RD-696: Add webview wrapper (#13)

Author: sasaprodribaba

MapTilerSDK/src/main/java/com/maptiler/maptilersdk/bridge/WebViewExecutor.kt

@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2025, MapTiler
+ * All rights reserved.
+ * SPDX-License-Identifier: BSD 3-Clause
+ */
+
+package com.maptiler.maptilersdk.bridge
+
+import android.content.Context
+import android.webkit.WebView
+import com.maptiler.maptilersdk.MTConfig
+import com.maptiler.maptilersdk.logging.MTLogLevel
+import com.maptiler.maptilersdk.logging.MTLogType
+import com.maptiler.maptilersdk.logging.MTLogger
+import kotlinx.coroutines.CompletableDeferred
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+
+internal interface WebViewExecutorDelegate {
+    fun onNavigationFinished(url: String)
+}
+
+internal class WebViewExecutor(
+    context: Context,
+) : WebViewManagerDelegate {
+    private val exceptionKey = "WKJavaScriptExceptionMessage"
+    private var webView: WebView? = null
+    private val webViewManager: WebViewManager =
+        WebViewManager(context).apply {
+            delegate = this@WebViewExecutor
+        }
+
+    var delegate: WebViewExecutorDelegate? = null
+
+    init {
+        webView = webViewManager.getAttachableWebView()
+        webView?.isVerticalScrollBarEnabled = false
+    }
+
+    fun getWebView(): WebView? = webView
+
+    suspend fun execute(command: MTCommand): MTBridgeReturnType =
+        withContext(Dispatchers.Main) {
+            val webView = webView ?: throw MTError.BridgeNotLoaded
+            val isVerbose = MTConfig.logLevel == MTLogLevel.Debug(true)
+
+            val deferred = CompletableDeferred<MTBridgeReturnType>()
+            webView.evaluateJavascript(command.toJS()) { result ->
+                try {
+                    if (result == null) {
+                        if (isVerbose) {
+                            MTLogger.log("$command completed with unsupported return type.", MTLogType.WARNING)
+                        }
+
+                        deferred.complete(MTBridgeReturnType.UnsupportedType)
+                    } else {
+                        try {
+                            val parsedResult = MTBridgeReturnType.from(result)
+                            deferred.complete(parsedResult)
+                        } catch (e: Exception) {
+                            deferred.completeExceptionally(MTError.InvalidResultType(result))
+                        }
+                    }
+                } catch (e: Exception) {
+                    if (isVerbose) {
+                        MTLogger.log("Bridging error occurred for $command: ${e.message}", MTLogType.ERROR)
+                    }
+
+                    deferred.completeExceptionally(MTError.Unknown(e.message ?: "Unknown error"))
+                }
+            }
+
+            return@withContext deferred.await()
+        }
+
+    override fun onNavigationFinished(url: String) {
+        delegate?.onNavigationFinished(url)
+    }
+}

MapTilerSDK/src/main/java/com/maptiler/maptilersdk/bridge/WebViewManager.kt

@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2025, MapTiler
+ * All rights reserved.
+ * SPDX-License-Identifier: BSD 3-Clause
+ */
+
+package com.maptiler.maptilersdk.bridge
+
+import android.annotation.SuppressLint
+import android.content.Context
+import android.webkit.WebChromeClient
+import android.webkit.WebView
+import android.webkit.WebViewClient
+
+internal interface WebViewManagerDelegate {
+    fun onNavigationFinished(url: String)
+}
+
+@SuppressLint("SetJavaScriptEnabled")
+internal class WebViewManager(
+    private val context: Context,
+) {
+    object Constants {
+        object Error {
+            const val HANDLER = "errorHandler"
+            const val MESSAGE = "message"
+            const val UNKNOWN = "Unknown Error"
+        }
+
+        object Map {
+            const val HANDLER = "mapHandler"
+            const val EVENT = "event"
+            const val DATA = "data"
+        }
+
+        object JSResources {
+            const val MAPTILER_MAP = "MapTilerMap"
+            const val MAPTILER_SDK = "maptiler-sdk.umd.min"
+            const val MAPTILER_STYLESHEET = "maptiler-sdk"
+
+            const val HTML_EXTENSION = "html"
+            const val JS_EXTENSION = "js"
+            const val CSS_EXTENSION = "css"
+        }
+    }
+
+    var delegate: WebViewManagerDelegate? = null
+    private var webView: WebView? = null
+
+    fun getAttachableWebView(): WebView {
+        if (webView == null) {
+            webView =
+                WebView(context).apply {
+                    settings.javaScriptEnabled = true
+                    settings.allowFileAccess = false
+                    settings.allowContentAccess = false
+
+                    webChromeClient = WebChromeClient()
+                    webViewClient =
+                        object : WebViewClient() {
+                            override fun onPageFinished(
+                                view: WebView?,
+                                url: String?,
+                            ) {
+                                url?.let { delegate?.onNavigationFinished(it) }
+                            }
+                        }
+
+                    loadUrl("file:///android_asset/${Constants.JSResources.MAPTILER_MAP}.${Constants.JSResources.HTML_EXTENSION}")
+                }
+        }
+
+        return webView!!
+    }
+}