Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
680 views
in Technique[技术] by (71.8m points)

javascript - Stop jQuery fixed position scrolling when bottom of scrolling element reaches end of parent element

I'm using the below jQuery (answered by James Montagne) to begin fixed position scrolling after the user scrolls down 250px so that the element stays fixed to the top of the browser.

$(window).scroll(function(){
    $("#theFixed").css("top",Math.max(0,250-$(this).scrollTop()));
});

QUESTION: In addition, I'd like to stop the fixed position scrolling when the bottom of the scrolling fixed position element comes to the end of the parent div element. This way preventing the fixed position element from overflowing the parent element and getting cutoff.

My example code is here: http://jsfiddle.net/b43hj/2020/

<div>
    <div id="theFixed" style="position: fixed; top: 250px; background-color: red">
        0 SOMETHING<br />
        1 SOMETHING<br />
        2 SOMETHING<br />
        3 SOMETHING<br />
        4 SOMETHING<br />
        5 SOMETHING<br />
        6 SOMETHING<br />
        7 SOMETHING<br />
        8 SOMETHING<br />
        9 SOMETHING<br />
        10 SOMETHING<br />
        11 SOMETHING<br />
        12 SOMETHING<br />
        13 SOMETHING<br />
        14 SOMETHING<br />
        15 SOMETHING<br />
        16 SOMETHING<br />
        17 SOMETHING<br />
        18 SOMETHING<br />
        19 SOMETHING<br />
        20 SOMETHING<br />
        21 SOMETHING<br />
        22 SOMETHING<br />
        23 SOMETHING<br />
        24 SOMETHING<br />
        25 SOMETHING<br />
        26 SOMETHING<br />
        27 SOMETHING<br />
        28 SOMETHING<br />
        29 SOMETHING<br />
    </div>
    THIS IS A LONG SENTENCE THAT GOES PAST THE RED SOMETHINGS
    <br>
    THIS IS A LONG SENTENCE THAT GOES PAST THE RED SOMETHINGS
    <br>
    ... END
</div>

Screenshot: screenshot of issue

(Add-on question to this original question and answer: Stopping fixed position scrolling at a certain point?)

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

To prevent the fixed element from overflowing the parent element, I present this solution. Example code

$(window).scroll(function(){
    var scroll_top = $(this).scrollTop(); // get scroll position top
    var height_element_parent =  $("#theFixed").parent().outerHeight(); //get high parent element
    var height_element = $("#theFixed").height(); //get high of elemeneto
    var position_fixed_max = height_element_parent - height_element; // get the maximum position of the elemen
    var position_fixed = scroll_top < 250 ? 250 - scroll_top : position_fixed_max > scroll_top ? 0 : position_fixed_max - scroll_top;
    $("#theFixed").css("top",position_fixed);
});

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...