feat: Support custom masking for SessionReplay in MAUI Android apps

Author: jamescrosswell

samples/Sentry.Samples.Maui/MainPage.xaml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8" ?>
 <ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
              xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             xmlns:sentry="http://schemas.sentry.io/maui"
              x:Class="Sentry.Samples.Maui.MainPage">
 
     <ScrollView>
@@ -38,13 +39,15 @@
             <Button
                 x:Name="ThrowAndCaptureBtn"
                 Text="Throw and Capture Exception"
+                sentry:SessionReplay.Mask="sentry-unmask"
                 SemanticProperties.Hint="Throws an exception and captures it."
                 Clicked="OnCapturedExceptionClicked"
                 HorizontalOptions="Center" />
 
             <Button
                 x:Name="ThrowUnhandledBtn"
                 Text="Throw Unhandled .NET Exception (Crash)"
+                sentry:SessionReplay.Mask="sentry-unmask"
                 SemanticProperties.Hint="Throws an unhandled .NET exception, crashing the app."
                 Clicked="OnUnhandledExceptionClicked"
                 HorizontalOptions="Center" />
@@ -59,20 +62,23 @@
             <Button
                 x:Name="JavaCrashBtn"
                 Text="Throw Java Exception (Crash)"
+                sentry:SessionReplay.Mask="sentry-unmask"
                 SemanticProperties.Hint="Throws an unhandled Java exception, crashing the app."
                 Clicked="OnJavaCrashClicked"
                 HorizontalOptions="Center" />
 
             <Button
                 x:Name="NativeCrashBtn"
                 Text="Cause Native Crash"
+                sentry:SessionReplay.Mask="sentry-unmask"
                 SemanticProperties.Hint="Performs an invalid native operation, crashing the app."
                 Clicked="OnNativeCrashClicked"
                 HorizontalOptions="Center" />
 
             <Button
                 x:Name="FeedbackBtn"
                 Text="Submit Feedback"
+                sentry:SessionReplay.Mask="sentry-unmask"
                 SemanticProperties.Hint="Provides a form that can be used to capture open feedback from the user."
                 Clicked="OnFeedbackClicked"
                 HorizontalOptions="Center" />

samples/Sentry.Samples.Maui/MauiProgram.cs

@@ -29,8 +29,10 @@ public static MauiApp CreateMauiApp()
                 // Currently experimental support is only available on Android
                 options.Native.ExperimentalOptions.SessionReplay.OnErrorSampleRate = 1.0;
                 options.Native.ExperimentalOptions.SessionReplay.SessionSampleRate = 1.0;
-                options.Native.ExperimentalOptions.SessionReplay.MaskAllImages = false;
-                options.Native.ExperimentalOptions.SessionReplay.MaskAllText = false;
+                // Mask all images and text by default.
+                // This can be overridden for individual view elements (see MainPage.xaml for an example)
+                options.Native.ExperimentalOptions.SessionReplay.MaskAllImages = true;
+                options.Native.ExperimentalOptions.SessionReplay.MaskAllText = true;
 #endif
 
                 options.SetBeforeScreenshotCapture((@event, hint) =>

src/Sentry.Maui/AssemblyInfo.cs

@@ -0,0 +1,3 @@
+// XML namespaces for custom XAML elements defined in the Sentry.Maui assembly (e.g. Bindable Properties)
+[assembly: XmlnsDefinition("http://schemas.sentry.io/maui", "Sentry.Maui")]
+[assembly: Microsoft.Maui.Controls.XmlnsPrefix("http://schemas.sentry.io/maui", "sentry")]

src/Sentry.Maui/SessionReplay.cs

@@ -0,0 +1,56 @@
+#if __ANDROID__
+using View = Android.Views.View;
+#endif
+
+namespace Sentry.Maui;
+
+/// <summary>
+/// Contains custom <see cref="BindableProperty"/> definitions used to control the behaviour of the Sentry SessionReplay
+/// feature in MAUI apps.
+/// </summary>
+public static class SessionReplay
+{
+    /// <summary>
+    /// Mask can be used to either unmask or mask a view.
+    /// </summary>
+    public static readonly BindableProperty MaskProperty =
+        BindableProperty.CreateAttached(
+            "Mask",
+            typeof(string),
+            typeof(SessionReplay),
+            defaultValue: "sentry-mask", // default: masked
+            propertyChanged: OnMaskChanged);
+
+    /// <summary>
+    /// Gets the value of the Mask property for a view
+    /// </summary>
+    public static string GetMask(BindableObject view) => (string)view.GetValue(MaskProperty);
+
+    /// <summary>
+    /// Sets the value of the Mask property for a view. .
+    /// </summary>
+    /// <param name="view">The view element to mask or unmask</param>
+    /// <param name="value">The value to assign. Can be either "sentry-mask" or "sentry-unmask".</param>
+    public static void SetMask(BindableObject view, string value) => view.SetValue(MaskProperty, value);
+
+    private static void OnMaskChanged(BindableObject bindable, object oldValue, object newValue)
+    {
+#if __ANDROID__
+            if (bindable is VisualElement ve)
+            {
+                ve.HandlerChanged += (s, e) =>
+                {
+                    if (ve.Handler?.PlatformView is View nativeView && newValue is string maskSetting)
+                    {
+                        if (string.IsNullOrEmpty(maskSetting))
+                        {
+                            return;
+                        }
+                        // "sentry-unmask" if true; remove tag if false
+                        nativeView.Tag = maskSetting;
+                    }
+                };
+            }
+#endif
+    }
+}