Add Demo Helpers

evanplaice · evanplaice · commit fcab3bc202f6 · 2019-02-28T17:18:26.000-07:00
Includes:
- HTML5 File API check
- Sine graph point generator
diff --git a/examples/_helpers.js b/examples/_helpers.js
@@ -0,0 +1,36 @@
+function isFileAPIAvailable() {
+  // Check for the various File API support.
+  if (window.File && window.FileReader && window.FileList && window.Blob) {
+    // Great success! All the File APIs are supported.
+    return true;
+  } else {
+    // source: File API availability - http://caniuse.com/#feat=fileapi
+    // source: <output> availability - http://html5doctor.com/the-output-element/
+    document.writeln('The HTML5 APIs used in this form are only available in the following browsers:<br />');
+    // 6.0 File API & 13.0 <output>
+    document.writeln(' - Google Chrome: 13.0 or later<br />');
+    // 3.6 File API & 6.0 <output>
+    document.writeln(' - Mozilla Firefox: 6.0 or later<br />');
+    // 10.0 File API & 10.0 <output>
+    document.writeln(' - Internet Explorer: Not supported (partial support expected in 10.0)<br />');
+    // ? File API & 5.1 <output>
+    document.writeln(' - Safari: Not supported<br />');
+    // ? File API & 9.2 <output>
+    document.writeln(' - Opera: Not supported');
+    return false;
+  }
+}
+
+// Used to generate the data for the sine wave demo
+// source: http://coding.smashingmagazine.com/2011/10/04/quick-look-math-animations-javascript/
+function drawSine() {
+  var counter = 0;
+  // 100 iterations
+  var increase = Math.PI * 2 / 100;
+  for ( i = 0; i <= 1; i += 0.01 ) {
+    x = i;
+    y = Math.sin( counter ) / 2 + 0.5;
+    counter += increase;
+    console.log(x + ',' + y);
+  }
+}
