egui_graphs

Graph visualization with rust, petgraph and egui in its DNA.

The project implements a Widget for the egui framework, enabling easy visualization of interactive graphs in rust. The goal is to implement the very basic engine for graph visualization within egui, which can be easily extended and customized for your needs.

• Visualization of any complex graphs;
• Zooming and panning;
• Node and Edge labels;
• Node and edges interactions and events reporting: click, double click, select, drag;
• Style configuration via egui context styles;
• Dark/Light theme support via egui context styles;
• Events reporting to extend the graph functionality by the user handling them;

Status

The project is on track for a stable release v1.0.0. For the moment, breaking releases are still possible.

Features

Events

Can be enabled with events feature. Events describe a change made in graph whether it changed zoom level or node dragging.

Combining this feature with custom node draw function allows to implement custom node behavior and drawing according to the events happening.

Egui crates features support

Persistence

To use egui persistence feature you need to enable egui_persistence feature of this crate. For example:

egui_graphs = { version = "0", features = ["egui_persistence"]}
egui = {version="0.23", features = ["persistence"]}

Examples

Basic setup example

Step 1: Setting up the BasicApp struct.

First, let's define the BasicApp struct that will hold the graph.

pub struct BasicApp {
    g: Graph<(), (), Directed>,
}

Step 2: Implementing the new() function.

Next, implement the new() function for the BasicApp struct.

impl BasicApp {
    fn new(_: &CreationContext<'_>) -> Self {
        let g = generate_graph();
        Self { g: Graph::from(&g) }
    }
}

Step 3: Generating the graph.

Create a helper function called generate_graph(). In this example, we create three nodes with and three edges connecting them in a triangular pattern.

fn generate_graph() -> StableGraph<(), (), Directed> {
    let mut g: StableGraph<(), ()> = StableGraph::new();

    let a = g.add_node(());
    let b = g.add_node(());
    let c = g.add_node(());

    g.add_edge(a, b, ());
    g.add_edge(b, c, ());
    g.add_edge(c, a, ());

    g
}

Step 4: Implementing the update() function.

Now, lets implement the update() function for the BasicApp. This function creates a GraphView widget providing a mutable reference to the graph, and adds it to egui::CentralPanel using the ui.add() function for adding widgets.

impl App for BasicApp {
    fn update(&mut self, ctx: &Context, _: &mut eframe::Frame) {
        egui::CentralPanel::default().show(ctx, |ui| {
            ui.add(&mut GraphView::<
                _,
                _,
                _,
                _,
                DefaultNodeShape,
                DefaultEdgeShape,
            >::new(&mut self.g));
        });
    }
}

Step 5: Running the application.

Finally, run the application using the run_native() function with the specified native options and the BasicApp.

fn main() {
    let native_options = eframe::NativeOptions::default();
    run_native(
        "egui_graphs_basic_demo",
        native_options,
        Box::new(|cc| Box::new(BasicApp::new(cc))),
    )
    .unwrap();
}

You can further customize the appearance and behavior of your graph by modifying the settings or adding more nodes and edges as needed.