Add beforeScreenshotCallback to SentryFlutterOptions

CHANGELOG.md

@@ -11,6 +11,7 @@
 - APM for isar ([#1726](https://github.com/getsentry/sentry-dart/pull/1726))
 - Add isar breadcrumbs ([#1800](https://github.com/getsentry/sentry-dart/pull/1800))
 - Starting with Flutter 3.16, Sentry adds the [`appFlavor`](https://api.flutter.dev/flutter/services/appFlavor-constant.html) to the `flutter_context` ([#1799](https://github.com/getsentry/sentry-dart/pull/1799))
+- Add beforeScreenshotCallback to SentryFlutterOptions ([#1805](https://github.com/getsentry/sentry-dart/pull/1805))
 
 ### Dependencies
 

flutter/lib/src/event_processor/screenshot_event_processor.dart

@@ -30,6 +30,32 @@ class ScreenshotEventProcessor implements EventProcessor {
         _hasSentryScreenshotWidget) {
       return event;
     }
+    final beforeScreenshot = _options.beforeScreenshot;
+    if (beforeScreenshot != null) {
+      try {
+        final result = beforeScreenshot(event, hint: hint);
+        bool takeScreenshot;
+        if (result is Future<bool>) {
+          takeScreenshot = await result;
+        } else {
+          takeScreenshot = result;
+        }
+        if (!takeScreenshot) {
+          return event;
+        }
+      } catch (exception, stackTrace) {
+        _options.logger(
+          SentryLevel.error,
+          'The beforeScreenshot callback threw an exception',
+          exception: exception,
+          stackTrace: stackTrace,
+        );
+        // ignore: invalid_use_of_internal_member
+        if (_options.automatedTestMode) {
+          rethrow;
+        }
+      }
+    }
 
     final renderer = _options.rendererWrapper.getRenderer();
 

flutter/lib/src/native/cocoa/binding.dart

@@ -37603,8 +37603,7 @@ class ObjCBlock_bool_ObjCObject_ffiUnsignedLong_bool extends _ObjCBlockBase {
   ObjCBlock_bool_ObjCObject_ffiUnsignedLong_bool.fromFunctionPointer(
       SentryCocoa lib,
       ffi.Pointer<
-              ffi
-              .NativeFunction<
+              ffi.NativeFunction<
                   ffi.Bool Function(ffi.Pointer<ObjCObject> arg0,
                       ffi.UnsignedLong arg1, ffi.Pointer<ffi.Bool> arg2)>>
           ptr)
@@ -42032,17 +42031,15 @@ class ObjCBlock_bool_ObjCObject_bool extends _ObjCBlockBase {
                       ffi.Pointer<ffi.Bool> arg1)>>
           ptr)
       : this._(
-            lib
-                ._newBlock1(
-                    _cFuncTrampoline ??= ffi.Pointer.fromFunction<
-                                ffi.Bool Function(
-                                    ffi.Pointer<_ObjCBlock> block,
-                                    ffi.Pointer<ObjCObject> arg0,
-                                    ffi.Pointer<ffi.Bool> arg1)>(
-                            _ObjCBlock_bool_ObjCObject_bool_fnPtrTrampoline,
-                            false)
-                        .cast(),
-                    ptr.cast()),
+            lib._newBlock1(
+                _cFuncTrampoline ??= ffi.Pointer.fromFunction<
+                            ffi.Bool Function(
+                                ffi.Pointer<_ObjCBlock> block,
+                                ffi.Pointer<ObjCObject> arg0,
+                                ffi.Pointer<ffi.Bool> arg1)>(
+                        _ObjCBlock_bool_ObjCObject_bool_fnPtrTrampoline, false)
+                    .cast(),
+                ptr.cast()),
             lib);
   static ffi.Pointer<ffi.Void>? _cFuncTrampoline;
 

flutter/lib/src/sentry_flutter_options.dart

@@ -1,12 +1,15 @@
+import 'dart:async';
+
 import 'package:meta/meta.dart';
 import 'package:sentry/sentry.dart';
 import 'package:flutter/widgets.dart';
 
 import 'binding_wrapper.dart';
 import 'renderer/renderer.dart';
 import 'screenshot/sentry_screenshot_quality.dart';
+import 'event_processor/screenshot_event_processor.dart';
 
-/// This class adds options which are only availble in a Flutter environment.
+/// This class adds options which are only available in a Flutter environment.
 /// Note that some of these options require native Sentry integration, which is
 /// not available on all platforms.
 class SentryFlutterOptions extends SentryOptions {
@@ -169,6 +172,11 @@ class SentryFlutterOptions extends SentryOptions {
   /// Only attach a screenshot when the app is resumed.
   bool attachScreenshotOnlyWhenResumed = false;
 
+  /// Sets a callback which is executed before capturing screenshots. Only
+  /// relevant if `attachScreenshot` is set to true. When false is returned
+  /// from the function, no screenshot will be attached.
+  BeforeScreenshotCallback? beforeScreenshot;
+
   /// Enable or disable automatic breadcrumbs for User interactions Using [Listener]
   ///
   /// Requires adding the [SentryUserInteractionWidget] to the widget tree.
@@ -289,3 +297,10 @@ class SentryFlutterOptions extends SentryOptions {
   /// The [navigatorKey] is used to add information of the currently used locale to the contexts.
   GlobalKey<NavigatorState>? navigatorKey;
 }
+
+/// Callback being executed in [ScreenshotEventProcessor], deciding if a
+/// screenshot should be recorded and attached.
+typedef BeforeScreenshotCallback = FutureOr<bool> Function(
+  SentryEvent event, {
+  Hint? hint,
+});

flutter/test/event_processor/screenshot_event_processor_test.dart

@@ -14,6 +14,9 @@ void main() {
   TestWidgetsFlutterBinding.ensureInitialized();
   late Fixture fixture;
 
+  late SentryEvent event;
+  late Hint hint;
+
   setUp(() {
     fixture = Fixture();
   });
@@ -34,8 +37,8 @@ void main() {
               textDirection: TextDirection.ltr)));
 
       final throwable = Exception();
-      final event = SentryEvent(throwable: throwable);
-      final hint = Hint();
+      event = SentryEvent(throwable: throwable);
+      hint = Hint();
       await sut.apply(event, hint: hint);
 
       expect(hint.screenshot != null, added);
@@ -91,6 +94,87 @@ void main() {
     await _addScreenshotAttachment(tester, null,
         added: true, isWeb: false, expectedMaxWidthOrHeight: widthOrHeight);
   });
+
+  group('beforeScreenshot', () {
+    testWidgets('does add screenshot if beforeScreenshot returns true',
+        (tester) async {
+      fixture.options.beforeScreenshot = (SentryEvent event, {Hint? hint}) {
+        return true;
+      };
+      await _addScreenshotAttachment(tester, FlutterRenderer.canvasKit,
+          added: true, isWeb: false);
+    });
+
+    testWidgets('does add screenshot if async beforeScreenshot returns true',
+        (tester) async {
+      fixture.options.beforeScreenshot =
+          (SentryEvent event, {Hint? hint}) async {
+        await Future<void>.delayed(Duration(milliseconds: 1));
+        return true;
+      };
+      await _addScreenshotAttachment(tester, FlutterRenderer.canvasKit,
+          added: true, isWeb: false);
+    });
+
+    testWidgets('does not add screenshot if beforeScreenshot returns false',
+        (tester) async {
+      fixture.options.beforeScreenshot = (SentryEvent event, {Hint? hint}) {
+        return false;
+      };
+      await _addScreenshotAttachment(tester, FlutterRenderer.canvasKit,
+          added: false, isWeb: false);
+    });
+
+    testWidgets(
+        'does not add screenshot if async beforeScreenshot returns false',
+        (tester) async {
+      fixture.options.beforeScreenshot =
+          (SentryEvent event, {Hint? hint}) async {
+        await Future<void>.delayed(Duration(milliseconds: 1));
+        return false;
+      };
+      await _addScreenshotAttachment(tester, FlutterRenderer.canvasKit,
+          added: false, isWeb: false);
+    });
+
+    testWidgets('does add screenshot if beforeScreenshot throws',
+        (tester) async {
+      fixture.options.beforeScreenshot = (SentryEvent event, {Hint? hint}) {
+        throw Error();
+      };
+      await _addScreenshotAttachment(tester, FlutterRenderer.canvasKit,
+          added: true, isWeb: false);
+    });
+
+    testWidgets('does add screenshot if async beforeScreenshot throws',
+        (tester) async {
+      fixture.options.beforeScreenshot =
+          (SentryEvent event, {Hint? hint}) async {
+        await Future<void>.delayed(Duration(milliseconds: 1));
+        throw Error();
+      };
+      await _addScreenshotAttachment(tester, FlutterRenderer.canvasKit,
+          added: true, isWeb: false);
+    });
+
+    testWidgets('passes event & hint to beforeScreenshot callback',
+        (tester) async {
+      SentryEvent? beforeScreenshotEvent;
+      Hint? beforeScreenshotHint;
+
+      fixture.options.beforeScreenshot = (SentryEvent event, {Hint? hint}) {
+        beforeScreenshotEvent = event;
+        beforeScreenshotHint = hint;
+        return true;
+      };
+
+      await _addScreenshotAttachment(tester, FlutterRenderer.canvasKit,
+          added: true, isWeb: false);
+
+      expect(beforeScreenshotEvent, event);
+      expect(beforeScreenshotHint, hint);
+    });
+  });
 }
 
 class Fixture {