wolf_graph_dot/
dot_encodable.rs

1use wolf_graph::prelude::*;
2
3use crate::{EdgeAttributes, GraphAttributes, GroupAttributes, NodeAttributes};
4
5// Docs: https://graphviz.org/doc/info/lang.html
6// Editor: http://magjac.com/graphviz-visual-editor/
7
8pub trait DotEncodable<GData, NData, EData>: VisitableGraph + Sized {
9    fn dot_graph_attributes(&self) -> Option<GraphAttributes> {
10        None
11    }
12
13    fn dot_node_attributes(&self, _node: &NodeID) -> Option<NodeAttributes> {
14        None
15    }
16
17    fn dot_edge_attributes(&self, _edge: &EdgeID) -> Option<EdgeAttributes> {
18        None
19    }
20
21    // This should only return `true` if the graph is a compound graph.
22    fn dot_is_compound(&self) -> bool {
23        false
24    }
25
26    // This returns the children of a group node, or the roots of the forest if `node` is `nil`.
27    fn dot_children(&self, _node: Option<&NodeID>) -> Nodes {
28        Nodes::new()
29    }
30
31    // Default implementation presumes that if a node has children, it is a group.
32    // Override if you wish to, for example, support empty groups.
33    fn dot_is_group(&self, node: &NodeID) -> bool {
34        !self.dot_children(Some(node)).is_empty()
35    }
36
37    fn dot_group_attributes(&self, _group: &NodeID) -> Option<GroupAttributes> {
38        None
39    }
40}
41
42pub trait DotFormat<GData, NData, EData>: DotEncodable<GData, NData, EData> {
43    fn dot_format(&self) -> String {
44        let mut lines = Vec::new();
45        format_graph(self, &mut lines);
46        format_lines(&lines)
47    }
48}
49
50// Blanket implementation of `DotFormat` for all types that implement `DotEncodable`.
51impl<GData, NData, EData, T> DotFormat<GData, NData, EData> for T where T: DotEncodable<GData, NData, EData> {}
52
53fn format_graph<GData, NData, EData>(
54    graph: &impl DotEncodable<GData, NData, EData>,
55    lines: &mut Vec<(usize, String)>
56) {
57    let indent = 0;
58
59    let graph_label = graph
60        .dot_graph_attributes()
61        .and_then(|attrs| attrs.label)
62        .unwrap_or_else(|| "G".to_string());
63    lines.push((indent, format!("digraph {} {{", graph_label)));
64    if graph.dot_is_compound() {
65        format_group(graph, lines, None, indent + 1);
66    } else {
67        format_nodes(graph, lines, &graph.all_nodes(), indent + 1);
68    }
69    format_edges(graph, lines, &graph.all_edges(), indent + 1);
70    lines.push((indent, "}".to_string()));
71}
72
73fn format_group<GData, NData, EData>(
74    graph: &impl DotEncodable<GData, NData, EData>,
75    lines: &mut Vec<(usize, String)>,
76    parent: Option<&NodeID>,
77    indent: usize
78) {
79    if let Some(attrs) = parent
80        .and_then(|parent| graph.dot_group_attributes(parent))
81        .and_then(|attributes| attributes.attributes(false))
82    {
83        lines.push((indent, attrs));
84    }
85    format_nodes(graph, lines, &graph.dot_children(parent), indent);
86}
87
88fn format_subgraph<GData, NData, EData>(graph: &impl DotEncodable<GData, NData, EData>, lines: &mut Vec<(usize, String)>, parent: &NodeID, indent: usize) {
89    lines.push((indent, format!("subgraph cluster_{} {{", parent)));
90    format_group(graph, lines, Some(parent), indent + 1);
91    lines.push((indent, "}".to_string()));
92}
93
94fn format_nodes<GData, NData, EData>(graph: &impl DotEncodable<GData, NData, EData>, lines: &mut Vec<(usize, String)>, nodes: &Nodes, indent: usize) {
95    for node in nodes {
96        if graph.dot_is_group(node) {
97            format_subgraph(graph, lines, node, indent);
98        } else {
99            format_leaf_node(graph, lines, node, indent);
100        }
101    }
102}
103
104fn format_leaf_node<GData, NData, EData>(graph: &impl DotEncodable<GData, NData, EData>, lines: &mut Vec<(usize, String)>, node: &NodeID, indent: usize) {
105    let mut line_components = vec![node.to_string()];
106    line_components.push(" ".to_string());
107    if let Some(attributes) = graph.dot_node_attributes(node) {
108        if let Some(attrs) = attributes.attributes() {
109            line_components.push(attrs);
110        }
111    }
112    lines.push((indent, line_components.join("")));
113}
114
115fn format_edges<GData, NData, EData>(graph: &impl DotEncodable<GData, NData, EData>, lines: &mut Vec<(usize, String)>, edges: &Edges, indent: usize) {
116    for edge in edges {
117        format_edge(graph, lines, edge, indent);
118    }
119}
120
121fn format_edge<GData, NData, EData>(graph: &impl DotEncodable<GData, NData, EData>, lines: &mut Vec<(usize, String)>, edge: &EdgeID, indent: usize) {
122    let mut line_components = vec![graph.source(edge).unwrap().to_string()];
123    line_components.push(" -> ".to_string());
124    line_components.push(graph.target(edge).unwrap().to_string());
125    line_components.push(" ".to_string());
126    if let Some(attributes) = graph.dot_edge_attributes(edge) {
127        if let Some(attrs) = attributes.attributes() {
128            line_components.push(attrs);
129        }
130    }
131    lines.push((indent, line_components.join("")));
132}
133
134fn format_lines(lines: &[(usize, String)]) -> String {
135    lines
136        .iter()
137        .map(|(indent, s)| format!("{}{}", " ".repeat(indent * 4), s))
138        .collect::<Vec<_>>()
139        .join("\n")
140}
wolf_graph_dot/dot_encodable.rs

wolf_graph_dot/
dot_encodable.rs
