bigbluebutton-Github/bigbluebutton-html5/imports/ui/components/whiteboard/annotations/triangle/component.jsx

import React, { Component } from 'react';
import PropTypes from 'prop-types';
import { getFormattedColor, getStrokeWidth, denormalizeCoord } from '../helpers';

export default class TriangleDrawComponent extends Component {
  shouldComponentUpdate(nextProps) {
    const { version } = this.props;
    return version !== nextProps.version;
  }

  getCoordinates() {
    const { slideWidth, slideHeight, annotation } = this.props;
    const { points } = annotation;

    const xApex = ((points[2] - points[0]) / 2) + points[0];
    const yApex = points[1];

    const path = `M${denormalizeCoord(xApex, slideWidth)
    },${denormalizeCoord(yApex, slideHeight)
    },${denormalizeCoord(points[0], slideWidth)
    },${denormalizeCoord(points[3], slideHeight)
    },${denormalizeCoord(points[2], slideWidth)
    },${denormalizeCoord(points[3], slideHeight)
    }Z`;

    return path;
  }

  render() {
    const path = this.getCoordinates();
    const { annotation, slideWidth } = this.props;
    const { fill } = annotation;
    return (
      <path
        style={{ WebkitTapHighlightColor: 'rgba(0, 0, 0, 0)' }}
        fill={ fill ? getFormattedColor(annotation.color) : "none" }
        stroke={getFormattedColor(annotation.color)}
        d={path}
        strokeWidth={getStrokeWidth(annotation.thickness, slideWidth)}
        strokeLinejoin="miter"
        data-test="drawnTriangle"
      />
    );
  }
}

TriangleDrawComponent.propTypes = {
  // Defines a version of the shape, so that we know if we need to update the component or not
  version: PropTypes.number.isRequired,
  // Defines an annotation object, which contains all the basic info we need to draw a triangle
  annotation: PropTypes.shape({
    points: PropTypes.arrayOf(PropTypes.number).isRequired,
    color: PropTypes.number.isRequired,
    thickness: PropTypes.number.isRequired,
    fill: PropTypes.bool.isRequired,
  }).isRequired,
  // Defines the width of the slide (svg coordinate system), which needed in calculations
  slideWidth: PropTypes.number.isRequired,
  // Defines the height of the slide (svg coordinate system), which needed in calculations
  slideHeight: PropTypes.number.isRequired,
};