BBeOS/docs/PHASE_4_IMPLEMENTATION.md

Phase 4 Implementation Plan - UI Layer

🎯 Phase 4 Goals

Create a complete user interface layer for the BlackBerry Classic Q20 that provides:

• Display Server: Wayland-based compositor optimized for 720x720 display
• Application Framework: Keyboard-optimized application launcher and navigation
• Core Applications: Basic applications for productivity and system management
• User Experience: Intuitive keyboard navigation and trackpad support

📋 Implementation Tasks

1. Display Server Architecture (Week 1-2)

1.1 Wayland Compositor Development

• Basic Compositor Structure: Created q20-compositor.c with wlroots integration
• 720x720 Display Support: Configured for Q20's square display
• Keyboard Input Handling: Integrated keyboard event processing
• Trackpad Support: Add trackpad input handling
• Window Management: Implement window positioning and management
• Rendering Pipeline: Optimize rendering for ARMv7 performance

1.2 Display Integration

• DRM Integration: Connect compositor to Q20 display driver
• Hardware Acceleration: Enable GPU acceleration if available
• Display Modes: Support different refresh rates and power modes
• Backlight Control: Integrate with backlight driver

2. Application Framework (Week 2-3)

2.1 Home Screen Application

• Basic Structure: Created home-screen.c with Cairo rendering
• App Grid Layout: 4x4 grid optimized for 720x720 display
• Keyboard Navigation: Arrow key navigation between apps
• App Launcher: Implement application launching system
• Status Bar: System status, time, battery, network indicators
• Settings Integration: Quick access to system settings

2.2 Application Management

• App Registry: System for registering and managing applications
• App Icons: Standardized icon system for applications
• App Categories: Organize apps by category (System, Productivity, etc.)
• App Search: Keyboard-based application search

3. Core Applications (Week 3-4)

3.1 System Applications

• Terminal: Basic terminal emulator for system access
• Settings: System configuration and preferences
• File Manager: Basic file browser with keyboard navigation
• System Monitor: CPU, memory, battery status display

3.2 Productivity Applications

• Notes: Simple text editor for notes
• Calculator: Basic calculator application
• Calendar: Date and time management
• Contacts: Contact management system

4. User Experience (Week 4-5)

4.1 Keyboard Optimization

• Keyboard Shortcuts: Standardized keyboard shortcuts
• Function Keys: F1-F12 key assignments for common actions
• Modifier Keys: Ctrl, Alt, Shift combinations
• Navigation: Arrow keys, Tab, Enter, Escape handling

4.2 Trackpad Integration

• Cursor Movement: Trackpad to cursor mapping
• Click Actions: Left/right click handling
• Scroll Support: Vertical/horizontal scrolling
• Gesture Recognition: Basic gesture support

4.3 Visual Design

• Theme System: Configurable color schemes and themes
• Font System: Optimized fonts for small display
• Icons: Consistent icon design language
• Animations: Smooth transitions and feedback

🛠️ Technical Implementation

Display Server Architecture

// Core compositor structure
struct q20_server {
    struct wl_display *wl_display;
    struct wlr_backend *backend;
    struct wlr_renderer *renderer;
    struct wlr_compositor *compositor;
    struct wlr_seat *seat;
    struct wlr_output *output;
    
    // Q20-specific components
    struct wlr_keyboard *q20_keyboard;
    struct wlr_pointer *q20_trackpad;
    struct wlr_view *focused_view;
};

Application Framework

// Application structure
struct q20_app {
    char *name;
    char *command;
    char *icon_path;
    int category;
    bool system_app;
    
    // Launch function
    int (*launch)(struct q20_app *app);
};

UI Components

// UI component base structure
struct q20_ui_component {
    int x, y, width, height;
    bool focused;
    bool visible;
    
    // Event handlers
    void (*draw)(struct q20_ui_component *comp, cairo_t *cr);
    void (*handle_key)(struct q20_ui_component *comp, uint32_t key);
    void (*handle_click)(struct q20_ui_component *comp, int x, int y);
};

📁 File Structure

ui/
├── compositor/
│   ├── q20-compositor.c          # Main compositor
│   ├── window-manager.c          # Window management
│   └── input-handler.c           # Input processing
├── applications/
│   ├── home-screen.c             # Main home screen
│   ├── terminal.c                # Terminal emulator
│   ├── settings.c                # Settings application
│   ├── file-manager.c            # File browser
│   ├── calculator.c              # Calculator app
│   ├── notes.c                   # Notes editor
│   └── calendar.c                # Calendar app
├── framework/
│   ├── app-manager.c             # Application management
│   ├── theme-engine.c            # Theme system
│   ├── keyboard-handler.c        # Keyboard processing
│   └── trackpad-handler.c        # Trackpad processing
└── assets/
    ├── icons/                    # Application icons
    ├── themes/                   # Theme files
    └── fonts/                    # Font files

🔧 Build System

Dependencies

• Wayland: Display server protocol
• wlroots: Wayland compositor library
• Cairo: 2D graphics library
• Pango: Text layout and rendering
• xkbcommon: Keyboard handling

Build Process

# Build UI components
./scripts/build-ui.sh

# Install to rootfs
make -C ui install

# Test on target
./scripts/flash-boot.sh

🧪 Testing Strategy

Unit Testing

• Compositor Tests: Test window management and rendering
• Input Tests: Test keyboard and trackpad input handling
• Application Tests: Test individual applications
• Integration Tests: Test complete UI system

Hardware Testing

• Display Testing: Verify 720x720 output on Q20
• Input Testing: Test keyboard and trackpad on actual hardware
• Performance Testing: Measure UI responsiveness
• Memory Testing: Monitor memory usage and leaks

User Testing

• Navigation Testing: Test keyboard navigation flow
• Usability Testing: Test application usability
• Accessibility Testing: Test for accessibility features

📊 Success Metrics

Phase 4 Goals

• Display Server: Wayland compositor running on Q20
• Home Screen: Functional app launcher with keyboard navigation
• Core Apps: At least 4 basic applications working
• Input System: Keyboard and trackpad fully functional
• Performance: UI responsive within 100ms

Quality Metrics

• Code Coverage: >80% test coverage
• Memory Usage: <50MB total UI memory usage
• Startup Time: <5 seconds to usable home screen
• Battery Impact: <10% additional battery drain

🚀 Next Steps

Immediate Priorities

1. Build and Test: Build current UI components and test on hardware
2. Display Integration: Connect compositor to Q20 display driver
3. Input Integration: Connect keyboard and trackpad drivers
4. Application Development: Develop core applications

Phase 5 Preparation

• Telephony Integration: Prepare for phone functionality
• Network Stack: Prepare for Wi-Fi and cellular integration
• Security Framework: Prepare for application sandboxing
• Update System: Prepare for OTA updates

📚 Documentation

Developer Documentation

• UI Architecture Guide: Complete architecture documentation
• Application Development Guide: How to create Q20 applications
• Theme Development Guide: How to create themes
• API Reference: Complete API documentation

User Documentation

• User Manual: Complete user guide
• Keyboard Shortcuts: Reference for all shortcuts
• Troubleshooting Guide: Common issues and solutions

🎯 Phase 4 Deliverables

Software Components

• Q20 Compositor: Wayland-based display server
• Home Screen: Application launcher and navigation
• Core Applications: Terminal, Settings, File Manager, Calculator
• UI Framework: Application management and theme system

Documentation

• Implementation Plan: This document
• Architecture Guide: Technical architecture documentation
• User Guide: End-user documentation
• Developer Guide: Application development guide

Testing Infrastructure

• Unit Tests: Automated testing for UI components
• Integration Tests: End-to-end UI testing
• Performance Tests: UI performance benchmarking

🔄 Iteration Plan

Week 1: Foundation

• Build and test basic compositor
• Implement keyboard input handling
• Create basic home screen

Week 2: Core Functionality

• Add trackpad support
• Implement window management
• Develop first core application

Week 3: Applications

• Develop remaining core applications
• Implement application launcher
• Add status bar functionality

Week 4: Polish

• Implement theme system
• Add animations and transitions
• Optimize performance

Week 5: Testing

• Comprehensive testing on hardware
• Bug fixes and optimizations
• Documentation completion

This implementation plan provides a structured approach to developing a complete UI layer for the BBeOS project, ensuring we create a functional and user-friendly interface for the BlackBerry Classic Q20.