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1022

answers:

2

I'm using the Jquery Scroll Follow plugin to allow a box to follow along as a user scrolls down the website. Scroll Follow allows users to disable or enable the scrolling feature and uses the cookie plugin to remember the users choice across pages.

Scroll Follow works great, but the code enables scrolling right away when a user first accesses the site. I'd like the default to be disabled when a user first enters the site, thereby giving the user the option to enable scrolling.

I've tried playing around with the true/false settings of the cookie, but I can't get this to work properly. I'm including the code below and appreciate any help to change the default to no scrolling.

I've tried asking for help on the developer's site, but have received no response: link text

Thanks.

/**
 * jquery.scrollFollow.js
 * Copyright (c) 2008 Net Perspective (http://kitchen.net-perspective.com/)
 * Licensed under the MIT License (http://www.opensource.org/licenses/mit-license.php)
 * 
 * @author R.A. Ray
 *
     * @projectDescription  jQuery plugin for allowing an element to animate down as the user scrolls the page.
 * 
 * @version 0.4.0
 * 
 * @requires jquery.js (tested with 1.2.6)
 * @requires ui.core.js (tested with 1.5.2)
 * 
 * @optional jquery.cookie.js (http://www.stilbuero.de/2006/09/17/cookie-plugin-for-jquery/)
 * @optional jquery.easing.js (http://gsgd.co.uk/sandbox/jquery/easing/ - tested with 1.3)
 * 
 * @param speed  int - Duration of animation (in milliseconds)
 *         default: 500
 * @param offset      int - Number of pixels box should remain from top of viewport
 *         default: 0
 * @param easing     string - Any one of the easing options from the easing plugin - Requires jQuery Easing Plugin < http://gsgd.co.uk/sandbox/jquery/easing/ >
 *         default: 'linear'
 * @param container string - ID of the containing div
 *         default:     box's immediate parent
 * @param killSwitch    string - ID of the On/Off toggle element
  *                default: 'killSwitch'
 * @param onText     string - killSwitch text to be displayed if sliding is enabled
 *             default: 'Turn Slide Off'
 * @param offText    string - killSwitch text to be displayed if sliding is disabled
 *             default: 'Turn Slide On'
 * @param relativeTo    string - Scroll animation can be relative to either the 'top'     or 'bottom' of the viewport
  *            default: 'top'
 * @param delay   int - Time between the end of the scroll and the beginning of the animation in milliseconds
 *         default: 0
 */

( function( jQuery ) {

jQuery.scrollFollow = function ( box, options )
{ 
 // Convert box into a jQuery object
 box = jQuery( box );

 // 'box' is the object to be animated
 var position = box.css( 'position' );

 function ani()
 {  
  // The script runs on every scroll which really means many times during a scroll.
  // We don't want multiple slides to queue up.
  box.queue( [ ] );

  // A bunch of values we need to determine where to animate to
  var viewportHeight = parseInt( jQuery( window ).height() ); 
  var pageScroll =  parseInt( jQuery( document ).scrollTop() );
  var parentTop =  parseInt( box.cont.offset().top );
  var parentHeight = parseInt( box.cont.attr( 'offsetHeight' ) );
  var boxHeight = parseInt( box.attr( 'offsetHeight' ) + ( parseInt( box.css( 'marginTop' ) ) || 0 ) + ( parseInt( box.css( 'marginBottom' ) ) || 0 ) );
  var aniTop;

  // Make sure the user wants the animation to happen
  if ( isActive )
  {
   // If the box should animate relative to the top of the window
   if ( options.relativeTo == 'top' )
   {
    // Don't animate until the top of the window is close enough to the top of the box
    if ( box.initialOffsetTop >= ( pageScroll + options.offset ) )
    {
     aniTop = box.initialTop;
    }
    else
    {
     aniTop = Math.min( ( Math.max( ( -parentTop ), ( pageScroll - box.initialOffsetTop + box.initialTop ) ) + options.offset ), ( parentHeight - boxHeight - box.paddingAdjustment ) );
    }
   }
   // If the box should animate relative to the bottom of the window
   else if ( options.relativeTo == 'bottom' )
   {
    // Don't animate until the bottom of the window is close enough to the bottom of the box
    if ( ( box.initialOffsetTop + boxHeight ) >= ( pageScroll + options.offset + viewportHeight ) )
    {
     aniTop = box.initialTop;
    }
    else
    {
     aniTop = Math.min( ( pageScroll + viewportHeight - boxHeight - options.offset ), ( parentHeight - boxHeight ) );
    }
   }

   // Checks to see if the relevant scroll was the last one
   // "-20" is to account for inaccuracy in the timeout
   if ( ( new Date().getTime() - box.lastScroll ) >= ( options.delay - 20 ) )
   {
    box.animate(
     {
      top: aniTop
     }, options.speed, options.easing
    );
   }
  }
 };

 // For user-initiated stopping of the slide
 var isActive = true;

 if ( jQuery.cookie != undefined )
 {
  if( jQuery.cookie( 'scrollFollowSetting' + box.attr( 'id' ) ) == 'false' )
  {
   var isActive = false;

   jQuery( '#' + options.killSwitch ).text( options.offText )
    .toggle( 
     function ()
     {
      isActive = true;

      jQuery( this ).text( options.onText );

      jQuery.cookie( 'scrollFollowSetting' + box.attr( 'id' ), true, { expires: 365, path: '/'} );

      ani();
     },
     function ()
     {
      isActive = false;

      jQuery( this ).text( options.offText );

      box.animate(
       {
        top: box.initialTop
       }, options.speed, options.easing
      ); 

      jQuery.cookie( 'scrollFollowSetting' + box.attr( 'id' ), false, { expires: 365, path: '/'} );
     }
    );
  }
  else
  {
   jQuery( '#' + options.killSwitch ).text( options.onText )
    .toggle( 
     function ()
     {
      isActive = false;

      jQuery( this ).text( options.offText );

      box.animate(
       {
        top: box.initialTop
       }, 0
      ); 

      jQuery.cookie( 'scrollFollowSetting' + box.attr( 'id' ), false, { expires: 365, path: '/'} );
     },
     function ()
     {
      isActive = true;

      jQuery( this ).text( options.onText );

      jQuery.cookie( 'scrollFollowSetting' + box.attr( 'id' ), true, { expires: 365, path: '/'} );

      ani();
     }
    );
  }
 }

 // If no parent ID was specified, and the immediate parent does not have an ID
 // options.container will be undefined. So we need to figure out the parent element.
 if ( options.container == '')
 {
  box.cont = box.parent();
 }
 else
 {
  box.cont = jQuery( '#' + options.container );
 }

 // Finds the default positioning of the box.
 box.initialOffsetTop =  parseInt( box.offset().top );
 box.initialTop = parseInt( box.css( 'top' ) ) || 0;

 // Hack to fix different treatment of boxes positioned 'absolute' and 'relative'
 if ( box.css( 'position' ) == 'relative' )
 {
  box.paddingAdjustment = parseInt( box.cont.css( 'paddingTop' ) ) + parseInt( box.cont.css( 'paddingBottom' ) );
 }
 else
 {
  box.paddingAdjustment = 0;
 }

 // Animate the box when the page is scrolled
 jQuery( window ).scroll( function ()
  {
   // Sets up the delay of the animation
   jQuery.fn.scrollFollow.interval = setTimeout( function(){ ani();} , options.delay );

   // To check against right before setting the animation
   box.lastScroll = new Date().getTime();
  }
 );

 // Animate the box when the page is resized
 jQuery( window ).resize( function ()
  {
   // Sets up the delay of the animation
   jQuery.fn.scrollFollow.interval = setTimeout( function(){ ani();} , options.delay );

   // To check against right before setting the animation
   box.lastScroll = new Date().getTime();
  }
 );

 // Run an initial animation on page load
 box.lastScroll = 0;

 ani();
};

jQuery.fn.scrollFollow = function ( options )
{
 options = options || {};
 options.relativeTo = options.relativeTo || 'top';
 options.speed = options.speed || 500;
 options.offset = options.offset || 0;
 options.easing = options.easing || 'swing';
 options.container = options.container || this.parent().attr( 'id' );
 options.killSwitch = options.killSwitch || 'killSwitch';
 options.onText = options.onText || 'Turn Slide Off';
 options.offText = options.offText || 'Turn Slide On';
 options.delay = options.delay || 0;

 this.each( function() 
  {
   new jQuery.scrollFollow( this, options );
  }
 );

 return this;
};
})( jQuery );
A: 

I added another flag for default setting in scrollFollow.js and on the page my scrollFollow function is called I added another option (property) named defaultText

var firstSetting = true;

if (firstSetting) {
    isActive = false;
    $('#' + options.killSwitch).html(options.defaultText);
    firstSetting = false;
}

Its working for me

PowerUser
A: 
Thomas