docs: how to prevent closing challenge upon back press

README.md

@@ -315,6 +315,19 @@ No: the SDK depends on WebView, which is a UI component and cannot be instantiat
 
 However, the SDK provides a completely silent (invisible to the end-user) mechanism with `hideDialog=true` config + "passive" site key (this is an Enterprise feature). But note that the token request still has to be called from the UI thread.
 
+> How can I prevent the hCaptcha verification from being canceled when the back button is pressed?
+
+It is possible by specifying `HCaptchaConfig.retryPredicate` as shown in the following code snippet:
+
+```java
+final HCaptchaConfig config = HCaptchaConfig.builder()
+        .siteKey("YOUR_API_SITE_KEY")
+        .retryPredicate((config, hCaptchaException) -> {
+            return hCaptchaException.getHCaptchaError() == HCaptchaError.CHALLENGE_CLOSED;
+        })
+        .build();
+```
+
 ## For maintainers
 
 If you plan to contribute to the repo, please see [MAINTAINERS.md](./MAINTAINERS.md) for detailed build, test, and release instructions.

sdk/src/androidTest/java/com/hcaptcha/sdk/HCaptchaDialogFragmentTest.java

@@ -17,6 +17,7 @@
 import static com.hcaptcha.sdk.HCaptchaDialogFragment.KEY_LISTENER;
 import static org.hamcrest.Matchers.not;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
@@ -32,6 +33,7 @@
 import android.view.KeyEvent;
 import android.view.LayoutInflater;
 import android.view.MotionEvent;
+import android.view.View;
 import androidx.fragment.app.testing.FragmentScenario;
 import androidx.lifecycle.Lifecycle;
 import androidx.test.core.app.ActivityScenario;
@@ -394,8 +396,10 @@ public void testBackShouldNotCloseCaptchaWithoutDefaultLoadingIndicator() {
             scenario.onFragment(fragment -> {
                 final Dialog dialog = fragment.getDialog();
                 assertNotNull(dialog);
+                final View rootView = dialog.getWindow().getDecorView().getRootView().findFocus();
+                assertNotNull(rootView);
                 final KeyEvent keyEvent = new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_BACK);
-                assertTrue(dialog.dispatchKeyEvent(keyEvent));
+                assertTrue(rootView.dispatchKeyEvent(keyEvent));
             });
         }
     }
@@ -426,4 +430,45 @@ public void testTouchShouldNotCloseCaptchaWithoutDefaultLoadingIndicator() {
             });
         }
     }
+
+    @Test
+    public void testBackShouldNotCloseCaptchaWithCustomRetry() {
+        try (FragmentScenario<HCaptchaDialogFragment> scenario = launch(
+                config.toBuilder()
+                        .loading(true)
+                        .retryPredicate((c, e) -> e.getHCaptchaError() == HCaptchaError.CHALLENGE_CLOSED)
+                        .build(),
+                internalConfig.toBuilder()
+                        .htmlProvider(new HCaptchaTestHtml(false))
+                        .build(),
+                new HCaptchaStateTestAdapter())) {
+
+            scenario.onFragment(fragment -> {
+                final Dialog dialog = fragment.getDialog();
+                assertNotNull(dialog);
+                final View rootView = dialog.getWindow().getDecorView().getRootView().findFocus();
+                assertNotNull(rootView);
+                final KeyEvent keyEvent = new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_BACK);
+                assertTrue(rootView.dispatchKeyEvent(keyEvent));
+            });
+        }
+    }
+
+    @Test
+    public void testNonBackShouldNotCloseCaptcha() throws InterruptedException {
+        try (FragmentScenario<HCaptchaDialogFragment> scenario = launch(
+                config,
+                internalConfig.toBuilder()
+                        .htmlProvider(new HCaptchaTestHtml(false))
+                        .build(),
+                new HCaptchaStateTestAdapter())) {
+
+            scenario.onFragment(fragment -> {
+                final Dialog dialog = fragment.getDialog();
+                assertNotNull(dialog);
+                final KeyEvent keyEvent = new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_ENTER);
+                assertFalse(dialog.dispatchKeyEvent(keyEvent));
+            });
+        }
+    }
 }

sdk/src/main/java/com/hcaptcha/sdk/HCaptchaDialogFragment.java

@@ -122,7 +122,7 @@ public View onCreateView(@Nullable LayoutInflater inflater,
                     requireContext(), config, internalConfig, this, listener, webView);
             readyForInteraction = false;
             return rootView;
-        } catch (BadParcelableException | InflateException | ClassCastException e) {
+        } catch (AssertionError | BadParcelableException | InflateException | ClassCastException e) {
             HCaptchaLog.w("Cannot create view. Dismissing dialog...");
             // Happens when fragment tries to reconstruct because the activity was killed
             // And thus there is no way of communicating back