highcharts
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JavaScript charting framework
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JavaScript
/* *
*
* Highcharts module with textPath functionality.
*
* (c) 2009-2024 Torstein Honsi
*
* License: www.highcharts.com/license
*
* !!!!!!! SOURCE GETS TRANSPILED BY TYPESCRIPT. EDIT TS FILE ONLY. !!!!!!!
*
* */
;
import H from '../Core/Globals.js';
import U from '../Core/Utilities.js';
const { deg2rad } = H;
const { addEvent, merge, uniqueKey, defined, extend } = U;
/**
* Set a text path for a `text` or `label` element, allowing the text to
* flow along a path.
*
* In order to unset the path for an existing element, call `setTextPath`
* with `{ enabled: false }` as the second argument.
*
* Text path support is not bundled into `highcharts.js`, and requires the
* `modules/textpath.js` file. However, it is included in the script files of
* those series types that use it by default
*
* @sample highcharts/members/renderer-textpath/ Text path demonstrated
*
* @function Highcharts.SVGElement#setTextPath
*
* @param {Highcharts.SVGElement|undefined} path
* Path to follow. If undefined, it allows changing options for the
* existing path.
*
* @param {Highcharts.DataLabelsTextPathOptionsObject} textPathOptions
* Options.
*
* @return {Highcharts.SVGElement} Returns the SVGElement for chaining.
*/
function setTextPath(path, textPathOptions) {
// Defaults
textPathOptions = merge(true, {
enabled: true,
attributes: {
dy: -5,
startOffset: '50%',
textAnchor: 'middle'
}
}, textPathOptions);
const url = this.renderer.url, textWrapper = this.text || this, textPath = textWrapper.textPath, { attributes, enabled } = textPathOptions;
path = path || (textPath && textPath.path);
// Remove previously added event
if (textPath) {
textPath.undo();
}
if (path && enabled) {
const undo = addEvent(textWrapper, 'afterModifyTree', (e) => {
if (path && enabled) {
// Set ID for the path
let textPathId = path.attr('id');
if (!textPathId) {
path.attr('id', textPathId = uniqueKey());
}
// Set attributes for the <text>
const textAttribs = {
// `dx`/`dy` options must by set on <text> (parent), the
// rest should be set on <textPath>
x: 0,
y: 0
};
if (defined(attributes.dx)) {
textAttribs.dx = attributes.dx;
delete attributes.dx;
}
if (defined(attributes.dy)) {
textAttribs.dy = attributes.dy;
delete attributes.dy;
}
textWrapper.attr(textAttribs);
// Handle label properties
this.attr({ transform: '' });
if (this.box) {
this.box = this.box.destroy();
}
// Wrap the nodes in a textPath
const children = e.nodes.slice(0);
e.nodes.length = 0;
e.nodes[0] = {
tagName: 'textPath',
attributes: extend(attributes, {
'text-anchor': attributes.textAnchor,
href: `${url}#${textPathId}`
}),
children
};
}
});
// Set the reference
textWrapper.textPath = { path, undo };
}
else {
textWrapper.attr({ dx: 0, dy: 0 });
delete textWrapper.textPath;
}
if (this.added) {
// Rebuild text after added
textWrapper.textCache = '';
this.renderer.buildText(textWrapper);
}
return this;
}
/**
* Attach a polygon to a bounding box if the element contains a textPath.
*
* @function Highcharts.SVGElement#setPolygon
*
* @param {any} event
* An event containing a bounding box object
*
* @return {Highcharts.BBoxObject} Returns the bounding box object.
*/
function setPolygon(event) {
const bBox = event.bBox, tp = this.element?.querySelector('textPath');
if (tp) {
const polygon = [], { b, h } = this.renderer.fontMetrics(this.element), descender = h - b, lineCleanerRegex = new RegExp('(<tspan>|' +
'<tspan(?!\\sclass="highcharts-br")[^>]*>|' +
'<\\/tspan>)', 'g'), lines = tp
.innerHTML
.replace(lineCleanerRegex, '')
.split(/<tspan class="highcharts-br"[^>]*>/), numOfLines = lines.length;
// Calculate top and bottom coordinates for
// either the start or the end of a single
// character, and append it to the polygon.
const appendTopAndBottom = (charIndex, positionOfChar) => {
const { x, y } = positionOfChar, rotation = (tp.getRotationOfChar(charIndex) - 90) * deg2rad, cosRot = Math.cos(rotation), sinRot = Math.sin(rotation);
return [
[
x - descender * cosRot,
y - descender * sinRot
],
[
x + b * cosRot,
y + b * sinRot
]
];
};
for (let i = 0, lineIndex = 0; lineIndex < numOfLines; lineIndex++) {
const line = lines[lineIndex], lineLen = line.length;
for (let lineCharIndex = 0; lineCharIndex < lineLen; lineCharIndex += 5) {
try {
const srcCharIndex = (i +
lineCharIndex +
lineIndex), [lower, upper] = appendTopAndBottom(srcCharIndex, tp.getStartPositionOfChar(srcCharIndex));
if (lineCharIndex === 0) {
polygon.push(upper);
polygon.push(lower);
}
else {
if (lineIndex === 0) {
polygon.unshift(upper);
}
if (lineIndex === numOfLines - 1) {
polygon.push(lower);
}
}
}
catch (e) {
// Safari fails on getStartPositionOfChar even if the
// character is within the `textContent.length`
break;
}
}
i += lineLen - 1;
try {
const srcCharIndex = i + lineIndex, charPos = tp.getEndPositionOfChar(srcCharIndex), [lower, upper] = appendTopAndBottom(srcCharIndex, charPos);
polygon.unshift(upper);
polygon.unshift(lower);
}
catch (e) {
// Safari fails on getStartPositionOfChar even if the character
// is within the `textContent.length`
break;
}
}
// Close it
if (polygon.length) {
polygon.push(polygon[0].slice());
}
bBox.polygon = polygon;
}
return bBox;
}
/**
* Draw text along a textPath for a dataLabel.
*
* @function Highcharts.SVGElement#setTextPath
*
* @param {any} event
* An event containing label options
*
* @return {void}
*/
function drawTextPath(event) {
const labelOptions = event.labelOptions, point = event.point, textPathOptions = (labelOptions[point.formatPrefix + 'TextPath'] ||
labelOptions.textPath);
if (textPathOptions && !labelOptions.useHTML) {
this.setTextPath(point.getDataLabelPath?.(this) || point.graphic, textPathOptions);
if (point.dataLabelPath &&
!textPathOptions.enabled) {
// Clean the DOM
point.dataLabelPath = (point.dataLabelPath.destroy());
}
}
}
function compose(SVGElementClass) {
addEvent(SVGElementClass, 'afterGetBBox', setPolygon);
addEvent(SVGElementClass, 'beforeAddingDataLabel', drawTextPath);
const svgElementProto = SVGElementClass.prototype;
if (!svgElementProto.setTextPath) {
svgElementProto.setTextPath = setTextPath;
}
}
const TextPath = {
compose
};
export default TextPath;