1// Copyright 2014 the V8 project authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5import { GNode, MINIMUM_EDGE_SEPARATION, DEFAULT_NODE_BUBBLE_RADIUS } from "../src/node";
6import { Graph } from "./graph";
7
8const BEZIER_CONSTANT = 0.3;
9
10export class Edge {
11  target: GNode;
12  source: GNode;
13  index: number;
14  type: string;
15  backEdgeNumber: number;
16  visible: boolean;
17
18  constructor(target: GNode, index: number, source: GNode, type: string) {
19    this.target = target;
20    this.source = source;
21    this.index = index;
22    this.type = type;
23    this.backEdgeNumber = 0;
24    this.visible = false;
25  }
26
27  stringID() {
28    return this.source.id + "," + this.index + "," + this.target.id;
29  }
30
31  isVisible() {
32    return this.visible && this.source.visible && this.target.visible;
33  }
34
35  getInputHorizontalPosition(graph: Graph, showTypes: boolean) {
36    if (this.backEdgeNumber > 0) {
37      return graph.maxGraphNodeX + this.backEdgeNumber * MINIMUM_EDGE_SEPARATION;
38    }
39    const source = this.source;
40    const target = this.target;
41    const index = this.index;
42    const inputX = target.x + target.getInputX(index);
43    const inputApproach = target.getInputApproach(this.index);
44    const outputApproach = source.getOutputApproach(showTypes);
45    if (inputApproach > outputApproach) {
46      return inputX;
47    } else {
48      const inputOffset = MINIMUM_EDGE_SEPARATION * (index + 1);
49      return (target.x < source.x)
50        ? (target.x + target.getTotalNodeWidth() + inputOffset)
51        : (target.x - inputOffset);
52    }
53  }
54
55  generatePath(graph: Graph, showTypes: boolean) {
56    const target = this.target;
57    const source = this.source;
58    const inputX = target.x + target.getInputX(this.index);
59    const arrowheadHeight = 7;
60    const inputY = target.y - 2 * DEFAULT_NODE_BUBBLE_RADIUS - arrowheadHeight;
61    const outputX = source.x + source.getOutputX();
62    const outputY = source.y + source.getNodeHeight(showTypes) + DEFAULT_NODE_BUBBLE_RADIUS;
63    let inputApproach = target.getInputApproach(this.index);
64    const outputApproach = source.getOutputApproach(showTypes);
65    const horizontalPos = this.getInputHorizontalPosition(graph, showTypes);
66
67    let result: string;
68
69    if (inputY < outputY) {
70      result = `M ${outputX} ${outputY}
71                L ${outputX} ${outputApproach}
72                L ${horizontalPos} ${outputApproach}`;
73
74      if (horizontalPos != inputX) {
75        result += `L ${horizontalPos} ${inputApproach}`;
76      } else {
77        if (inputApproach < outputApproach) {
78          inputApproach = outputApproach;
79        }
80      }
81
82      result += `L ${inputX} ${inputApproach}
83                 L ${inputX} ${inputY}`;
84    } else {
85      const controlY = outputY + (inputY - outputY) * BEZIER_CONSTANT;
86      result = `M ${outputX} ${outputY}
87                C ${outputX} ${controlY},
88                  ${inputX} ${outputY},
89                  ${inputX} ${inputY}`;
90    }
91
92    return result;
93  }
94
95  isBackEdge() {
96    return this.target.hasBackEdges() && (this.target.rank < this.source.rank);
97  }
98
99}
100
101export const edgeToStr = (e: Edge) => e.stringID();
102