Controls

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The Feedback Service — One Hook to Rule Them All

May 3, 2026

Allan Ritchie

One of the guys who builds this

Every tap, swipe, and keystroke in your app is an opportunity. An opportunity to confirm the user’s action, guide their attention, or add a layer of polish that separates “functional” from “delightful.” Most apps handle this with scattered HapticFeedback.Default.Perform() calls sprinkled across code-behind files. It works — until you want text-to-speech for accessibility, sound effects for a kiosk app, analytics for product telemetry, or different feedback for different controls. Then you’re threading conditional logic through every view in your app.

Shiny Controls v1.0 ships with IFeedbackService — a single injectable service that every interactive control in the library already calls. You implement it once. Every control uses it automatically.

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How It Works

Every Shiny control that supports feedback has a UseFeedback property (default: true). When a user interaction occurs — a message sent, a pin digit entered, a panel opened — the control calls IFeedbackService.OnRequested() with three things:

public interface IFeedbackService
{
    void OnRequested(object control, string eventName, object? args = null);
}

• control — the actual control instance, not a Type. Pattern match directly: control is ChatView, control is SecurityPin.
• eventName — what happened: "MessageReceived", "DigitEntered", "Opened".
• args — contextual data. For ChatView, this is the full ChatMessage object. For standard MAUI controls, it’s the native EventArgs. For SecurityPin completion, it’s "LongPress".

The default HapticFeedbackService does what you’d expect — click haptic for most events, long press haptic for completion events. But the real power is in replacing it.

Custom Feedback: TTS + Sound Effects

Here’s a real example from our sample app. One service, three behaviors — haptic, text-to-speech for incoming chat messages, and audio cues for PIN entry:

public class MyCustomFeedbackService(
    ITextToSpeechService textToSpeech,
    IAudioManager audioManager
) : HapticFeedbackService
{
    public override async void OnRequested(object control, string eventName, object? args)
    {
        // haptic first — always
        base.OnRequested(control, eventName, args);

        // speak incoming chat messages aloud
        if (control is ChatView && args is ChatMessage { IsFromMe: false } msg)
        {
            await textToSpeech.SpeakAsync(
                $"Message from {msg.SenderId}. {msg.Text}"
            );
        }
        // click and success sounds for PIN entry
        else if (control is SecurityPin)
        {
            var sound = eventName.Equals("completed", StringComparison.OrdinalIgnoreCase)
                ? "pin_success.wav"
                : "pin_click.wav";

            var raw = await FileSystem.OpenAppPackageFileAsync(sound);
            audioManager.CreatePlayer(raw).Play();
        }
    }
}

Register it in one line:

builder.UseShinyControls(cfg =>
{
    cfg.SetCustomFeedback<MyCustomFeedbackService>();
});

Because control is the live instance and args carries typed data, you can make nuanced decisions without parsing strings. The ChatMessage gives you sender, timestamp, text, and image URL. The SecurityPin instance gives you its current value and length. Cast, match, and go.

Pluggable MAUI Control Hooks

Shiny’s own controls call IFeedbackService internally. But what about standard MAUI controls — Button, Slider, Entry? The MauiControlFeedbackBuilder hooks them in automatically, with an AOT-compatible, fully pluggable design:

All defaults

cfg.AddDefaultMauiControlFeedback();

This registers hooks for 12 standard MAUI controls — Button.Clicked, Entry.TextChanged, Slider.ValueChanged, Switch.Toggled, and more. Each hook passes the control instance as control and the native event args as args.

Defaults + your own

cfg.AddDefaultMauiControlFeedback(x =>
{
    x.Hook<MyCustomControl>(nameof(MyCustomControl.Tapped),
        (c, h) => c.Tapped += h,
        (c, h) => c.Tapped -= h);
});

Only what you need

cfg.AddMauiControlFeedback(x =>
{
    x.Hook<Button>(nameof(Button.Clicked),
        (btn, h) => btn.Clicked += h,
        (btn, h) => btn.Clicked -= h);

    x.Hook<Slider, ValueChangedEventArgs>(nameof(Slider.ValueChanged),
        (s, h) => s.ValueChanged += h,
        (s, h) => s.ValueChanged -= h);
});

Two overloads cover every case:

• Hook<TControl>(eventName, subscribe, unsubscribe) for plain EventHandler events
• Hook<TControl, TEventArgs>(eventName, subscribe, unsubscribe) for typed EventHandler<TEventArgs> events

Under the hood, each hook uses a ConditionalWeakTable to track handlers per control instance — no leaks, no dictionaries to manage, proper unsubscription when controls leave the visual tree. Zero reflection, fully AOT-safe.

What Ships Built-In

Every Shiny control fires feedback through this system. Here’s the full event catalog:

Control	Events
ChatView	MessageSent, MessageReceived, MessageTapped (all pass ChatMessage), AttachImage
SecurityPin	DigitEntered, Completed
FloatingPanel	Opened, Closed, DetentChanged
ImageViewer	Opened, Closed, DoubleTapped
ImageEditor	ToolModeChanged, Undo, Redo, Rotate, Reset, CropApplied, Saved
Fab / FabMenu	Clicked, Toggled
Scheduler	DaySelected, EventSelected, TimeSlotSelected
TableView Cells	Tapped
Toast	Show

Any control’s feedback can be suppressed per-instance with UseFeedback="False".

The Design Philosophy

Most feedback systems are either too simple (a global haptic toggle) or too complex (per-control event subscriptions scattered across your app). IFeedbackService sits in the sweet spot:

1. One service, all controls. Implement once, every control calls it.
2. Instance, not type. You get the actual control, not typeof(Button). Inspect properties, check state, make decisions.
3. Typed args, not strings. ChatMessage, ValueChangedEventArgs, ToggledEventArgs — not "the message text".
4. Pluggable hooks, not hardcoded events. Add your own controls to the system with three lambdas.
5. AOT-safe. No reflection, no expressions, no Delegate.CreateDelegate. Just generics and delegates.

Whether you’re building an accessible app that speaks every incoming message, a kiosk that plays sound effects, or just want consistent haptic feedback across your entire UI — IFeedbackService is one implementation away.

Check out the full documentation and the sample app for a working demo with TTS and audio integration.

Tags:

• Controls
• Release