AdBlock for WebView

app/src/main/AndroidManifest.xml

@@ -5,7 +5,9 @@
 
 	<uses-permission android:name="android.permission.INTERNET" />
 	<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
-	<uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
+	<uses-permission
+		android:name="android.permission.FOREGROUND_SERVICE"
+		tools:ignore="ForegroundServicesPolicy" />
 	<uses-permission android:name="android.permission.WAKE_LOCK" />
 	<uses-permission android:name="android.permission.VIBRATE" />
 	<uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED" />
@@ -19,17 +21,19 @@
 	<uses-permission android:name="android.permission.WRITE_SYNC_SETTINGS" />
 	<uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
 	<uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC" />
-	<uses-permission android:name="android.permission.REQUEST_INSTALL_PACKAGES" />
+	<uses-permission
+		android:name="android.permission.REQUEST_INSTALL_PACKAGES"
+		tools:ignore="RequestInstallPackagesPolicy" />
 	<uses-permission android:name="android.permission.REQUEST_DELETE_PACKAGES" />
 	<uses-permission
 		android:name="android.permission.QUERY_ALL_PACKAGES"
-		tools:ignore="QueryAllPackagesPermission" />
+		tools:ignore="PackageVisibilityPolicy,QueryAllPackagesPermission" />
 	<uses-permission
 		android:name="android.permission.WRITE_EXTERNAL_STORAGE"
 		android:maxSdkVersion="29" />
 	<uses-permission
 		android:name="android.permission.MANAGE_EXTERNAL_STORAGE"
-		tools:ignore="ScopedStorage" />
+		tools:ignore="AllFilesAccessPolicy,ScopedStorage" />
 
 	<queries>
 		<intent>
@@ -338,6 +342,9 @@
 			android:name="org.koitharu.kotatsu.details.service.MangaPrefetchService"
 			android:exported="false"
 			android:label="@string/prefetch_content" />
+		<service
+			android:name="org.koitharu.kotatsu.browser.AdListUpdateService"
+			android:exported="false" />
 
 		<provider
 			android:name="org.koitharu.kotatsu.search.ui.MangaSuggestionsProvider"

app/src/main/kotlin/org/koitharu/kotatsu/browser/AdListUpdateService.kt

@@ -0,0 +1,20 @@
+package org.koitharu.kotatsu.browser
+
+import android.content.Intent
+import dagger.hilt.android.AndroidEntryPoint
+import org.koitharu.kotatsu.core.network.webview.adblock.AdBlock
+import org.koitharu.kotatsu.core.ui.CoroutineIntentService
+import javax.inject.Inject
+
+@AndroidEntryPoint
+class AdListUpdateService : CoroutineIntentService() {
+
+	@Inject
+	lateinit var updater: AdBlock.Updater
+
+	override suspend fun IntentJobContext.processIntent(intent: Intent) {
+		updater.updateList()
+	}
+
+	override fun IntentJobContext.onError(error: Throwable) = Unit
+}

app/src/main/kotlin/org/koitharu/kotatsu/browser/BaseBrowserActivity.kt

@@ -10,6 +10,7 @@ import org.koitharu.kotatsu.core.model.MangaSource
 import org.koitharu.kotatsu.core.nav.AppRouter
 import org.koitharu.kotatsu.core.network.CommonHeaders
 import org.koitharu.kotatsu.core.network.proxy.ProxyProvider
+import org.koitharu.kotatsu.core.network.webview.adblock.AdBlock
 import org.koitharu.kotatsu.core.parser.MangaRepository
 import org.koitharu.kotatsu.core.parser.ParserMangaRepository
 import org.koitharu.kotatsu.core.ui.BaseActivity
@@ -29,6 +30,9 @@ abstract class BaseBrowserActivity : BaseActivity<ActivityBrowserBinding>(), Bro
 	@Inject
 	lateinit var mangaRepositoryFactory: MangaRepository.Factory
 
+	@Inject
+	lateinit var adBlock: AdBlock
+
 	private lateinit var onBackPressedCallback: WebViewBackPressedCallback
 
 	override fun onCreate(savedInstanceState: Bundle?) {

app/src/main/kotlin/org/koitharu/kotatsu/browser/BrowserActivity.kt

@@ -24,7 +24,7 @@ class BrowserActivity : BaseBrowserActivity() {
 
 	override fun onCreate2(savedInstanceState: Bundle?, source: MangaSource, repository: ParserMangaRepository?) {
 		setDisplayHomeAsUp(isEnabled = true, showUpAsClose = true)
-		viewBinding.webView.webViewClient = BrowserClient(this)
+		viewBinding.webView.webViewClient = BrowserClient(this, adBlock)
 		lifecycleScope.launch {
 			try {
 				proxyProvider.applyWebViewConfig()

app/src/main/kotlin/org/koitharu/kotatsu/browser/BrowserClient.kt

@@ -1,11 +1,17 @@
 package org.koitharu.kotatsu.browser
 
 import android.graphics.Bitmap
+import android.webkit.WebResourceRequest
+import android.webkit.WebResourceResponse
 import android.webkit.WebView
 import android.webkit.WebViewClient
+import androidx.annotation.WorkerThread
+import org.koitharu.kotatsu.core.network.webview.adblock.AdBlock
+import java.io.ByteArrayInputStream
 
 open class BrowserClient(
-	private val callback: BrowserCallback
+	private val callback: BrowserCallback,
+	private val adBlock: AdBlock,
 ) : WebViewClient() {
 
 	/**
@@ -31,4 +37,29 @@ open class BrowserClient(
 		super.doUpdateVisitedHistory(view, url, isReload)
 		callback.onHistoryChanged()
 	}
+
+	@WorkerThread
+	@Deprecated("Deprecated in Java")
+	override fun shouldInterceptRequest(
+		view: WebView?,
+		url: String?
+	): WebResourceResponse? = if (url.isNullOrEmpty() || adBlock.shouldLoadUrl(url, view?.url)) {
+		super.shouldInterceptRequest(view, url)
+	} else {
+		emptyResponse()
+	}
+
+	@WorkerThread
+	override fun shouldInterceptRequest(
+		view: WebView?,
+		request: WebResourceRequest?
+	): WebResourceResponse? = if (request == null || adBlock.shouldLoadUrl(request.url.toString(), view?.url)) {
+		view?.originalUrl
+		super.shouldInterceptRequest(view, request)
+	} else {
+		emptyResponse()
+	}
+
+	private fun emptyResponse(): WebResourceResponse =
+		WebResourceResponse("text/plain", "utf-8", ByteArrayInputStream(byteArrayOf()))
 }

app/src/main/kotlin/org/koitharu/kotatsu/browser/cloudflare/CloudFlareActivity.kt

@@ -52,7 +52,7 @@ class CloudFlareActivity : BaseBrowserActivity(), CloudFlareCallback {
 			finishAfterTransition()
 			return
 		}
-		cfClient = CloudFlareClient(cookieJar, this, url)
+		cfClient = CloudFlareClient(cookieJar, this, adBlock, url)
 		viewBinding.webView.webViewClient = cfClient
 		lifecycleScope.launch {
 			try {

app/src/main/kotlin/org/koitharu/kotatsu/browser/cloudflare/CloudFlareClient.kt

@@ -4,6 +4,7 @@ import android.graphics.Bitmap
 import android.webkit.WebView
 import org.koitharu.kotatsu.browser.BrowserClient
 import org.koitharu.kotatsu.core.network.cookies.MutableCookieJar
+import org.koitharu.kotatsu.core.network.webview.adblock.AdBlock
 import org.koitharu.kotatsu.parsers.network.CloudFlareHelper
 
 private const val LOOP_COUNTER = 3
@@ -11,8 +12,9 @@ private const val LOOP_COUNTER = 3
 class CloudFlareClient(
 	private val cookieJar: MutableCookieJar,
 	private val callback: CloudFlareCallback,
+	adBlock: AdBlock,
 	private val targetUrl: String,
-) : BrowserClient(callback) {
+) : BrowserClient(callback, adBlock) {
 
 	private val oldClearance = getClearance()
 	private var counter = 0

app/src/main/kotlin/org/koitharu/kotatsu/core/network/CommonHeaders.kt

@@ -16,8 +16,12 @@ object CommonHeaders {
 	const val CACHE_CONTROL = "Cache-Control"
 	const val PROXY_AUTHORIZATION = "Proxy-Authorization"
 	const val RETRY_AFTER = "Retry-After"
+	const val LAST_MODIFIED = "Last-Modified"
+	const val IF_MODIFIED_SINCE = "If-Modified-Since"
 	const val MANGA_SOURCE = "X-Manga-Source"
 
 	val CACHE_CONTROL_NO_STORE: CacheControl
 		get() = CacheControl.Builder().noStore().build()
+
+	const val DATE_FORMAT = "EEE, dd MMM yyyy HH:mm:ss zzz"
 }

app/src/main/kotlin/org/koitharu/kotatsu/core/network/webview/adblock/AdBlock.kt

@@ -0,0 +1,122 @@
+package org.koitharu.kotatsu.core.network.webview.adblock
+
+import android.content.Context
+import android.util.Log
+import androidx.annotation.WorkerThread
+import dagger.Reusable
+import dagger.hilt.android.qualifiers.ApplicationContext
+import okhttp3.HttpUrl
+import okhttp3.HttpUrl.Companion.toHttpUrlOrNull
+import okhttp3.OkHttpClient
+import okhttp3.Request
+import okio.sink
+import org.koitharu.kotatsu.core.network.BaseHttpClient
+import org.koitharu.kotatsu.core.network.CommonHeaders
+import org.koitharu.kotatsu.core.prefs.AppSettings
+import org.koitharu.kotatsu.core.util.ext.isNotEmpty
+import org.koitharu.kotatsu.core.util.ext.printStackTraceDebug
+import org.koitharu.kotatsu.parsers.util.await
+import org.koitharu.kotatsu.parsers.util.requireBody
+import org.koitharu.kotatsu.parsers.util.runCatchingCancellable
+import java.io.File
+import java.net.HttpURLConnection
+import java.text.SimpleDateFormat
+import java.util.Date
+import java.util.Locale
+import javax.inject.Inject
+
+@Reusable
+class AdBlock @Inject constructor(
+	@ApplicationContext private val context: Context,
+	private val settings: AppSettings,
+) {
+
+	private var rules: RulesList? = null
+
+	@WorkerThread
+	fun shouldLoadUrl(url: String, baseUrl: String?): Boolean {
+		return shouldLoadUrl(
+			url.lowercase().toHttpUrlOrNull() ?: return true,
+			baseUrl?.lowercase()?.toHttpUrlOrNull(),
+		)
+	}
+
+	@WorkerThread
+	fun shouldLoadUrl(url: HttpUrl, baseUrl: HttpUrl?): Boolean {
+		if (!settings.isAdBlockEnabled) {
+			return true
+		}
+		return synchronized(this) {
+			rules ?: parseRules().also { rules = it }
+		}?.let {
+			val rule = it[url, baseUrl]
+			if (rule != null) {
+				Log.i(TAG, "Blocked $url by $rule")
+			}
+			rule == null
+		} ?: true
+	}
+
+	@WorkerThread
+	private fun parseRules() = runCatchingCancellable {
+		listFile(context).useLines { lines ->
+			val rules = RulesList()
+			lines.forEach { line -> rules.add(line) }
+			rules.trimToSize()
+			rules
+		}
+	}.onFailure { e ->
+		e.printStackTraceDebug()
+	}.getOrNull()
+
+	class Updater @Inject constructor(
+		@ApplicationContext private val context: Context,
+		@BaseHttpClient private val okHttpClient: OkHttpClient,
+	) {
+
+		suspend fun updateList() {
+			val file = listFile(context)
+			val dateFormat = SimpleDateFormat(CommonHeaders.DATE_FORMAT, Locale.ENGLISH)
+			val requestBuilder = Request.Builder()
+				.url(EASYLIST_URL)
+				.get()
+			if (file.exists() && file.isNotEmpty()) {
+				val lastModified = file.lastModified()
+				requestBuilder.header(CommonHeaders.IF_MODIFIED_SINCE, dateFormat.format(Date(lastModified)))
+			}
+			okHttpClient.newCall(
+				requestBuilder.build(),
+			).await().use { response ->
+				if (response.code == HttpURLConnection.HTTP_NOT_MODIFIED) {
+					return
+				}
+				val lastModified = response.header(CommonHeaders.LAST_MODIFIED)?.let {
+					runCatching {
+						dateFormat.parse(it)
+					}.getOrNull()
+				}?.time ?: System.currentTimeMillis()
+				response.requireBody().source().use { source ->
+					file.sink().use { sink ->
+						source.readAll(sink)
+					}
+					file.setLastModified(lastModified)
+				}
+			}
+		}
+
+	}
+
+	private companion object {
+
+		fun listFile(context: Context): File {
+			val root = File(context.externalCacheDir ?: context.cacheDir, LIST_DIR)
+			root.mkdir()
+			return File(root, LIST_FILENAME)
+		}
+
+		private const val LIST_FILENAME = "easylist.txt"
+		private const val LIST_DIR = "adblock"
+		private const val EASYLIST_URL = "https://easylist.to/easylist/easylist.txt"
+		private const val TAG = "AdBlock"
+	}
+}

app/src/main/kotlin/org/koitharu/kotatsu/core/network/webview/adblock/CSSRuleBuilder.kt

@@ -0,0 +1,21 @@
+package org.koitharu.kotatsu.core.network.webview.adblock
+
+import androidx.collection.ArraySet
+
+class CSSRuleBuilder {
+
+	private val selectors = ArraySet<String>()
+
+	fun add(selector: String) {
+		selectors.add(selector)
+	}
+
+	fun build() = buildString {
+		append("<style> {")
+		for (selector in selectors) {
+			append(selector)
+			append(";")
+		}
+		append("}!important</style>")
+	}
+}

app/src/main/kotlin/org/koitharu/kotatsu/core/network/webview/adblock/Rule.kt

@@ -0,0 +1,57 @@
+package org.koitharu.kotatsu.core.network.webview.adblock
+
+import okhttp3.HttpUrl
+
+sealed interface Rule {
+
+	operator fun invoke(url: HttpUrl, baseUrl: HttpUrl?): Boolean
+
+	data class Domain(private val domain: String) : Rule {
+
+		override fun invoke(url: HttpUrl, baseUrl: HttpUrl?): Boolean = (url.topPrivateDomain() ?: url.host) == domain
+	}
+
+	data class ExactUrl(private val url: HttpUrl) : Rule {
+
+		override operator fun invoke(url: HttpUrl, baseUrl: HttpUrl?): Boolean = url == this.url
+	}
+
+	data class Path(private val path: String, private val contains: Boolean) : Rule {
+
+		override fun invoke(url: HttpUrl, baseUrl: HttpUrl?): Boolean {
+			val fullPath = url.host + "/" + url.encodedPath
+			return if (contains) {
+				fullPath.contains(path)
+			} else {
+				fullPath.endsWith(path)
+			}
+		}
+	}
+
+	data class WithModifiers(
+		private val baseRule: Rule,
+		private val script: Boolean?,
+		private val thirdParty: Boolean?,
+		private val domains: Set<String>?,
+		private val domainsNot: Set<String>?,
+	) : Rule {
+
+		override fun invoke(url: HttpUrl, baseUrl: HttpUrl?): Boolean {
+			if (!baseRule.invoke(url, baseUrl)) {
+				return false
+			}
+			if (baseUrl == null) {
+				return true
+			}
+			thirdParty?.let {
+				val isThirdPartyRequest =
+					(url.topPrivateDomain() ?: url.host) != (baseUrl.topPrivateDomain() ?: baseUrl.host)
+				if (isThirdPartyRequest != it) {
+					return false
+				}
+			}
+			// TODO check other modifiers
+			return true
+		}
+	}
+}

app/src/main/kotlin/org/koitharu/kotatsu/core/network/webview/adblock/RulesList.kt

@@ -0,0 +1,91 @@
+package org.koitharu.kotatsu.core.network.webview.adblock
+
+import androidx.annotation.CheckResult
+import okhttp3.HttpUrl
+import okhttp3.HttpUrl.Companion.toHttpUrlOrNull
+
+/**
+ * Very simple implementation of adblock list parser
+ * Not all features are supported
+ */
+class RulesList {
+
+	private val blockRules = ArrayList<Rule>()
+	private val allowRules = ArrayList<Rule>()
+
+	operator fun get(url: HttpUrl, baseUrl: HttpUrl?): Rule? {
+		val rule = blockRules.find { x -> x(url, baseUrl) }
+		return rule?.takeIf { allowRules.none { x -> x(url, baseUrl) } }
+	}
+
+	fun add(line: String) {
+		val parts = line.lowercase().trim().split('$')
+		parts.first().addImpl(isWhitelist = false, modifiers = parts.getOrNull(1))
+	}
+
+	fun trimToSize() {
+		blockRules.trimToSize()
+		allowRules.trimToSize()
+	}
+
+	private fun String.addImpl(isWhitelist: Boolean, modifiers: String?) {
+		val list = if (isWhitelist) allowRules else blockRules
+
+		when {
+			startsWith('!') || startsWith('[') -> {
+				// Comment, do nothing
+			}
+
+			startsWith("||") -> {
+				// domain
+				list += Rule.Domain(substring(2).substringBefore('^').trim()).withModifiers(modifiers)
+			}
+
+			startsWith('|') -> {
+				val url = substring(1).substringBefore('^').trim().toHttpUrlOrNull()
+				if (url != null) {
+					list += Rule.ExactUrl(url).withModifiers(modifiers)
+				}
+			}
+
+			startsWith("@@") -> {
+				substring(2).substringBefore('^').trim().addImpl(!isWhitelist, modifiers)
+			}
+
+			startsWith("##") -> {
+				// TODO css rules
+			}
+
+			else -> {
+				if (endsWith('*')) {
+					list += Rule.Path(this.dropLast(1), contains = true).withModifiers(modifiers)
+				} else if (!contains('*')) { // wildcards is not supported yet
+					list += Rule.Path(this, contains = false).withModifiers(modifiers)
+				}
+			}
+		}
+	}
+
+	@CheckResult
+	private fun Rule.withModifiers(options: String?): Rule {
+		if (options.isNullOrEmpty()) {
+			return this
+		}
+		var script: Boolean? = null
+		var thirdParty: Boolean? = null
+		options.split(',').forEach {
+			val isNot = it.startsWith('~')
+			when (it.removePrefix("~")) {
+				"script" -> script = !isNot
+				"third-party" -> thirdParty = !isNot
+			}
+		}
+		return Rule.WithModifiers(
+			baseRule = this,
+			script = script,
+			thirdParty = thirdParty,
+			domains = null, //TODO
+			domainsNot = null, //TODO
+		)
+	}
+}

app/src/main/kotlin/org/koitharu/kotatsu/core/prefs/AppSettings.kt

@@ -320,6 +320,9 @@ class AppSettings @Inject constructor(@ApplicationContext context: Context) {
 	val screenshotsPolicy: ScreenshotsPolicy
 		get() = prefs.getEnumValue(KEY_SCREENSHOTS_POLICY, ScreenshotsPolicy.ALLOW)
 
+	val isAdBlockEnabled: Boolean
+		get() = prefs.getBoolean(KEY_ADBLOCK, false)
+
 	var userSpecifiedMangaDirectories: Set<File>
 		get() {
 			val set = prefs.getStringSet(KEY_LOCAL_MANGA_DIRS, emptySet()).orEmpty()
@@ -598,6 +601,7 @@ class AppSettings @Inject constructor(@ApplicationContext context: Context) {
 		const val TRACK_HISTORY = "history"
 		const val TRACK_FAVOURITES = "favourites"
 
+		const val KEY_ADBLOCK = "adblock"
 		const val KEY_LIST_MODE = "list_mode_2"
 		const val KEY_LIST_MODE_HISTORY = "list_mode_history"
 		const val KEY_LIST_MODE_FAVORITES = "list_mode_favorites"

app/src/main/kotlin/org/koitharu/kotatsu/main/ui/MainActivity.kt

@@ -43,6 +43,7 @@ import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 import org.koitharu.kotatsu.R
+import org.koitharu.kotatsu.browser.AdListUpdateService
 import org.koitharu.kotatsu.core.exceptions.resolve.SnackbarErrorObserver
 import org.koitharu.kotatsu.core.nav.router
 import org.koitharu.kotatsu.core.os.VoiceInputContract
@@ -290,6 +291,9 @@ class MainActivity : BaseActivity<ActivityMainBinding>(), AppBarOwner, BottomNav
 			}
 			startService(Intent(this@MainActivity, LocalIndexUpdateService::class.java))
 			startService(Intent(this@MainActivity, PeriodicalBackupService::class.java))
+			if (settings.isAdBlockEnabled) {
+				startService(Intent(this@MainActivity, AdListUpdateService::class.java))
+			}
 		}
 	}
 

app/src/main/kotlin/org/koitharu/kotatsu/settings/sources/auth/SourceAuthActivity.kt

@@ -45,7 +45,7 @@ class SourceAuthActivity : BaseBrowserActivity(), BrowserCallback {
 			return
 		}
 		setDisplayHomeAsUp(isEnabled = true, showUpAsClose = true)
-		viewBinding.webView.webViewClient = BrowserClient(this)
+		viewBinding.webView.webViewClient = BrowserClient(this, adBlock)
 		lifecycleScope.launch {
 			try {
 				proxyProvider.applyWebViewConfig()

app/src/main/res/values/strings.xml

@@ -842,4 +842,6 @@
 	<string name="changelog_summary">Changes history for recently released versions</string>
 	<string name="collapse">Collapse</string>
 	<string name="expand">Expand</string>
+	<string name="adblock">Block ads in browser</string>
+	<string name="adblock_summary">Block advertisement in the built-in browser (beta)</string>
 </resources>

app/src/main/res/xml/pref_network.xml

@@ -2,8 +2,8 @@
 <PreferenceScreen
 	xmlns:android="http://schemas.android.com/apk/res/android"
 	xmlns:app="http://schemas.android.com/apk/res-auto"
-	android:title="@string/network"
+	xmlns:tools="http://schemas.android.com/tools"
-	xmlns:tools="http://schemas.android.com/tools">
+	android:title="@string/network">
 
 	<ListPreference
 		android:defaultValue="0"
@@ -34,6 +34,12 @@
 		android:title="@string/dns_over_https"
 		app:useSimpleSummaryProvider="true" />
 
+	<SwitchPreferenceCompat
+		android:defaultValue="false"
+		android:key="adblock"
+		android:summary="@string/adblock_summary"
+		android:title="@string/adblock" />
+
 	<ListPreference
 		android:defaultValue="-1"
 		android:entries="@array/image_proxies"