jQuery toggleClass example

Toggle class name on click in jQuery

by Shakti Patel

HTML

<canvas id="canvas" width="550" height="500"></canvas>

JavaScript

const canvas = document.getElementById('canvas');
const ctx = canvas.getContext('2d');

const baselinesAboveAlphabetic = ['fontBoundingBoxAscent', 'actualBoundingBoxAscent', 
                   'emHeightAscent', 'hangingBaseline'];
const baselinesBelowAlphabetic = ['ideographicBaseline', 'emHeightDescent', 
                   'actualBoundingBoxDescent', 'fontBoundingBoxDescent'];
const baselines = [...baselinesAboveAlphabetic, ...baselinesBelowAlphabetic];
ctx.font = '25px serif';
ctx.strokeStyle = 'red';

baselines.forEach(function (baseline, index) {
  let text = 'Abcdefghijklmnop (' + baseline + ')';
  let textMetrics = ctx.measureText(text);
  let y = 50 + index * 50;
  ctx.beginPath();
  ctx.fillText(text, 0, y);
  let lineY = y - Math.abs(textMetrics[baseline]);
  if (baselinesBelowAlphabetic.includes(baseline)) {
      debugger;
    lineY = y + Math.abs(textMetrics[baseline]);
  }
  ctx.moveTo(0, lineY);
  ctx.lineTo(550, lineY);
  ctx.stroke();
  
});