/*
* Copyright (C) 1998-2023 by Northwoods Software Corporation. All Rights Reserved.
*/
/*
* This is an extension and not part of the main GoJS library.
* Note that the API for this class may change with any version, even point releases.
* If you intend to use an extension in production, you should copy the code to your own source directory.
* Extensions can be found in the GoJS kit under the extensions or extensionsJSM folders.
* See the Extensions intro page (https://gojs.net/latest/intro/extensions.html) for more information.
*/
import * as go from '../release/go.js';
/**
* This custom {@link Link} class customizes its {@link Shape} to surround the comment node (the from node).
* If the Shape is filled, it will obscure the comment itself unless the Link is behind the comment node.
* Thus the default layer for BalloonLinks is "Background".
*
* The "corner" property controls the radius of the curves at the corners of the rectangular area surrounding the comment node,
* rather than the curve at corners along the route, which is always straight.
* The default value is 10.
*
* If you want to experiment with this extension, try the Balloon Links sample.
* @category Part Extension
*/
export class BalloonLink extends go.Link {
private _base: number = 15;
/**
* Constructs a BalloonLink and sets the {@link Part#layerName} property to "Background".
*/
constructor() {
super();
this.layerName = 'Background';
this.corner = 10;
this.defaultToPoint = new go.Point(0, 0);
}
/**
* Copies properties to a cloned BalloonLink.
*/
protected override cloneProtected(copy: this): void {
super.cloneProtected(copy);
copy._base = this._base;
}
/**
* Gets or sets width of the base of the triangle at the center point of the {@link Link#fromNode}.
*
* The default value is 15.
*/
get base(): number { return this._base; }
set base(value: number) { this._base = value; }
/**
* Produce a Geometry from the Link's route that draws a "balloon" shape around the {@link Link#fromNode}
* and has a triangular shape with the base at the fromNode and the top at the toNode.
*/
public override makeGeometry(): go.Geometry {
if (this.fromNode === null) return new go.Geometry();
// assume the fromNode is the comment and the toNode is the commented-upon node
const bb = this.fromNode.actualBounds.copy().addMargin(this.fromNode.margin);
let pn = this.pointsCount === 0 ? bb.center : this.getPoint(this.pointsCount - 1);
if (this.toNode !== null && bb.intersectsRect(this.toNode.actualBounds)) {
pn = this.toNode.actualBounds.center;
} else if (this.toNode === null && this.pointsCount === 0) {
pn = new go.Point(bb.centerX, bb.bottom + 50);
}
const base = Math.max(0, this.base);
const corner = Math.min(Math.max(0, this.corner), Math.min(bb.width/2, bb.height/2));
const cornerext = Math.min(base, corner + base/2);
const fig = new go.PathFigure();
let prevx = 0;
let prevy = 0;
// helper functions
function start(x: number, y: number) {
fig.startX = prevx = x;
fig.startY = prevy = y;
}
function point(x: number, y: number, v: number, w: number) {
fig.add(new go.PathSegment(go.PathSegment.Line, x, y));
fig.add(new go.PathSegment(go.PathSegment.Line, v, w));
prevx = v;
prevy = w;
}
function turn(x: number, y: number) {
if (prevx === x && prevy > y) { // top left
fig.add(new go.PathSegment(go.PathSegment.Line, x, y + corner));
fig.add(new go.PathSegment(go.PathSegment.Arc, 180, 90, x+corner, y+corner, corner, corner));
} else if (prevx < x && prevy === y) { // top right
fig.add(new go.PathSegment(go.PathSegment.Line, x - corner, y));
fig.add(new go.PathSegment(go.PathSegment.Arc, 270, 90, x-corner, y+corner, corner, corner));
} else if (prevx === x && prevy < y) { // bottom right
fig.add(new go.PathSegment(go.PathSegment.Line, x, y - corner));
fig.add(new go.PathSegment(go.PathSegment.Arc, 0, 90, x-corner, y-corner, corner, corner));
} else if (prevx > x && prevy === y) { // bottom left
fig.add(new go.PathSegment(go.PathSegment.Line, x + corner, y));
fig.add(new go.PathSegment(go.PathSegment.Arc, 90, 90, x+corner, y-corner, corner, corner));
} // else if prevx === x && prevy === y, no-op
prevx = x;
prevy = y;
}
if (pn.x < bb.left) {
if (pn.y < bb.top) {
start(bb.left, Math.min(bb.top + cornerext, bb.bottom - corner));
point(pn.x, pn.y, Math.min(bb.left + cornerext, bb.right - corner), bb.top);
turn(bb.right, bb.top); turn(bb.right, bb.bottom); turn(bb.left, bb.bottom);
} else if (pn.y > bb.bottom) {
start(Math.min(bb.left + cornerext, bb.right - corner), bb.bottom);
point(pn.x, pn.y, bb.left, Math.max(bb.bottom - cornerext, bb.top + corner));
turn(bb.left, bb.top); turn(bb.right, bb.top); turn(bb.right, bb.bottom);
} else { // pn.y >= bb.top && pn.y <= bb.bottom
const y = Math.min(Math.max(pn.y + base/3, bb.top + corner + base), bb.bottom - corner);
start(bb.left, y);
point(pn.x, pn.y, bb.left, Math.max(y-base, bb.top + corner));
turn(bb.left, bb.top); turn(bb.right, bb.top); turn(bb.right, bb.bottom); turn(bb.left, bb.bottom);
}
} else if (pn.x > bb.right) {
if (pn.y < bb.top) {
start(Math.max(bb.right - cornerext, bb.left + corner), bb.top);
point(pn.x, pn.y, bb.right, Math.min(bb.top + cornerext, bb.bottom - corner));
turn(bb.right, bb.bottom); turn(bb.left, bb.bottom); turn(bb.left, bb.top);
} else if (pn.y > bb.bottom) {
start(bb.right, Math.max(bb.bottom - cornerext, bb.top + corner));
point(pn.x, pn.y, Math.max(bb.right - cornerext, bb.left + corner), bb.bottom);
turn(bb.left, bb.bottom); turn(bb.left, bb.top); turn(bb.right, bb.top);
} else { // pn.y >= bb.top && pn.y <= bb.bottom
const y = Math.min(Math.max(pn.y + base/3, bb.top + corner + base), bb.bottom - corner);
start(bb.right, Math.max(y-base, bb.top + corner));
point(pn.x, pn.y, bb.right, y);
turn(bb.right, bb.bottom); turn(bb.left, bb.bottom); turn(bb.left, bb.top); turn(bb.right, bb.top);
}
} else { // pn.x >= bb.left && pn.x <= bb.right
const x = Math.min(Math.max(pn.x + base/3, bb.left + corner + base), bb.right - corner);
if (pn.y < bb.top) {
start(Math.max(x-base, bb.left + corner), bb.top);
point(pn.x, pn.y, x, bb.top);
turn(bb.right, bb.top); turn(bb.right, bb.bottom); turn(bb.left, bb.bottom); turn(bb.left, bb.top);
} else if (pn.y > bb.bottom) {
start(x, bb.bottom);
point(pn.x, pn.y, Math.max(x-base, bb.left + corner), bb.bottom);
turn(bb.left, bb.bottom); turn(bb.left, bb.top); turn(bb.right, bb.top); turn(bb.right, bb.bottom);
} else { // inside
start(bb.left, bb.top+bb.height/2);
// no "point", just corners
turn(bb.left, bb.top); turn(bb.right, bb.top); turn(bb.right, bb.bottom); turn(bb.left, bb.bottom);
}
}
const geo = new go.Geometry();
(fig.segments.last()).close();
geo.add(fig);
geo.offset(-this.routeBounds.x, -this.routeBounds.y);
return geo;
}
}