Fix WebView's infinite expansion

app/src/main/java/eu/kanade/tachiyomi/ui/webview/BaseWebViewActivity.kt

@@ -15,6 +15,7 @@ import eu.kanade.tachiyomi.R
 import eu.kanade.tachiyomi.ui.base.activity.BaseActivity
 import eu.kanade.tachiyomi.util.system.ThemeUtil
 import eu.kanade.tachiyomi.util.system.getResourceColor
+import eu.kanade.tachiyomi.util.system.isBottomTappable
 import eu.kanade.tachiyomi.util.system.isInNightMode
 import eu.kanade.tachiyomi.util.system.setDefaultSettings
 import eu.kanade.tachiyomi.util.view.invisible
@@ -88,12 +89,13 @@ open class BaseWebViewActivity : BaseActivity() {
                 else getResourceColor(android.R.attr.colorPrimary)
             }
             // if the android q+ device has gesture nav, transparent nav bar
-            else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q &&
+            else if (v.rootWindowInsets.isBottomTappable()) {
-                (v.rootWindowInsets.systemWindowInsetBottom != v.rootWindowInsets.tappableElementInsets.bottom)
-            ) {
                 getColor(android.R.color.transparent)
             } else {
-                getResourceColor(android.R.attr.colorBackground)
+                ColorUtils.setAlphaComponent(
+                    getResourceColor(R.attr.colorPrimaryVariant),
+                    179
+                )
             }
             v.setPadding(
                 insets.systemWindowInsetLeft,
@@ -123,9 +125,7 @@ open class BaseWebViewActivity : BaseActivity() {
             }
             val marginB = webview.marginBottom
             webview.setOnApplyWindowInsetsListener { v, insets ->
-                val bottomInset =
+                val bottomInset = insets.systemWindowInsetBottom
-                    if (Build.VERSION.SDK_INT >= 29) insets.tappableElementInsets.bottom
-                    else insets.systemWindowInsetBottom
                 v.updateLayoutParams<ViewGroup.MarginLayoutParams> {
                     bottomMargin = marginB + bottomInset
                 }

app/src/main/java/eu/kanade/tachiyomi/ui/webview/WebViewActivity.kt

@@ -4,6 +4,7 @@ import android.content.Context
 import android.content.Intent
 import android.content.res.Configuration
 import android.graphics.Bitmap
+import android.graphics.Color
 import android.os.Bundle
 import android.view.Menu
 import android.view.MenuItem
@@ -11,6 +12,7 @@ import android.view.View
 import android.view.ViewGroup
 import android.webkit.WebView
 import android.widget.LinearLayout
+import androidx.annotation.ColorInt
 import androidx.core.graphics.ColorUtils
 import eu.kanade.tachiyomi.R
 import eu.kanade.tachiyomi.source.SourceManager
@@ -69,6 +71,9 @@ open class WebViewActivity : BaseWebViewActivity() {
                     title = view?.title
                     swipe_refresh.isEnabled = true
                     swipe_refresh?.isRefreshing = false
+                    val thing = view?.evaluateJavascript("getComputedStyle(document.querySelector('body')).backgroundColor") {
+                        nested_view.setBackgroundColor(parseHTMLColor(it))
+                    }
                 }
 
                 override fun onPageStarted(view: WebView?, url: String?, favicon: Bitmap?) {
@@ -87,6 +92,16 @@ open class WebViewActivity : BaseWebViewActivity() {
         }
     }
 
+    @ColorInt
+    fun parseHTMLColor(color: String): Int {
+        val trimmedColor = color.trim('"')
+        val rgb = Regex("""^rgb\((\d+),\s*(\d+),\s*(\d+)\)$""").find(trimmedColor)
+        val red = rgb?.groupValues?.getOrNull(1)?.toIntOrNull() ?: return getResourceColor(android.R.attr.colorBackground)
+        val green = rgb.groupValues.getOrNull(2)?.toIntOrNull() ?: return getResourceColor(android.R.attr.colorBackground)
+        val blue = rgb.groupValues.getOrNull(3)?.toIntOrNull() ?: return getResourceColor(android.R.attr.colorBackground)
+        return Color.rgb(red, green, blue)
+    }
+
     override fun onConfigurationChanged(newConfig: Configuration) {
         super.onConfigurationChanged(newConfig)
         invalidateOptionsMenu()

app/src/main/res/layout/webview_activity.xml

@@ -13,6 +13,7 @@
         android:orientation="vertical"
         android:id="@+id/web_linear_layout"
         android:layout_width="match_parent"
+        android:fitsSystemWindows="true"
         android:layout_height="wrap_content">
 
         <androidx.appcompat.widget.Toolbar
@@ -22,7 +23,7 @@
             android:background="?attr/colorSecondary"
             android:theme="?attr/actionBarTheme"
             app:navigationIcon="@drawable/ic_close_24dp"
-            app:layout_scrollFlags="scroll|enterAlways|snap" />
+            app:layout_scrollFlags="scroll|enterAlways" />
 
     </com.google.android.material.appbar.AppBarLayout>
 
@@ -38,8 +39,9 @@
         android:layout_height="match_parent">
         <WebView
             android:id="@+id/webview"
+            android:nestedScrollingEnabled="true"
             android:layout_width="match_parent"
-            android:layout_height="match_parent" >
+            android:layout_height="wrap_content" >
 
             <ProgressBar
                 android:id="@+id/progressBar"