ExtBit ProtoUI Reference Engine

Overview

ExtBit ProtoUI (.pui) is an ultra-lightweight, line-based declarative UI streaming protocol. This repository contains the official C++20 parsing and rendering engine built for Dear ImGui.

Engineered for zero-trust IPC, terminal toolchains, CLI utilities, and P2P networks (cpp-libp2p), this engine parses declarative streams incrementally in a single $O(N)$ zero-heap-allocation pass directly into immediate-mode render loops.

📖 Official Specification: For the formal EBNF grammar, widget reference, and P2P cryptographic attestation envelopes, please read the official specification: https://extbit.com/protoui

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Engine Features

• Zero-Allocation Parser: Written in C++20 using std::string_view slice evaluation, ensuring the parser runs without stalling high-frequency 60 FPS UI threads.
• Drop-In ImGui Integration: Renders natively into any existing Dear ImGui context without requiring complex layout abstractions.
• Reactive Event Dispatching: Event routing operators (->) stream widget state changes and user interactions directly to C++ lambda handlers.

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Integration & Build

Direct Source Inclusion (Recommended)

The easiest way to integrate ProtoUI into your existing ImGui application is to include the source directly in your build system (CMake, Make, etc.).

Add ProtoUI/include to your project’s header search paths and compile ProtoUI/src/ProtoUI.cpp alongside your project files.

#include <extbit/ProtoUI.h>

Building the Static Library (libProtoUI.a)

If you prefer to link statically:

cd ProtoUI
make IMGUI_DIR=/path/to/imgui

This outputs build/*.o object files and generates lib/libProtoUI.a.

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C++ API Quick Start

This engine is designed to wrap seamlessly inside your existing ImGui render loop. Use extbit::protoui::Context to ingest stream payloads and emit ImGui draw calls.

#include <extbit/ProtoUI.h>
#include <iostream>

extbit::protoui::Context uiContext;

void InitializeUI() {
    // 1. Bind native action callback for '->' event streams
    uiContext.onAction = [](std::string_view action, const extbit::protoui::StateValue& value) {
        if (action == "extbit:demo.click") {
            std::cout << "Button clicked natively!\n";
        }
    };

    // 2. Parse a minimal ProtoUI Stream
    uiContext.Parse(R"(
@protoui:v1
@title Hello ProtoUI
@kv Status | Engine Initialized
@button Run Diagnostic -> extbit:demo.click
    )");
}

void RenderFrame() {
    // 3. Call inside your main Dear ImGui frame loop
    ImGui::Begin("ProtoUI Window");
    uiContext.Render();
    ImGui::End();
}

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Project Status: Under Active Development (v0.1-alpha)

ExtBit ProtoUI is currently in active refinement alongside the ExtBit Console. The underlying DSL specification is stabilized, but C++ engine APIs and layout stack behaviors may undergo minor optimizations.

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License

ExtBit ProtoUI Reference Implementation is open-source software dual-licensed under the Apache License 2.0 and the MIT License. Copyright (c) 2026 ExtBit LLC. Created by Duzy Chan.