DrmKit.Avalonia 1.0.1

DrmKit.Avalonia

Helpers for running Avalonia apps directly on Linux DRM/Framebuffer (kiosk / embedded, no X11 / Wayland).

• evdev keyboard: EN/RU, Alt+Shift, CapsLock, text input into focused control;
• on‑screen keyboard overlay (KeyboardOverlay) for touch UI;
• soft cursor overlay with auto‑hide and proper pointer over events;
• evdev mouse fallback for DRM when there is no windowing system;
• SmartPlatform — runtime switch: DRM ↔ desktop with CLI options.

Main namespace: Avalonia.DrmKit
Recommended: Avalonia 11, .NET 8, Linux with /dev/dri/card* and /dev/input/event*.

Install

dotnet add package DrmKit.Avalonia

Quick start

Program.cs:

using Avalonia;
using Avalonia.DrmKit;

internal static class Program
{
    public static int Main(string[] args)
        => SmartPlatform.Start(BuildAvaloniaApp(), args);

    public static AppBuilder BuildAvaloniaApp()
        => AppBuilder.Configure<App>()
            .UsePlatformDetect()
            .LogToTrace()
            .UseReactiveUI()
            .UseDrmSoftCursor()         // soft cursor overlay for DRM
            .UseLinuxKeyboardListener() // evdev keyboard (EN/RU, Alt+Shift, CapsLock)
            .UseEvdevMouseFallback();   // evdev mouse + pointerover fix for DRM
}

Run in DRM mode:

# user should be in 'video' and 'input' groups
./YourApp --system=drm --drm=card1 --resolution=1280x720

# debug evdev input
DRMKIT_DEBUG=1 ./YourApp --system=drm --drm=card1

If DRM cannot be initialized, SmartPlatform falls back to the standard Avalonia desktop backend.

On‑screen keyboard overlay

Attach overlay keyboard to any TextBox:

<TextBox
    xmlns:osk="clr-namespace:Avalonia.DrmKit.OnScreenKeyboard;assembly=Avalonia.DrmKit"
    osk:KeyboardOverlay.IsEnabled="True"
    Watermark="Tap to enter text" />

Behaviour:

• when a TextBox with KeyboardOverlay.IsEnabled="True" receives focus, a shared on‑screen keyboard panel appears at the bottom of the main window;
• when focus leaves all such TextBox controls, the keyboard hides;
• physical keyboard state (EN/RU, CapsLock) is synchronized with the overlay.

Layouts:

• EN and RU (йцукен);
• switching: Alt+Shift on physical keyboard or button on the overlay;
• CapsLock is synchronized both ways.

Soft cursor & auto‑hide

UseDrmSoftCursor() adds an overlay layer that renders a software cursor on top of the window.

Features:

• always visible in DRM even without hardware cursor;
• correct PointerEntered / PointerExited / PointerMoved for Avalonia controls;
• auto‑hide after idle (default: 3 seconds) with smooth fade‑out;
• theming for light/dark themes and full customization via styles/templates.

Example style in App.axaml:

<Application.Styles>
  <Style Selector="t|SoftCursorLayer">
    <Setter Property="AutoHideDelay" Value="0:0:3" /> 
    <Setter Property="StrokeBrush"   Value="White" />
    <Setter Property="FillBrush"     Value="#80FFFFFF" />
    <Setter Property="PressedFillBrush" Value="#C0FFFFFF" />
  </Style>
</Application.Styles>

To fully replace visuals (text, image, custom shape), set DisableDefaultRendering="True" and provide your own Template or Content.

SmartPlatform CLI (very short)

SmartPlatform understands several useful command‑line options:

--system=auto|drm|desktop
--drm=card0|card1|/dev/dri/card1|1
--resolution=1280x720

Typical DRM run:

./YourApp --system=drm --drm=card0 --resolution=1920x1080

If no DRM card is found (no /dev/dri/card*), the library automatically starts the regular Avalonia desktop backend instead.

Кратко по‑русски

• Пакет для запуска Avalonia в чистом DRM/Framebuffer.
• Даёт: экранную клавиатуру‑оверлей, evdev‑клавиатуру, мышь через evdev, софт‑курсор с авто‑скрытием и нормальными pointerover‑событиями.
• Интеграция — один вызов SmartPlatform.Start(...) + три extension‑метода для AppBuilder.

Input behavior defaults (current)

On-screen keyboard (KeyboardOverlay):

• opens on pointer/touch focus by default;
• does not auto-open from keyboard Tab focus by default;
• Esc hides overlay without rollback;
• text rollback is only performed by explicit Cancel on overlay keyboard.

Useful attached properties:

• osk:KeyboardOverlay.OpenOnProgrammaticFocus (default: False)
• osk:KeyboardOverlay.OpenOnKeyboardFocus (default: False)
• osk:KeyboardOverlay.InputGateTimeoutMs (default: 300)

DRM keyboard backend (DrmKeyboardOptions) defaults:

• UseRoutedControlKeys = true
• EnableRawControlKeysFallback = false
• TabAsNavigation = true
• EnterAsTextFallback = false