Merge branch 'FLUID-6180'

* FLUID-6180:
  FLUID-6180: Cleaning up getClosestPanelIndex function.
  FLUID-6180: Adding debounce delay to options.
  FLUID-6180: using fluid.debounce for scroll event
  FLUID-6180: Adding debounce function to infusion
  FLUID-6180: Renamed source from "manualScroll" to "scrollEvent"
  FLUID-6180: Correcting typo
  FLUID-6180: Adding unit tests
  FLUID-6180: Adding in perstence for manual scrolling.

src/framework/core/js/Fluid.js

@@ -23,6 +23,11 @@ Licenses.
 
 You may obtain a copy of the ECL 2.0 License and BSD License at
 https://github.com/fluid-project/infusion/raw/master/Infusion-LICENSE.txt
+
+Includes code from Underscore.js 1.4.3
+http://underscorejs.org
+(c) 2009-2012 Jeremy Ashkenas, DocumentCloud Inc.
+Underscore may be freely distributed under the MIT license.
 */
 
 /* global console */
@@ -859,6 +864,35 @@ var fluid = fluid || fluid_3_0_0;
         }
     };
 
+    /**
+     * Copied from Underscore.js 1.4.3 - see licence at head of this file
+     *
+     * Will execute the passed in function after the specified about of time since it was last executed.
+     * @param {Function} func - the function to execute
+     * @param {Number} wait - the number of milliseconds to wait before executing the function
+     * @param {Boolean} immediate - Whether to trigger the function at the start (true) or end (false) of
+     *                              the wait interval.
+     */
+    fluid.debounce = function (func, wait, immediate) {
+        var timeout, result;
+        return function () {
+            var context = this, args = arguments;
+            var later = function () {
+                timeout = null;
+                if (!immediate) {
+                    result = func.apply(context, args);
+                }
+            };
+            var callNow = immediate && !timeout;
+            clearTimeout(timeout);
+            timeout = setTimeout(later, wait);
+            if (callNow) {
+                result = func.apply(context, args);
+            }
+            return result;
+        };
+    };
+
     /** Calls Object.freeze at each level of containment of the supplied object
      * @return The supplied argument, recursively frozen
      */

src/framework/preferences/js/ArrowScrolling.js

@@ -27,12 +27,14 @@ var fluid_3_0_0 = fluid_3_0_0 || {};
             // panels: "", // should be supplied by the fluid.prefs.prefsEditor grade.
             scrollContainer: ".flc-prefsEditor-scrollContainer"
         },
+        onScrollDelay: 100, // in ms, used to set the delay for debouncing the scroll event relay
         model: {
             // panelMaxIndex: null, // determined by the number of panels calculated after the onPrefsEditorMarkupReady event fired
             panelIndex: 0
         },
         events: {
-            beforeReset: null // should be fired by the fluid.prefs.prefsEditor grade
+            beforeReset: null, // should be fired by the fluid.prefs.prefsEditor grade
+            onScroll: null
         },
         modelRelay: {
             target: "panelIndex",
@@ -49,10 +51,23 @@ var fluid_3_0_0 = fluid_3_0_0 || {};
             "panelIndex": {
                 listener: "fluid.prefs.arrowScrolling.scrollToPanel",
                 args: ["{that}", "{change}.value"],
+                excludeSource: ["scrollEvent"],
                 namespace: "scrollToPanel"
             }
         },
         listeners: {
+            "onReady.scrollEvent": {
+                "this": "{that}.dom.scrollContainer",
+                method: "scroll",
+                args: [{
+                    expander: {
+                        // Relaying the scroll event to onScroll but debounced to reduce the rate of fire.  A high rate
+                        // of fire may negatively effect performance for complex handlers.
+                        func: "fluid.debounce",
+                        args: ["{that}.events.onScroll.fire", "{that}.options.onScrollDelay"]
+                    }
+                }]
+            },
             "onReady.windowResize": {
                 "this": window,
                 method: "addEventListener",
@@ -77,6 +92,16 @@ var fluid_3_0_0 = fluid_3_0_0 || {};
             "beforeReset.resetPanelIndex": {
                 listener: "{that}.applier.fireChangeRequest",
                 args: {path: "panelIndex", value: 0, type: "ADD", source: "reset"}
+            },
+            "onScroll.setPanelIndex": {
+                changePath: "panelIndex",
+                value: {
+                    expander: {
+                        funcName: "fluid.prefs.arrowScrolling.getClosestPanelIndex",
+                        args: "{that}.dom.panels"
+                    }
+                },
+                source: "scrollEvent"
             }
         },
         invokers: {
@@ -95,7 +120,6 @@ var fluid_3_0_0 = fluid_3_0_0 || {};
             },
             target: "{that > fluid.prefs.panel}.options.listeners"
         }]
-
     });
 
     fluid.prefs.arrowScrolling.calculatePanelMaxIndex = function (panels) {
@@ -118,4 +142,17 @@ var fluid_3_0_0 = fluid_3_0_0 || {};
         }
     };
 
+    fluid.prefs.arrowScrolling.getClosestPanelIndex = function (panels) {
+        var panelArray = fluid.transform(panels, function (panel, idx) {
+            return {
+                index: idx,
+                offset: Math.abs($(panel).offset().left)
+            };
+        });
+        panelArray.sort(function (a, b) {
+            return a.offset - b.offset;
+        });
+        return fluid.get(panelArray, ["0", "index"]) || 0;
+    };
+
 })(jQuery, fluid_3_0_0);

tests/framework-tests/core/js/FluidJSTests.js

@@ -307,6 +307,27 @@ https://github.com/fluid-project/infusion/raw/master/Infusion-LICENSE.txt
         });
     });
 
+    fluid.tests.debounceTests = [1, 2, 3, 4 ,5];
+
+    jqUnit.asyncTest("fluid.debounce", function () {
+        var result = {};
+        var lead = fluid.debounce(function (val) {
+            result.lead = val;
+        }, 3, true);
+        var trail = fluid.debounce(function (val) {
+            result.trail = val;
+        }, 3);
+
+        setTimeout(function () {
+            jqUnit.assertEquals("The first value should be returned when accepting the leading response", fluid.tests.debounceTests[0], result.lead);
+            jqUnit.assertEquals("The last value should be returned when accepting the trailing response", fluid.tests.debounceTests[4], result.trail);
+            jqUnit.start();
+        }, 5);
+
+        fluid.each(fluid.tests.debounceTests, lead);
+        fluid.each(fluid.tests.debounceTests, trail);
+    });
+
     jqUnit.test("merge", function () {
         jqUnit.expect(8);
 

tests/framework-tests/preferences/js/SeparatedPanelPrefsEditorResponsiveTests.js

@@ -182,6 +182,8 @@ https://github.com/fluid-project/infusion/raw/master/Infusion-LICENSE.txt
                 jqUnit.assertNotEquals(testName + ": The panel at index " + idx + " should not be scrolled into view and have an offset greater or less than 0", 0, panelOffset);
             }
         });
+
+        jqUnit.assertEquals("fluid.prefs.arrowScrolling.getClosestPanelIndex should return " + panelIndex, panelIndex, fluid.prefs.arrowScrolling.getClosestPanelIndex(panels));
     };
 
     fluid.tests.prefs.responsive.clickArrow = function (elm, direction) {
@@ -212,7 +214,7 @@ https://github.com/fluid-project/infusion/raw/master/Infusion-LICENSE.txt
         modules: [{
             name: "Separated panel integration tests",
             tests: [{
-                expect: 70,
+                expect: 77,
                 name: "Separated panel integration tests",
                 sequenceGrade: "fluid.tests.prefs.responsive.iframeSequence",
                 sequence: [{
@@ -265,6 +267,13 @@ https://github.com/fluid-project/infusion/raw/master/Infusion-LICENSE.txt
                     listener: "jqUnit.assert",
                     event: "{separatedPanel}.prefsEditor.events.onSignificantDOMChange",
                     args: ["A window resize event triggered the onSignificantDOMChange event"]
+                }, {
+                    jQueryTrigger: "scroll",
+                    element: "{separatedPanel}.prefsEditor.dom.scrollContainer"
+                }, {
+                    listener: "jqUnit.assert",
+                    event: "{separatedPanel}.prefsEditor.events.onScroll",
+                    args: ["A scroll event triggered the onScroll event"]
                 }]
             }]
         }]
@@ -305,7 +314,7 @@ https://github.com/fluid-project/infusion/raw/master/Infusion-LICENSE.txt
         modules: [{
             name: "Separated panel initial panelIndex tester",
             tests: [{
-                expect: 39,
+                expect: 40,
                 name: "Separated panel initial panelIndex tester",
                 sequenceGrade: "fluid.tests.prefs.responsive.iframeSequence",
                 sequence: [{