How to show "back to top" button using jquery only if browser height is shorter than page?
How to add/show "back to top" button at bottom in a div using jquery only if height browser height is shorter than page, other wise it should be hidden?
<p><a href="#mainwrapper">Back to top</a></p>
to this
<div id="mainwrapper">
<p> Paragraph 1 </p>
&l开发者_如何学编程t;p> Paragraph 1 </p>
<p> Paragraph 1 </p>
<p> Paragraph 1 </p>
<p><a href="#mainwrapper">Back to top</a></p>
</div>
i need almost same like my this question but condition is different How to detect linked PDF on a page and show message to download Adobe reader using jquery?
I need lightweight simple solution
Something like:
var wrapper = $('#mainwrapper');
if (wrapper.outerHeight(true) > $(window).height()) {
wrapper.append('<p><a href="#' + wrapper.attr('id') + '">Back to top</a></p>');
}
Do something like this:
$(document).ready(function(){
showHideControl();
$(window).resize(function(){
showHideControl();
});
});
function showHideControl() {
var h = $(window).height();
var ch = $("#content").height();
if (ch < h) {
$("#backControl").hide();
}
else {
$("#backControl").show();
}
}
The html needs to be updated a little too:
<div id="mainwrapper">
<div id="content">
<p> Paragraph 1 </p>
<p> Paragraph 1 </p>
<p> Paragraph 1 </p>
<p> Paragraph 1 </p>
</div>
<p id="backControl"><a href="#mainwrapper">Back to top</a></p>
</div>
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