Refactor architecture for extensibility: configuration, protocols, and capability interfaces

[Copilot]

The project lacked extensibility—adding new projector models required hardcoded changes, duplicated serial handling, and tight coupling to BenQ-specific commands.

Changes

Configuration System

• ProjectorConfig with builder pattern decouples connection parameters from implementation
• Factory methods for common configurations (e.g., createBenQConfig())

Protocol Abstraction

• CommandProtocol interface separates command formatting from projector logic
• Implementations: BenQProtocol (\r*pow=on#\r), EpsonProtocol (PWR ON\r)
• Different terminators, charsets, and baud rates per vendor

Capability Interfaces

• PowerControl, SourceControl, CommandCapability define clear contracts
• Runtime capability discovery via instanceof checks
• Projectors implement only supported features

Factory Pattern

• ProjectorFactory centralizes creation with type-safe enum selection
• Multiple construction strategies: default port, custom port, custom config

Refactored Core

• Projector base class now uses dependency injection (config + protocol)
• W1070 implements capability interfaces, maintains backward compatibility
• EpsonGeneric demonstrates adding new projector type

Usage

// Factory-based creation
Projector projector = ProjectorFactory.createProjector(
    ProjectorType.BENQ_W1070, 
    "/dev/ttyUSB0"
);

// Capability checking
if (projector instanceof PowerControl) {
    ((PowerControl) projector).turnOn();
}

// Custom configuration
ProjectorConfig config = new ProjectorConfig.Builder()
    .portName("COM3")
    .baudRate(9600)
    .build();

Adding New Projector Types

Three steps:

1. Implement CommandProtocol (command format)
2. Extend Projector, implement capability interfaces
3. Add to ProjectorFactory enum

Time reduced from hours to minutes.

Documentation

• ARCHITECTURE.md: Design patterns, component relationships
• EXTENSIBILITY_EXAMPLES.md: Adding Sony, network-based projectors, custom capabilities
• ARCHITECTURE_DIAGRAM.md: Visual class structure and data flows

Original prompt

Analyse improvements to the generic structure (extensibility, how easy it would be to add another projector that might work a bit different) of the project!

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[APayerl]

do not include a Epson config. we want to be sure that it is correct before we add it (need to see specification!)

[APayerl]

generally in these situations use the java syntax to auto create a variable as well. "if (benq instanceof PowerControl pc) {" to get shorter syntax

[APayerl]

same here with "projector instanceof PowerControl pc)