Isolate window dependency on boot

maxwellito · May 2, 2017 · 115e88f · 115e88f
1 parent 5ddb348
commit 115e88f
Showing 1 changed file with 50 additions and 40 deletions.
diff --git a/src/vivus.js b/src/vivus.js
@@ -52,6 +52,8 @@ var requestAnimFrame, cancelAnimFrame, parsePositiveInt;
  */
 function Vivus (element, options, callback) {
 
+  setupEnv();
+
   // Setup
   this.isReady = false;
   this.setElement(element, options);
@@ -685,12 +687,6 @@ Vivus.prototype.isInViewport = function (el, h) {
   return (elTop + elHeight * h) <= viewed && (elBottom) >= scrolled;
 };
 
-/**
- * Alias for document element
- *
- * @type {DOMelement}
- */
-Vivus.prototype.docElem = window.document.documentElement;
 
 /**
  * Get the viewport height in pixels
@@ -718,41 +714,55 @@ Vivus.prototype.scrollY = function () {
   return window.pageYOffset || this.docElem.scrollTop;
 };
 
-/**
- * Alias for `requestAnimationFrame` or
- * `setTimeout` function for deprecated browsers.
- *
- */
-requestAnimFrame = (function () {
-  return (
-    window.requestAnimationFrame       ||
-    window.webkitRequestAnimationFrame ||
-    window.mozRequestAnimationFrame    ||
-    window.oRequestAnimationFrame      ||
-    window.msRequestAnimationFrame     ||
-    function(/* function */ callback){
-      return window.setTimeout(callback, 1000 / 60);
-    }
-  );
-})();
+var setupEnv = function () {
 
-/**
- * Alias for `cancelAnimationFrame` or
- * `cancelTimeout` function for deprecated browsers.
- *
- */
-cancelAnimFrame = (function () {
-  return (
-    window.cancelAnimationFrame       ||
-    window.webkitCancelAnimationFrame ||
-    window.mozCancelAnimationFrame    ||
-    window.oCancelAnimationFrame      ||
-    window.msCancelAnimationFrame     ||
-    function(id){
-      return window.clearTimeout(id);
-    }
-  );
-})();
+  if (Vivus.prototype.docElem) {
+    return;
+  }
+
+  /**
+   * Alias for document element
+   *
+   * @type {DOMelement}
+   */
+  Vivus.prototype.docElem = window.document.documentElement;
+
+  /**
+   * Alias for `requestAnimationFrame` or
+   * `setTimeout` function for deprecated browsers.
+   *
+   */
+  requestAnimFrame = (function () {
+    return (
+      window.requestAnimationFrame       ||
+      window.webkitRequestAnimationFrame ||
+      window.mozRequestAnimationFrame    ||
+      window.oRequestAnimationFrame      ||
+      window.msRequestAnimationFrame     ||
+      function(/* function */ callback){
+        return window.setTimeout(callback, 1000 / 60);
+      }
+    );
+  })();
+
+  /**
+   * Alias for `cancelAnimationFrame` or
+   * `cancelTimeout` function for deprecated browsers.
+   *
+   */
+  cancelAnimFrame = (function () {
+    return (
+      window.cancelAnimationFrame       ||
+      window.webkitCancelAnimationFrame ||
+      window.mozCancelAnimationFrame    ||
+      window.oCancelAnimationFrame      ||
+      window.msCancelAnimationFrame     ||
+      function(id){
+        return window.clearTimeout(id);
+      }
+    );
+  })();
+}
 
 /**
  * Parse string to integer.