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)
+		}
+	}
+}