Architecture

This section covers Guido’s internal architecture for developers who want to understand how the library works or contribute to it.

System Overview

┌─────────────────────────────────────────────────────────────────┐
│                          Application                             │
│  ┌─────────────┐  ┌─────────────┐  ┌─────────────────────────┐  │
│  │   Widgets   │  │  Reactive   │  │       Platform          │  │
│  │  Container  │  │   Signals   │  │   Wayland Layer Shell   │  │
│  │    Text     │  │    Memo     │  │   Event Loop (calloop)  │  │
│  │   Layout    │  │   Effects   │  │                         │  │
│  └──────┬──────┘  └──────┬──────┘  └───────────┬─────────────┘  │
│         │                │                     │                 │
│         └────────────────┼─────────────────────┘                 │
│                          │                                       │
│                    ┌─────┴─────┐                                 │
│                    │  Renderer │                                 │
│                    │   wgpu    │                                 │
│                    │  glyphon  │                                 │
│                    └───────────┘                                 │
└─────────────────────────────────────────────────────────────────┘

Module Structure

In This Section

• System Overview - Module structure and key types
• Rendering Pipeline - How shapes and text are drawn
• Event System - Input event flow and handling

Key Design Decisions

Fine-Grained Reactivity

Guido uses signals rather than virtual DOM diffing. Widgets are created once; their properties update automatically through signal subscriptions.

Builder Pattern

All configuration uses the builder pattern with method chaining:

#![allow(unused)]
fn main() {
container()
    .padding(16.0)
    .background(Color::RED)
    .child(text("Hello"))
}

SDF Rendering

Shapes use Signed Distance Fields for resolution-independent rendering with crisp anti-aliasing at any scale.

Layer Shell Native

Guido is built specifically for Wayland layer shell, not as a general windowing toolkit with layer shell support added later.