From b53fc5eca7728cd11e40f8fc2db53ff00d4ec514 Mon Sep 17 00:00:00 2001
From: dimitris <jimitrakis11@gmail.com>
Date: Fri, 15 May 2026 22:03:04 +0200
Subject: [PATCH] fix(webview): surface main-frame load failures in the in-app
 browser

WebViewFragment in addedit/ is the screen the user types or navigates
a URL into so it can be picked for monitoring. The WebViewClient
overrides onPageStarted and onPageFinished to drive the progress bar
but does not override onReceivedError, so a failed navigation (DNS,
certificate, offline, 4xx/5xx) just leaves a blank page with no clue
what went wrong.

Add an onReceivedError override that hides the progress bar and shows
a short Toast with the failure reason. Gated on
request.isForMainFrame so a blocked sub-resource does not also pop a
Toast. Adds webview_load_failed / webview_load_failed_with_reason
strings to keep the message translatable.
---
 .../addedit/WebViewFragment.kt                | 27 +++++++++++++++++++
 app/src/main/res/values/strings.xml           |  2 ++
 2 files changed, 29 insertions(+)

diff --git a/app/src/main/java/com/bernaferrari/changedetection/addedit/WebViewFragment.kt b/app/src/main/java/com/bernaferrari/changedetection/addedit/WebViewFragment.kt
index 80a6e63..d11ad78 100644
--- a/app/src/main/java/com/bernaferrari/changedetection/addedit/WebViewFragment.kt
+++ b/app/src/main/java/com/bernaferrari/changedetection/addedit/WebViewFragment.kt
@@ -1,14 +1,18 @@
 package com.bernaferrari.changedetection.addedit
 
 import android.graphics.Bitmap
+import android.os.Build
 import android.os.Bundle
 import android.text.Editable
 import android.view.KeyEvent
 import android.view.LayoutInflater
 import android.view.View
 import android.view.ViewGroup
+import android.webkit.WebResourceError
+import android.webkit.WebResourceRequest
 import android.webkit.WebView
 import android.webkit.WebViewClient
+import android.widget.Toast
 import androidx.core.view.isVisible
 import androidx.lifecycle.ViewModelProviders
 import androidx.navigation.findNavController
@@ -60,6 +64,29 @@ class WebViewFragment : ScopedFragment() {
                 progress?.visibility = View.GONE
                 super.onPageFinished(view, url)
             }
+
+            override fun onReceivedError(
+                view: WebView?,
+                request: WebResourceRequest?,
+                error: WebResourceError?
+            ) {
+                super.onReceivedError(view, request, error)
+                // Only surface the main-frame failure, otherwise every blocked
+                // sub-resource would pop a toast
+                if (request?.isForMainFrame != true) return
+                progress?.visibility = View.GONE
+                val description = if (Build.VERSION.SDK_INT >= 23) {
+                    error?.description?.toString().orEmpty()
+                } else {
+                    ""
+                }
+                val message = if (description.isNotBlank()) {
+                    getString(R.string.webview_load_failed_with_reason, description)
+                } else {
+                    getString(R.string.webview_load_failed)
+                }
+                Toast.makeText(context, message, Toast.LENGTH_SHORT).show()
+            }
         }
 
         close.setOnClickListener { goPreviousFragment() }
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 9eeb210..bfdfd00 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -3,6 +3,8 @@
 
     <string name="yes">Yes</string>
     <string name="no">No</string>
+    <string name="webview_load_failed">Page failed to load</string>
+    <string name="webview_load_failed_with_reason">Page failed to load: %1$s</string>
 
     <string name="save">Save</string>
     <string name="cancel">Cancel</string>