facett_graph/
lib.rs

1//! **facett-graph** — the graph (node/edge) viewer component, on
2//! [`facett_core`]. Build a [`Scene`] from a labelled edge list (the common
3//! shape: a graph query, a dataflow DAG) and draw it. Source-agnostic — the
4//! caller turns its Arrow/Cypher/whatever into edges first.
5
6use std::collections::{BTreeMap, HashMap};
7
8pub use facett_core::{Edge, Facet, FacetCaps, Layout, Node, Scene, Theme, draw, hash_color, set_theme, theme};
9
10mod depgraph;
11pub use depgraph::{DepEdge, DepGraphView, DepNode, draw_arrow};
12
13/// Build a [`Scene`] from a labelled edge list — each row is
14/// `(src_id, dst_id, src_label, dst_label)`. Distinct ids become nodes, coloured
15/// per label (FNV-hashed). The reusable "graph from edges" adapter korp's Graph
16/// and Pipelines views both want.
17pub fn scene_from_labeled_edges<I>(rows: I) -> Scene
18where
19    I: IntoIterator<Item = (i64, i64, String, String)>,
20{
21    let mut scene = Scene::new();
22    let mut idx: HashMap<i64, usize> = HashMap::new();
23    for (s, d, sl, dl) in rows {
24        let si = *idx.entry(s).or_insert_with(|| scene.node(sl.clone(), hash_color(&sl)));
25        let di = *idx.entry(d).or_insert_with(|| scene.node(dl.clone(), hash_color(&dl)));
26        scene.edge(si, di);
27    }
28    scene
29}
30
31/// A simple graph-view widget: a [`Scene`] + a [`Layout`]. Implements [`Facet`],
32/// so it drops into a `FacetDeck` and exposes `state_json` for free.
33pub struct GraphView {
34    pub scene: Scene,
35    pub layout: Layout,
36    pub empty_hint: String,
37    pub title: String,
38}
39
40impl GraphView {
41    pub fn new(scene: Scene) -> Self {
42        Self { scene, layout: Layout::default(), empty_hint: "empty".into(), title: "graph".into() }
43    }
44    pub fn empty_hint(mut self, hint: impl Into<String>) -> Self {
45        self.empty_hint = hint.into();
46        self
47    }
48    pub fn with_title(mut self, title: impl Into<String>) -> Self {
49        self.title = title.into();
50        self
51    }
52    pub fn show(&self, ui: &mut egui::Ui) {
53        draw(ui, &self.scene, self.layout, &self.empty_hint);
54    }
55    /// Per-label node counts (for the introspection).
56    pub fn label_counts(&self) -> BTreeMap<String, usize> {
57        let mut m = BTreeMap::new();
58        for n in &self.scene.nodes {
59            *m.entry(n.label.clone()).or_insert(0) += 1;
60        }
61        m
62    }
63}
64
65impl Facet for GraphView {
66    fn title(&self) -> &str {
67        &self.title
68    }
69    fn ui(&mut self, ui: &mut egui::Ui) {
70        self.show(ui);
71    }
72    fn state_json(&self) -> serde_json::Value {
73        serde_json::json!({
74            "nodes": self.scene.nodes.len(),
75            "edges": self.scene.edges.len(),
76            "labels": self.label_counts(),
77        })
78    }
79    /// Painted via [`draw`], which reads the active [`Theme`] (edges/labels/empty
80    /// hint) from the context; its canvas takes the host's `available_size`.
81    fn caps(&self) -> FacetCaps {
82        FacetCaps::NONE.themeable().resizable()
83    }
84}
85
86#[cfg(test)]
87mod tests {
88    use super::*;
89
90    #[test]
91    fn builds_scene_from_labeled_edges() {
92        let scene = scene_from_labeled_edges(vec![
93            (1, 2, "Person".into(), "Company".into()),
94            (1, 3, "Person".into(), "Address".into()),
95        ]);
96        assert_eq!(scene.nodes.len(), 3, "1, 2, 3 distinct");
97        assert_eq!(scene.edges.len(), 2);
98        assert_eq!(scene.nodes[0].label, "Person");
99    }
100}
facett_graph/lib.rs

facett_graph/
lib.rs
