aprillz/MewUI — Gitpedia

😺 MewUI is a cross-platform and lightweight, code-first .NET GUI framework aimed at NativeAOT.

[!NOTE]
The official pronunciation of MewUI is /mjuː aɪ/ (“myoo-eye”).

🧪 Experimental Prototype

[!IMPORTANT]
This project is a proof-of-concept prototype for validating ideas and exploring design directions.
As it evolves toward v1.0, APIs, internal architecture, and runtime behavior may change significantly.
Backward compatibility is not guaranteed at this stage.

🤖 AI-Assisted Development

[!NOTE]
This project was developed using an AI prompt–driven workflow.
Design and implementation were performed through iterative prompting without direct manual code edits,
with each step reviewed and refined by the developer.

🚀 Try It Out

No clone. No download. No project setup.
You can run MewUI immediately with a single command on Windows, Linux or macOS. (.NET 10 SDK required)

[!TIP]
This is the quickest way to try MewUI without going through the usual repository and project setup steps.

bash
curl -sL https://raw.githubusercontent.com/aprillz/MewUI/refs/heads/main/samples/FBASample/fba_gallery.cs -o - | dotnet run -

[!WARNING]
This command downloads and executes code directly from GitHub.

Video

https://github.com/user-attachments/assets/fc2d6ad8-3317-4784-a6e5-a00c68e9ed3b

Screenshots

Light	Dark

✨ Highlights

📦 NativeAOT + trimming first
🪶 Lightweight by design (small EXE, low memory footprint, fast first frame)
🧩 Fluent C# markup (no XAML)

🚀 Quickstart

NuGet: https://www.nuget.org/packages/Aprillz.MewUI/
- Aprillz.MewUI is a metapackage that bundles Core, all platform hosts, and all rendering backends.
- Platform-specific packages are also available: Aprillz.MewUI.Windows, .Linux, .MacOS
- Install: dotnet add package Aprillz.MewUI
- See: Installation & Packages

Single-file app (VS Code friendly)

See: samples/FBASample/fba_calculator.cs

Minimal header (without AOT/Trim options):

csharp
#:sdk Microsoft.NET.Sdk
#:property OutputType=Exe
#:property TargetFramework=net10.0

#:package Aprillz.MewUI@0.10.3

// ...

Run: dotnet run your_app.cs

🧪 C# Markup at a Glance

Sample source: https://github.com/aprillz/MewUI/blob/main/samples/MewUI.Sample/Program.cs

csharp
 var window = new Window()
     .Title("Hello MewUI")
     .Size(520, 360)
     .Padding(12)
     .Content(
         new StackPanel()
             .Spacing(8)
             .Children(
                 new Label()
                     .Text("Hello, Aprillz.MewUI")
                     .FontSize(18)
                     .Bold(),
                 new Button()
                     .Content("Quit")
                     .OnClick(() => Application.Quit())
             )
     );

 Application.Run(window);

🎯 Concept

MewUI is a code-first GUI framework with four priorities:

NativeAOT + trimming friendliness
Small footprint, fast startup, low memory usage
Fluent C# markup for building UI trees (no XAML)
AOT-friendly binding

Non-goals (by design):

WPF-style animations, visual effects, or heavy composition pipelines
A large, “kitchen-sink” control catalog (keep the surface area small and predictable)
Complex path-based data binding
Full XAML/WPF compatibility or designer-first workflows

✂️ NativeAOT / Trim

The library aims to be trimming-safe by default (explicit code paths, no reflection-based binding).
Windows interop uses source-generated P/Invoke (LibraryImport) for NativeAOT compatibility.
On Linux, building with NativeAOT requires the AOT workload in addition to the regular .NET SDK (e.g. install dotnet-sdk-aot-10.0).
If you introduce new interop or dynamic features, verify with the trimmed publish profile above.

To check output size locally:

Publish: dotnet publish .\samples\MewUI.Gallery\MewUI.Gallery.csproj -c Release -p:PublishProfile=win-x64-trimmed
Inspect: .artifacts\publish\MewUI.Gallery\win-x64-trimmed\

Reference (Aprillz.MewUI.Gallery.exe @v0.10.0)

win-x64: ~3,545 KB
osx-arm64: ~2,664 KB
linux-arm64: ~3939 KB

🔗 State & Binding (AOT-friendly)

Bindings are explicit and delegate-based (no reflection):

csharp
using Aprillz.MewUI.Binding;
using Aprillz.MewUI.Controls;

var percent = new ObservableValue<double>(
    initialValue: 0.25,
    coerce: v => Math.Clamp(v, 0, 1));

var slider = new Slider()
            .BindValue(percent);
var label  = new Label()
            .BindText(percent, v => $"Percent ({v:P0})");

🧱 Controls / Panels

Controls (Implemented):

Button, ToggleButton
Label, TextBlock, Image
TextBox, MultiLineTextBox, PasswordBox
CheckBox, RadioButton, ToggleSwitch
ComboBox, ListBox, TreeView, GridView
Slider, ProgressBar, ProgressRing, NumericUpDown
TabControl, GroupBox, Expander, Border
ColorPicker, DatePicker, Calendar
MenuBar, ContextMenu, ToolTip (in-window popups)
ScrollViewer
Window, DispatcherTimer

Panels:

Grid (rows/columns with Auto, *, pixel)
StackPanel (horizontal/vertical)
DockPanel (dock edges + last-child fill)
UniformGrid (equal cells)
WrapPanel (wrap + item size)
Canvas (absolute positioning)
SplitPanel (drag splitter)

All panels except Canvas (absolute) and SplitPanel support Spacing.

🧩 Extensions

Optional packages layered on top of the core - reference only what you need.

Extension	Description	Package
MewDock	Visual Studio style docking - document/tool tabs, drag rearranging, splits, auto-hide, maximize, popouts	`Aprillz.MewUI.MewDock`
SVG	Pure C# SVG parsing/rendering (no System.Drawing, AOT compatible)	`Aprillz.MewUI.Svg`
Skia	`SkiaCanvasView` (draw with SkiaSharp) + GPU zero-copy interop	`Aprillz.MewUI.Skia`
MewCharts	Charts (Cartesian/Pie/Polar) via the LiveChartsCore engine, no SkiaSharp dependency	`Aprillz.MewUI.MewCharts`
WebView2	Win32 WebView2 control (requires the Microsoft Edge WebView2 runtime, Windows only)	`Aprillz.MewUI.WebView2.Win32`

Skia interop - add the zero-copy bridge matching your backend to enable the GPU fast path.

Backend	Package
Direct2D	`Aprillz.MewUI.Skia.Interop.Direct2D`
GDI	`Aprillz.MewUI.Skia.Interop.Gdi`
MewVG / Win32	`Aprillz.MewUI.Skia.Interop.MewVG.Win32`
MewVG / X11	`Aprillz.MewUI.Skia.Interop.MewVG.X11`
MewVG / macOS	`Aprillz.MewUI.Skia.Interop.MewVG.MacOS`

Without an interop package, Skia content still renders via the CPU upload fallback. Skia is also bundled as metapackages Aprillz.MewUI.Skia.Windows / .Linux / .MacOS / .All.

MewDock is a C# port of FlexLayout (MIT). MewCharts bundles the LiveChartsCore engine (MIT). See THIRD_PARTY_NOTICES.md for license notices.

🎨 Theme

MewUI uses a Theme object (colors + metrics) and ThemeManager to control defaults and runtime changes.

Configure defaults before Application.Run(...) via ThemeManager.Default*
Change at runtime via Application.Current.SetTheme(...) / Application.Current.SetAccent(...)

See: docs/Theme.md

🖌️ Rendering Backends

Rendering is abstracted through:

IGraphicsFactory / IGraphicsContext

Backends:

Backend	Platform	Package
Direct2D	Windows	`Aprillz.MewUI.Backend.Direct2D`
GDI	Windows	`Aprillz.MewUI.Backend.Gdi`
MewVG	Windows	`Aprillz.MewUI.Backend.MewVG.Win32`
MewVG	Linux/X11	`Aprillz.MewUI.Backend.MewVG.X11`
MewVG	macOS	`Aprillz.MewUI.Backend.MewVG.MacOS`