Added a global UUID to cornerstone enabled elements to allow for easy…

… tracking of elements from other libraries (e.g. cornerstoneTools).

src/enable.js

@@ -4,6 +4,7 @@ import drawImageSync from './internal/drawImageSync.js';
 import requestAnimationFrame from './internal/requestAnimationFrame.js';
 import tryEnableWebgl from './internal/tryEnableWebgl.js';
 import triggerEvent from './triggerEvent.js';
+import generateUUID from './generateUUID.js';
 import EVENTS from './events.js';
 import getCanvas from './internal/getCanvas.js';
 
@@ -60,7 +61,8 @@ export default function (element, options) {
     options,
     layers: [],
     data: {},
-    renderingTools: {}
+    renderingTools: {},
+    uuid: generateUUID()
   };
 
   addEnabledElement(enabledElement);

src/generateUUID.js

@@ -0,0 +1,21 @@
+/**
+* Generates a UUID for the enabledElement.
+*
+* @return {String} the UUID.
+*/
+export default function () { // https://stackoverflow.com/a/8809472/9208320 Public Domain/MIT
+  /* eslint no-bitwise: ["error", { "allow": ["&","|"] }] */
+  let d = new Date().getTime();
+
+  if (typeof performance !== 'undefined' && typeof performance.now === 'function') {
+    d += performance.now(); // Use high-precision timer if available
+  }
+
+  return 'x.x.x.x.x.x.xxxx.xxx.x.x.xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'.replace(/[xy]/g, function (c) {
+    const r = (d + Math.random() * 16) % 16 | 0;
+
+    d = Math.floor(d / 16);
+
+    return (c === 'x' ? r : (r & 0x3 | 0x8)).toString(16);
+  });
+}