dom/canvas/test/test_toDataURL_parameters.html

   1 <!DOCTYPE HTML>
   2 <title>Canvas test: toDataURL parameters (Bug 564388)</title>
   3 <script src="/tests/SimpleTest/SimpleTest.js"></script>
   4 <link rel="stylesheet" href="/tests/SimpleTest/test.css">
   5 <body>
   6 <p>
   7 This test covers the JPEG and webp quality parameter. If (when) the HTML5 spec changes the
   8 allowed parameters for ToDataURL, new tests should go here.
   9 </p>
  10 <canvas id="c" width="100" height="100"><p class="fallback">FAIL (fallback content)</p></canvas>
  11 <script>
  12 let canvas = document.getElementById('c');
  13 let ctx = canvas.getContext("2d");
  14
  15 ctx.strokeStyle = '#FF0000';
  16 ctx.fillStyle = '#00FF00';
  17 ctx.fillRect(0, 0, 100, 100);
  18 ctx.beginPath();
  19 ctx.moveTo(10, 10);
  20 ctx.lineTo(90, 90);
  21 ctx.stroke();
  22
  23 let pngData = canvas.toDataURL('image/png');
  24 let pngQuality = canvas.toDataURL('image/png', 0.1);
  25 is(pngQuality, pngData, "Quality is not supported for PNG images");
  26
  27 function checkType(imagetype) {
  28     let imageTypeString = 'image/' + imagetype;
  29     let imageTypeUpperString = 'IMAGE/' + imagetype.toUpperCase();
  30     let data = canvas.toDataURL(imageTypeString);
  31     if (data.match(new RegExp('^data:image\/' + imagetype + '[;,]'))) {
  32         // Test the JPEG/wepb quality parameter
  33
  34         let fullQuality = canvas.toDataURL(imageTypeString, 1.0);
  35         let lowQuality = canvas.toDataURL(imageTypeString, 0.1);
  36         isnot(lowQuality, fullQuality, "A low quality (0.1) should differ from high quality (1.0) " + imageTypeString);
  37
  38         let medQuality = canvas.toDataURL(imageTypeString, 0.5);
  39         isnot(medQuality, fullQuality, "A medium quality (0.5) should differ from high (1.0) " + imageTypeString);
  40         isnot(medQuality, lowQuality, "A medium quality (0.5) should differ from low (0.5) " + imageTypeString);
  41
  42         let tooHigh = canvas.toDataURL(imageTypeString, 2.0);
  43         is(tooHigh, data, "Quality above 1.0 is treated as unspecified " + imageTypeString);
  44
  45         let tooLow = canvas.toDataURL(imageTypeString, -1.0);
  46         is(tooLow, data, "Quality below 0.0 is treated as unspecified " + imageTypeString);
  47
  48         let lowQualityExtra = canvas.toDataURL(imageTypeString, 0.1, 'foo', 'bar', null);
  49         is(lowQualityExtra, lowQuality, "Quality applies even if extra arguments are present " + imageTypeString);
  50
  51         let lowQualityUppercase = canvas.toDataURL(imageTypeUpperString, 0.1);
  52         is(lowQualityUppercase, lowQuality, "Quality applies to " + imageTypeString + " regardless of case");
  53
  54         let lowQualityString = canvas.toDataURL(imageTypeString, '0.1');
  55         isnot(lowQualityString, lowQuality, "Quality must be a number (should not be a string) " + imageTypeString);
  56     } else {
  57         ok(false, "should get a data url " + imageTypeString);
  58     }
  59 }
  60
  61 checkType('jpeg');
  62 checkType('webp');
  63 </script>