kdroidfilter.webview.util.KLogger
 import kotlinx.cinterop.ExperimentalForeignApi
 import kotlinx.coroutines.CoroutineScope
-import platform.Foundation.NSArray
-import platform.Foundation.NSBundle
-import platform.Foundation.NSDocumentDirectory
-import platform.Foundation.NSFileManager
-import platform.Foundation.NSMutableURLRequest
-import platform.Foundation.NSSearchPathForDirectoriesInDomains
-import platform.Foundation.NSString
-import platform.Foundation.NSURL
-import platform.Foundation.NSUserDomainMask
-import platform.Foundation.setValue
-import platform.Foundation.stringByDeletingLastPathComponent
+import platform.Foundation.*
 import platform.WebKit.WKWebView
 
 internal const val IOS_JS_BRIDGE_HANDLER_NAME: String = "iosJsBridge"
 
 internal class IOSWebView(
-    override val webView: WKWebView,
+    override val nativeWebView: WKWebView,
     override val scope: CoroutineScope,
     override val webViewJsBridge: WebViewJsBridge?,
 ) : IWebView {
     init {
         initWebView()
     }
 
-    override fun canGoBack(): Boolean = webView.canGoBack
+    override fun canGoBack(): Boolean = nativeWebView.canGoBack
 
-    override fun canGoForward(): Boolean = webView.canGoForward
+    override fun canGoForward(): Boolean = nativeWebView.canGoForward
 
     override fun loadUrl(url: String, additionalHttpHeaders: Map<String, String>) {
         if (url.startsWith("file://")) {
@@ -52,7 +42,7 @@ internal class IOSWebView(
                     }
 
                 if (readAccessURL != null) {
-                    webView.loadFileURL(fileURL, readAccessURL)
+                    nativeWebView.loadFileURL(fileURL, readAccessURL)
                     return
                 }
             }
@@ -66,7 +56,7 @@ internal class IOSWebView(
                 forHTTPHeaderField = key,
             )
         }
-        webView.loadRequest(request = request)
+        nativeWebView.loadRequest(request = request)
     }
 
     override suspend fun loadHtml(
@@ -77,7 +67,7 @@ internal class IOSWebView(
         historyUrl: String?,
     ) {
         if (html == null) return
-        webView.loadHTMLString(
+        nativeWebView.loadHTMLString(
             string = html,
             baseURL = baseUrl?.let { NSURL.URLWithString(it) },
         )
@@ -154,7 +144,7 @@ internal class IOSWebView(
                 return
             }
 
-            webView.loadFileURL(fileURL, readAccessURL!!)
+            nativeWebView.loadFileURL(fileURL, readAccessURL!!)
         } catch (e: Exception) {
             KLogger.e(e, tag = "IOSWebView") { "Error loading HTML file: $fileName (readType: $readType)" }
             val errorHtml =
@@ -172,24 +162,24 @@ internal class IOSWebView(
     }
 
     override fun goBack() {
-        webView.goBack()
+        nativeWebView.goBack()
     }
 
     override fun goForward() {
-        webView.goForward()
+        nativeWebView.goForward()
     }
 
     override fun reload() {
-        webView.reload()
+        nativeWebView.reload()
     }
 
     override fun stopLoading() {
-        webView.stopLoading()
+        nativeWebView.stopLoading()
     }
 
     @OptIn(ExperimentalForeignApi::class)
     override fun evaluateJavaScript(script: String, callback: ((String) -> Unit)?) {
-        webView.evaluateJavaScript(script) { result, error ->
+        nativeWebView.evaluateJavaScript(script) { result, error ->
             if (callback == null) return@evaluateJavaScript
             if (error != null) {
                 KLogger.e { "evaluateJavaScript error: $error" }
@@ -217,6 +207,9 @@ internal class IOSWebView(
 
     override fun initJsBridge(webViewJsBridge: WebViewJsBridge) {
         val jsMessageHandler = WKJsMessageHandler(webViewJsBridge)
-        webView.configuration.userContentController.addScriptMessageHandler(jsMessageHandler, IOS_JS_BRIDGE_HANDLER_NAME)
+        nativeWebView.configuration.userContentController.addScriptMessageHandler(
+            scriptMessageHandler = jsMessageHandler,
+            name = IOS_JS_BRIDGE_HANDLER_NAME
+        )
     }
 }

webview-compose/src/jvmMain/kotlin/io/github/kdroidfilter/webview/web/DesktopWebView.kt

@@ -6,23 +6,23 @@ import kotlinx.coroutines.CoroutineScope
 import java.net.URL
 
 internal class DesktopWebView(
-    override val webView: NativeWebView,
+    override val nativeWebView: NativeWebView,
     override val scope: CoroutineScope,
     override val webViewJsBridge: WebViewJsBridge?,
 ) : IWebView {
     init {
         initWebView()
     }
 
-    override fun canGoBack(): Boolean = webView.canGoBack()
+    override fun canGoBack(): Boolean = nativeWebView.canGoBack()
 
-    override fun canGoForward(): Boolean = webView.canGoForward()
+    override fun canGoForward(): Boolean = nativeWebView.canGoForward()
 
     override fun loadUrl(
         url: String,
         additionalHttpHeaders: Map<String, String>,
     ) {
-        webView.loadUrl(url, additionalHttpHeaders)
+        nativeWebView.loadUrl(url, additionalHttpHeaders)
     }
 
     override suspend fun loadHtml(
@@ -33,7 +33,7 @@ internal class DesktopWebView(
         historyUrl: String?,
     ) {
         if (html == null) return
-        webView.loadHtml(html)
+        nativeWebView.loadHtml(html)
     }
 
     override suspend fun loadHtmlFile(
@@ -58,7 +58,8 @@ internal class DesktopWebView(
                         candidates.add("compose-resources/assets/$normalized")
                         candidates.add("composeResources/files/$normalized")
                         candidates.add("composeResources/assets/$normalized")
-                        val loaders = listOfNotNull(Thread.currentThread().contextClassLoader, this::class.java.classLoader)
+                        val loaders =
+                            listOfNotNull(Thread.currentThread().contextClassLoader, this::class.java.classLoader)
                         candidates.asSequence()
                             .mapNotNull { path ->
                                 loaders.asSequence()
@@ -69,6 +70,7 @@ internal class DesktopWebView(
                             .firstOrNull()
                             ?: error("Resource not found: ${candidates.joinToString()}")
                     }
+
                     WebViewFileReadType.COMPOSE_RESOURCE_FILES ->
                         URL(fileName).openStream().use { it.readBytes().toString(Charsets.UTF_8) }
                 }
@@ -87,23 +89,23 @@ internal class DesktopWebView(
                     """.trimIndent()
                 KLogger.e(e, tag = "DesktopWebView") { "loadHtmlFile failed" }
                 errorHtml
-        }
-        webView.loadHtml(html)
+            }
+        nativeWebView.loadHtml(html)
     }
 
-    override fun goBack() = webView.goBack()
+    override fun goBack() = nativeWebView.goBack()
 
-    override fun goForward() = webView.goForward()
+    override fun goForward() = nativeWebView.goForward()
 
-    override fun reload() = webView.reload()
+    override fun reload() = nativeWebView.reload()
 
-    override fun stopLoading() = webView.stopLoading()
+    override fun stopLoading() = nativeWebView.stopLoading()
 
     override fun evaluateJavaScript(script: String, callback: ((String) -> Unit)?) {
         KLogger.d {
             "evaluateJavaScript: $script"
         }
-        webView.evaluateJavaScript(script) { result ->
+        nativeWebView.evaluateJavaScript(script) { result ->
             callback?.invoke(result)
         }
     }

webview-compose/src/jvmMain/kotlin/io/github/kdroidfilter/webview/web/WebViewDesktop.kt

@@ -84,16 +84,17 @@ actual fun ActualWebView(
     }
 
     key(effectiveSettingsKey) {
-        val nativeWebView = remember(state, factory) { factory(WebViewFactoryParam(state)) }
-
-        val desktopWebView =
-            remember(nativeWebView, scope, webViewJsBridge) {
-                DesktopWebView(
-                    webView = nativeWebView,
-                    scope = scope,
-                    webViewJsBridge = webViewJsBridge,
-                )
-            }
+        val nativeWebView = remember(state, factory) {
+            state.webView?.nativeWebView ?: factory(WebViewFactoryParam(state))
+        }
+
+        val desktopWebView = remember(nativeWebView, scope, webViewJsBridge) {
+            DesktopWebView(
+                nativeWebView = nativeWebView,
+                scope = scope,
+                webViewJsBridge = webViewJsBridge,
+            )
+        }
 
         LaunchedEffect(desktopWebView) {
             state.webView = desktopWebView

wrywebview/src/main/kotlin/io/github/kdroidfilter/webview/wry/WryWebViewPanel.kt

@@ -388,6 +388,11 @@ class WryWebViewPanel(
         val dataDir = dataDirectory
         val initialUrl = pendingUrl
         val handleSnapshot = parentHandle
+
+        if (!host.isDisplayable) {
+            return false
+        }
+
         if (!IS_MAC) {
             return try {
                 webviewId = NativeBindings.createWebview(
@@ -439,6 +444,7 @@ class WryWebViewPanel(
                 true
             }
         }
+
         createInFlight = true
         stopCreateTimer()
         thread(name = "wry-webview-create", isDaemon = true) {