Monday, 8 June 2020

how to get the scroll bar position

window height and document height
In this video we will discuss
1. Difference between window height and document height
2. How to detect if the user has scrolled to the bottom of the page
$(window).height() - Returns height of the browser window i.e browser viewport
$(document).height() - Returns height of HTML document
$(window).scrollTop() - Returns the current vertical position of the scroll bar
What is the difference between window height and document height
The window height is what you see (i.e browser viewport), but the document height includes everything below or above the visible area.
How to detect if the user has scrolled to the bottom of the page
Here is the formula to detect if the user has scrolled to the bottom of the page
if (verticalScrollBarPosition == $(document).height() - $(window).height()) {
 floatingDiv.html('Reached the bottom of the page');
}
Why window height and document height are the same in Google chrome
Without DOCTYPE tag Chrome reports the same value for both window height and document height. Include the following DOCTYPE declaration
<!DOCTYPE html>
Example used in the demo
<!DOCTYPE html>
<html>
<head>
 <script src="jquery-1.11.2.js"></script>
 <script type="text/javascript">
  $(document).ready(function () {
var floatingDiv = $("#divfloating");
var floatingDivPosition = floatingDiv.position();
$(window).scroll(function () {
 var scrollPosition = $(window).scrollTop();
 if (scrollPosition >= floatingDivPosition.top) {
  floatingDiv.css({
position': 'fixed',
top': 3
  });
 } else {
  floatingDiv.css({
position': 'relative',
top': 0
  });
 }
  to know in number at where we are using this below and print on the browser
 floatingDiv.html('Window Height = ' + $(window).height() + '<br/>' +
Document Height = ' + $(document).height() + '<br/>' +
Vertical Scrollbar Position = ' + scrollPosition
  );
  to told we reached the bottom of page
 if (scrollPosition == $(document).height() - $(window).height()) {
  floatingDiv.html('Reached the bottom of the page');
 }
});
  });
 </script>
</head>
<body style="font-family:Arial;">
 <table align="center" border="1" style="border-collapse:collapse">
  <tr>
<td style="width:500px">
 <div>
  Main Page Content
 </div>
</td>
<td style="width:150px; vertical-align:top">
 Side panel content
 <br /><br />
 <div id="divfloating" style="background-color:silver; width:150px; height:150px">
  Floating Div - Keeps floating as you scroll down the page
 </div>
</td>
  </tr>
 </table>
</body>
</html>
In our next video we will discuss how to load data like facebook as you scroll down the page.
Load data on page scroll using jquery ajax needs 
window.height
document.height
window.scrolltop
html
scrolltop
document.height
window.height


how to get the scroll bar position 
how to fix the one element positon with respect to positon of scroll bar
how to fix the one element positon with respect to positon of scroll bar
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