dampen-core 0.2.4

Core parser, IR, and traits for Dampen UI framework
Documentation

Dampen

Crates.io Documentation License: MIT/Apache-2.0 Rust Version

Declarative UI framework for Rust with Iced backend, hot reloading and advanced styling.

Dampen allows you to define your user interface in XML and render it via Iced.

⚠️ DEVELOPMENT STATUS

Dampen is currently under active development and is NOT ready for production use.

The framework is functional and can be tested for experimentation, learning, and contributing to its development. However, the API is unstable and subject to breaking changes. Features may be incomplete, and there may be bugs or performance issues.

Use Dampen for:

  • ✅ Experimentation and learning
  • ✅ Contributing to development
  • ✅ Testing and providing feedback
  • ✅ Prototype applications

Do NOT use Dampen for:

  • ❌ Production applications
  • ❌ Mission-critical systems
  • ❌ Applications requiring API stability

We welcome your feedback and contributions! See CONTRIBUTING.md to get involved.

Features

  • ✅ Declarative XML definitions
  • ✅ Advanced styling system (themes, classes, state styles)
  • ✅ Responsive design with breakpoints (mobile, tablet, desktop)
  • ✅ Type-safe event handlers
  • ✅ Expression evaluation in XML attributes
  • ✅ Full Iced widget support (text, buttons, inputs, layouts, etc.)
  • ✅ Radio button groups with single-selection behavior
  • ✅ Data binding with #[derive(UiModel)]
  • ✅ CLI validation tools for syntax checking
  • ✅ Dual-mode architecture: Hot-reload for development, codegen for production
  • ✅ Hot-reload support: See UI changes instantly without recompiling

Installation

cargo install dampen-cli

Quick Start

Create a New Project

Use the CLI command to scaffold a new Dampen project:

# Create a new project
dampen new my-app

# Navigate to the project
cd my-app

# Run the application
dampen run

Add New UI Windows

NEW! Quickly scaffold new UI windows with the dampen add command:

# Add a settings window
dampen add --ui settings

# Add a window in custom directory
dampen add --ui order_form --path "src/ui/orders"

This creates:

  • settings.rs - Model, handlers, and AppState setup
  • settings.dampen - Basic UI layout with data binding example

Then add to src/ui/mod.rs:

pub mod settings;

Benefits:

  • ✅ Production-ready code in < 1 second
  • ✅ Consistent structure across windows
  • ✅ Prevents accidental overwrites
  • ✅ Reduces manual boilerplate

See dampen add --help for more options.

Project Structure

The dampen new command creates a complete project structure:

my-app/
├── Cargo.toml              # Project dependencies
├── README.md               # Getting started guide
├── build.rs                # Code generation (XML → Rust)
├── src/
│   ├── main.rs             # Application entry point
│   └── ui/
│       ├── mod.rs          # UI module exports
│       ├── window.rs       # Model and handlers with #[dampen_ui]
│       └── window.dampen   # Declarative UI definition (XML)
└── tests/
    └── integration.rs      # Integration tests

Key Files:

File Description
src/ui/window.dampen XML UI definition with widgets, bindings, handlers
src/ui/window.rs Model with #[derive(UiModel)], handler registry
src/main.rs Application orchestration (view, update)
build.rs Compiles .dampen files to Rust code

Generated UI Example:

<?xml version="1.0" encoding="UTF-8" ?>
<dampen>
    <column padding="40" spacing="20">
        <text value="Hello, Dampen!" size="32" weight="bold" />
        <button label="Click me!" on_click="greet" />
        <text value="{message}" size="24" />
    </column>
</dampen>

Project Validation

# Validate XML syntax and widget names
dampen check

# Build the project
dampen build

# Inspect generated IR
dampen inspect src/ui/window.dampen

Advanced Features

Data Binding

#[derive(UiModel, Default, Serialize, Deserialize, Clone)]
struct Model {
    count: i32,
    name: String,
    items: Vec<TodoItem>,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
struct TodoItem {
    id: usize,
    text: String,
    completed: bool,
}

Type-Safe Event Handlers

#[ui_handler]
fn increment(model: &mut Model) {
    model.count += 1;
}

#[ui_handler]
fn add_item(model: &mut Model, text: String) {
    model.items.push(TodoItem {
        id: model.next_id,
        text,
        completed: false,
    });
    model.next_id += 1;
}

#[ui_handler]
fn toggle_item(model: &mut Model, id: usize) {
    if let Some(item) = model.items.iter_mut().find(|i| i.id == id) {
        item.completed = !item.completed;
    }
}

Advanced Theming System

<themes>
    <theme name="light">
        <palette 
            primary="#3498db" 
            secondary="#2ecc71"
            background="#ecf0f1"
            text="#2c3e50" />
        <typography font_family="Inter, sans-serif" font_size_base="16" />
        <spacing unit="8" />
    </theme>
    
    <theme name="dark">
        <palette 
            primary="#5dade2" 
            secondary="#52be80"
            background="#2c3e50"
            text="#ecf0f1" />
        <typography font_family="Inter, sans-serif" font_size_base="16" />
        <spacing unit="8" />
    </theme>
</themes>

<global_theme name="light" />

Reusable Style Classes

<styles>
    <style name="btn_primary">
        <base
            background="#3498db"
            color="#ffffff"
            padding="8 16"
            border_radius="6"
            border_width="0" />
        <hover background="#5dade2" />
        <active background="#2874a6" />
        <disabled opacity="0.5" />
    </style>
    
    <style name="btn_danger">
        <base
            background="#e74c3c"
            color="#ffffff"
            padding="8 16"
            border_radius="6" />
        <hover background="#ec7063" />
    </style>
</styles>

<button class="btn_primary" label="Submit" on_click="submit" />
<button class="btn_danger" label="Delete" on_click="delete" />

Responsive Design with Breakpoints

<column 
    mobile:spacing="10"
    tablet:spacing="15"
    desktop:spacing="20">
    <text 
        mobile:size="18"
        desktop:size="32"
        value="Responsive text" />
</column>

Available Widgets

Widget Description Main Attributes
text Text display value, size, weight, color
button Interactive button label, on_click, enabled, class
text_input Text input field value, on_input, placeholder
checkbox Checkbox checked, on_toggle
toggler Toggle switch active, on_toggle, label
pick_list Dropdown list options, selected, on_select
radio Radio button label, value, selected, on_select
column Vertical layout spacing, padding, align
row Horizontal layout spacing, padding, align
scrollable Scrollable area width, height
container Container padding, width, height
for Dynamic loop each, in
grid Grid layout columns, spacing
progress_bar Progress bar min, max, value
svg SVG image path, width, height
tooltip Tooltip message, position

Dual-Mode Architecture

Dampen supports two compilation modes optimized for different use cases:

Interpreted Mode (Development)

Enabled by default in development builds

  • ✅ Fast iteration: Hot-reload UI changes without recompiling
  • ✅ Runtime parsing: XML loaded and parsed at application startup
  • ✅ Instant feedback: See changes in <300ms
  • ✅ Debugging friendly: Error overlays with detailed messages
# Development mode (automatic)
dampen run

# Explicit interpreted mode
dampen run --features interpreted

Hot-reload example:

use dampen_dev::watch_files;

fn subscription(app: &App) -> Subscription<Message> {
    watch_files(vec![PathBuf::from("src/ui/window.dampen")], "xml")
        .map(|_| Message::ReloadUI)
}

Codegen Mode (Production)

Enabled by default in release builds

  • ✅ Zero runtime overhead: All XML parsed at compile time
  • ✅ Optimal performance: Direct widget construction
  • ✅ Smaller binaries: No runtime parser included
  • ✅ Build-time validation: Catch errors before deployment
# Production build (automatic codegen)
dampen release

# Debug build with codegen
dampen build

How it works:

  1. build.rs processes .dampen files at compile time
  2. Generated Rust code embedded via macros
  3. No runtime XML parsing required

Mode Selection

Mode selection is automatic based on build profile:

CLI Command Mode Use Case
dampen new - Create new project
dampen add - Scaffold new UI window
dampen run Interpreted Development with hot-reload
dampen build Codegen Debug builds with codegen
dampen release Codegen Production deployments (optimized)
dampen test Interpreted Fast test iteration
dampen check - Validate XML syntax

Advanced usage:

# Enable additional features
dampen release --features tokio,logging

# Run tests in release mode
dampen test --release

# Verbose output
dampen build -v

Migration Guide

Migrating existing projects to dual-mode architecture? See our Migration Guide for step-by-step instructions.

Architecture

Crate Structure

crates/
├── dampen-core/           # XML parser, IR, traits (no Iced dependency)
├── dampen-macros/         # Macros #[derive(UiModel)], #[dampen_ui]
├── dampen-iced/           # Iced backend implementation
├── dampen-dev/            # Development mode tooling for Dampen
└── dampen-cli/            # Developer CLI (build, check, inspect)

Core Principles

  1. Declarative-First: XML is the source of truth for UI structure
  2. Type Safety: No type erasure for messages/state
  3. Production Mode: Static code generation for deployments
  4. Backend-Agnostic: Core crate has no Iced dependency
  5. Test-First: TDD for all features

Examples

See the examples/ directory for progressive demonstrations:

Example Features
hello-world Minimal static UI rendering
counter Interactive event handlers
todo-app Complete data binding with lists
styling Themes, classes, state styles
responsive Responsive design with breakpoints
settings Multiple views and navigation
widget-showcase Demonstration of all widgets

CLI Commands

# Generate production code
dampen build --ui ui --output src/ui_generated.rs

# Validate UI files without running
dampen check --ui ui

# Inspect IR or generated code
dampen inspect --file ui/main.dampen
dampen inspect --file ui/main.dampen --codegen --handlers increment,decrement

Documentation

Contributing

We welcome contributions from the community! Whether you're fixing bugs, adding features, improving documentation, or reporting issues, your help is appreciated.

Before contributing, please read our Contributing Guide which covers:

  • Code of conduct and community standards
  • Setting up your development environment
  • Coding standards and style guidelines
  • Testing requirements (TDD is mandatory)
  • Pull request process and commit message format
  • How to report issues and request features

Quick start for contributors:

# Fork and clone the repository
git clone https://github.com/YOUR_USERNAME/dampen.git
cd dampen

# Build and test
cargo build --workspace
cargo test --workspace
cargo clippy --workspace -- -D warnings

# Try the examples
dampen run -p hello-world

All contributions must:

  • ✅ Pass all tests (cargo test --workspace)
  • ✅ Pass clippy lints (cargo clippy --workspace -- -D warnings)
  • ✅ Be properly formatted (cargo fmt --all)
  • ✅ Include tests for new functionality
  • ✅ Update documentation as needed

See docs/CONTRIBUTING.md for complete details.

License

This project is dual-licensed under Apache 2.0 or MIT, at your option.

Built with ❤️ using Rust and Iced