Performance Optimized

Author: didarul-codes

README.MD

@@ -35,10 +35,11 @@ Add AdBlockerWebview In your layout
 In your Activity or Fragment
 
 ```Kotlin
- webview.setAdBlockEnabled(true)
+ AdBlockerUtil.getInstance().initialize(context)
+ webview.setAdBlockerEnabled(true)
  webview.loadUrl("https://google.com")
 ```
 
-You can also extend `AdBlockerWebView` to add additional functionality
+You can also extend `AdBlockerWebView` to include additional functionality
 
 For a complete example, see the sample app

adblockerwebview/build.gradle

@@ -8,8 +8,8 @@ android {
     defaultConfig {
         minSdkVersion 14
         targetSdkVersion 29
-        versionCode 2
-        versionName "0.1.1"
+        versionCode 3
+        versionName "0.1.2"
 
         testInstrumentationRunner 'androidx.test.runner.AndroidJUnitRunner'
 

adblockerwebview/src/main/java/com/islamdidarmd/adblockerwebview/AdBlockerUtil.kt

@@ -2,37 +2,56 @@ package com.islamdidarmd.adblockerwebview
 
 import android.content.Context
 import android.net.Uri
+import android.util.Log
 import android.webkit.WebResourceResponse
 import kotlinx.coroutines.*
+import kotlinx.coroutines.channels.awaitClose
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.callbackFlow
+import kotlinx.coroutines.flow.catch
+import kotlinx.coroutines.flow.collect
 import okhttp3.*
+import okio.Okio
 import okio.buffer
 import okio.source
-import java.io.ByteArrayInputStream
-import java.io.IOException
-import java.io.InputStream
+import java.io.*
+import java.net.URL
+import kotlin.coroutines.suspendCoroutine
+
+class AdBlockerUtil private constructor() {
+    private var isStillLoading: Boolean = false
+
+    private val TAG = "AdBlockerUtil"
 
-class AdBlockerUtil(context: Context) {
-    val TAG = "AdBlockerUtil"
     private val AD_HOSTS_FILE_NAME = "adblocker_webview_hosts.txt"
     private val hostsList = mutableListOf<String>()
 
-    init {
-        CoroutineScope(Dispatchers.Default).launch {
-            //loading hostname from asset
-            withContext(Dispatchers.IO) {
-                try {
-                    loadHostsFromInputStream(context.assets.open(AD_HOSTS_FILE_NAME))
-                } catch (e: Exception) {
-                    e.printStackTrace()
-                }
-            }
-            delay(200)
-            //updating list from server
+    companion object {
+        private val mInstance by lazy { AdBlockerUtil() }
+        fun getInstance(): AdBlockerUtil {
+            return mInstance
+        }
+    }
+
+    fun initialize(context: Context, scope: CoroutineScope = CoroutineScope(Dispatchers.Default)) {
+        scope.launch {
             loadHostFromServer()
+                    .collect { value: InputStream? ->
+                        try {
+                            val stream = value ?: context.assets.open(AD_HOSTS_FILE_NAME)
+                            loadHostsFromInputStream(stream)
+                        } catch (e: Exception) {
+                            e.printStackTrace()
+                        }
+                    }
         }
     }
 
     fun isAd(url: String?): Boolean {
+        if (isStillLoading) {
+            Log.e(TAG, "isAd: Host entries are still loading.")
+            return false
+        }
         if (url == null) return false
         val host = Uri.parse(url).host ?: return false
 
@@ -48,11 +67,8 @@ class AdBlockerUtil(context: Context) {
         return WebResourceResponse("text/plain", "utf-8", ByteArrayInputStream("".toByteArray()))
     }
 
-    private fun loadHostsFromInputStream(inputStream: InputStream?) {
-        if (inputStream == null) {
-            return
-        }
-
+    private fun loadHostsFromInputStream(inputStream: InputStream) {
+        isStillLoading = true
         val tempList: MutableList<String> = ArrayList()
 
         inputStream.source().buffer().use { source ->
@@ -64,9 +80,11 @@ class AdBlockerUtil(context: Context) {
 
         hostsList.clear()
         hostsList.addAll(tempList)
+        isStillLoading = false
     }
 
-    private fun loadHostFromServer() {
+    @ExperimentalCoroutinesApi
+    private fun loadHostFromServer() = callbackFlow<InputStream?> {
         val url = "https://pgl.yoyo.org/as/serverlist.php?hostformat=nohtml&showintro=0"
         val client = OkHttpClient.Builder().build()
 
@@ -76,15 +94,23 @@ class AdBlockerUtil(context: Context) {
         try {
             client.newCall(request).enqueue(object : Callback {
                 override fun onResponse(call: Call, response: Response) {
-                    loadHostsFromInputStream(response.body?.byteStream())
+                    offer(response.body?.byteStream())
+                    close()
                 }
 
                 override fun onFailure(call: Call, e: IOException) {
                     e.printStackTrace()
+                    offer(null)
+                    close()
                 }
             })
         } catch (e: Exception) {
             e.printStackTrace()
+
+            offer(null)
+            close()
         }
+
+        awaitClose()
     }
 }

adblockerwebview/src/main/java/com/islamdidarmd/adblockerwebview/AdBlockerWebView.kt

@@ -25,13 +25,11 @@ open class AdBlockerWebView : WebView {
             defStyleAttrs
     )
 
-    private val adBlockerUtil by lazy {
-        AdBlockerUtil(context)
-    }
+    private val adBlockerUtil = AdBlockerUtil.getInstance()
 
-    fun setAdBlockEnabled(enabled: Boolean) {
-        this._blockAds = enabled
-        if (BuildConfig.DEBUG) Log.d(TAG, "setAdBlockEnabled $enabled")
+    fun setAdBlockerEnabled(isEnabled: Boolean) {
+        this._blockAds = isEnabled
+        if (BuildConfig.DEBUG) Log.d(TAG, "setAdBlockEnabled $isEnabled")
     }
 
     init {
@@ -215,7 +213,11 @@ open class AdBlockerWebView : WebView {
                     resend: Message?
             ) {
                 client?.onFormResubmission(view, dontResend, resend)
-                super.onFormResubmission(view, dontResend, resend)
+                try {
+                    super.onFormResubmission(view, dontResend, resend)
+                } catch (e: Exception) {
+                    e.printStackTrace()
+                }
             }
 
             override fun onLoadResource(view: WebView?, url: String?) {

app/src/main/java/com/islamdidarmd/adblockerwebviewsample/MainActivity.kt

@@ -8,6 +8,7 @@ import android.webkit.WebChromeClient
 import android.webkit.WebView
 import android.webkit.WebViewClient
 import androidx.appcompat.app.AppCompatActivity
+import com.islamdidarmd.adblockerwebview.AdBlockerUtil
 import kotlinx.android.synthetic.main.activity_main.*
 
 class MainActivity : AppCompatActivity() {
@@ -17,6 +18,8 @@ class MainActivity : AppCompatActivity() {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
 
+        AdBlockerUtil.getInstance().initialize(this)
+
         webview.settings.apply {
             javaScriptEnabled = true
             domStorageEnabled = true
@@ -42,7 +45,7 @@ class MainActivity : AppCompatActivity() {
         }
 
         switchAdblock.setOnCheckedChangeListener { buttonView, isChecked ->
-            webview.setAdBlockEnabled(isChecked)
+            webview.setAdBlockerEnabled(isChecked)
         }
 
         btnGo.setOnClickListener {