QtNodes

Introduction

QtNodes is conceived as a general-purpose Qt-based library aimed at developing Node Editors for various applications. The library could be used for simple graph visualization and editing or extended further for using the Dataflow paradigm .

The library is written using the Model-View approach. The whole graph structure is defined by the user-provided class deriving from AbstractGraphModel class. It is possible to create or add Nodes and Connections. The underlying data structures could be of any arbitrary type or representation.

An instance of AbstractGraphModel could or could not be attached to specialized QGraphicsScene and QGraphicsView objects. I.e. the so-called "headless" modus operandi is possible.

Navigation

• Introduction
• Data Flow Paradigm
• Supported Environments
  • Platforms
  • Dependencies
• Current State
• Building
  • Linux
  • Qt Creator
• Version 3 Roadmap
• Contributing
• Citing
• Support
• Showcase
  • Youtube videos
  • CANdevStudio
  • Chigraph
  • Spkgen particle editor

Data Flow Paradigm

The extended model class DataFlowGraphModel allows to register "processing algorithms" represented by nodes and is equipped with a set of Qt's signals and slots for propagating the data though the nodes.

The node's algorithm is triggered upon arriving of any new input data. The computed result is propagated to the output connections. Each new connection fetches available data and propagates is further. Each change in the source node is immediately propagated through all the connections updating the whole graph.

Supported Environments

Platforms

• Linux (x64, gcc-7.0, clang-7)
• OSX (Apple Clang - LLVM 3.6)

• Windows (Win32, x64, msvc2017, MinGW 5.3)

Dependencies

• Qt >5.2
• CMake 3.2
• Catch2

Current State

• Model-based nodes
• Automatic data propagation
• Datatype-aware connections
• Embedded Qt widgets
• One-output to many-input connections
• JSON-based interface styles
• Saving scenes to JSON files

Building

Linux

git clone git@github.com:paceholder/nodeeditor.git
cd nodeeditor
mkdir build
cd build
cmake ..
make -j && make install

Qt Creator

1. Open CMakeLists.txt as project.
2. If you don't have the Catch2 library installed, go to Build Settings, disable the checkbox BUILD_TESTING.
3. Build -> Run CMake
4. Build -> Build All
5. Click the button Run

Version 3 Roadmap

1. Headless mode. [done] You can create, populate, modify the derivative of AbstractGraphModel without adding it to the actual Flow Scene. The library is now designed to be general-purpose graph visualization and modification tool, without specialization on only data propagation.
2. Build data propagation on top of the graph code [done].
   1. Fix old unit-tests. [in progress].
   2. Fix save/restore. [done].
   3. Fix CI scriptst on travis and appveyor. [partially done].
3. Backward compatibility with Qt5 [not started/help needed].
4. Write improved documentation based on Sphynx platform [done].
5. Extend set of examples [partially done].
6. Undo Redo [done].
7. Delegate Node Painter [not started].
8. Vertical Node/Connection Layout.
9. Python wrappring using PySide [HELP NEEDED].
10. Implement grouping nodes [not started].

Any suggestions are welcome!

Contributing

1. Be polite, respectful and collaborative.

2. For submitting a bug:

   1. Describe your environment (Qt version, compiler, OS etc)
   2. Describe steps to reproduce the issue

3. For submitting a pull request:

   1. Create a proposal task first. We can come up with a better design together.

   2. Create a pull-request. If applicable create a simple example to your

      iescribe your problem in details, provide use cases,

4. For submitting a development request:

   1. Describe your issue in details
   2. Provide some use cases.

5. I maintain this probject in my free time, when I am not busy with my work or my family. If I do not react or do not answer for too long, please ping me.

Citing

Dmitry Pinaev et al, Qt Node Editor, (2017), GitHub repository, https://github.com/paceholder/nodeeditor

BibTeX:

@misc{Pinaev2017,
  author = {Dmitry Pinaev et al},
  title = {QtNodes. Node Editor},
  year = {2017},
  publisher = {GitHub},
  journal = {GitHub repository},
  howpublished = {\url{https://github.com/paceholder/nodeeditor}},
  commit = {1d1757d09b03cea0e4921bc19659465fe6e65b9b}
}

Support

If you like the project you could donate me on PayPal

If you send more than $100, I'll forward $100 to some fund supporting sick children and report to you back.

Showcase

Youtube videos

CANdevStudio

CANdevStudio is a cost-effective, cross-platform replacement for CAN simulation software. CANdevStudio enables to simulate CAN signals such as ignition status, doors status or reverse gear by every automotive developer. Thanks to modularity it is easy to implement new, custom features.

Chigraph

Chigraph is a visual programming language for beginners that is unique in that it is an intuitive flow graph:

It features easy bindings to C/C++, package management, and a cool interface.

Spkgen particle editor

Spkgen is an editor for the SPARK particles engine that uses a node-based interface to create particles effects for games