Show WebView loading progress

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

@@ -29,6 +29,7 @@ class BrowserActivity : BaseActivity<ActivityBrowserBinding>(), BrowserCallback
 			javaScriptEnabled = true
 		}
 		binding.webView.webViewClient = BrowserClient(this)
+		binding.webView.webChromeClient = ProgressChromeClient(binding.progressBar)
 		if (savedInstanceState != null) {
 			return
 		}

app/src/main/java/org/koitharu/kotatsu/browser/ProgressChromeClient.kt

@@ -0,0 +1,31 @@
+package org.koitharu.kotatsu.browser
+
+import android.webkit.WebChromeClient
+import android.webkit.WebView
+import androidx.core.view.isVisible
+import com.google.android.material.progressindicator.BaseProgressIndicator
+import org.koitharu.kotatsu.utils.ext.setIndeterminateCompat
+
+private const val PROGRESS_MAX = 100
+
+class ProgressChromeClient(
+	private val progressIndicator: BaseProgressIndicator<*>,
+) : WebChromeClient() {
+
+	init {
+		progressIndicator.max = PROGRESS_MAX
+	}
+
+	override fun onProgressChanged(view: WebView?, newProgress: Int) {
+		super.onProgressChanged(view, newProgress)
+		if (!progressIndicator.isVisible) {
+			return
+		}
+		if (newProgress in 1 until PROGRESS_MAX) {
+			progressIndicator.setIndeterminateCompat(false)
+			progressIndicator.setProgressCompat(newProgress.coerceAtMost(PROGRESS_MAX), true)
+		} else {
+			progressIndicator.setIndeterminateCompat(true)
+		}
+	}
+}

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

@@ -6,22 +6,6 @@
 	android:layout_width="match_parent"
 	android:layout_height="match_parent">
 
-	<com.google.android.material.appbar.AppBarLayout
-		android:id="@+id/appbar"
-		android:layout_width="0dp"
-		android:layout_height="wrap_content"
-		app:layout_constraintEnd_toEndOf="parent"
-		app:layout_constraintStart_toStartOf="parent"
-		app:layout_constraintTop_toTopOf="parent">
-
-		<com.google.android.material.appbar.MaterialToolbar
-			android:id="@id/toolbar"
-			android:layout_width="match_parent"
-			android:layout_height="wrap_content"
-			app:layout_scrollFlags="scroll|enterAlways" />
-
-	</com.google.android.material.appbar.AppBarLayout>
-
 	<WebView
 		android:id="@+id/webView"
 		android:layout_width="0dp"
@@ -43,4 +27,20 @@
 		app:layout_constraintTop_toBottomOf="@id/appbar"
 		tools:visibility="visible" />
 
+	<com.google.android.material.appbar.AppBarLayout
+		android:id="@+id/appbar"
+		android:layout_width="0dp"
+		android:layout_height="wrap_content"
+		app:layout_constraintEnd_toEndOf="parent"
+		app:layout_constraintStart_toStartOf="parent"
+		app:layout_constraintTop_toTopOf="parent">
+
+		<com.google.android.material.appbar.MaterialToolbar
+			android:id="@id/toolbar"
+			android:layout_width="match_parent"
+			android:layout_height="wrap_content"
+			app:layout_scrollFlags="scroll|enterAlways" />
+
+	</com.google.android.material.appbar.AppBarLayout>
+
 </androidx.constraintlayout.widget.ConstraintLayout>