From e61a67134d8ba2c6363c951031456870be34f3cb Mon Sep 17 00:00:00 2001
From: Ivan Malopinsky <ivan@imsky.co>
Date: Sun, 25 Jan 2015 00:00:00 -0500
Subject: [PATCH] jsdoc for invisible image functions, polyfill for rAF

---
 src/holder.js    | 49 ++++++++++++++++++++++++++++++------------------
 src/polyfills.js | 32 +++++++++++++++++++++++++++++++
 2 files changed, 63 insertions(+), 18 deletions(-)

diff --git a/src/holder.js b/src/holder.js
index 49a8aa3..20d2222 100644
--- a/src/holder.js
+++ b/src/holder.js
@@ -869,28 +869,36 @@ Holder.js - client side image placeholders
         }
     }
 
-    //todo jsdoc
+    /**
+     * Iterates through all current invisible images, and if they're visible, renders them and removes them from further checks. Runs every animation frame.
+     *
+     * @private
+     */
     function visibilityCheck() {
-            var renderableImages = [];
-            var keys = Object.keys(App.vars.invisibleImages);
-            var el;
-            for (var i = 0, l = keys.length; i < l; i++) {
-                el = App.vars.invisibleImages[keys[i]];
-                if (dimensionCheck(el) && el.nodeName.toLowerCase() == 'img') {
-                    renderableImages.push(el);
-                    delete App.vars.invisibleImages[keys[i]];
-                }
+        var renderableImages = [];
+        var keys = Object.keys(App.vars.invisibleImages);
+        var el;
+        for (var i = 0, l = keys.length; i < l; i++) {
+            el = App.vars.invisibleImages[keys[i]];
+            if (dimensionCheck(el) && el.nodeName.toLowerCase() == 'img') {
+                renderableImages.push(el);
+                delete App.vars.invisibleImages[keys[i]];
             }
+        }
 
-            if (renderableImages.length) {
-                Holder.run({
-                    images: renderableImages
-                });
-            }
-            global.requestAnimationFrame(visibilityCheck);
+        if (renderableImages.length) {
+            Holder.run({
+                images: renderableImages
+            });
+        }
+        global.requestAnimationFrame(visibilityCheck);
     }
 
-    //todo jsdoc
+    /**
+     * Starts checking for invisible placeholders if not doing so yet. Does nothing otherwise.
+     *
+     * @private
+     */
     function startVisibilityCheck() {
         if (!App.vars.visibilityCheckStarted) {
             global.requestAnimationFrame(visibilityCheck);
@@ -898,7 +906,12 @@ Holder.js - client side image placeholders
         }
     }
 
-    //todo jsdoc
+    /**
+     * Sets a unique ID for an image detected to be invisible and adds it to the map of invisible images checked by visibilityCheck
+     *
+     * @private
+     * @param el Invisible DOM element
+     */
     function setInvisible(el) {
         if (!el.holderData.invisibleId) {
             App.vars.invisibleId += 1;
diff --git a/src/polyfills.js b/src/polyfills.js
index 1ce1ab2..79c7edb 100644
--- a/src/polyfills.js
+++ b/src/polyfills.js
@@ -257,3 +257,35 @@ if (!Object.prototype.hasOwnProperty){
 	}
     /*jshint +W001, +W103 */
 }
+
+//requestAnimationFrame polyfill for older Firefox/Chrome versions
+if (!window.requestAnimationFrame) {
+  if (window.webkitRequestAnimationFrame) {
+	//https://github.com/Financial-Times/polyfill-service/blob/master/polyfills/requestAnimationFrame/polyfill-webkit.js
+	(function (global) {
+	  // window.requestAnimationFrame
+	  global.requestAnimationFrame = function (callback) {
+		  return webkitRequestAnimationFrame(function () {
+			  callback(performance.now());
+		  });
+	  };
+	  
+	  // window.cancelAnimationFrame
+	  global.cancelAnimationFrame = webkitCancelAnimationFrame;
+	}(this));
+  } else if (window.mozRequestAnimationFrame) {
+	  //https://github.com/Financial-Times/polyfill-service/blob/master/polyfills/requestAnimationFrame/polyfill-moz.js
+	  (function (global) {
+		// window.requestAnimationFrame
+		global.requestAnimationFrame = function (callback) {
+			return mozRequestAnimationFrame(function () {
+				callback(performance.now());
+			});
+		};
+
+		// window.cancelAnimationFrame
+		global.cancelAnimationFrame = mozCancelAnimationFrame;
+
+	  }(this));
+  }
+}
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